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Lorey MB, Öörni K, Kovanen PT. Modified Lipoproteins Induce Arterial Wall Inflammation During Atherogenesis. Front Cardiovasc Med 2022; 9:841545. [PMID: 35310965 PMCID: PMC8927694 DOI: 10.3389/fcvm.2022.841545] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 01/26/2022] [Indexed: 12/15/2022] Open
Abstract
Circulating apolipoprotein B-containing lipoproteins, notably the low-density lipoproteins, enter the inner layer of the arterial wall, the intima, where a fraction of them is retained and modified by proteases, lipases, and oxidizing agents and enzymes. The modified lipoproteins and various modification products, such as fatty acids, ceramides, lysophospholipids, and oxidized lipids induce inflammatory reactions in the macrophages and the covering endothelial cells, initiating an increased leukocyte diapedesis. Lipolysis of the lipoproteins also induces the formation of cholesterol crystals with strong proinflammatory properties. Modified and aggregated lipoproteins, cholesterol crystals, and lipoproteins isolated from human atherosclerotic lesions, all can activate macrophages and thereby induce the secretion of proinflammatory cytokines, chemokines, and enzymes. The extent of lipoprotein retention, modification, and aggregation have been shown to depend largely on differences in the composition of the circulating lipoprotein particles. These properties can be modified by pharmacological means, and thereby provide opportunities for clinical interventions regarding the prevention and treatment of atherosclerotic vascular diseases.
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Affiliation(s)
- Martina B. Lorey
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Katariina Öörni
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- *Correspondence: Katariina Öörni
| | - Petri T. Kovanen
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
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2
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Morris G, Berk M, Walder K, O'Neil A, Maes M, Puri BK. The lipid paradox in neuroprogressive disorders: Causes and consequences. Neurosci Biobehav Rev 2021; 128:35-57. [PMID: 34118292 DOI: 10.1016/j.neubiorev.2021.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 04/27/2021] [Accepted: 06/06/2021] [Indexed: 02/07/2023]
Abstract
Chronic systemic inflammation is associated with an increased risk of cardiovascular disease in an environment of low low-density lipoprotein (LDL) and low total cholesterol and with the pathophysiology of neuroprogressive disorders. The causes and consequences of this lipid paradox are explored. Circulating activated neutrophils can release inflammatory molecules such as myeloperoxidase and the pro-inflammatory cytokines interleukin-1 beta, interleukin-6 and tumour necrosis factor-alpha. Since activated neutrophils are associated with atherosclerosis and cardiovascular disease and with major depressive disorder, bipolar disorder and schizophrenia, it seems reasonable to hypothesise that the inflammatory molecules released by them may act as mediators of the link between systemic inflammation and the development of atherosclerosis in neuroprogressive disorders. This hypothesis is tested by considering the association at a molecular level of systemic inflammation with increased LDL oxidation; increased small dense LDL levels; increased lipoprotein (a) concentration; secretory phospholipase A2 activation; cytosolic phospholipase A2 activation; increased platelet activation; decreased apolipoprotein A1 levels and function; decreased paroxonase-1 activity; hyperhomocysteinaemia; and metabolic endotoxaemia. These molecular mechanisms suggest potential therapeutic targets.
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Affiliation(s)
- Gerwyn Morris
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Michael Berk
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Deakin University, CMMR Strategic Research Centre, School of Medicine, Geelong, Victoria, Australia; Orygen, The National Centre of Excellence in Youth Mental Health, the Department of Psychiatry and the Florey Institute for Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Ken Walder
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Adrienne O'Neil
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia
| | - Michael Maes
- Deakin University, IMPACT - the Institute for Mental and Physical Health and Clinical Translation, School of Medicine, Barwon Health, Geelong, Australia; Department of Psychiatry, King Chulalongkorn University Hospital, Bangkok, Thailand
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3
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Giglio RV, Stoian AP, Haluzik M, Pafili K, Patti AM, Rizvi AA, Ciaccio M, Papanas N, Rizzo M. Novel molecular markers of cardiovascular disease risk in type 2 diabetes mellitus. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166148. [PMID: 33892081 DOI: 10.1016/j.bbadis.2021.166148] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 03/15/2021] [Accepted: 04/13/2021] [Indexed: 02/07/2023]
Abstract
Diabetes represents the leading risk factor for the development of cardiovascular disease (CVD). Chronic hyperglycemia and/or acute post-prandial changes in blood glucose determine an increase in reactive oxygen species (ROS), which play a fundamental role in endothelial dysfunction and in the nuclear transport of pro-atherogenic transcription factors that activate the "inflammasome". In addition, the glycemic alteration favors the formation and stabilization of atherosclerotic plaque through the mechanism of non-enzymatic glycation of different molecules, with the establishment of the so-called "advanced glycosylation end products" (AGE). Laboratory information provided by the level of biomarkers could make a quantitative and qualitative contribution to the clinical process of screening, prediction, prevention, diagnosis, prognosis and monitoring of cardiovascular (CV) risk linked to diabetes. This review describes the importance of specific biomarkers, with particular focus on novel ones, for stratifying and management of diabetes CV risk.
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Affiliation(s)
- Rosaria Vincenza Giglio
- Department of Biomedicine, Neuroscience, and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine, and Laboratory Medicine, University of Palermo, Palermo, Italy
| | - Anca Pantea Stoian
- Faculty of General Medicine, Diabetes, Nutrition and Metabolic Diseases Department, Carol Davila University, Bucharest, Romania
| | - Martin Haluzik
- Centre for Experimental Medicine and Department of Diabetes, Diabetes Centre, Institute for Clinical and Experimental Medicine, Prague, Czech Republic; Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Kalliopi Pafili
- Diabetes Centre, Second Department of Internal Medicine, Democritus University of Thrace, University Hospital of Alexandroupolis, Greece
| | - Angelo Maria Patti
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties, University of Palermo, Palermo, Italy.
| | - Ali Abbas Rizvi
- Division of Endocrinology, Metabolism, and Lipids, Department of Medicine, Emory University, Atlanta, Georgia, USA; Division of Endocrinology, Diabetes and Metabolism, University of South Carolina School of Medicine Columbia, South Carolina, USA
| | - Marcello Ciaccio
- Department of Biomedicine, Neuroscience, and Advanced Diagnostics, Institute of Clinical Biochemistry, Clinical Molecular Medicine, and Laboratory Medicine, University of Palermo, Palermo, Italy; Department of Laboratory Medicine, University-Hospital, Palermo, Italy
| | - Nikolaos Papanas
- Diabetes Centre, Second Department of Internal Medicine, Democritus University of Thrace, University Hospital of Alexandroupolis, Greece
| | - Manfredi Rizzo
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties, University of Palermo, Palermo, Italy; Division of Endocrinology, Diabetes and Metabolism, University of South Carolina School of Medicine Columbia, South Carolina, USA
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4
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Zhang S, Liu Y, Wang X, Tian Z, Qi D, Li Y, Jiang H. Antihypertensive activity of oleanolic acid is mediated via downregulation of secretory phospholipase A2 and fatty acid synthase in spontaneously hypertensive rats. Int J Mol Med 2020; 46:2019-2034. [PMID: 33125128 PMCID: PMC7595669 DOI: 10.3892/ijmm.2020.4744] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/28/2020] [Indexed: 12/11/2022] Open
Abstract
Oleanolic acid (OA) is reported to possess antihypertensive activity via the regulation of lipid metabolism; however, the mechanisms underlying lipid regulation by OA are yet to be fully elucidated. The aim of the present study was to evaluate the mechanisms via which OA regulates lipid metabolism in spontaneously hypertensive rats (SHRs) via ultra‑performance liquid chromatography‑quadrupole/Orbitrap‑mass spectrometry (MS)‑based lipidomics analysis. SHRs were treated with OA (1.08 mg/kg) for 4 weeks. The liver tissues were excised, homogenized in dichloromethane and centrifuged, and subsequently the supernatant layer was collected and concentrated under vacuum to dryness. The dichloromethane extract was subjected to MS analysis and database searching, and comparison of standards was performed to identify potential biomarkers. Partial least squares‑discriminant analysis performed on the liver lipidome revealed a total of 14 endogenous metabolites that were significantly changed in the SHR model group (SH group) compared with Wistar Kyoto rats [normal control (NC group)], including glycerophospholipids, sphingolipids and glycerides. Heatmaps revealed that the liver lipid profiles in the OA group were clustered more closely compared with those observed in the NC group, indicating that the antihypertensive effect of OA was mediated via regulation of liver lipid metabolites. It was observed that the protein levels of secretory phospholipase A2 (sPLA2) and fatty acid synthase (FAS) were increased in the SH group compared with the NC group. In addition, the levels of lysophosphatidylcholine and triglycerides in the liver were elevated, whereas the levels of low‑density lipoprotein cholesterol and high‑density lipoprotein cholesterol were reduced in the SH group. Upon treatment with OA, the mRNA and protein levels of PLA2 and FAS were observed to be downregulated. Collectively, the present study indicated that the antihypertensive activity of OA was mediated via downregulation of sPLA2 and FAS in SHRs, and that treatment with OA resulted in significant improvements in blood pressure and associated abnormalities in the lipid metabolites.
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Affiliation(s)
- Shiming Zhang
- Experimental Centre, Shandong University of Traditional Chinese Medicine
| | - Yuecheng Liu
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education
| | - Xiaoming Wang
- Experimental Centre, Shandong University of Traditional Chinese Medicine
| | - Zhenhua Tian
- Experimental Centre, Shandong University of Traditional Chinese Medicine
| | - Dongmei Qi
- Experimental Centre, Shandong University of Traditional Chinese Medicine
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education
- Shandong Provincial Key Laboratory of Traditional Chinese Medicine for Basic Research, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250355, P.R. China
| | - Yunlun Li
- Experimental Centre, Shandong University of Traditional Chinese Medicine
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education
- Shandong Provincial Key Laboratory of Traditional Chinese Medicine for Basic Research, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250355, P.R. China
| | - Haiqiang Jiang
- Experimental Centre, Shandong University of Traditional Chinese Medicine
- Key Laboratory of Traditional Chinese Medicine Classical Theory, Ministry of Education
- Shandong Provincial Key Laboratory of Traditional Chinese Medicine for Basic Research, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250355, P.R. China
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5
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Watanabe K, Taketomi Y, Miki Y, Kugiyama K, Murakami M. Group V secreted phospholipase A 2 plays a protective role against aortic dissection. J Biol Chem 2020; 295:10092-10111. [PMID: 32482892 DOI: 10.1074/jbc.ra120.013753] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/22/2020] [Indexed: 12/23/2022] Open
Abstract
Aortic dissection is a life-threatening aortopathy involving separation of the aortic wall, whose underlying mechanisms are still incompletely understood. Epidemiological evidence suggests that unsaturated fatty acids improve cardiovascular health. Here, using quantitative RT-PCR, histological analyses, magnetic cell sorting and flow cytometry assays, and MS-based lipidomics, we show that the activity of a lipid-metabolizing enzyme, secreted phospholipase A2 group V (sPLA2-V), protects against aortic dissection by endogenously mobilizing vasoprotective lipids. Global and endothelial cell-specific sPLA2-V-deficient mice frequently developed aortic dissection shortly after infusion of angiotensin II (AT-II). We observed that in the AT-II-treated aorta, endothelial sPLA2-V mobilized oleic and linoleic acids, which attenuated endoplasmic reticulum stress, increased the expression of lysyl oxidase, and thereby stabilized the extracellular matrix in the aorta. Of note, dietary supplementation with oleic or linoleic acid reversed the increased susceptibility of sPLA2-V-deficient mice to aortic dissection. These findings reveal an unexplored functional link between sPLA2-driven phospholipid metabolism and aortic stability, possibly contributing to the development of improved diagnostic and/or therapeutic strategies for preventing aortic dissection.
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Affiliation(s)
- Kazuhiro Watanabe
- Department of Internal Medicine II, University of Yamanashi, Department of Internal Medicine II, Chuo, Yamanashi Japan.,Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yoshitaka Taketomi
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.,Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Yoshimi Miki
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.,Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Kiyotaka Kugiyama
- Department of Internal Medicine II, University of Yamanashi, Department of Internal Medicine II, Chuo, Yamanashi Japan .,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan
| | - Makoto Murakami
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan .,Laboratory of Microenvironmental and Metabolic Health Science, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan.,FORCE, Japan Agency for Medical Research and Development, Tokyo, Japan
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6
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WITHDRAWN: Functional diversity of glycerolipid acylhydrolases in plant metabolism and physiology. Prog Lipid Res 2019. [DOI: 10.1016/j.plipres.2019.100994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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7
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Functional diversity of glycerolipid acylhydrolases in plant metabolism and physiology. Prog Lipid Res 2019; 75:100987. [PMID: 31078649 DOI: 10.1016/j.plipres.2019.100987] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/06/2019] [Accepted: 05/07/2019] [Indexed: 11/22/2022]
Abstract
Most current knowledge about plant lipid metabolism has focused on the biosynthesis of lipids and their transport between different organelles. However, lipid composition changes during development and in response to environmental cues often go beyond adjustments of lipid biosynthesis. When lipids have to be removed to adjust the extent of membranes during down regulation of photosynthesis, or lipid composition has to be adjusted to alter the biophysical properties of membranes, or lipid derived chemical signals have to be produced, lipid-degrading enzymes come into play. This review focuses on glycerolipid acylhydrolases that remove acyl groups from glycerolipids and will highlight their roles in lipid remodeling and lipid-derived signal generation. One emerging theme is that these enzymes are involved in the dynamic movement of acyl groups through different lipid pools, for example from polar membrane lipids to neutral lipids sequestered in lipid droplets during de novo triacylglycerol synthesis. Another example of acyl group sequestration in the form of triacylglycerols in lipid droplets is membrane lipid remodeling in response to abiotic stresses. Fatty acids released for membrane lipids can also give rise to potent signaling molecules and acylhydrolases are therefore often the first step in initiating the formation of these lipid signals.
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8
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Aldi S, Matic LP, Hamm G, van Keulen D, Tempel D, Holmstrøm K, Szwajda A, Nielsen BS, Emilsson V, Ait-Belkacem R, Lengquist M, Paulsson-Berne G, Eriksson P, Lindeman JHN, Gool AJ, Stauber J, Hedin U, Hurt-Camejo E. Integrated Human Evaluation of the Lysophosphatidic Acid Pathway as a Novel Therapeutic Target in Atherosclerosis. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2018; 10:17-28. [PMID: 30003117 PMCID: PMC6039967 DOI: 10.1016/j.omtm.2018.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/13/2018] [Indexed: 11/05/2022]
Abstract
Variants in the PLPP3 gene encoding for lipid phosphate phosphohydrolase 3 have been associated with susceptibility to atherosclerosis independently of classical risk factors. PLPP3 inactivates lysophosphatidic acid (LPA), a pro-inflammatory, pro-thrombotic product of phospholipase activity. Here we performed the first exploratory analysis of PLPP3, LPA, and LPA receptors (LPARs 1–6) in human atherosclerosis. PLPP3 transcript and protein were repressed when comparing plaques versus normal arteries and plaques from symptomatic versus asymptomatic patients, and they were negatively associated with risk of adverse cardiovascular events. PLPP3 localized to macrophages, smooth muscle, and endothelial cells (ECs) in plaques. LPAR 2, 5, and especially 6 showed increased expression in plaques, with LPAR6 localized in ECs and positively correlated to PLPP3. Utilizing in situ mass spectrometry imaging, LPA and its precursors were found in the plaque fibrous cap, co-localizing with PLPP3 and LPAR6. In vitro, PLPP3 silencing in ECs under LPA stimulation resulted in increased expression of adhesion molecules and cytokines. LPAR6 silencing inhibited LPA-induced cell activation, but not when PLPP3 was silenced simultaneously. Our results show that repression of PLPP3 plays a key role in atherosclerosis by promoting EC activation. Altogether, the PLPP3 pathway represents a suitable target for investigations into novel therapeutic approaches to ameliorate atherosclerosis.
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Affiliation(s)
- Silvia Aldi
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Sweden
| | | | | | | | | | | | - Agnieszka Szwajda
- Translational Sciences, Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden
| | | | - Valur Emilsson
- Icelandic Heart Association, Kopavogur, Iceland.,Faculty of Pharmaceutical Sciences, University of Iceland, Reykjavik, Iceland
| | | | - Mariette Lengquist
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Sweden
| | - Gabrielle Paulsson-Berne
- Cardiovascular Medicine Unit, Department of Medicine, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Per Eriksson
- Cardiovascular Medicine Unit, Department of Medicine, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Jan H N Lindeman
- Department of Vascular Surgery, Leiden University Medical Center, the Netherlands
| | | | | | - Ulf Hedin
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Sweden
| | - Eva Hurt-Camejo
- Translational Sciences, Cardiovascular, Renal and Metabolism, IMED Biotech Unit, AstraZeneca, Gothenburg, Sweden.,Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Sweden
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9
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Gordts PLSM, Esko JD. The heparan sulfate proteoglycan grip on hyperlipidemia and atherosclerosis. Matrix Biol 2018; 71-72:262-282. [PMID: 29803939 DOI: 10.1016/j.matbio.2018.05.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 12/20/2022]
Abstract
Heparan sulfate proteoglycans are found at the cell surface and in the extracellular matrix, where they interact with a plethora of proteins involved in lipid homeostasis and inflammation. Over the last decade, new insights have emerged regarding the mechanism and biological significance of these interactions in the context of cardiovascular disease. The majority of cardiovascular disease-related deaths are caused by complications of atherosclerosis, a disease that results in narrowing of the arterial lumen, thereby reducing blood flow to critical levels in vital organs, such as the heart and brain. Here, we discuss novel insights into how heparan sulfate proteoglycans modulate risk factors such as hyperlipidemia and inflammation that drive the initiation and progression of atherosclerotic plaques to their clinical critical endpoint.
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Affiliation(s)
- Philip L S M Gordts
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, San Diego, La Jolla, CA, USA; Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA, USA.
| | - Jeffrey D Esko
- Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, USA.
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10
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Shridas P, Noffsinger VP, Trumbauer AC, Webb NR. The dual role of group V secretory phospholipase A 2 in pancreatic β-cells. Endocrine 2017; 58:47-58. [PMID: 28825176 PMCID: PMC5693688 DOI: 10.1007/s12020-017-1379-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 07/21/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE Group X (GX) and group V (GV) secretory phospholipase A2 (sPLA2) potently release arachidonic acid (AA) from the plasma membrane of intact cells. We previously demonstrated that GX sPLA2 negatively regulates glucose-stimulated insulin secretion (GSIS) by a prostaglandin E2 (PGE2)-dependent mechanism. In this study we investigated whether GV sPLA2 similarly regulates GSIS. METHODS GSIS and pancreatic islet-size were assessed in wild-type (WT) and GV sPLA2-knock out (GV KO) mice. GSIS was also assessed ex vivo in isolated islets and in vitro using MIN6 pancreatic beta cell lines with or without GV sPLA2 overexpression or silencing. RESULTS GSIS was significantly decreased in islets isolated from GV KO mice compared to WT mice and in MIN6 cells with siRNA-mediated GV sPLA2 suppression. MIN6 cells overexpressing GV sPLA2 (MIN6-GV) showed a significant increase in GSIS compared to control cells. Though the amount of AA released into the media by MIN6-GV cells was significantly higher, PGE2 production was not enhanced or cAMP content decreased compared to control MIN6 cells. Surprisingly, GV KO mice exhibited a significant increase in plasma insulin levels following i.p. injection of glucose compared to WT mice. This increase in GSIS in GV KO mice was associated with a significant increase in pancreatic islet size and number of proliferating cells in β-islets compared to WT mice. CONCLUSIONS Deficiency of GV sPLA2 results in diminished GSIS in isolated pancreatic beta-cells. However, the reduced GSIS in islets lacking GV sPLA2 appears to be compensated by increased islet mass in GV KO mice.
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Affiliation(s)
- Preetha Shridas
- Saha Cardiovascular Research Center, University of Kentucky Medical Center, Lexington, KY, 40536, USA.
- Departments of Internal Medicine, University of Kentucky Medical Center, Lexington, KY, 40536, USA.
| | - Victoria P Noffsinger
- Saha Cardiovascular Research Center, University of Kentucky Medical Center, Lexington, KY, 40536, USA
- Departments of Internal Medicine, University of Kentucky Medical Center, Lexington, KY, 40536, USA
| | - Andrea C Trumbauer
- Saha Cardiovascular Research Center, University of Kentucky Medical Center, Lexington, KY, 40536, USA
| | - Nancy R Webb
- Saha Cardiovascular Research Center, University of Kentucky Medical Center, Lexington, KY, 40536, USA
- Pharmacology and Nutritional Sciences, Division of Nutritional Sciences, University of Kentucky Medical Center, Lexington, KY, 40536, USA
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11
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Menschikowski M, Hagelgans A, Nacke B, Jandeck C, Mareninova OA, Asatryan L, Siegert G. Epigenetic control of group V phospholipase A2 expression in human malignant cells. Tumour Biol 2015; 37:8097-105. [PMID: 26715269 DOI: 10.1007/s13277-015-4670-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 12/16/2015] [Indexed: 12/27/2022] Open
Abstract
Secreted phospholipases A2 (sPLA2) are suggested to play an important role in inflammation and tumorigenesis. Different mechanisms of epigenetic regulation are involved in the control of group IIA, III and X sPLA2s expression in cancer cells, but group V sPLA2 (GV-PLA2) in this respect has not been studied. Here, we demonstrate the role of epigenetic mechanisms in regulation of GV-PLA2 expression in different cell lines originating from leukaemia and solid cancers. In blood leukocytes from leukaemic patients, levels of GV-PLA2 transcripts were significantly lower in comparison to those from healthy individuals. Similarly, in DU-145 and PC-3 prostate and CAL-51 and MCF-7 mammary cancer cell lines, levels of GV-PLA2 transcripts were significantly lower in relation to those found in normal epithelial cells of prostate or mammary. By sequencing and methylation-specific high-resolution melting (MS-HRM) analyses of bisulphite-modified DNA, distinct CpG sites in the GV-PLA2 promoter region were identified that were differentially methylated in cancer cells in comparison to normal epithelial and endothelial cells. Spearman rank order analysis revealed a significant negative correlation between the methylation degree and the cellular expression of GV-PLA2 (r = -0.697; p = 0.01). The effects of demethylating agent (5-aza-2'-deoxycytidine) and histone deacetylase inhibitor (trichostatin A) on GV-PLA2 transcription in the analysed cells confirmed the importance of DNA methylation and histone modification in the regulation of the GV-PLA2 gene expression in leukaemic, prostate and mammary cancer cell lines. The exposure of tumour cells to human recombinant GV-PLA2 resulted in a reduced colony forming activity of MCF-7, HepG2 and PC-3 cells, but not of DU-145 cells suggesting a cell-type-dependent effect of GV-PLA2 on cell growth. In conclusion, our results suggest that epigenetic mechanisms such as DNA methylation and histone modification play an important role in downregulation of GV-PLA2 expression in cancer cells.
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Affiliation(s)
- Mario Menschikowski
- Institute of Clinical Chemistry and Laboratory Medicine, Carl Gustav Carus University Hospital, Technical University of Dresden, Fetscherstr. 74, D-01307, Dresden, Germany.
| | - Albert Hagelgans
- Institute of Clinical Chemistry and Laboratory Medicine, Carl Gustav Carus University Hospital, Technical University of Dresden, Fetscherstr. 74, D-01307, Dresden, Germany
| | - Brit Nacke
- Institute of Clinical Chemistry and Laboratory Medicine, Carl Gustav Carus University Hospital, Technical University of Dresden, Fetscherstr. 74, D-01307, Dresden, Germany
| | - Carsten Jandeck
- Institute of Clinical Chemistry and Laboratory Medicine, Carl Gustav Carus University Hospital, Technical University of Dresden, Fetscherstr. 74, D-01307, Dresden, Germany
| | - Olga A Mareninova
- Veterans Affairs Greater Los Angeles Healthcare System and University of California at Los Angeles, Los Angeles, CA, USA
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy, USC School of Pharmacy, Los Angeles, CA, USA
| | - Gabriele Siegert
- Institute of Clinical Chemistry and Laboratory Medicine, Carl Gustav Carus University Hospital, Technical University of Dresden, Fetscherstr. 74, D-01307, Dresden, Germany
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12
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Pruzanski W, Kopilov J, Kuksis A. Hydrolysis of lipoproteins by sPLA2's enhances mitogenesis and eicosanoid release from vascular smooth muscle cells: Diverse activity of sPLA2's IIA, V and X. Prostaglandins Other Lipid Mediat 2015; 122:64-8. [PMID: 26711221 DOI: 10.1016/j.prostaglandins.2015.12.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 12/01/2015] [Accepted: 12/08/2015] [Indexed: 11/30/2022]
Abstract
Mitogenesis of Vascular Smooth Muscle Cells (VSMC) plays an important role in atherogenesis. Until recently, the effect of lipid subfractions has not been clarified. Secretory phospholipases A2 (sPLA2's) hydrolyse glycerophospholipids and release pro-inflammatory lyso-lipids, oxidized and non-oxidized fatty acids and isoprostanes. They localize in the vascular wall. We hypothesized that structurally similar sPLA2's may exert different impact on VSMC. The influence of sPLA2's, IIA, V, X, HDL, LDL, and hydrolysis products was tested on mitogenesis of VSMC, i.e., the early effect on the cell membrane phospholipids, and on PGE2 and LTB4 release, i.e., late effect of Cyclooxygenase and 5-lipooxygenase activity in VSMC. Mitogenesis was significantly enhanced by HDL and LDL, and by products of sPLA2 hydrolysis. Hydrolysis of HDL or LDL enhanced mitogenic activity in order V>X>IIA. The release of PGE2 was enhanced by group X sPLA2 and by HDL hydrolyzed by groups V and X. LDL and its hydrolysis products enhanced the release of PGE2 in order X>V>IIA. The release of LTB4 was markedly increased by LDL and HDL, and by hydrolytic products of group V and X, but not group IIA sPLA2. Our study demonstrates a diverse interaction of pro-inflammatory sPLA2's with HDL and LDL affecting both mitogenesis and eicosanoid release from VSMC, therefore potentially enhancing their pro-atherogenic activity.
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Affiliation(s)
- Waldemar Pruzanski
- St. Michael's Hopital, Toronto, Canada; University of Toronto, Toronto, Canada.
| | | | - Arnis Kuksis
- The Banting and Best Department of Medical Research, Toronto, Canada; University of Toronto, Toronto, Canada
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Talmud PJ, Holmes MV. Deciphering the Causal Role of sPLA2s and Lp-PLA2 in Coronary Heart Disease. Arterioscler Thromb Vasc Biol 2015; 35:2281-9. [PMID: 26338298 DOI: 10.1161/atvbaha.115.305234] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 08/19/2015] [Indexed: 11/16/2022]
Abstract
Over the last 10 to 15 years, animal and human observational studies have identified elevated levels of both proinflammatory secretory phospholipase A2-IIA and lipoprotein-associated phospholipase A2 as potential risk factors for coronary heart disease. However, Mendelian randomization, a genetic tool to test causality of a biomarker, and phase III randomized controlled trials of inhibitors of theses enzymes (varespladib and darapladib) converged to indicate that elevated levels are unlikely to be themselves causal of coronary heart disease and that inhibition had little or no clinical utility. The concordance of findings from Mendelian randomization and clinical trials suggests that for these 2 drugs, and for other novel biomarkers in future, validation of potential therapeutic targets by genetic studies (such as Mendelian randomization) before embarking on costly phase III randomized controlled trials could increase efficiency and offset the high risk of drug development, thereby facilitating discovery of new therapeutics and mitigating against the exuberant costs of drug development.
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Affiliation(s)
- Philippa J Talmud
- From the Center for Cardiovascular Genetics, Institute of Cardiovascular Science, University College London, London, UK (P.J.T.); and Clinical Trial Service Unit & Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK (M.V.H.).
| | - Michael V Holmes
- From the Center for Cardiovascular Genetics, Institute of Cardiovascular Science, University College London, London, UK (P.J.T.); and Clinical Trial Service Unit & Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK (M.V.H.)
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Pruzanski W, Kopilov J, Kuksis A. Diverse activity of human secretory phospholipases A2 on the migration of human vascular smooth muscle cells. Inflamm Res 2015; 64:497-500. [PMID: 25999087 DOI: 10.1007/s00011-015-0830-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 04/29/2015] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVE Investigation of the diversity of human secretory phospholipases A2 (sPLA2) on the migration of human vascular smooth muscle cells (VSMC). MATERIAL We investigated the impact of sPLA2 IIA, V, and X and of oleic acid, linoleic acid and lysophosphatidylcholine on the migration of human VSMC. METHODS Recombinant human sPLA2's and Boyden's chamber method were applied. RESULTS sPLA2, IIA but not V or X enhanced migration of VSMC in a dose/time dependent manner. Oleic and linoleic acids, and lysophosphatidylcholine markedly enhanced migration. CONCLUSIONS These results imply that sPLA2 IIA, which is known to be present in the arterial wall in the vicinity of VSMC, as well as products of lipid hydrolysis induced by sPLA2, enhance the migration of VSMC, and thus may contribute to atherogenic process.
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Affiliation(s)
- W Pruzanski
- Department of Medicine, University of Toronto, Toronto, Canada,
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Berry E, Hernandez-Anzaldo S, Ghomashchi F, Lehner R, Murakami M, Gelb MH, Kassiri Z, Wang X, Fernandez-Patron C. Matrix metalloproteinase-2 negatively regulates cardiac secreted phospholipase A2 to modulate inflammation and fever. J Am Heart Assoc 2015; 4:jah3908. [PMID: 25820137 PMCID: PMC4579961 DOI: 10.1161/jaha.115.001868] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Background Matrix metalloproteinase (MMP)‐2 deficiency makes humans and mice susceptible to inflammation. Here, we reveal an MMP‐2–mediated mechanism that modulates the inflammatory response via secretory phospholipase A2 (sPLA2), a phospholipid hydrolase that releases fatty acids, including precursors of eicosanoids. Methods and Results Mmp2−/− (and, to a lesser extent, Mmp7−/− and Mmp9−/−) mice had between 10‐ and 1000‐fold elevated sPLA2 activity in plasma and heart, increased eicosanoids and inflammatory markers (both in the liver and heart), and exacerbated lipopolysaccharide‐induced fever, all of which were blunted by adenovirus‐mediated MMP‐2 overexpression and varespladib (pharmacological sPLA2 inhibitor). Moreover, Mmp2 deficiency caused sPLA2‐mediated dysregulation of cardiac lipid metabolic gene expression. Compared with liver, kidney, and skeletal muscle, the heart was the single major source of the Ca2+‐dependent, ≈20‐kDa, varespladib‐inhibitable sPLA2 that circulates when MMP‐2 is deficient. PLA2G5, which is a major cardiac sPLA2 isoform, was proinflammatory when Mmp2 was deficient. Treatment of wild‐type (Mmp2+/+) mice with doxycycline (to inhibit MMP‐2) recapitulated the Mmp2−/− phenotype of increased cardiac sPLA2 activity, prostaglandin E2 levels, and inflammatory gene expression. Treatment with either indomethacin (to inhibit cyclooxygenase‐dependent eicosanoid production) or varespladib (which inhibited eicosanoid production) triggered acute hypertension in Mmp2−/− mice, revealing their reliance on eicosanoids for blood pressure homeostasis. Conclusions A heart‐centric MMP‐2/sPLA2 axis may modulate blood pressure homeostasis, inflammatory and metabolic gene expression, and the severity of fever. This discovery helps researchers to understand the cardiovascular and systemic effects of MMP‐2 inhibitors and suggests a disease mechanism for human MMP‐2 gene deficiency.
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Affiliation(s)
- Evan Berry
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (E.B., S.H.A., X.W., C.F.P.)
| | - Samuel Hernandez-Anzaldo
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (E.B., S.H.A., X.W., C.F.P.)
| | - Farideh Ghomashchi
- Department of Chemistry, University of Washington, Seattle, WA (F.G., M.H.G.)
| | - Richard Lehner
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (R.L.) Group on Molecular and Cell Biology of Lipids, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (R.L.)
| | - Makoto Murakami
- Lipid Metabolism Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan (M.M.) CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, Japan (M.M.)
| | - Michael H Gelb
- Department of Chemistry, University of Washington, Seattle, WA (F.G., M.H.G.)
| | - Zamaneh Kassiri
- Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (Z.K.) Cardiovascular Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (Z.K., C.F.P.) Mazankowski Alberta Heart Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (Z.K., C.F.P.)
| | - Xiang Wang
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (E.B., S.H.A., X.W., C.F.P.)
| | - Carlos Fernandez-Patron
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (E.B., S.H.A., X.W., C.F.P.) Cardiovascular Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (Z.K., C.F.P.) Mazankowski Alberta Heart Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada (Z.K., C.F.P.)
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Öörni K, Rajamäki K, Nguyen SD, Lähdesmäki K, Plihtari R, Lee-Rueckert M, Kovanen PT. Acidification of the intimal fluid: the perfect storm for atherogenesis. J Lipid Res 2014; 56:203-14. [PMID: 25424004 DOI: 10.1194/jlr.r050252] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Atherosclerotic lesions are often hypoxic and exhibit elevated lactate concentrations and local acidification of the extracellular fluids. The acidification may be a consequence of the abundant accumulation of lipid-scavenging macrophages in the lesions. Activated macrophages have a very high energy demand and they preferentially use glycolysis for ATP synthesis even under normoxic conditions, resulting in enhanced local generation and secretion of lactate and protons. In this review, we summarize our current understanding of the effects of acidic extracellular pH on three key players in atherogenesis: macrophages, apoB-containing lipoproteins, and HDL particles. Acidic extracellular pH enhances receptor-mediated phagocytosis and antigen presentation by macrophages and, importantly, triggers the secretion of proinflammatory cytokines from macrophages through activation of the inflammasome pathway. Acidity enhances the proteolytic, lipolytic, and oxidative modifications of LDL and other apoB-containing lipoproteins, and strongly increases their affinity for proteoglycans, and may thus have major effects on their retention and the ensuing cellular responses in the arterial intima. Finally, the decrease in the expression of ABCA1 at acidic pH may compromise cholesterol clearance from atherosclerotic lesions. Taken together, acidic extracellular pH amplifies the proatherogenic and proinflammatory processes involved in atherogenesis.
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The (G>A) rs11573191 polymorphism of PLA2G5 gene is associated with premature coronary artery disease in the Mexican Mestizo population: the genetics of atherosclerotic disease Mexican study. BIOMED RESEARCH INTERNATIONAL 2014; 2014:931361. [PMID: 24959594 PMCID: PMC4052156 DOI: 10.1155/2014/931361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 05/02/2014] [Accepted: 05/04/2014] [Indexed: 11/20/2022]
Abstract
Coronary artery disease (CAD) is a multifactorial disorder that results from an excessive inflammatory response. Secretory phospholipase A2-V (sPLA2-V) encoded by PLA2G5 gene promotes diverse proinflammatory processes. The aim of the present study was to analyze if PLA2G5 gene polymorphisms are associated with premature CAD. Three PLA2G5 polymorphisms (rs11573187, rs2148911, and rs11573191) were analyzed in 707 patients with premature CAD and 749 healthy controls. Haplotypes were constructed after linkage disequilibrium analysis. Under dominant, recessive, and additive models, the rs11573191 polymorphism was associated with increased risk of premature CAD (OR = 1.51, Pdom = 3.5 × 10−3; OR = 2.95, Prec = 0.023; OR = 1.51, Padd = 1.2 × 10−3). According to the informatics software, this polymorphism had a functional effect modifying the affinity of the sequence by the MZF1 transcription factor. PLA2G5 polymorphisms were in linkage disequilibrium and the CGA haplotype was associated with increased risk of premature CAD (OR = 1.49, P = 0.0023) and with hypertension in these patients (OR = 1.75, P = 0.0072). Our results demonstrate the association of the PLA2G5 rs11573191 polymorphism with premature CAD. In our study, it was possible to distinguish one haplotype associated with increased risk of premature CAD and hypertension.
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Holmes MV, Exeter HJ, Folkersen L, Nelson CP, Guardiola M, Cooper JA, Sofat R, Boekholdt SM, Khaw KT, Li KW, Smith AJP, Van't Hooft F, Eriksson P, Franco-Cereceda A, Asselbergs FW, Boer JMA, Onland-Moret NC, Hofker M, Erdmann J, Kivimaki M, Kumari M, Reiner AP, Keating BJ, Humphries SE, Hingorani AD, Mallat Z, Samani NJ, Talmud PJ. Novel genetic approach to investigate the role of plasma secretory phospholipase A2 (sPLA2)-V isoenzyme in coronary heart disease: modified Mendelian randomization analysis using PLA2G5 expression levels. ACTA ACUST UNITED AC 2014; 7:144-50. [PMID: 24563418 DOI: 10.1161/circgenetics.113.000271] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Secretory phospholipase A2 (sPLA2) enzymes are considered to play a role in atherosclerosis. sPLA2 activity encompasses several sPLA2 isoenzymes, including sPLA2-V. Although observational studies show a strong association between elevated sPLA2 activity and CHD, no assay to measure sPLA2-V levels exists, and the only evidence linking the sPLA2-V isoform to atherosclerosis progression comes from animal studies. In the absence of an assay that directly quantifies sPLA2-V levels, we used PLA2G5 mRNA levels in a novel, modified Mendelian randomization approach to investigate the hypothesized causal role of sPLA2-V in coronary heart disease (CHD) pathogenesis. METHODS AND RESULTS Using data from the Advanced Study of Aortic Pathology, we identified the single-nucleotide polymorphism in PLA2G5 showing the strongest association with PLA2G5 mRNA expression levels as a proxy for sPLA2-V levels. We tested the association of this SNP with sPLA2 activity and CHD events in 4 prospective and 14 case-control studies with 27 230 events and 70 500 controls. rs525380C>A showed the strongest association with PLA2G5 mRNA expression (P=5.1×10(-6)). There was no association of rs525380C>A with plasma sPLA2 activity (difference in geometric mean of sPLA2 activity per rs525380 A-allele 0.4% (95% confidence intervals [-0.9%, 1.6%]; P=0.56). In meta-analyses, the odds ratio for CHD per A-allele was 1.02 (95% confidence intervals [0.99, 1.04]; P=0.20). CONCLUSIONS This novel approach for single-nucleotide polymorphism selection for this modified Mendelian randomization analysis showed no association between rs525380 (the lead single-nucleotide polymorphism for PLA2G5 expression, a surrogate for sPLA2-V levels) and CHD events. The evidence does not support a causal role for sPLA2-V in CHD.
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Telmisartan and N-acetylcysteine Suppress Group V Secretory Phospholipase A2 Expression in TNFα-stimulated Human Endothelial Cells and Reduce Associated Atherogenicity. J Cardiovasc Pharmacol 2012; 60:367-74. [DOI: 10.1097/fjc.0b013e3182646ccc] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Affiliation(s)
- R Montes
- Division of Cardiovascular Sciences, Centre of Applied Medical Research, University of Navarra, Pamplona, Spain.
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Lähdesmäki K, Öörni K, Alanne-Kinnunen M, Jauhiainen M, Hurt-Camejo E, Kovanen PT. Acidity and lipolysis by group V secreted phospholipase A2 strongly increase the binding of apoB-100-containing lipoproteins to human aortic proteoglycans. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:257-67. [DOI: 10.1016/j.bbalip.2011.10.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 10/11/2011] [Accepted: 10/17/2011] [Indexed: 11/16/2022]
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Abstract
Phospholipids are present in all living organisms. They are a major component of all biological membranes, along with glycolipids and cholesterol. Enzymes aimed at cleaving the various bonds in phospholipids, namely phospholipases, are consequently widespread in nature, playing very diverse roles from aggression in snake venom to signal transduction, lipid mediators production, and digestion in humans. Although all phospholipases target phospholipids as substrates, they vary in the site of action on the phospholipids molecules, physiological function, mode of action, and their regulation. Significant studies on phospholipases characterization, physiological role, and industrial potential have been conducted worldwide. Some of them have been directed for biotechnological advances, such as gene discovery and functional enhancement by protein engineering. Others reported phospholipases as virulence factors and major causes of pathophysiological effects. In this introductory chapter, we provide brief details of different phospholipases.
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Affiliation(s)
- Ahmed Aloulou
- National School of Engineers of Sfax, University of Sfax, Sfax, Tunisia.
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sPLA2-V inhibits EPCR anticoagulant and antiapoptotic properties by accommodating lysophosphatidylcholine or PAF in the hydrophobic groove. Blood 2011; 119:2914-21. [PMID: 22167755 DOI: 10.1182/blood-2011-05-353409] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The endothelial protein C receptor (EPCR) plays an important role in cardiovascular disease by binding protein C/activated protein C (APC). EPCR structure contains a hydrophobic groove filled with an unknown phospholipid needed to perform its function. It has not been established whether lipid exchange takes place in EPCR as a regulatory mechanism of its activity. Our objective was to identify this phospholipid and to explore the possibility of lipid exchange as a regulatory mechanism of EPCR activity driven by the endothelially expressed secretory group V phospholipase A(2) (sPLA(2)-V). We identified phosphatidylcholine (PCh) as the major phospholipid bound to human soluble EPCR (sEPCR). PCh in EPCR could be exchanged for lysophosphatidylcholine (lysoPCh) and platelet activating factor (PAF). Remarkably, lysoPCh and PAF impaired the protein C binding ability of sEPCR. Inhibition of sPLA(2)-V, responsible for lysoPCh and PAF generation, improved APC binding to endothelial cells. EPCR-dependent protein C activation and APC antiapoptotic effect were thus significantly enhanced. In contrast, endothelial cell supplementation with sPLA(2)-V inhibited both APC generation and its antiapoptotic effects. We conclude that APC generation and function can be modulated by changes in phospholipid occupancy of its endothelial cell receptor.
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Blache D, Gautier T, Tietge UJF, Lagrost L. Activated platelets contribute to oxidized low‐density lipoproteins and dysfunctional high‐density lipoproteins through a phospholipase A2‐dependent mechanism. FASEB J 2011; 26:927-37. [DOI: 10.1096/fj.11-191593] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Denis Blache
- Institut National de la Santé et de la Recherche Médicale (INSERM)/Université de Bourgogne, Lipids, Nutrition, Cancer, Faculté de Médecine Dijon France
| | - Thomas Gautier
- Institut National de la Santé et de la Recherche Médicale (INSERM)/Université de Bourgogne, Lipids, Nutrition, Cancer, Faculté de Médecine Dijon France
| | - Uwe J. F. Tietge
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic DiseaseUniversity Medical Center Groningen, University of Groningen Groningen The Netherlands
| | - Laurent Lagrost
- Institut National de la Santé et de la Recherche Médicale (INSERM)/Université de Bourgogne, Lipids, Nutrition, Cancer, Faculté de Médecine Dijon France
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Yamamoto K, Isogai Y, Sato H, Taketomi Y, Murakami M. Secreted phospholipase A2, lipoprotein hydrolysis, and atherosclerosis: integration with lipidomics. Anal Bioanal Chem 2011; 400:1829-42. [PMID: 21445663 PMCID: PMC3098357 DOI: 10.1007/s00216-011-4864-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Revised: 02/14/2011] [Accepted: 03/01/2011] [Indexed: 01/22/2023]
Abstract
Phospholipase A2 (PLA2) is a group of enzymes that hydrolyze the sn-2 position of glycerophospholipids to yield fatty acids and lysophospholipids. Of many PLA2s or related enzymes identified to date, secreted PLA2s (sPLA2s) comprise the largest family that contains 10 catalytically active isozymes. Besides arachidonic acid released from cellular membranes for eicosanoid synthesis, several if not all sPLA2s have recently been implicated in hydrolysis of phospholipids in lipoprotein particles. The sPLA2-processed low-density lipoprotein (LDL) particles contain a large amount of lysophospholipids and exhibit the property of “small-dense” or “modified” LDL, which facilitates foam cell formation from macrophages. Transgenic overexpression of these sPLA2s leads to development of atherosclerosis in mice. More importantly, genetic deletion or pharmacological inhibition of particular sPLA2s significantly attenuates atherosclerosis and aneurysm. In this article, we will give an overview of current understanding of the role of sPLA2s in atherosclerosis, with recent lipidomics data showing the action of a subset of sPLA2s on lipoprotein phospholipids.
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Affiliation(s)
- Kei Yamamoto
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
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Mallat Z, Lambeau G, Tedgui A. Lipoprotein-associated and secreted phospholipases A₂ in cardiovascular disease: roles as biological effectors and biomarkers. Circulation 2010; 122:2183-200. [PMID: 21098459 DOI: 10.1161/circulationaha.110.936393] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Ziad Mallat
- INSERM, Paris-Cardiovascular Research Center, Université Paris Descartes, UMR, Paris, France
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Murakami M, Taketomi Y, Miki Y, Sato H, Hirabayashi T, Yamamoto K. Recent progress in phospholipase A₂ research: from cells to animals to humans. Prog Lipid Res 2010; 50:152-92. [PMID: 21185866 DOI: 10.1016/j.plipres.2010.12.001] [Citation(s) in RCA: 368] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian genomes encode genes for more than 30 phospholipase A₂s (PLA₂s) or related enzymes, which are subdivided into several classes including low-molecular-weight secreted PLA₂s (sPLA₂s), Ca²+-dependent cytosolic PLA₂s (cPLA₂s), Ca²+-independent PLA₂s (iPLA₂s), platelet-activating factor acetylhydrolases (PAF-AHs), lysosomal PLA₂s, and a recently identified adipose-specific PLA. Of these, the intracellular cPLA₂ and iPLA₂ families and the extracellular sPLA₂ family are recognized as the "big three". From a general viewpoint, cPLA₂α (the prototypic cPLA₂ plays a major role in the initiation of arachidonic acid metabolism, the iPLA₂ family contributes to membrane homeostasis and energy metabolism, and the sPLA₂ family affects various biological events by modulating the extracellular phospholipid milieus. The cPLA₂ family evolved along with eicosanoid receptors when vertebrates first appeared, whereas the diverse branching of the iPLA₂ and sPLA₂ families during earlier eukaryote development suggests that they play fundamental roles in life-related processes. During the past decade, data concerning the unexplored roles of various PLA₂ enzymes in pathophysiology have emerged on the basis of studies using knockout and transgenic mice, the use of specific inhibitors, and information obtained from analysis of human diseases caused by mutations in PLA₂ genes. This review focuses on current understanding of the emerging biological functions of PLA₂s and related enzymes.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Rosenson RS, Elliott M, Stasiv Y, Hislop C. Randomized trial of an inhibitor of secretory phospholipase A2 on atherogenic lipoprotein subclasses in statin-treated patients with coronary heart disease. Eur Heart J 2010; 32:999-1005. [PMID: 21081550 DOI: 10.1093/eurheartj/ehq374] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
AIMS To investigate the effects of secretory phospholipase A2 (sPLA(2)) inhibition on plasma lipoproteins. Secretory phospholipase A2 isoenzymes promote atherosclerosis by mechanisms that include lipoprotein modification, retention, and oxidation. METHODS AND RESULTS Phospholipase Levels And Serological Markers of Atherosclerosis II (PLASMA II) is a Phase II, randomized, double-blind, placebo-controlled parallel-arm study of two once-daily doses of the novel sPLA(2) inhibitor, 1-H-indole-3-glyoxamide or varespladib methyl (Anthera Pharmaceuticals, Hayward, CA, USA). One hundred and thirty-five stable coronary heart disease patients were treated with either varespladib methyl 250 mg once daily, varespladib methyl 500 mg once daily, or placebo for 8 weeks. Varespladib methyl treatment resulted in statistically significant dose-dependent reductions that were different from placebo in sPLA(2) concentration, low-density lipoprotein (LDL) cholesterol, and non-high-density lipoprotein (HDL) cholesterol. When compared with placebo, varespladib methyl 500 mg once daily reduced LDL cholesterol by 15% (P < 0.001), non-HDL cholesterol by 15% (P < 0.001), total very LDL (VLDL) particle concentration by 14% (P = 0.022), and small VLDL particle concentration by 24% (P = 0.030). Relative to baseline, varespladib methyl 500 mg once daily reduced total LDL particle concentration (7%, P = 0.002) and small LDL particle concentration (11%, P = 0.014). CONCLUSION Reductions in atherogenic lipoproteins suggest that varespladib methyl 500 mg once daily may be an effective anti-atherosclerotic agent. Trial registered at ClinicalTrials.gov, identifier: NCT00525954.
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Affiliation(s)
- Robert S Rosenson
- Mount Sinai Heart-Box 1030, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY 10029, USA.
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Suckling K. Phospholipase A2s: Developing drug targets for atherosclerosis. Atherosclerosis 2010; 212:357-66. [DOI: 10.1016/j.atherosclerosis.2010.03.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 03/08/2010] [Accepted: 03/08/2010] [Indexed: 12/24/2022]
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Pioglitazone suppresses the lipopolysaccharide-induced production of inflammatory factors in mouse macrophages by inactivating NF-kappaB. Cell Biol Int 2010; 34:723-30. [PMID: 19947950 DOI: 10.1042/cbi20090005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
TZDs (thiazolidinediones) are prescribed as anti-Type II diabetes drugs, but little is known regarding whether TZDs regulate the expression of sPLA2 (secretory phospholipase A2) in macrophages. We have investigated the effects of pioglitazone on LPS (lipopolysaccharide)-induced production of TNF-alpha (tumour necrosis factor alpha), sPLA2-V and -X (groups V and X sPLA2) in RAW 264.7 macrophages. TNF-alpha, sPLA2-V and -X mRNA and protein expression were determined by RT-PCR (reverse transcriptase-PCR) and Western blot analysis, respectively. The activity of NF-kappaB (nuclear factor kappaB) was determined by Western blot and confocal microscopy. LPS induced TNF-alpha, sPLA2-V and sPLA2-X mRNA and protein expression. Pretreatment with 10 mumol/l pioglitazone significantly suppressed LPS-induced TNF-alpha, sPLA2-V and sPLA2-X mRNA and protein expression. LPS induced NF-kappaB expression and translocation in the nucleus, but the inductive effects were inhibited by pioglitazone. Our findings indicate that pioglitazone inhibits production of inflammatory factors induced by LPS in murine macrophage cells by inactivating NF-kappaB. Pioglitazone appears to play an anti-inflammatory role in the atherosclerotic process.
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Varespladib (A-002), a secretory phospholipase A2 inhibitor, reduces atherosclerosis and aneurysm formation in ApoE-/- mice. J Cardiovasc Pharmacol 2010; 53:60-5. [PMID: 19129734 DOI: 10.1097/fjc.0b013e318195bfbc] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The family of secretory phospholipase A2 (sPLA2) enzymes has been associated with inflammatory diseases and tissue injury including atherosclerosis. A-001 is a novel inhibitor of sPLA2 enzymes discovered by structure-based drug design, and A-002 is the orally bioavailable prodrug currently in clinical development. A-001 inhibited human and mouse sPLA2 group IIA, V, and X enzymes with IC50 values in the low nM range. A-002 (1 mg/kg) led to high serum levels of A-001 and inhibited PLA2 activity in transgenic mice overexpressing human sPLA2 group IIA in C57BL/6J background. In addition, the effects of A-002 on atherosclerosis in 2 ApoE mouse models were evaluated using en face analysis. (1) In a high-fat diet model, A-002 (30 and 90 mg/kg twice a day for 16 weeks) reduced aortic atherosclerosis by 50% (P < 0.05). Plasma total cholesterol was decreased (P < 0.05) by 1 month and remained lowered throughout the study. (2) In an accelerated atherosclerosis model, with angiotensin II-induced aortic lesions and aneurysms, A-002 (30 mg/kg twice a day) reduced aortic atherosclerosis by approximately 40% (P < 0.05) and attenuated aneurysm formation (P = 0.0096). Thus, A-002 was effective at significantly decreasing total cholesterol, atherogenesis, and aneurysm formation in these 2 ApoE mouse models.
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Rosenson RS, Fraser H, Trias J, Hislop C. Varespladib methyl in cardiovascular disease. Expert Opin Investig Drugs 2010; 19:1245-55. [DOI: 10.1517/13543784.2010.517193] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Froidure S, Canonne J, Daniel X, Jauneau A, Brière C, Roby D, Rivas S. AtsPLA2-alpha nuclear relocalization by the Arabidopsis transcription factor AtMYB30 leads to repression of the plant defense response. Proc Natl Acad Sci U S A 2010; 107:15281-6. [PMID: 20696912 PMCID: PMC2930548 DOI: 10.1073/pnas.1009056107] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The hypersensitive response (HR), characterized by a rapid and localized cell death at the inoculation site, is one of the most efficient resistance reactions to pathogen attack in plants. The transcription factor AtMYB30 was identified as a positive regulator of the HR and resistance responses during interactions between Arabidopsis and bacteria. Here, we show that AtMYB30 and the secreted phospholipase AtsPLA(2)-alpha physically interact in vivo, following the AtMYB30-mediated specific relocalization of AtsPLA(2)-alpha from cytoplasmic vesicles to the plant cell nucleus. This protein interaction leads to repression of AtMYB30 transcriptional activity and negative regulation of plant HR. Moreover, Atspla(2)-alpha mutant plants are more resistant to bacterial inoculation, whereas AtsPLA(2)-alpha overexpression leads to decreased resistance, confirming that AtsPLA(2)-alpha is a negative regulator of AtMYB30-mediated defense. These data underline the importance of cellular dynamics and, particularly, protein translocation to the nucleus, for defense-associated gene regulation in plants.
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Affiliation(s)
- Solène Froidure
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), Unité Mixte de Recherche, Centre National de la Recherche Scientifique-Institut National de la Recherche Agronomique 2594/441, F-31320 Castanet-Tolosan, France
| | - Joanne Canonne
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), Unité Mixte de Recherche, Centre National de la Recherche Scientifique-Institut National de la Recherche Agronomique 2594/441, F-31320 Castanet-Tolosan, France
| | - Xavier Daniel
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), Unité Mixte de Recherche, Centre National de la Recherche Scientifique-Institut National de la Recherche Agronomique 2594/441, F-31320 Castanet-Tolosan, France
| | - Alain Jauneau
- Institut Fédératif de Recherche 40, Plateforme Imagerie, Pôle de Biotechnologie Végétale, F-31320 Castanet-Tolosan, France; and
| | - Christian Brière
- Surfaces Cellulaires et Signalisation Chez les Végétaux, Université de Toulouse Unité Mixte de Recherche, Centre National de la Recherche Scientifique-Université Paul Sabatier 5546, BP 42617 Auzeville, 31326 Castanet-Tolosan, France
| | - Dominique Roby
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), Unité Mixte de Recherche, Centre National de la Recherche Scientifique-Institut National de la Recherche Agronomique 2594/441, F-31320 Castanet-Tolosan, France
| | - Susana Rivas
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), Unité Mixte de Recherche, Centre National de la Recherche Scientifique-Institut National de la Recherche Agronomique 2594/441, F-31320 Castanet-Tolosan, France
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Murakami M, Taketomi Y, Girard C, Yamamoto K, Lambeau G. Emerging roles of secreted phospholipase A2 enzymes: Lessons from transgenic and knockout mice. Biochimie 2010; 92:561-82. [PMID: 20347923 DOI: 10.1016/j.biochi.2010.03.015] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 03/18/2010] [Indexed: 11/15/2022]
Abstract
Among the emerging phospholipase A(2) (PLA(2)) superfamily, the secreted PLA(2) (sPLA(2)) family consists of low-molecular-mass, Ca(2+)-requiring extracellular enzymes with a His-Asp catalytic dyad. To date, more than 10 sPLA(2) enzymes have been identified in mammals. Individual sPLA(2)s exhibit unique tissue and cellular localizations and enzymatic properties, suggesting their distinct pathophysiological roles. Despite numerous enzymatic and cell biological studies on this enzyme family in the past two decades, their precise in vivo functions still remain largely obscure. Recent studies using transgenic and knockout mice for several sPLA(2) enzymes, in combination with lipidomics approaches, have opened new insights into their distinct contributions to various biological events such as food digestion, host defense, inflammation, asthma and atherosclerosis. In this article, we overview the latest understanding of the pathophysiological functions of individual sPLA(2) isoforms fueled by studies employing transgenic and knockout mice for several sPLA(2)s.
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Affiliation(s)
- Makoto Murakami
- Biomembrane Signaling Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Karakas M, Koenig W. Phospholipase A2 as a therapeutic target for atherosclerosis. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/clp.09.74] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Plihtari R, Hurt-Camejo E, Oörni K, Kovanen PT. Proteolysis sensitizes LDL particles to phospholipolysis by secretory phospholipase A2 group V and secretory sphingomyelinase. J Lipid Res 2010; 51:1801-9. [PMID: 20124257 DOI: 10.1194/jlr.m003103] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
LDL particles that enter the arterial intima become exposed to proteolytic and lipolytic modifications. The extracellular hydrolases potentially involved in LDL modification include proteolytic enzymes, such as chymase, cathepsin S, and plasmin, and phospholipolytic enzymes, such as secretory phospholipases A2 (sPLA2-IIa and sPLA2-V) and secretory acid sphingomyelinase (sSMase). Here, LDL was first proteolyzed and then subjected to lipolysis, after which the effects of combined proteolysis and lipolysis on LDL fusion and on binding to human aortic proteoglycans (PG) were studied. Chymase and cathepsin S led to more extensive proteolysis and release of peptide fragments from LDL than did plasmin. sPLA2-IIa was not able to hydrolyze unmodified LDL, and even preproteolysis of LDL particles failed to enhance lipolysis by this enzyme. However, preproteolysis with chymase and cathepsin S accelerated lipolysis by sPLA2-V and sSMase, which resulted in enhanced fusion and proteoglycan binding of the preproteolyzed LDL particles. Taken together, the results revealed that proteolysis sensitizes the LDL particles to hydrolysis by sPLA2-V and sSMase. By promoting fusion and binding of LDL to human aortic proteoglycans, the combination of proteolysis and phospholipolysis of LDL particles potentially enhances extracellular accumulation of LDL-derived lipids during atherogenesis.
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Phospholipase A2-modified LDL particles retain the generated hydrolytic products and are more atherogenic at acidic pH. Atherosclerosis 2009; 207:352-9. [DOI: 10.1016/j.atherosclerosis.2009.04.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 04/20/2009] [Accepted: 04/28/2009] [Indexed: 11/21/2022]
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Lee SH, Park DW, Park SC, Park YK, Hong SY, Kim JR, Lee CH, Baek SH. Calcium-independent phospholipase A2beta-Akt signaling is involved in lipopolysaccharide-induced NADPH oxidase 1 expression and foam cell formation. THE JOURNAL OF IMMUNOLOGY 2009; 183:7497-504. [PMID: 19917703 DOI: 10.4049/jimmunol.0900503] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Foam cell formation is the most important process in atherosclerosis, and low density lipoprotein oxidation by reactive oxygen species (ROS) is the key step in the conversion of macrophages to foam cells. This study reveals the control mechanism of the gene for NADPH oxidase 1 (Nox1), which produces ROS in the formation of foam cells by stimulating TLR4. Treatment of macrophages by the TLR4 agonist LPS stimulated ROS production and ROS-mediated macrophage to foam cell conversion. This LPS-induced ROS production and foam cell formation could be abrogated by pretreatment of macrophages with N-acetyl cysteine or apocynin. LPS increased Nox1 promoter activity, and resultant expression of mRNA and protein. Small interfering RNA mediated inhibition of Nox1 expression decreased LPS-induced ROS production and foam cell formation. LPS-mediated Nox1 expression and the responses occurred in a calcium-independent phospholipase A(2) (iPLA(2))-dependent manner. The iPLA(2)beta-specific inhibitor S-BEL or iPLA(2)beta small interfering RNA attenuated LPS-induced Nox1 expression, ROS production, and foam cell formation. In addition, activation of iPLA(2)beta by LPS caused Akt phosphorylation and was followed by increased Nox1 expression. These results suggest that the binding of LPS and TLR4 increases Nox1 expression through the iPLA(2)beta-Akt signaling pathway, and control ROS production and foam cell formation.
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Affiliation(s)
- Sun-Hye Lee
- Aging-associated Vascular Disease Research Center, Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu, South Korea
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Oörni K, Kovanen PT. Lipoprotein modification by secretory phospholipase A(2) enzymes contributes to the initiation and progression of atherosclerosis. Curr Opin Lipidol 2009; 20:421-7. [PMID: 19593123 DOI: 10.1097/mol.0b013e32832fa14d] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE OF REVIEW Secretory phospholipase A2s (sPLA2s) are considered to be important enzymes in the initiation and progression of atherosclerosis. In this review, we discuss the various mechanisms by which the direct action of the sPLA2s on LDL particles in the arterial intima may contribute to atherogenesis. RECENT FINDINGS A wealth of evidence, both in vitro and in vivo, supports a role for the sPLA2s in atherogenesis. Very recently, systemic inhibition of sPLA2s was found to reduce measures of arterial inflammation. The mechanisms behind this inhibition, however, are largely unknown. Here, we discuss the consequences of sPLA2 action on LDL in the arterial intima and address the recent findings regarding the effects of the lipolytic products of sPLA2, lysophosphatidylcholine, and fatty acids on intimal cells. LDL modified by sPLA2 can accumulate in the arterial intima both extracellularly and intracellularly. Importantly, the lipolytic products promote atherosclerosis by monocyte/macrophage recruitment, by enhancing the production of proretentive molecules by vascular smooth muscle cells, and by inducing cell death. SUMMARY Recent findings on sPLA2s support the idea that the enzymes contribute to human atherogenesis not only as initiating agents but also in maintaining plaque inflammation.
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Fujioka D, Kugiyama K. Novel Insights of Secretory Phospholipase A2 Action in Cardiology. Trends Cardiovasc Med 2009; 19:100-3. [DOI: 10.1016/j.tcm.2009.06.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Rosenson RS, Hislop C, McConnell D, Elliott M, Stasiv Y, Wang N, Waters DD. Effects of 1-H-indole-3-glyoxamide (A-002) on concentration of secretory phospholipase A2 (PLASMA study): a phase II double-blind, randomised, placebo-controlled trial. Lancet 2009; 373:649-58. [PMID: 19231633 DOI: 10.1016/s0140-6736(09)60403-7] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Secretory phospholipase A(2) (sPLA(2)) enzymes, produced and secreted in human blood vessels and hepatocytes, contribute to the development of atherosclerosis through mechanisms that are both dependent and independent of lipoprotein. We examined the effects of an sPLA(2) inhibitor on enzyme concentration and on plasma lipoproteins and inflammatory biomarkers in patients with coronary heart disease. METHODS Patients aged 18 years and older with stable coronary heart disease from the USA and Ukraine were eligible for enrolment in this phase II, randomised, double-blind, placebo-controlled, parallel-arm, dose-response study. 393 patients were randomly assigned by computer-generated sequence to receive either placebo (n=79) or one of four doses of an sPLA(2) inhibitor, A-002 (1-H-indole-3-glyoxamide; 50 mg [n=79], 100 mg [n=80], 250 mg [n=78], or 500 mg [n=77] twice daily), for 8 weeks. The primary endpoint was the change in sPLA(2) group IIA (sPLA(2)-IIA) concentration or activity from baseline to week 8. Analysis was by modified intention to treat (ITT). The ITT population consisted of all patients who received one dose of study treatment; data for patients who dropped out before the end of the study were carried forward from last observation. This trial is registered with ClinicalTrials.gov, number NCT00455546. FINDINGS All randomised patients received at least one dose and were included in the ITT population. Data for 45 patients were carried forward from last observation (36 in the A-002 group and nine in the placebo group); the main reason for dropout before completion was because of adverse events. 348 patients reached the primary endpoint (A-002 n=278, placebo n=70). Mean sPLA(2)-IIA concentration fell by 86.7%, from 157 pmol/L to 21 [corrected] pmol/L, in the overall active treatment group, and by 4.8%, from 157 pmol/L to 143 [corrected] pmol/L, in the placebo group (p<0.0001 treatment vs placebo). The reductions in sPLA(2)-IIA concentration in the A-002 groups were dose dependent (ranging from 69.2% in the 50 mg group to 95.8% in the 500 mg group) and differed significantly from placebo (p<0.0001 for all doses). In the 500 mg A-002 treatment group, there was one serious adverse event (exacerbation of underlying chronic obstructive pulmonary disease), but the proportion of patients reporting treatment-emergent adverse events did not differ from placebo. The main side-effects of the drug included headache (n=20), nausea (n=17), and diarrhoea (n=12). INTERPRETATION The reductions in sPLA(2)-IIA concentration suggest that A-002 might be an effective anti-atherosclerotic agent.
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Affiliation(s)
- Robert S Rosenson
- Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI, USA
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Tiwari A. Current and emerging paradigms in the therapeutic management of atherosclerosis. Expert Opin Ther Targets 2009; 12:1523-46. [PMID: 19007321 DOI: 10.1517/14728220802544061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
BACKGROUND The pathogenesis of atherosclerosis lies in abnormalities in lipoprotein metabolism leading to pathological interactions with vessel walls and the release of inflammatory components, which further aggravate the disease condition. OBJECTIVE To elucidate current and emerging trends in drug discovery towards the development of new entities regulating lipoprotein metabolism and inflammatory components to combat the progression of atherosclerosis. METHODS Research/review articles in the public domain and press releases were employed. RESULTS/CONCLUSION With the recent failure of torcetrapib and succinobucol, drug discovery and development efforts towards the treatment of atherosclerosis have received a big jolt and have been slowed down to a certain extent [corrected]. But this could be a starting point for several new mechanisms that are emerging to discover new drugs to combat the disease.
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Affiliation(s)
- Atul Tiwari
- Jubilant Biosys Ltd., CardioMetabolic Disorder Group, Drug Discovery Unit-Biology, #96, 2nd Stage, Industrial Suburb, Yeshwantpur, Bangalore-560022, Karnatka, India.
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Future Role for Selective Phospholipase A2 Inhibitors in the Prevention of Atherosclerotic Cardiovascular Disease. Cardiovasc Drugs Ther 2009; 23:93-101. [DOI: 10.1007/s10557-008-6148-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Accepted: 10/07/2008] [Indexed: 12/21/2022]
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Nijstad N, Wiersma H, Gautier T, van der Giet M, Maugeais C, Tietge UJF. Scavenger receptor BI-mediated selective uptake is required for the remodeling of high density lipoprotein by endothelial lipase. J Biol Chem 2009; 284:6093-100. [PMID: 19136670 DOI: 10.1074/jbc.m807683200] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Endothelial lipase (EL) is a negative regulator of high density lipoprotein (HDL) cholesterol plasma levels, and scavenger receptor BI (SR-BI) is involved in remodeling of HDL. The present study investigates the requirement of SR-BI for the effects of EL-mediated phospholipid hydrolysis on HDL metabolism in vivo. In vitro, selective uptake from EL-modified HDL was 129% higher than selective uptake from control HDL in SR-BI-overexpressing cells (p=0.01). In vivo overexpression of human EL by means of recombinant adenovirus decreased HDL plasma levels significantly (p<0.01). Fast protein liquid chromatography analysis and agarose gel electrophoresis revealed that EL expression resulted in the generation of small pre-beta HDL particles in wild-type mice, whereas in SR-BI-/- mice small HDL were preferentially removed. In kinetic experiments the fractional catabolic rate (FCR) of HDL cholesteryl ester increased by 110% (p<0.001), and the FCR of HDL apolipoproteins increased by 64% (p<0.001) in response to EL overexpression in wild-type mice. In SR-BI-/- mice a similar increase in the HDL apolipoprotein FCR occurred (p<0.001); however, there was no further increase in HDL cholesteryl ester catabolism. The apparent whole body selective uptake was increased 3-fold by EL in wild-type mice (p<0.001), whereas there was no selective uptake in SR-BI knock-out mice. EL overexpression increased hepatic selective uptake as well as holoparticle uptake (each p<0.01) in wild-type mice, whereas in SR-BI knock-out mice only holoparticle uptake increased (p<0.01). Our results indicate that SR-BI-mediated selective uptake of HDL cholesteryl ester is essential for the remodeling of large alpha-migrating HDL particles by EL.
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Affiliation(s)
- Niels Nijstad
- Center for Liver, Digestive and Metabolic Diseases, Laboratory of Pediatrics, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
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Boyanovsky BB, Shridas P, Simons M, van der Westhuyzen DR, Webb NR. Syndecan-4 mediates macrophage uptake of group V secretory phospholipase A2-modified LDL. J Lipid Res 2008; 50:641-50. [PMID: 19056705 DOI: 10.1194/jlr.m800450-jlr200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously reported that LDL modified by group V secretory phospholipase A2 (GV-LDL) promotes macrophage foam cell formation through a mechanism independent of scavenger receptors SR-A and CD36, and dependent on cellular proteoglycans. This study investigates the role of syndecans, a family of cell surface proteoglycans known to mediate endocytosis through macropinocytosis, in macrophage uptake of GV-LDL. LY 294002, a phosphatidylinositol 3-kinase inhibitor, significantly reduced internalization of (125)I-labeled GV-LDL in J-774 macrophages, consistent with a macropinocytic uptake pathway. Using small, interfering RNA-directed gene silencing, we demonstrated a direct relationship between (125)I-labeled GV-LDL binding and the level of syndecan-3 and syndecan-4 expression in J-774 cells. However, (125)I-labeled GV-LDL uptake was significantly reduced only when syndecan-4 expression was suppressed. Peritoneal macrophages from syndecan-4-deficient mice exhibited markedly reduced uptake of fluorescently labeled GV-LDL compared with wild-type cells. Furthermore, cholesteryl ester accumulation induced by GV-LDL was dependent on syndecan-4 expression. Syndecan-4 expression and GV-LDL binding were significantly increased in J-774 cells treated with lipopolysaccharide, suggesting that GV-LDL uptake via this pathway may be enhanced during inflammation. Taken together, our data point to a novel role for syndecan-4 in mediating the uptake of GV-LDL, a process implicated in atherosclerotic lesion progression.
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Affiliation(s)
- Boris B Boyanovsky
- Department of Internal Medicine, Endocrinology Division, University of Kentucky Medical Center, Lexington, KY 40536, USA
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Shaposhnik Z, Wang X, Trias J, Fraser H, Lusis AJ. The synergistic inhibition of atherogenesis in apoE-/- mice between pravastatin and the sPLA2 inhibitor varespladib (A-002). J Lipid Res 2008; 50:623-9. [PMID: 19029066 DOI: 10.1194/jlr.m800361-jlr200] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Secretory phospholipase A2 (sPLA2) activity promotes foam cell formation, increases proinflammatory bioactive lipid levels, decreases HDL levels, increases atherosclerosis in transgenic mice, and is an independent marker of cardiovascular disease. The effects of the sPLA2 inhibitor A-002 (varespladib) and pravastatin as monotherapies and in combination on atherosclerosis, lipids, and paraoxonase (PON) activity in apoE(-/-) mice were investigated. Male apoE(-/-) mice were placed on a 12-week high-fat diet supplemented with A-002 alone or combined with pravastatin. Atherosclerotic lesions were examined for size and composition using en face analysis, Movat staining, anti-CD68, and anti-alpha actin antibodies. Plasma lipids and PON activity were measured. A-002 decreased atherosclerotic lesion area by approximately 75% while increasing fibrous cap size by over 200%. HDL levels increased 40% and plasma PON activity increased 80%. Pravastatin monotherapy had no effect on lesion size but when combined with A-002, decreased lesion area 50% and total cholesterol levels 18% more than A-002 alone. A-002, a sPLA2 inhibitor, acts synergistically with pravastatin to decrease atherosclerosis, possibly through decreased levels of systemic inflammation or decreased lipid levels. A-002 treatment also resulted in a profound increase in plasma PON activity and significantly larger fibrous caps, suggesting the formation of more stable plaque architecture.
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Affiliation(s)
- Zory Shaposhnik
- Division of Cardiology, David Geffen School of Medicine at University of California at Los Angeles (UCLA), Los Angeles, CA 90095, USA
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Abstract
Introduction The secretory phospholipase A2 (sPLA2) family provides a seemingly endless array of potential biological functions that is only beginning to be appreciated. In humans, this family comprises 9 different members that vary in their tissue distribution, hydrolytic activity, and phospholipid substrate specificity. Through their lipase activity, these enzymes trigger various cell-signaling events to regulate cellular functions, directly kill bacteria, or modulate inflammatory responses. In addition, some sPLA2’s are high affinity ligands for cellular receptors. Objective This review merely scratches the surface of some of the actions of sPLA2s in innate immunity, inflammation, and atherosclerosis. The goal is to provide an overview of recent findings involving sPLA2s and to point to potential pathophysiologic mechanisms that may become targets for therapy.
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