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Checkouri E, Blanchard V, Meilhac O. Macrophages in Atherosclerosis, First or Second Row Players? Biomedicines 2021; 9:biomedicines9091214. [PMID: 34572399 PMCID: PMC8465019 DOI: 10.3390/biomedicines9091214] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/08/2021] [Accepted: 09/11/2021] [Indexed: 12/24/2022] Open
Abstract
Macrophages represent a cell type that has been widely described in the context of atherosclerosis since the earliest studies in the 17th century. Their role has long been considered to be preponderant in the onset and aggravation of atherosclerosis, in particular by participating in the establishment of a chronic inflammatory state by the release of pro-inflammatory cytokines and by uncontrolled engorgement of lipids resulting in the formation of foam cells and later of the necrotic core. However, recent evidence from mouse models using an elegant technique of tracing vascular smooth muscle cells (VSMCs) during plaque development revealed that resident VSMCs display impressive plastic properties in response to an arterial injury, allowing them to switch into different cell types within the plaque, including mesenchymal-like cells, macrophage-like cells and osteochondrogenic-like cells. In this review, we oppose the arguments in favor or against the influence of macrophages versus VSMCs in all stages of atherosclerosis including pre-atherosclerosis, formation of lipid-rich foam cells, development of the necrotic core and the fibrous cap as well as calcification and rupture of the plaque. We also analyze the relevance of animal models for the investigation of the pathophysiological mechanisms of atherosclerosis in humans, and discuss potential therapeutic strategies targeting either VSMCs or macrophage to prevent the development of cardiovascular events. Overall, although major findings have been made from animal models, efforts are still needed to better understand and therefore prevent the development of atherosclerotic plaques in humans.
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Affiliation(s)
- Eloïse Checkouri
- INSERM, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Université de La Réunion, 97400 Sainte-Clotilde, France; (E.C.); (V.B.)
- Habemus Papam, Food Industry, 97470 Saint-Benoit, France
| | - Valentin Blanchard
- INSERM, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Université de La Réunion, 97400 Sainte-Clotilde, France; (E.C.); (V.B.)
- Departments of Medicine, Centre for Heart Lung Innovation, Providence Healthcare Research Institute, St Paul’s Hospital, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Olivier Meilhac
- INSERM, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Université de La Réunion, 97400 Sainte-Clotilde, France; (E.C.); (V.B.)
- CHU de La Réunion, INSERM, CIC1410, 97500 Saint-Pierre, France
- Correspondence: ; Tel.: +33-262-93-8811
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A mega-analysis of expression quantitative trait loci (eQTL) provides insight into the regulatory architecture of gene expression variation in liver. Sci Rep 2018; 8:5865. [PMID: 29650998 PMCID: PMC5897392 DOI: 10.1038/s41598-018-24219-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 03/27/2018] [Indexed: 01/11/2023] Open
Abstract
Genome-wide association studies (GWAS) have identified numerous genetic variants in the human genome associated with diseases and traits. Nevertheless, for most loci the causative variant is still unknown. Expression quantitative trait loci (eQTL) in disease relevant tissues is an excellent approach to correlate genetic association with gene expression. While liver is the primary site of gene transcription for two pathways relevant to age-related macular degeneration (AMD), namely the complement system and cholesterol metabolism, we explored the contribution of AMD associated variants to modulate liver gene expression. We extracted publicly available data and computed the largest eQTL data set for liver tissue to date. Genotypes and expression data from all studies underwent rigorous quality control. Subsequently, Matrix eQTL was used to identify significant local eQTL. In total, liver samples from 588 individuals revealed 202,489 significant eQTL variants affecting 1,959 genes (Q-Value < 0.001). In addition, a further 101 independent eQTL signals were identified in 93 of the 1,959 eQTL genes. Importantly, our results independently reinforce the notion that high density lipoprotein metabolism plays a role in AMD pathogenesis. Taken together, our study generated a first comprehensive map reflecting the genetic regulatory landscape of gene expression in liver.
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Goeritzer M, Vujic N, Schlager S, Chandak PG, Korbelius M, Gottschalk B, Leopold C, Obrowsky S, Rainer S, Doddapattar P, Aflaki E, Wegscheider M, Sachdev V, Graier WF, Kolb D, Radovic B, Kratky D. Active autophagy but not lipophagy in macrophages with defective lipolysis. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1304-1316. [PMID: 26143381 PMCID: PMC4562370 DOI: 10.1016/j.bbalip.2015.06.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 05/29/2015] [Accepted: 06/20/2015] [Indexed: 11/30/2022]
Abstract
During autophagy, autophagosomes fuse with lysosomes to degrade damaged organelles and misfolded proteins. Breakdown products are released into the cytosol and contribute to energy and metabolic building block supply, especially during starvation. Lipophagy has been defined as the autophagy-mediated degradation of lipid droplets (LDs) by lysosomal acid lipase. Adipose triglyceride lipase (ATGL) is the major enzyme catalyzing the initial step of lipolysis by hydrolyzing triglycerides (TGs) in cytosolic LDs. Consequently, most organs and cells, including macrophages, lacking ATGL accumulate TGs, resulting in reduced intracellular free fatty acid concentrations. Macrophages deficient in hormone-sensitive lipase (H0) lack TG accumulation albeit reduced in vitro TG hydrolase activity. We hypothesized that autophagy is activated in lipase-deficient macrophages to counteract their energy deficit. We therefore generated mice lacking both ATGL and HSL (A0H0). Macrophages from A0H0 mice showed 73% reduced neutral TG hydrolase activity, resulting in TG-rich LD accumulation. Increased expression of cathepsin B, accumulation of LC3-II, reduced expression of p62 and increased DQ-BSA dequenching suggest intact autophagy and functional lysosomes in A0H0 macrophages. Markedly decreased acid TG hydrolase activity and lipid flux independent of bafilomycin A1 treatment, however, argue against effective lysosomal degradation of LDs in A0H0 macrophages. We conclude that autophagy of proteins and cell organelles but not of LDs is active as a compensatory mechanism to circumvent and balance the reduced availability of energy substrates in A0H0 macrophages.
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Affiliation(s)
- Madeleine Goeritzer
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Nemanja Vujic
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Stefanie Schlager
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Prakash G Chandak
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Melanie Korbelius
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Benjamin Gottschalk
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Christina Leopold
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Sascha Obrowsky
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Silvia Rainer
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Prakash Doddapattar
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Elma Aflaki
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Martin Wegscheider
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Vinay Sachdev
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Wolfgang F Graier
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Dagmar Kolb
- Center for Medical Research/Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Branislav Radovic
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology & Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21, 8010 Graz, Austria
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Hime NJ, Black AS, Bonnet DJ, Curtiss LK. Bone marrow-derived HL mitigates bone marrow-derived CETP-mediated decreases in HDL in mice globally deficient in HL and the LDLr. J Lipid Res 2014; 55:1864-75. [PMID: 24818611 DOI: 10.1194/jlr.m046318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The objective of this study was to determine the combined effects of HL and cholesteryl ester transfer protein (CETP), derived exclusively from bone marrow (BM), on plasma lipids and atherosclerosis in high-fat-fed, atherosclerosis-prone mice. We transferred BM expressing these proteins into male and female double-knockout HL-deficient, LDL receptor-deficient mice (HL(-/-)LDLr(-/-)). Four BM chimeras were generated, where BM-derived cells expressed 1) HL but not CETP, 2) CETP and HL, 3) CETP but not HL, or 4) neither CETP nor HL. After high-fat feeding, plasma HDL-cholesterol (HDL-C) was decreased in mice with BM expressing CETP but not HL (17 ± 4 and 19 ± 3 mg/dl, female and male mice, respectively) compared with mice with BM expressing neither CETP nor HL (87 ± 3 and 95 ± 4 mg/dl, female and male mice, respectively, P < 0.001 for both sexes). In female mice, the presence of BM-derived HL mitigated this CETP-mediated decrease in HDL-C. BM-derived CETP decreased the cholesterol component of HDL particles and increased plasma cholesterol. BM-derived HL mitigated these effects of CETP. Atherosclerosis was not significantly different between BM chimeras. These results suggest that BM-derived HL mitigates the HDL-lowering, HDL-modulating, and cholesterol-raising effects of BM-derived CETP and warrant further studies to characterize the functional properties of these protein interactions.
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Affiliation(s)
- Neil J Hime
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Audrey S Black
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - David J Bonnet
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Linda K Curtiss
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
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Wang Z, Li S, Sun L, Fan J, Liu Z. Comparative analyses of lipoprotein lipase, hepatic lipase, and endothelial lipase, and their binding properties with known inhibitors. PLoS One 2013; 8:e72146. [PMID: 23991054 PMCID: PMC3749185 DOI: 10.1371/journal.pone.0072146] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Accepted: 07/08/2013] [Indexed: 11/30/2022] Open
Abstract
The triglyceride lipase gene subfamily plays a central role in lipid and lipoprotein metabolism. There are three members of this subfamily: lipoprotein lipase, hepatic lipase, and endothelial lipase. Although these lipases are implicated in the pathophysiology of hyperlipidemia and atherosclerosis, their structures have not been fully solved. In the current study, we established homology models of these three lipases, and carried out analysis of their activity sites. In addition, we investigated the kinetic characteristics for the catalytic residues using a molecular dynamics simulation strategy. To elucidate the molecular interactions and determine potential key residues involved in the binding to lipase inhibitors, we analyzed the binding pockets and binding poses of known inhibitors of the three lipases. We identified the spatial consensus catalytic triad “Ser-Asp-His”, a characteristic motif in all three lipases. Furthermore, we found that the spatial characteristics of the binding pockets of the lipase molecules play a key role in ligand recognition, binding poses, and affinities. To the best of our knowledge, this is the first report that systematically builds homology models of all the triglyceride lipase gene subfamily members. Our data provide novel insights into the molecular structures of lipases and their structure-function relationship, and thus provides groundwork for functional probe design towards lipase-based therapeutic inhibitors for the treatment of hyperlipidemia and atherosclerosis.
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Affiliation(s)
- Ziyun Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, P. R. China
| | - Shen Li
- Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi, Japan
| | - Lidan Sun
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, P. R. China
| | - Jianglin Fan
- Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi, Japan
- * E-mail: (ZML); (JLF)
| | - Zhenming Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, P. R. China
- * E-mail: (ZML); (JLF)
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6
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Rosenson RS, Brewer HB, Davidson WS, Fayad ZA, Fuster V, Goldstein J, Hellerstein M, Jiang XC, Phillips MC, Rader DJ, Remaley AT, Rothblat GH, Tall AR, Yvan-Charvet L. Cholesterol efflux and atheroprotection: advancing the concept of reverse cholesterol transport. Circulation 2012; 125:1905-19. [PMID: 22508840 PMCID: PMC4159082 DOI: 10.1161/circulationaha.111.066589] [Citation(s) in RCA: 699] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Robert S Rosenson
- Mount Sinai Heart, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1030, New York, NY 10029, USA.
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Ghatreh Samani K, Noori M, Nobar MR, Chaleshtory MH, Farrokhi E, Amin MD. The -514C/T Polymorphism of Hepatic Lipase Gene among Iranian Patients with Coronary Heart Disease. IRANIAN JOURNAL OF PUBLIC HEALTH 2012; 41:59-65. [PMID: 23113123 PMCID: PMC3481668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Accepted: 11/12/2011] [Indexed: 12/03/2022]
Abstract
BACKGROUND The T allele of the hepatic lipase (HL) C-514T polymorphism was previously found to be associated with lower plasma HL activity. Here, we examined the association between this polymorphism and plasma HDL-cholesterol concentrations in patients with coronary arteries stenosis. METHODS We studied 342 subjects undergoing coronary angiography in two groups of non CAD (n=146) and CAD (n=196). -514C→T polymorphism was determined using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). RESULTS After adjustment for age, smoking and body mass index, HDL-cholesterol concentrations were significantly higher in men with the C/T&T/T genotype than those with the C/C genotype(mean 38.6 and 34.7 respectively P=0.01). The frequency of T allele in non CAD was 0.136 and 0.226 in female and male respectively and 0.170 and 0.223 for female and male in CAD subjects. There was no difference in T allele frequency in CAD and none CAD groups in male and female (P=0.466 and 0.722 respectively). CONCLUSION -514C→T of LIPC gene have a positive effect on HDL-C concentration especially in male gender. However, no difference was determined in frequency of T allele between CAD and normal arteries subjects.
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Affiliation(s)
- K Ghatreh Samani
- Dept. of Biochemistry, School of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran,Corresponding Author: Tel: +98 913 280 0382; Fax: +98 381 3330709, E-mail address:
| | - M Noori
- Drug Applied Research Center and Biotechnology Research Canter, Tabriz University of Medical Sciences, Tabriz, Iran
| | - M Rohbani Nobar
- Drug Applied Research Center and Biotechnology Research Canter, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - E Farrokhi
- Cellular and Molecular Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - M Darabi Amin
- Drug Applied Research Center and Biotechnology Research Canter, Tabriz University of Medical Sciences, Tabriz, Iran
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Role of hepatic lipase and endothelial lipase in high-density lipoprotein-mediated reverse cholesterol transport. Curr Atheroscler Rep 2011; 13:257-65. [PMID: 21424685 PMCID: PMC3085744 DOI: 10.1007/s11883-011-0175-2] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Reverse cholesterol transport (RCT) constitutes a key part of the atheroprotective properties of high-density lipoproteins (HDL). Hepatic lipase (HL) and endothelial lipase (EL) are negative regulators of plasma HDL cholesterol levels. Although overexpression of EL decreases overall macrophage-to-feces RCT, knockout of both HL and EL leaves RCT essentially unaffected. With respect to important individual steps of RCT, current data on the role of EL and HL in cholesterol efflux are not conclusive. Both enzymes increase hepatic selective cholesterol uptake; however, this does not translate into altered biliary cholesterol secretion, which is regarded the final step of RCT. Also, the impact of HL and EL on atherosclerosis is not clear cut; rather it depends on respective experimental conditions and chosen models. More mechanistic insights into the diverse biological properties of these enzymes are therefore required to firmly establish EL and HL as targets for the treatment of atherosclerotic cardiovascular disease.
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Brown JD, Oligino E, Rader DJ, Saghatelian A, Plutzky J. VLDL hydrolysis by hepatic lipase regulates PPARδ transcriptional responses. PLoS One 2011; 6:e21209. [PMID: 21750705 PMCID: PMC3130023 DOI: 10.1371/journal.pone.0021209] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 05/23/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND PPARs (α,γ,δ) are a family of ligand-activated transcription factors that regulate energy balance, including lipid metabolism. Despite these critical functions, the integration between specific pathways of lipid metabolism and distinct PPAR responses remains obscure. Previous work has revealed that lipolytic pathways can activate PPARs. Whether hepatic lipase (HL), an enzyme that regulates VLDL and HDL catabolism, participates in PPAR responses is unknown. METHODS/PRINCIPAL FINDINGS Using PPAR ligand binding domain transactivation assays, we found that HL interacted with triglyceride-rich VLDL (>HDL≫LDL, IDL) to activate PPARδ preferentially over PPARα or PPARγ, an effect dependent on HL catalytic activity. In cell free ligand displacement assays, VLDL hydrolysis by HL activated PPARδ in a VLDL-concentration dependent manner. Extended further, VLDL stimulation of HL-expressing HUVECs and FAO hepatoma cells increased mRNA expression of canonical PPARδ target genes, including adipocyte differentiation related protein (ADRP), angiopoietin like protein 4 and pyruvate dehydrogenase kinase-4. HL/VLDL regulated ADRP through a PPRE in the promoter region of this gene. In vivo, adenoviral-mediated hepatic HL expression in C57BL/6 mice increased hepatic ADRP mRNA levels by 30%. In ob/ob mice, a model with higher triglycerides than C57BL/6 mice, HL overexpression increased ADRP expression by 70%, demonstrating the importance of triglyceride substrate for HL-mediated PPARδ activation. Global metabolite profiling identified HL/VLDL released fatty acids including oleic acid and palmitoleic acid that were capable of recapitulating PPARδ activation and ADRP gene regulation in vitro. CONCLUSIONS These data define a novel pathway involving HL hydrolysis of VLDL that activates PPARδ through generation of specific monounsaturated fatty acids. These data also demonstrate how integrating cell biology with metabolomic approaches provides insight into specific lipid mediators and pathways of lipid metabolism that regulate transcription.
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Affiliation(s)
- Jonathan D. Brown
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- VA Boston Healthcare, West Roxbury, Massachusetts, United States of America
| | - Eric Oligino
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Cardiology, Yale-New Haven Hospital, New Haven, Connecticut, United States of America
| | - Daniel J. Rader
- Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Alan Saghatelian
- Department of Chemistry, Harvard University, Cambridge, Massachusetts, United States of America
| | - Jorge Plutzky
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
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Yu Y, Reynolds R, Fagerness J, Rosner B, Daly MJ, Seddon JM. Association of variants in the LIPC and ABCA1 genes with intermediate and large drusen and advanced age-related macular degeneration. Invest Ophthalmol Vis Sci 2011; 52:4663-70. [PMID: 21447678 DOI: 10.1167/iovs.10-7070] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Intermediate and large drusen usually precede advanced age-related macular degeneration (AMD). There is little information about which genes influence drusen accumulation. Discovery of genetic variants associated with drusen may lead to prevention and treatments of AMD in its early stages. METHODS A total of 3066 subjects were evaluated on the basis of ocular examinations and fundus photography and categorized as control (n = 221), intermediate drusen (n = 814), large drusen (n = 949), or advanced AMD (n = 1082). SNPs in the previously identified CFH, C2, C3, CFB, CFI, APOE, and ARMS2/HTRA1 genes/regions and the novel genes LIPC, CETP, and ABCA1 in the high-density lipoprotein (HDL) cholesterol pathway were genotyped. Associations between stage of AMD and SNPs were assessed using logistic regression. RESULTS Controlling for age, sex, education, smoking, body mass index, and antioxidant treatment, the number of minor (T) alleles of the genes LIPC and ABCA1 were significantly associated with a reduced risk of intermediate drusen (LIPC [P trend = 0.045], ABCA1 [P = 4.4 × 10(-3)]), large drusen (LIPC [P = 0.041], ABCA1 [P = 7.7 × 10(-4)]), and advanced AMD (LIPC [P = 1.8 × 10(-3)], ABCA1 [P = 3 × 10(-4)]). After further adjustment for known genetic factors, the protective effect of the TT genotype was significant for intermediate drusen (LIPC [odds ratio (OR), 0.56; 95% confidence interval (CI), 0.33-0.94], ABCA1 [OR, 0.48; 95% CI, 0.27-0.85]), large drusen (LIPC [OR, 0.58; 95% CI, 0.34-0.98)], ABCA1 [OR, 0.41; 95% CI, 0.23-0.74)]), and advanced AMD (LIPC [OR, 0.39; 95% CI, 0.21-0.74)], ABCA1 [OR, 0.35; 95% CI, 0.17-0.71)]). CFH, C3, C2, and ARMS2/HTRA1 were associated with large drusen and advanced AMD. CONCLUSIONS LIPC and ABCA1 are related to intermediate and large drusen, as well as advanced AMD. CFH, C3, C2, and ARMS2/HTRA1 are associated with large drusen and advanced AMD. Genes may have varying effects on different stages of AMD.
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Affiliation(s)
- Yi Yu
- Ophthalmic Epidemiology and Genetics Service, Department of Ophthalmology, Tufts Medical Center, Boston, Massachusetts, USA
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11
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Amar MJA, Shamburek RD, Vaisman B, Knapper CL, Foger B, Hoyt RF, Santamarina-Fojo S, Brewer HB, Remaley AT. Adenoviral expression of human lecithin-cholesterol acyltransferase in nonhuman primates leads to an antiatherogenic lipoprotein phenotype by increasing high-density lipoprotein and lowering low-density lipoprotein. Metabolism 2009; 58:568-75. [PMID: 19303980 PMCID: PMC3703629 DOI: 10.1016/j.metabol.2008.11.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Accepted: 11/26/2008] [Indexed: 01/30/2023]
Abstract
Lecithin-cholesterol acyltransferase (LCAT), a key enzyme in high-density lipoprotein (HDL) metabolism, has been proposed to have atheroprotective properties by promoting reverse cholesterol transport. Overexpression of LCAT in various animal models, however, has led to conflicting results on its overall effect on lipoproteins and atherosclerosis. In this study, the effect of overexpression of LCAT in nonhuman primates on lipoprotein metabolism is examined. Human LCAT was expressed with adenovirus in squirrel monkeys (n = 8), resulting on day 4 in a 22-fold increase of LCAT activity (257 +/- 23 vs 5618 +/- 799 nmol mL(-1) h(-1), P < .0001). At its peak, LCAT was found to nearly double the level of HDL cholesterol from baseline (113 +/- 7 vs 260 +/- 24 mg/dL, P < .01). High-density lipoprotein formed after treatment with the adenovirus was larger in size, as assessed by fast protein liquid chromatography (FPLC) analysis. By kinetic studies, it was determined that there was a decrease in apolipoprotein (Apo) A-I resident time (0.373 +/- 0.027 vs 0.685 +/- 0.045 d(-1), P < .0001) and almost a doubling in the ApoA-I synthetic rate (22 +/- 2 vs 41 +/- 3 mg kg(-1) d(-1), P < .0001), but no overall change in ApoA-I levels. In addition, increased expression of LCAT was associated with a 37% reduction of ApoB levels (12 +/- 1 vs 19 +/- 1 mg/dL, P < .05) due to increased low-density lipoprotein catabolism (fractional catabolic rate = 1.7 +/- 0.1 d(-1) in controls vs 4.2 +/- 0.3 d(-1) in LCAT-treated group, P < .05). In summary, overexpression of LCAT in nonhuman primates leads to an antiatherogenic lipoprotein profile by increasing HDL cholesterol and lowering ApoB, thus making LCAT a potential drug target for reducing atherosclerosis.
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Affiliation(s)
- Marcelo J A Amar
- Lipoprotein Metabolism Section, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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12
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Hime NJ, Black AS, Bulgrien JJ, Curtiss LK. Leukocyte-derived hepatic lipase increases HDL and decreases en face aortic atherosclerosis in LDLr-/- mice expressing CETP. J Lipid Res 2008; 49:2113-23. [PMID: 18599739 DOI: 10.1194/jlr.m700564-jlr200] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In addition to hepatic expression, cholesteryl ester transfer protein (CETP) and hepatic lipase (HL) are expressed by human macrophages. The combined actions of these proteins have profound effects on HDL structure and function. It is not known how these HDL changes influence atherosclerosis. To elucidate the role of leukocyte-derived HL on atherosclerosis in a background of CETP expression, we studied low density lipoprotein receptor-deficient mice expressing human CETP (CETPtgLDLr -/-) with a leukocyte-derived HL deficiency (HL -/- BM). HL(-/-) bone marrow (BM), CETPtgLDLr(-/-) mice were generated via bone marrow transplantation. Wild-type bone marrow was transplanted into CETPtgLDLr(-/-) mice to generate HL +/+ BM, CETPtgLDLr(-/-) controls. The chimeras were fed a high-fat, high-cholesterol diet for 14 weeks to promote atherosclerosis. In female HL(-/-) BM, CETPtgLDLr(-/-) mice plasma HDL-cholesterol concentration during high-fat feeding was decreased 27% when compared with HL +/+ BM, CETPtgLDLr(-/-) mice (P < 0.05), and this was associated with a 96% increase in en face aortic atherosclerosis (P < 0.05). In male CETPtgLDLr(-/-) mice, leukocyte-derived HL deficiency was associated with a 16% decrease in plasma HDL-cholesterol concentration and a 25% increase in aortic atherosclerosis. Thus, leukocyte-derived HL in CETPtgLDLr(-/-) mice has an atheroprotective role that may involve increased HDL levels.
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Affiliation(s)
- Neil J Hime
- Department of Immunology, The Scripps Research Institute, La Jolla, California, USA.
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Age-dependent association between hepatic lipase gene C-480T polymorphism and the risk of pre-hospital sudden cardiac death: the Helsinki Sudden Death Study. Atherosclerosis 2006; 192:421-7. [PMID: 16793047 DOI: 10.1016/j.atherosclerosis.2006.05.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Revised: 04/11/2006] [Accepted: 05/15/2006] [Indexed: 11/23/2022]
Abstract
OBJECTIVE We investigated the association between hepatic lipase (HL) C-480T polymorphism and the risk of acute myocardial infarction (AMI) as well as pre-hospital sudden cardiac death (SCD). METHODS Seven hundred sudden or unnatural pre-hospital deaths of middle-aged (33-70 years, mean 53 years) Caucasian Finnish men were subjected to detailed autopsy (Helsinki Sudden Death Study). Genotype data were obtained for 682 men. RESULTS In logistic regression analysis with age, body mass index, hypertension, diabetes, smoking and alcohol consumption as covariates, men with the TT genotype had an increased risk for SCD and AMI compared to CC carriers (OR=3.0, P=0.011; and OR=3.7, P=0.003). There was a significant age-by-genotype interaction (P<0.05) on the risk of SCD. Compared to CC genotype carriers, the association between the TT genotype and SCD was particularly strong (P=0.001) among men <53 years of age, but this association was non-significant among older men. This was mainly due to a strong association between the TT genotype and AMI due to severe coronary disease in the absence of thrombosis. Carriers of the TT genotype were more likely to have severe coronary stenoses (> or =50%) than men with the CT or CC genotype (P=0.019). CONCLUSIONS The results suggest that HL C-480T polymorphism is a strong age-dependent risk factor of SCD in early middle-aged men.
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Makui H, Soares RJ, Jiang W, Constante M, Santos MM. Contribution of Hfe expression in macrophages to the regulation of hepatic hepcidin levels and iron loading. Blood 2005; 106:2189-95. [PMID: 15914561 PMCID: PMC2891009 DOI: 10.1182/blood-2005-02-0629] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hereditary hemochromatosis (HH), an iron overload disease associated with mutations in the HFE gene, is characterized by increased intestinal iron absorption and consequent deposition of excess iron, primarily in the liver. Patients with HH and Hfe-deficient (Hfe-/-) mice manifest inappropriate expression of the iron absorption regulator hepcidin, a peptide hormone produced by the liver in response to iron loading. In this study, we investigated the contribution of Hfe expression in macrophages to the regulation of liver hepcidin levels and iron loading. We used bone marrow transplantation to generate wild-type (wt) and Hfe-/- mice chimeric for macrophage Hfe gene expression. Reconstitution of Hfe-deficient mice with wt bone marrow resulted in augmented capacity of the spleen to store iron and in significantly decreased liver iron loading, accompanied by a significant increase of hepatic hepcidin mRNA levels. Conversely, wt mice reconstituted with Hfe-deficient bone marrow had a diminished capacity to store iron in the spleen but no significant alterations of liver iron stores or hepcidin mRNA levels. Our results suggest that macrophage Hfe participates in the regulation of splenic and liver iron concentrations and liver hepcidin expression.
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Affiliation(s)
- Hortence Makui
- Centre de recherche, CHUM-Hôpital Notre-Dame, Pav. De Sève Y5625, 1560 Sherbrooke est, Montréal, Québec H2L 4M1, Canada
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15
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Abstract
Hepatic lipase (HL) plays a role in the metabolism of chylomicron and very low-density lipoprotein remnants, low-density lipoproteins (LDL), and high-density lipoproteins (HDL), which are all implicated in atherosclerosis. Considering the effects of HL on these lipoproteins, it appears that HL has pro- as well as antiatherogenic potential. In line with clinical observations, most effects of HL on lipoprotein metabolism during hypertriglyceridemia may be interpreted as promoting atherosclerosis (formation of small, dense LDL, lowering of HDL levels), whereas most effects during hypercholesterolemia seem to be potentially antiatherogenic (stimulation of reverse cholesterol transport, clearing of intermediate-density lipoprotein). The potential modulation of pro- or antiatherogenics effect of HL by other factors, such as LDL receptor, cholesterol ester transfer protein, lipoprotein lipase, and ATP-binding cassette A-1 activity, is discussed.
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Affiliation(s)
- Hans Jansen
- Department of Clinical Chemistry (Room 175), ErasmusMC, Postbus 2040, 3000 CA Rotterdam, Netherlands.
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