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Pisciotta L, Ossoli A, Ronca A, Garuti A, Fresa R, Favari E, Calabresi L, Calandra S, Bertolini S. Plasma HDL pattern, cholesterol efflux and cholesterol loading capacity of serum in carriers of a novel missense variant (Gly176Trp) of endothelial lipase. J Clin Lipidol 2022; 16:694-703. [PMID: 36002365 DOI: 10.1016/j.jacl.2022.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 05/14/2022] [Accepted: 08/08/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Loss of function variants of LIPG gene encoding endothelial lipase (EL) are associated with primary hyperalphalipoproteinemia (HALP), a lipid disorder characterized by elevated plasma levels of high density lipoprotein cholesterol (HDL-C). OBJECTIVE Aim of the study was the phenotypic and genotypic characterization of a family with primary HALP. METHODS HDL subclasses distribution was determined by polyacrylamide gradient gel electrophoresis. Serum content of preβ-HDL was assessed by (2D)-electrophoresis. Cholesterol efflux capacity (CEC) of serum mediated by ABCA1, ABCG1 or SR-BI was assessed using cells expressing these proteins. Cholesterol loading capacity (CLC) of serum was assayed using cultured human macrophages. Next generation sequencing was used for DNA analysis. Plasma EL mass was determined by ELISA. RESULTS Three family members had elevated plasma HDL-C, apoA-I and total phospholipids, as well as a reduced content of preβ-HDL. These subjects were heterozygous carriers of a novel variant of LIPG gene [c.526 G>T, p.(Gly176Trp)] found to be deleterious in silico. Plasma EL mass in carriers was lower than in controls. CEC of sera mediated by ABCA1 and ABCG1 transporters was substantially reduced in the carriers. This effect was maintained after correction for serum HDL concentration. The sera of carriers were found to have a higher CLC in cultured human macrophages than control sera. CONCLUSION The novel p.(Gly176Trp) variant of endothelial lipase is associated with changes in HDL composition and subclass distribution as well as with functional changes affecting cholesterol efflux capacity of serum which suggest a defect in the early steps of revere cholesterol transport.
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Affiliation(s)
- Livia Pisciotta
- Department of Internal Medicine, University of Genoa, Genoa, Italy (Drs Pisciotta, Garuti, and Bertolini); Dietetics and Clinical Nutrition Unit, IRCCS-Polyclinic Hospital San Martino, Genoa, Italy (Dr Pisciotta).
| | - Alice Ossoli
- Centro E. Grossi Paoletti, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy (Dr Ossoli)
| | - Annalisa Ronca
- Department of Food and Drug, University of Parma, Parma, Italy (Drs Ronca and Favari)
| | - Anna Garuti
- Department of Internal Medicine, University of Genoa, Genoa, Italy (Drs Pisciotta, Garuti, and Bertolini)
| | - Raffaele Fresa
- Department of Internal Medicine, University of Genoa, Genoa, Italy (Drs Pisciotta, Garuti, and Bertolini)
| | - Elda Favari
- Department of Food and Drug, University of Parma, Parma, Italy (Drs Ronca and Favari)
| | - Laura Calabresi
- Centro E. Grossi Paoletti, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy (Dr Ossoli)
| | - Sebastiano Calandra
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy (Dr Calandra)
| | - Stefano Bertolini
- Department of Internal Medicine, University of Genoa, Genoa, Italy (Drs Pisciotta, Garuti, and Bertolini)
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2
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Serine Hydrolases in Lipid Homeostasis of the Placenta-Targets for Placental Function? Int J Mol Sci 2022; 23:ijms23126851. [PMID: 35743292 PMCID: PMC9223866 DOI: 10.3390/ijms23126851] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 02/01/2023] Open
Abstract
The metabolic state of pregnant women and their unborn children changes throughout pregnancy and adapts to the specific needs of each gestational week. These adaptions are accomplished by the actions of enzymes, which regulate the occurrence of their endogenous substrates and products in all three compartments: mother, placenta and the unborn. These enzymes determine bioactive lipid signaling, supply, and storage through the generation or degradation of lipids and fatty acids, respectively. This review focuses on the role of lipid-metabolizing serine hydrolases during normal pregnancy and in pregnancy-associated pathologies, such as preeclampsia, gestational diabetes mellitus, or preterm birth. The biochemical properties of each class of lipid hydrolases are presented, with special emphasis on their role in placental function or dysfunction. While, during a normal pregnancy, an appropriate tonus of bioactive lipids prevails, dysregulation and aberrant signaling occur in diseased states. A better understanding of the dynamics of serine hydrolases across gestation and their involvement in placental lipid homeostasis under physiological and pathophysiological conditions will help to identify new targets for placental function in the future.
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3
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Espinoza C, Fuenzalida B, Leiva A. Increased Fetal Cardiovascular Disease Risk: Potential Synergy Between Gestational Diabetes Mellitus and Maternal Hypercholesterolemia. Curr Vasc Pharmacol 2021; 19:601-623. [PMID: 33902412 DOI: 10.2174/1570161119666210423085407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/27/2021] [Accepted: 03/16/2021] [Indexed: 01/25/2023]
Abstract
Cardiovascular diseases (CVD) remain a major cause of death worldwide. Evidence suggests that the risk for CVD can increase at the fetal stages due to maternal metabolic diseases, such as gestational diabetes mellitus (GDM) and maternal supraphysiological hypercholesterolemia (MSPH). GDM is a hyperglycemic, inflammatory, and insulin-resistant state that increases plasma levels of free fatty acids and triglycerides, impairs endothelial vascular tone regulation, and due to the increased nutrient transport, exposes the fetus to the altered metabolic conditions of the mother. MSPH involves increased levels of cholesterol (mainly as low-density lipoprotein cholesterol) which also causes endothelial dysfunction and alters nutrient transport to the fetus. Despite that an association has already been established between MSPH and increased CVD risk, however, little is known about the cellular processes underlying this relationship. Our knowledge is further obscured when the simultaneous presentation of MSPH and GDM takes place. In this context, GDM and MSPH may substantially increase fetal CVD risk due to synergistic impairment of placental nutrient transport and endothelial dysfunction. More studies on the separate and/or cumulative role of both processes are warranted to suggest specific treatment options.
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Affiliation(s)
- Cristian Espinoza
- Faculty of Biological Sciences, Pontificia Universidad Catolica de Chile, Santiago 8330024, Chile
| | - Barbara Fuenzalida
- Institute of Biochemistry and Molecular Medicine, University of Bern, CH-3012 Bern, Switzerland
| | - Andrea Leiva
- School of Medical Technology, Health Sciences Faculty, Universidad San Sebastian, Providencia 7510157, Chile
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4
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Khetarpal SA, Vitali C, Levin MG, Klarin D, Park J, Pampana A, Millar JS, Kuwano T, Sugasini D, Subbaiah PV, Billheimer JT, Natarajan P, Rader DJ. Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins. PLoS Genet 2021; 17:e1009802. [PMID: 34543263 PMCID: PMC8483387 DOI: 10.1371/journal.pgen.1009802] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 09/30/2021] [Accepted: 09/02/2021] [Indexed: 11/18/2022] Open
Abstract
Triglyceride-rich lipoproteins (TRLs) are circulating reservoirs of fatty acids used as vital energy sources for peripheral tissues. Lipoprotein lipase (LPL) is a predominant enzyme mediating triglyceride (TG) lipolysis and TRL clearance to provide fatty acids to tissues in animals. Physiological and human genetic evidence support a primary role for LPL in hydrolyzing TRL TGs. We hypothesized that endothelial lipase (EL), another extracellular lipase that primarily hydrolyzes lipoprotein phospholipids may also contribute to TRL metabolism. To explore this, we studied the impact of genetic EL loss-of-function on TRL metabolism in humans and mice. Humans carrying a loss-of-function missense variant in LIPG, p.Asn396Ser (rs77960347), demonstrated elevated plasma TGs and elevated phospholipids in TRLs, among other lipoprotein classes. Mice with germline EL deficiency challenged with excess dietary TG through refeeding or a high-fat diet exhibited elevated TGs, delayed dietary TRL clearance, and impaired TRL TG lipolysis in vivo that was rescued by EL reconstitution in the liver. Lipidomic analyses of postprandial plasma from high-fat fed Lipg-/- mice demonstrated accumulation of phospholipids and TGs harboring long-chain polyunsaturated fatty acids (PUFAs), known substrates for EL lipolysis. In vitro and in vivo, EL and LPL together promoted greater TG lipolysis than either extracellular lipase alone. Our data positions EL as a key collaborator of LPL to mediate efficient lipolysis of TRLs in humans and mice.
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Affiliation(s)
- Sumeet A. Khetarpal
- Departments of Medicine and Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America,Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Cecilia Vitali
- Departments of Medicine and Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Michael G. Levin
- Division of Cardiovascular Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America,Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America,Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, United States of America
| | - Derek Klarin
- Boston VA Healthcare System, Boston, Massachusetts, United States of America,Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Joseph Park
- Departments of Medicine and Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Akhil Pampana
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America,Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America,Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - John S. Millar
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Takashi Kuwano
- Departments of Medicine and Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Dhavamani Sugasini
- Section of Endocrinology, Department of Medicine, University of Illinois at Chicago; Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Papasani V. Subbaiah
- Section of Endocrinology, Department of Medicine, University of Illinois at Chicago; Jesse Brown VA Medical Center, Chicago, Illinois, United States of America
| | - Jeffrey T. Billheimer
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Pradeep Natarajan
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, Massachusetts, United States of America,Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America,Department of Medicine, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Daniel J. Rader
- Departments of Medicine and Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America,* E-mail:
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5
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NAD(H)-mediated tetramerization controls the activity of Legionella pneumophila phospholipase PlaB. Proc Natl Acad Sci U S A 2021; 118:2017046118. [PMID: 34074754 DOI: 10.1073/pnas.2017046118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The virulence factor PlaB promotes lung colonization, tissue destruction, and intracellular replication of Legionella pneumophila, the causative agent of Legionnaires' disease. It is a highly active phospholipase exposed at the bacterial surface and shows an extraordinary activation mechanism by tetramer deoligomerization. To unravel the molecular basis for enzyme activation and localization, we determined the crystal structure of PlaB in its tetrameric form. We found that the tetramer is a dimer of identical dimers, and a monomer consists of an N-terminal α/β-hydrolase domain expanded by two noncanonical two-stranded β-sheets, β-6/β-7 and β-9/β-10. The C-terminal domain reveals a fold displaying a bilobed β-sandwich with a hook structure required for dimer formation and structural complementation of the enzymatic domain in the neighboring monomer. This highlights the dimer as the active form. Δβ-9/β-10 mutants showed a decrease in the tetrameric fraction and altered activity profiles. The variant also revealed restricted binding to membranes resulting in mislocalization and bacterial lysis. Unexpectedly, we observed eight NAD(H) molecules at the dimer/dimer interface, suggesting that these molecules stabilize the tetramer and hence lead to enzyme inactivation. Indeed, addition of NAD(H) increased the fraction of the tetramer and concomitantly reduced activity. Together, these data reveal structural elements and an unprecedented NAD(H)-mediated tetramerization mechanism required for spatial and enzymatic control of a phospholipase virulence factor. The allosteric regulatory process identified here is suited to fine tune PlaB in a way that protects Legionella pneumophila from self-inflicted lysis while ensuring its activity at the pathogen-host interface.
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6
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Yang Q, Pu N, Li XY, Shi XL, Chen WW, Zhang GF, Hu YP, Zhou J, Chen FX, Li BQ, Tong ZH, Férec C, Cooper DN, Chen JM, Li WQ. Digenic Inheritance and Gene-Environment Interaction in a Patient With Hypertriglyceridemia and Acute Pancreatitis. Front Genet 2021; 12:640859. [PMID: 34040631 PMCID: PMC8143378 DOI: 10.3389/fgene.2021.640859] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/30/2021] [Indexed: 12/12/2022] Open
Abstract
The etiology of hypertriglyceridemia (HTG) and acute pancreatitis (AP) is complex. Herein, we dissected the underlying etiology in a patient with HTG and AP. The patient had a 20-year history of heavy alcohol consumption and an 8-year history of mild HTG. He was hospitalized for alcohol-triggered AP, with a plasma triglyceride (TG) level up to 21.4 mmol/L. A temporary rise in post-heparin LPL concentration (1.5–2.5 times of controls) was noted during the early days of AP whilst LPL activity was consistently low (50∼70% of controls). His TG level rapidly decreased to normal in response to treatment, and remained normal to borderline high during a ∼3-year follow-up period during which he had abstained completely from alcohol. Sequencing of the five primary HTG genes (i.e., LPL, APOC2, APOA5, GPIHBP1 and LMF1) identified two heterozygous variants. One was the common APOA5 c.553G > T (p.Gly185Cys) variant, which has been previously associated with altered TG levels as well as HTG-induced acute pancreatitis (HTG-AP). The other was a rare variant in the LPL gene, c.756T > G (p.Ile252Met), which was predicted to be likely pathogenic and found experimentally to cause a 40% loss of LPL activity without affecting either protein synthesis or secretion. We provide evidence that both a gene-gene interaction (between the common APOA5 variant and the rare LPL variant) and a gene-environment interaction (between alcohol and digenic inheritance) might have contributed to the development of mild HTG and alcohol-triggered AP in the patient, thereby improving our understanding of the complex etiology of HTG and HTG-AP.
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Affiliation(s)
- Qi Yang
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Na Pu
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Xiao-Yao Li
- Department of Intensive Care Unit, The Affiliated Drum Tower Hospital, Medical School of Nanjing University, Nanjing, China
| | - Xiao-Lei Shi
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Wei-Wei Chen
- Department of Gastroenterology, Clinical Medical College, Yangzhou University, Yangzhou, China
| | - Guo-Fu Zhang
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Yue-Peng Hu
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Jing Zhou
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Fa-Xi Chen
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Bai-Qiang Li
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Zhi-Hui Tong
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Claude Férec
- Univ Brest, INSERM, EFS, UMR 1078, GGB, Brest, France.,Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, Brest, France
| | - David N Cooper
- School of Medicine, Institute of Medical Genetics, Cardiff University, Cardiff, United Kingdom
| | - Jian-Min Chen
- Univ Brest, INSERM, EFS, UMR 1078, GGB, Brest, France
| | - Wei-Qin Li
- Department of Critical Care Medicine, Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
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7
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Hong C, Deng R, Wang P, Lu X, Zhao X, Wang X, Cai R, Lin J. LIPG: an inflammation and cancer modulator. Cancer Gene Ther 2020; 28:27-32. [PMID: 32572177 DOI: 10.1038/s41417-020-0188-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 06/03/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022]
Abstract
Endothelial lipase (LIPG/EL) performs fundamental and vital roles in the human body, including cell composition, cytokine expression, and energy provision. Since LIPG predominantly functions as a phospholipase as well as presents low levels of triglyceride lipase activity, it plays an essential role in lipoprotein metabolism, and involves in the metabolic syndromes such as inflammatory response and atherosclerosis. Cytokines significantly affect LIPG expression in endothelial cells in many diseases. Recently, it is suggested that LIPG contributes to cancer initiation and progression, and LIPG attached increasing importance to its potential for future targeted therapy.
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Affiliation(s)
- Chang Hong
- The First Clinical Medical School (Nanfang Hospital), Southern Medical University, Guangzhou, 510515, PR China
| | - Ruxia Deng
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Ping Wang
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Xiansheng Lu
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Xin Zhao
- The First Clinical Medical School (Nanfang Hospital), Southern Medical University, Guangzhou, 510515, PR China
| | - Xiaoyu Wang
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Rui Cai
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Jie Lin
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, PR China.
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8
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Koerner CM, Roberts BS, Neher SB. Endoplasmic reticulum quality control in lipoprotein metabolism. Mol Cell Endocrinol 2019; 498:110547. [PMID: 31442546 PMCID: PMC6814580 DOI: 10.1016/j.mce.2019.110547] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/16/2019] [Accepted: 08/17/2019] [Indexed: 12/26/2022]
Abstract
Lipids play a critical role in energy metabolism, and a suite of proteins is required to deliver lipids to tissues. Several of these proteins require an intricate endoplasmic reticulum (ER) quality control (QC) system and unique secondary chaperones for folding. Key examples include apolipoprotein B (apoB), which is the primary scaffold for many lipoproteins, dimeric lipases, which hydrolyze triglycerides from circulating lipoproteins, and the low-density lipoprotein receptor (LDLR), which clears cholesterol-rich lipoproteins from the circulation. ApoB requires specialized proteins for lipidation, dimeric lipases lipoprotein lipase (LPL) and hepatic lipase (HL) require a transmembrane maturation factor for secretion, and the LDLR requires several specialized, domain-specific chaperones. Deleterious mutations in these proteins or their chaperones may result in dyslipidemias, which are detrimental to human health. Here, we review the ER quality control systems that ensure secretion of apoB, LPL, HL, and LDLR with a focus on the specialized chaperones required by each protein.
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Affiliation(s)
- Cari M Koerner
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, USA
| | - Benjamin S Roberts
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, USA
| | - Saskia B Neher
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, USA.
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9
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Meng W, Adam LP, Behnia K, Zhao L, Yang R, Kopcho LM, Locke GA, Taylor DS, Yin X, Wexler RR, Finlay H. Benzothiazole-based compounds as potent endothelial lipase inhibitors. Bioorg Med Chem Lett 2019; 29:126673. [DOI: 10.1016/j.bmcl.2019.126673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 09/03/2019] [Accepted: 09/04/2019] [Indexed: 10/26/2022]
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10
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Nagao M, Miyashita K, Mori K, Irino Y, Toh R, Hara T, Hirata KI, Shinohara M, Nakajima K, Ishida T. Serum concentration of full-length- and carboxy-terminal fragments of endothelial lipase predicts future cardiovascular risks in patients with coronary artery disease. J Clin Lipidol 2019; 13:839-846. [PMID: 31473149 DOI: 10.1016/j.jacl.2019.07.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 06/18/2019] [Accepted: 07/21/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND Endothelial lipase (EL), a regulator of plasma high-density lipoprotein cholesterol (HDL-C), is secreted as a 68-kDa mature glycoprotein, and then cleaved by proprotein convertases. However, the clinical significance of the circulating EL fragments remains unclear. OBJECTIVE The objective of this study was to analyze the impact of serum EL fragments on HDL-C levels and major adverse cardiovascular events (MACE). METHODS Using novel monoclonal antibodies (RC3A6) against carboxy-terminal EL protein, we have established a new enzyme-linked immunosorbent assay (ELISA) system, which can detect both full-length EL protein (full EL) and carboxy-terminal truncated fragments (total EL) in serum. The previous sandwich ELISA detected only full EL. The full and total EL mass were measured in 556 patients with coronary artery disease. Among them, 272 patients who underwent coronary intervention were monitored for 2 years for MACE. RESULTS There was a significant correlation between serum full and total EL mass (R = 0.45, P < .0001). However, the total EL mass showed a stronger inverse correlation with serum HDL-cholesterol concentration than the full EL mass (R = -0.17 vs -0.02). Kaplan-Meier analysis documented an association of serum total EL mass and MACE (log-rank P = .037). When an optimal cutoff value was set at 96.23 ng/mL, total EL mass was an independent prognostic factor for MACE in the Cox proportional hazard model (HR; 1.75, 95% CI; 1.10-2.79, P = .018). CONCLUSION Serum total EL mass could be a predictor for MACE in patients with coronary artery disease. This novel ELISA will be useful for further clarifying the impact of EL on HDL metabolism and atherosclerosis.
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Affiliation(s)
- Manabu Nagao
- Division of Cardiovascular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | | | - Kenta Mori
- Division of Cardiovascular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yasuhiro Irino
- Division of Evidence-based Laboratory Medicine, Kobe University Graduate School of Medicine
| | - Ryuji Toh
- Division of Evidence-based Laboratory Medicine, Kobe University Graduate School of Medicine
| | - Tetsuya Hara
- Division of Cardiovascular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Ken-Ichi Hirata
- Division of Cardiovascular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan; Division of Evidence-based Laboratory Medicine, Kobe University Graduate School of Medicine
| | - Masakazu Shinohara
- Division of Epidemiology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Katsuyuki Nakajima
- Laboratory of Clinical Nutrition and Medicine, Kagawa Nutrition University, Tokyo, Japan
| | - Tatsuro Ishida
- Division of Cardiovascular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
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11
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Kim SH, Johnson JA, Jiang J, Parkhurst B, Phillips M, Pi Z, Qiao JX, Tora G, Ye Chen A, Liu E, Yin X, Yang R, Zhao L, Taylor DS, Basso M, Behnia K, Onorato J, Chen XQ, Abell LM, Lu H, Locke G, Caporuscio C, Adam LP, Gordon D, Wexler RR, Finlay HJ. Identification of substituted benzothiazole sulfones as potent and selective inhibitors of endothelial lipase. Bioorg Med Chem Lett 2019; 29:1918-1921. [PMID: 31176700 DOI: 10.1016/j.bmcl.2019.05.048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/22/2019] [Accepted: 05/24/2019] [Indexed: 12/13/2022]
Abstract
A low level of high density lipoprotein (HDL) is an independent risk factor for cardiovascular disease. HDL reduces inflammation and plays a central role in reverse cholesterol transport, where cholesterol is removed from peripheral tissues and atherosclerotic plaque. One approach to increase plasma HDL is through inhibition of endothelial lipase (EL). EL hydrolyzes phospholipids in HDL resulting in reduction of plasma HDL. A series of benzothiazole sulfone amides was optimized for EL inhibition potency, lipase selectivity and improved pharmacokinetic profile leading to the identification of Compound 32. Compound 32 was evaluated in a mouse pharmacodynamic model and found to show no effect on HDL cholesterol level despite achieving targeted plasma exposure (Ctrough > 15 fold over mouse plasma EL IC50 over 4 days).
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Affiliation(s)
- Soong-Hoon Kim
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States.
| | - James A Johnson
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Ji Jiang
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Brandon Parkhurst
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Monique Phillips
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Zulan Pi
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Jennifer X Qiao
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - George Tora
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Alice Ye Chen
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Eddie Liu
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Xiaohong Yin
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Richard Yang
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Lei Zhao
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - David S Taylor
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Michael Basso
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Kamelia Behnia
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Joelle Onorato
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Xue-Qing Chen
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Lynn M Abell
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Hao Lu
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Gregory Locke
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Christian Caporuscio
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Leonard P Adam
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - David Gordon
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Ruth R Wexler
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
| | - Heather J Finlay
- Research and Development, Bristol-Myers Squibb, Princeton, NJ 08543, United States
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12
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Wang C, Nishijima K, Kitajima S, Niimi M, Yan H, Chen Y, Ning B, Matsuhisa F, Liu E, Zhang J, Chen YE, Fan J. Increased Hepatic Expression of Endothelial Lipase Inhibits Cholesterol Diet-Induced Hypercholesterolemia and Atherosclerosis in Transgenic Rabbits. Arterioscler Thromb Vasc Biol 2017; 37:1282-1289. [PMID: 28546217 DOI: 10.1161/atvbaha.117.309139] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/12/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Endothelial lipase (EL) is a key determinant in plasma high-density lipoprotein-cholesterol. However, functional roles of EL on the development of atherosclerosis have not been clarified. We investigated whether hepatic expression of EL affects plasma lipoprotein metabolism and cholesterol diet-induced atherosclerosis. APPROACH AND RESULTS We generated transgenic (Tg) rabbits expressing the human EL gene in the liver and then examined the effects of EL expression on plasma lipids and lipoproteins and compared the susceptibility of Tg rabbits with cholesterol diet-induced atherosclerosis with non-Tg littermates. On a chow diet, hepatic expression of human EL in Tg rabbits led to remarkable reductions in plasma levels of total cholesterol, phospholipids, and high-density lipoprotein-cholesterol compared with non-Tg controls. On a cholesterol-rich diet for 16 weeks, Tg rabbits exhibited significantly lower hypercholesterolemia and less atherosclerosis than non-Tg littermates. In Tg rabbits, gross lesion area of aortic atherosclerosis was reduced by 52%, and the lesions were characterized by fewer macrophages and smooth muscle cells compared with non-Tg littermates. CONCLUSIONS Increased hepatic expression of EL attenuates cholesterol diet-induced hypercholesterolemia and protects against atherosclerosis.
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Affiliation(s)
- Chuan Wang
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Kazutoshi Nishijima
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Shuji Kitajima
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Manabu Niimi
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Haizhao Yan
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Yajie Chen
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Bo Ning
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Fumikazu Matsuhisa
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Enqi Liu
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Jifeng Zhang
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Y Eugene Chen
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.)
| | - Jianglin Fan
- From the Department of Molecular Pathology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, Graduate School, University of Yamanashi, Japan (C.W., M.N., B.N., H.Y., Y.C., J.F.); Department of Pathology, Xi'an Medical University, China (B.N., J.F.); Animal Research Laboratory, Bioscience Education-Research Support Center, Akita University, Japan (K.N.); Analytical Research Center for Experimental Sciences, Saga University, Japan (S.K., F.M.); Research Institute of Atherosclerotic Disease and Laboratory Animal Center, Xi'an Jiaotong University School of Medicine, China (E.L.); and Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor (J.Z., Y.E.C.).
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13
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Yu JE, Han SY, Wolfson B, Zhou Q. The role of endothelial lipase in lipid metabolism, inflammation, and cancer. Histol Histopathol 2017; 33:1-10. [PMID: 28540715 DOI: 10.14670/hh-11-905] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Endothelial lipase (LIPG) plays a critical role in lipoprotein metabolism, cytokine expression, and the lipid composition of cells. Thus far, the extensive investigations of LIPG have focused on its mechanisms and involvement in metabolic syndromes such as atherosclerosis. However, recent developments have found that LIPG plays a role in cancer. This review summarizes the field of LIPG study. We focus on the role of LIPG in lipid metabolism and the inflammatory response, and highlight the recent insights in its involvement in tumor progression. Finally, we discuss potential therapeutic strategies for targeting LIPG in cancer, and the therapeutic potential of LIPG as a drug target.
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Affiliation(s)
- Justine E Yu
- Department of Biochemistry and Molecular Biology, Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, USA
| | - Shu-Yan Han
- Department of Biochemistry and Molecular Biology, Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, USA.,Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Integration of Chinese and Western Medicine, Peking University Cancer Hospital and Institute, Beijing, People's Republic of China
| | - Benjamin Wolfson
- Department of Biochemistry and Molecular Biology, Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, USA
| | - Qun Zhou
- Department of Biochemistry and Molecular Biology, Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, USA.
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14
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Kuhle K, Krausze J, Curth U, Rössle M, Heuner K, Lang C, Flieger A. Oligomerization inhibits Legionella pneumophila PlaB phospholipase A activity. J Biol Chem 2014; 289:18657-66. [PMID: 24811180 DOI: 10.1074/jbc.m114.573196] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The intracellularly replicating lung pathogen Legionella pneumophila consists of an extraordinary variety of phospholipases, including at least 15 different phospholipases A (PLA). Among them, PlaB, the first characterized member of a novel lipase family, is a hemolytic virulence factor that exhibits the most prominent PLA activity in L. pneumophila. We analyzed here protein oligomerization, the importance of oligomerization for activity, addressed further essential regions for activity within the PlaB C terminus, and the significance of PlaB-derived lipolytic activity for L. pneumophila intracellular replication. We determined by means of analytical ultracentrifugation and small angle x-ray scattering analysis that PlaB forms homodimers and homotetramers. The C-terminal 5, 10, or 15 amino acids, although the individual regions contributed to PLA activity, were not essential for protein tetramerization. Infection of mouse macrophages with L. pneumophila wild type, plaB knock-out mutant, and plaB complementing or various mutated plaB-harboring strains showed that catalytic activity of PlaB promotes intracellular replication. We observed that PlaB was most active in the lower nanomolar concentration range but not at or only at a low level at concentration above 0.1 μm where it exists in a dimer/tetramer equilibrium. We therefore conclude that PlaB is a virulence factor that, on the one hand, assembles in inactive tetramers at micromolar concentrations. On the other hand, oligomer dissociation at nanomolar concentrations activates PLA activity. Our data highlight the first example of concentration-dependent phospholipase inactivation by tetramerization, which may protect the bacterium from internal PLA activity, but enzyme dissociation may allow its activation after export.
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Affiliation(s)
- Katja Kuhle
- From the Robert Koch-Institut, 38855 Wernigerode
| | - Joern Krausze
- the Helmholtz Center for Infection Research, 38124 Braunschweig
| | - Ute Curth
- the Institute for Biophysical Chemistry, Hannover Medical School, 30625 Hannover
| | - Manfred Rössle
- the European Molecular Biology Laboratory, 22603 Hamburg Branch, c/o DESY, Hamburg, and the Lübeck University of Applied Sciences, 23562 Lübeck, Germany
| | - Klaus Heuner
- From the Robert Koch-Institut, 38855 Wernigerode
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15
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Sun L, Ishida T, Miyashita K, Kinoshita N, Mori K, Yasuda T, Toh R, Nakajima K, Imamura S, Hirata KI. Plasma activity of endothelial lipase impacts high-density lipoprotein metabolism and coronary risk factors in humans. J Atheroscler Thromb 2013; 21:313-21. [PMID: 24369272 DOI: 10.5551/jat.20131] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIM Endothelial lipase (EL) is a determinant of plasma levels of high-density lipoprotein cholesterol (HDL-C). However, little is known about the impact of EL activity on plasma lipid profile. We aimed to establish a new method to evaluate EL-specific phospholipase activity in humans. METHODS Plasma samples were obtained from 115 patients with coronary artery disease (CAD) and 154 patients without CAD. Plasma EL protein was immunoprecipitated using an anti-EL monoclonal antibody after plasma non-specific immunoglobulins were removed by incubation with ProteinA. The phospholipase activity of the immunoprecipitated samples was measured using a fluorogenic phospholipase substrate, Bis-BODIPY FL C11-PC. RESULTS The EL-specific phospholipase assay revealed that plasma EL activity was inversely correlated with HDL-C levels (R = -0.3088, p<0.0001). In addition, the EL activity was associated with cigarette smoking. Furthermore, EL activity in CAD patients was significantly higher than that in nonCAD patients. Concomitantly, the HDL-C level in CAD patients were significantly lower than that in non-CAD patients. CONCLUSION We have established a method for human plasma EL-specific phospholipase activity by combination of EL immunoprecipitation and a fluorogenic phospholipid substrate. Plasma EL activity was associated with not only plasma HDL-C levels but also the risks for CAD.
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Affiliation(s)
- Li Sun
- Division of Cardiovascular Medicine, Kobe University Graduate School of Medicine
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16
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Razzaghi H, Tempczyk-Russell A, Haubold K, Santorico SA, Shokati T, Christians U, Churchill MEA. Genetic and structure-function studies of missense mutations in human endothelial lipase. PLoS One 2013; 8:e55716. [PMID: 23536757 PMCID: PMC3607615 DOI: 10.1371/journal.pone.0055716] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 12/29/2012] [Indexed: 11/18/2022] Open
Abstract
Endothelial lipase (EL) plays a pivotal role in HDL metabolism. We sought to characterize EL and its interaction with HDL as well as its natural variants genetically, functionally and structurally. We screened our biethnic population sample (n = 802) for selected missense mutations (n = 5) and identified T111I as the only common variant. Multiple linear regression analyses in Hispanic subjects revealed an unexpected association between T111I and elevated LDL-C (p-value = 0.012) and total cholesterol (p-value = 0.004). We examined lipase activity of selected missense mutants (n = 10) and found different impacts on EL function, ranging from normal to complete loss of activity. EL-HDL lipidomic analyses indicated that EL has a defined remodeling of HDL without exhaustion of the substrate and a distinct and preference for several fatty acids that are lipid mediators and known for their potent pro- and anti-inflammatory properties. Structural studies using homology modeling revealed a novel α/β motif in the C-domain, unique to EL. The EL dimer was found to have the flexibility to expand and to bind various sizes of HDL particles. The likely impact of the all known missense mutations (n = 18) on the structure of EL was examined using molecular modeling and the impact they may have on EL lipase activity using a novel structure-function slope based on their structural free energy differences. The results of this multidisciplinary approach delineated the impact of EL and its variants on HDL. Moreover, the results suggested EL to have the capacity to modulate vascular health through its role in fatty acid-based signaling pathways.
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Affiliation(s)
- Hamid Razzaghi
- Division of Cardiology, Department of Medicine, University of Colorado Denver, Aurora, Colorado, United States of America.
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17
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Dong X, Wang G, Zhang G, Ni Z, Suo J, Cui J, Cui A, Yang Q, Xu Y, Li F. The endothelial lipase protein is promising urinary biomarker for diagnosis of gastric cancer. Diagn Pathol 2013; 8:45. [PMID: 23510199 PMCID: PMC3621381 DOI: 10.1186/1746-1596-8-45] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 03/10/2013] [Indexed: 12/31/2022] Open
Abstract
Background Gastric cancer is one of the most common malignant tumors in the world. Finding effective diagnostic biomarkers in urine or serum would represent the most ideal solution to detecting gastric cancer during annual physical examination. This study was to evaluate the potential of endothelial lipase (EL) as a urinary biomarker for diagnosis of gastric cancer. Methods The expression levels of EL was measured using Western blotting and immunohistochemical staining experiments on (tissue, serum, and urine) samples of gastric cancer patients versus healthy people. We also checked the EL levels in the urine samples of other cancer types (lung, colon and rectum cancers) and benign lesions (gastritis and gastric leiomyoma) to check if EL was specific to gastric cancer. Result We observed a clear separation between the EL expression levels in the urine samples of 90 gastric cancer patients and of 57 healthy volunteers. It was approximately 9.9 fold average decrease of the EL expression levels in the urine samples of gastric cancer compared to the healthy controls (P <0.0001), achieving a 0.967 AUC value for the ROC (receiver operating characteristic) curve, demonstrating it’s highly accurate as a diagnostic marker for gastric cancer. Interestingly, the expression levels of EL in tissue and serum samples were not nearly as discriminative as in urine samples (P = 0.90 and P = 0.79). In immunohistochemical experiments, positive expression of the EL protein was found in 67% (8/12) of gastric adjacent noncancerous and in 58% (7/12) of gastric cancer samples. There was no significant statistical in the expression levels of this protein between the gastric cancer and the matching noncancerous tissues (P =0.67). Conclusions The urinary EL as a highly accurate gastric cancer biomarker that is potentially applicable to the general screening with high sensitivity and specificity. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4527331618757552
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Affiliation(s)
- Xueyan Dong
- Department of Pathogeny Biology, Norman Bethune Medical College of Jilin University, Changchun, Jilin, China
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18
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Abstract
All organisms use fatty acids (FAs) for energy substrates and as precursors for membrane and signaling lipids. The most efficient way to transport and store FAs is in the form of triglycerides (TGs); however, TGs are not capable of traversing biological membranes and therefore need to be cleaved by TG hydrolases ("lipases") before moving in or out of cells. This biochemical process is generally called "lipolysis." Intravascular lipolysis degrades lipoprotein-associated TGs to FAs for their subsequent uptake by parenchymal cells, whereas intracellular lipolysis generates FAs and glycerol for their release (in the case of white adipose tissue) or use by cells (in the case of other tissues). Although the importance of lipolysis has been recognized for decades, many of the key proteins involved in lipolysis have been uncovered only recently. Important new developments include the discovery of glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), the molecule that moves lipoprotein lipase from the interstitial spaces to the capillary lumen, and the discovery of adipose triglyceride lipase (ATGL) and comparative gene identification-58 (CGI-58) as crucial molecules in the hydrolysis of TGs within cells. This review summarizes current views of lipolysis and highlights the relevance of this process to human disease.
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Affiliation(s)
- Stephen G. Young
- Department of Medicine
- Department of Human Genetics, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California 90095
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
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19
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Basu D, Lei X, Josekutty J, Hussain MM, Jin W. Measurement of the phospholipase activity of endothelial lipase in mouse plasma. J Lipid Res 2012; 54:282-9. [PMID: 23103358 DOI: 10.1194/jlr.d031112] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Endothelial lipase (EL) is a major negative regulator of plasma HDL levels in mice, rabbits, and most probably, humans. Although this regulatory function is critically dependent on EL's hydrolysis of HDL phospholipids, as yet there is no phospholipase assay specific for EL in plasma. We developed such an assay for the mouse enzyme using a commercially available phospholipid-like fluorescent substrate in combination with an EL neutralizing antibody. The specificity of the assay was established using EL knockout mice and its utility demonstrated by detection of an increase in plasma EL phospholipase activity following exposure of wild-type mice to lipopolysaccharide. The assay revealed that murine pre-heparin plasma does not contain measurable EL activity, indicating that the hydrolysis of HDL phospholipids by EL in vivo likely occurs on the cell surface.
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Affiliation(s)
- Debapriya Basu
- Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, NY 11203, USA
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20
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Ishida T, Miyashita K, Shimizu M, Kinoshita N, Mori K, Sun L, Yasuda T, Imamura S, Nakajima K, Stanhope KL, Havel PJ, Hirata KI. ELISA system for human endothelial lipase. Clin Chem 2012; 58:1656-64. [PMID: 23071361 DOI: 10.1373/clinchem.2012.187914] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Endothelial lipase (EL) regulates the metabolism of HDL cholesterol (HDL-C). However, the role of EL in regulating plasma HDL-C concentrations and EL's potential involvement in atherosclerosis in humans has not been fully investigated due to the lack of reliable assays for EL mass. We developed an ELISA system for serum EL mass. METHODS Human recombinant EL proteins, purified from cultured media of human EL-transfected Chinese hamster ovary cells, were used as antigen and calibrator. Two specific monoclonal antibodies were generated in mice against recombinant EL protein for a sandwich ELISA. We measured EL mass in human serum using EL recombinant protein as a calibration standard. RESULTS The EL antibodies did not cross-react with lipoprotein lipase and hepatic triglyceride lipase. The detection limit of the ELISA was 20 pg/mL, which is approximately 10 times lower than that of previous ELISA systems. Recovery of spiked EL in serum was 90%-105%. Assay linearity was intact with a >4-fold dilution of serum. Intra- and interassay CVs were <5%. The serum EL mass in 645 human subjects was [mean (SE)] 344.4 (7.7) pg/mL (range 55.2-1387.7 pg/mL). Interestingly, serum EL mass was increased in patients with diagnosed cardiovascular disease and inversely correlated with serum HDL-C concentrations. There was no difference in EL mass between pre- and postheparin plasma samples. CONCLUSIONS This ELISA should be useful for clarifying the impact of EL on HDL metabolism and EL's potential role in atherosclerosis.
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Affiliation(s)
- Tatsuro Ishida
- Division of Cardiovascular Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
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21
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Hosseini M, Ehrhardt N, Weissglas-Volkov D, Lai CM, Mao HZ, Liao JL, Nikkola E, Bensadoun A, Taskinen MR, Doolittle MH, Pajukanta P, Péterfy M. Transgenic expression and genetic variation of Lmf1 affect LPL activity in mice and humans. Arterioscler Thromb Vasc Biol 2012; 32:1204-10. [PMID: 22345169 DOI: 10.1161/atvbaha.112.245696] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Lipoprotein lipase (LPL) is a principal enzyme in lipoprotein metabolism, tissue lipid utilization, and energy metabolism. LPL is synthesized by parenchymal cells in adipose, heart, and muscle tissues followed by secretion to extracellular sites, where lipolyic function is exerted. The catalytic activity of LPL is attained during posttranslational maturation, which involves glycosylation, folding, and subunit assembly within the endoplasmic reticulum. A lipase-chaperone, lipase maturation factor 1 (Lmf1), has recently emerged as a critical factor in this process. Previous studies demonstrated that loss-of-function mutations of Lmf1 result in diminished lipase activity and severe hypertriglyceridemia in mice and human subjects. The objective of this study is to investigate whether, beyond its role as a required factor in lipase maturation, variation in Lmf1 expression is sufficient to modulate LPL activity in vivo. METHODS AND RESULTS To assess the effects of Lmf1 overexpression in adipose and muscle tissues, we generated aP2-Lmf1 and Mck-Lmf1 transgenic mice. Characterization of relevant tissues revealed increased LPL activity in both mouse strains. In the omental and subcutaneous adipose depots, Lmf1 overexpression was associated with increased LPL specific activity without changes in LPL mass. In contrast, increased LPL activity was due to elevated LPL protein level in heart and gonadal adipose tissue. To extend these studies to humans, we detected association between LMF1 gene variants and postheparin LPL activity in a dyslipidemic cohort. CONCLUSIONS Our results suggest that variation in Lmf1 expression is a posttranslational determinant of LPL activity.
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Affiliation(s)
- Maryam Hosseini
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
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Darrow AL, Olson MW, Xin H, Burke SL, Smith C, Schalk-Hihi C, Williams R, Bayoumy SS, Deckman IC, Todd MJ, Damiano BP, Connelly MA. A novel fluorogenic substrate for the measurement of endothelial lipase activity. J Lipid Res 2011; 52:374-82. [PMID: 21062953 DOI: 10.1194/jlr.d007971] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Endothelial lipase (EL) is a phospholipase A1 (PLA1) enzyme that hydrolyzes phospholipids at the sn-1 position to produce lysophospholipids and free fatty acids. Measurement of the PLA1 activity of EL is usually accomplished by the use of substrates that are also hydrolyzed by lipases in other subfamilies such as PLA2 enzymes. In order to distinguish PLA1 activity of EL from PLA2 enzymatic activity in cell-based assays, cell supernatants, and other nonhomogeneous systems, a novel fluorogenic substrate with selectivity toward PLA1 hydrolysis was conceived and characterized. This substrate was preferred by PLA1 enzymes, such as EL and hepatic lipase, and was cleaved with much lower efficiency by lipases that exhibit primarily triglyceride lipase activity, such as LPL or a lipase with PLA2 activity. The phospholipase activity detected by the PLA1 substrate could be inhibited with the small molecule esterase inhibitor ebelactone B. Furthermore, the PLA1 substrate was able to detect EL activity in human umbilical vein endothelial cells in a cell-based assay. This substrate is a useful reagent for identifying modulators of PLA1 enzymes, such as EL, and aiding in characterizing their mechanisms of action.
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Affiliation(s)
- Andrew L Darrow
- Pharmaceutical Research and Development, Johnson & Johnson LLC , Spring House, PA 19477-0776, USA
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Comparative studies of vertebrate lipoprotein lipase: a key enzyme of very low density lipoprotein metabolism. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2011; 6:224-34. [PMID: 21561822 DOI: 10.1016/j.cbd.2011.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 04/13/2011] [Accepted: 04/18/2011] [Indexed: 11/24/2022]
Abstract
Lipoprotein lipase (LIPL or LPL; E.C.3.1.1.34) serves a dual function as a triglyceride lipase of circulating chylomicrons and very-low-density lipoproteins (VLDL) and facilitates receptor-mediated lipoprotein uptake into heart, muscle and adipose tissue. Comparative LPL amino acid sequences and protein structures and LPL gene locations were examined using data from several vertebrate genome projects. Mammalian LPL genes usually contained 9 coding exons on the positive strand. Vertebrate LPL sequences shared 58-99% identity as compared with 33-49% sequence identities with other vascular triglyceride lipases, hepatic lipase (HL) and endothelial lipase (EL). Two human LPL N-glycosylation sites were conserved among seven predicted sites for the vertebrate LPL sequences examined. Sequence alignments, key amino acid residues and conserved predicted secondary and tertiary structures were also studied. A CpG island was identified within the 5'-untranslated region of the human LPL gene which may contribute to the higher than average (×4.5 times) level of expression reported. Phylogenetic analyses examined the relationships and potential evolutionary origins of vertebrate lipase genes, LPL, LIPG (encoding EL) and LIPC (encoding HL) which suggested that these have been derived from gene duplication events of an ancestral neutral lipase gene, prior to the appearance of fish during vertebrate evolution. Comparative divergence rates for these vertebrate sequences indicated that LPL is evolving more slowly (2-3 times) than for LIPC and LIPG genes and proteins.
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Holmes RS, Vandeberg JL, Cox LA. Vertebrate hepatic lipase genes and proteins: a review supported by bioinformatic studies. ACTA ACUST UNITED AC 2011; 2011:85-95. [PMID: 22408368 DOI: 10.2147/oab.s18401] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Hepatic lipase (gene: LIPC; enzyme: HL; E.C.3.1.1.3) is one of three members of the triglyceride lipase family that contributes to vascular lipoprotein degradation and serves a dual role in triglyceride hydrolysis and in facilitating receptor-mediated lipoprotein uptake into the liver. Amino acid sequences, protein structures, and gene locations for vertebrate LIPC (or Lipc for mouse and rat) genes and proteins were sourced from previous reports and vertebrate genome databases. Lipc was distinct from other neutral lipase genes (Lipg encoding endothelial lipase and Lpl encoding lipoprotein lipase [LPL]) and was located on mouse chromosome 9 with nine coding exons on the negative strand. Exon 9 of human LIPC and mouse and rat Lipc genes contained "stop codons" in different positions, causing changes in C-termini length. Vertebrate HL protein subunits shared 58%-97% sequence identities, including active, signal peptide, disulfide bond, and N-glycosylation sites, as well as proprotein convertase ("hinge") and heparin binding regions. Predicted secondary and tertiary structures revealed similarities with the three-dimensional structure reported for horse and human pancreatic lipases. Potential sites for regulating LIPC gene expression included CpG islands near the 5″-untranslated regions of the mouse and rat LIPC genes. Phylogenetic analyses examined the relationships and potential evolutionary origins of the vertebrate LIPC gene family with other neutral triglyceride lipase gene families (LIPG and LPL). We conclude that the triglyceride lipase ancestral gene for vertebrate neutral lipase genes (LIPC, LIPG, and LPL) predated the appearance of fish during vertebrate evolution.
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Affiliation(s)
- Roger S Holmes
- Department of Genetics, Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas, USA
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25
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Ben-Zeev O, Hosseini M, Lai CM, Ehrhardt N, Wong H, Cefalù AB, Noto D, Averna MR, Doolittle MH, Péterfy M. Lipase maturation factor 1 is required for endothelial lipase activity. J Lipid Res 2011; 52:1162-1169. [PMID: 21447484 DOI: 10.1194/jlr.m011155] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Lipase maturation factor 1 (Lmf1) is an endoplasmic reticulum (ER) membrane protein involved in the posttranslational folding and/or assembly of lipoprotein lipase (LPL) and hepatic lipase (HL) into active enzymes. Mutations in Lmf1 are associated with diminished LPL and HL activities ("combined lipase deficiency") and result in severe hypertriglyceridemia in mice as well as in human subjects. Here, we investigate whether endothelial lipase (EL) also requires Lmf1 to attain enzymatic activity. We demonstrate that cells harboring a (cld) loss-of-function mutation in the Lmf1 gene are unable to generate active EL, but they regain this capacity after reconstitution with the Lmf1 wild type. Furthermore, we show that cellular EL copurifies with Lmf1, indicating their physical interaction in the ER. Finally, we determined that post-heparin phospholipase activity in a patient with the LMF1(W464X) mutation is reduced by more than 95% compared with that in controls. Thus, our study indicates that EL is critically dependent on Lmf1 for its maturation in the ER and demonstrates that Lmf1 is a required factor for all three vascular lipases, LPL, HL, and EL.
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Affiliation(s)
- Osnat Ben-Zeev
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA
| | - Maryam Hosseini
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA; Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Ching-Mei Lai
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA
| | - Nicole Ehrhardt
- Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Howard Wong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA
| | - Angelo B Cefalù
- Department of Clinical Medicine and Emerging Diseases, University of Palermo, Palermo, Italy
| | - Davide Noto
- Department of Clinical Medicine and Emerging Diseases, University of Palermo, Palermo, Italy
| | - Maurizio R Averna
- Department of Clinical Medicine and Emerging Diseases, University of Palermo, Palermo, Italy
| | - Mark H Doolittle
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA
| | - Miklós Péterfy
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA; Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA; Medical Genetics Institute, Cedars-Sinai Medical Center, Los Angeles, CA.
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26
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Hong CS, Cui J, Ni Z, Su Y, Puett D, Li F, Xu Y. A computational method for prediction of excretory proteins and application to identification of gastric cancer markers in urine. PLoS One 2011; 6:e16875. [PMID: 21365014 PMCID: PMC3041827 DOI: 10.1371/journal.pone.0016875] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 12/31/2010] [Indexed: 11/18/2022] Open
Abstract
A novel computational method for prediction of proteins excreted into urine is presented. The method is based on the identification of a list of distinguishing features between proteins found in the urine of healthy people and proteins deemed not to be urine excretory. These features are used to train a classifier to distinguish the two classes of proteins. When used in conjunction with information of which proteins are differentially expressed in diseased tissues of a specific type versus control tissues, this method can be used to predict potential urine markers for the disease. Here we report the detailed algorithm of this method and an application to identification of urine markers for gastric cancer. The performance of the trained classifier on 163 proteins was experimentally validated using antibody arrays, achieving >80% true positive rate. By applying the classifier on differentially expressed genes in gastric cancer vs normal gastric tissues, it was found that endothelial lipase (EL) was substantially suppressed in the urine samples of 21 gastric cancer patients versus 21 healthy individuals. Overall, we have demonstrated that our predictor for urine excretory proteins is highly effective and could potentially serve as a powerful tool in searches for disease biomarkers in urine in general.
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Affiliation(s)
- Celine S. Hong
- Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, Georgia, United States of America
| | - Juan Cui
- Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, Georgia, United States of America
| | - Zhaohui Ni
- Department of Pathogenobiology, Jilin University, Changchun, Jilin, China
| | - Yingying Su
- Department of Pathogenobiology, Jilin University, Changchun, Jilin, China
| | - David Puett
- Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, Georgia, United States of America
| | - Fan Li
- Department of Pathogenobiology, Jilin University, Changchun, Jilin, China
| | - Ying Xu
- Department of Biochemistry and Molecular Biology, and Institute of Bioinformatics, University of Georgia, Athens, Georgia, United States of America
- College of Computer Science and Technology, Jilin University, Changchun, Jilin, China
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Holmes RS, Vandeberg JL, Cox LA. Vertebrate endothelial lipase: comparative studies of an ancient gene and protein in vertebrate evolution. Genetica 2011; 139:291-304. [PMID: 21267636 DOI: 10.1007/s10709-011-9549-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 01/11/2011] [Indexed: 11/26/2022]
Abstract
Endothelial lipase (gene: LIPG; enzyme: EL) is one of three members of the triglyceride lipase family that contributes to lipoprotein degradation within the circulation system and plays a major role in HDL metabolism in the body. In this study, in silico methods were used to predict the amino acid sequences, secondary and tertiary structures, and gene locations for LIPG genes and encoded proteins using data from several vertebrate genome projects. LIPG is located on human chromosome 18 and is distinct from other human 'neutral lipase' genes, hepatic lipase (gene: LIPC; enzyme: HL) and lipoprotein lipase (gene: LPL; enzyme: LPL) examined. Vertebrate LIPG genes usually contained 10 coding exons located on the positive strand for most primates, as well as for horse, bovine, opossum, platypus and frog genomes. The rat LIPG gene however contained only 9 coding exons apparently due to the presence of a 'stop' codon' within exon 9. Vertebrate EL protein subunits shared 58-97% sequence identity as compared with 38-45% sequence identities with human HL and LPL. Four previously reported human EL N-glycosylation sites were predominantly conserved among the 10 potential N-glycosylation sites observed for the vertebrate EL sequences examined. Sequence alignments and identities for key EL amino acid residues were observed as well as conservation of predicted secondary and tertiary structures with those previously reported for horse pancreatic lipase (PL) (Bourne et al. 1994). Several potential sites for regulating LIPG gene expression were observed including CpG islands near the LIPG gene promoter and a predicted microRNA binding site near the 3'-untranslated region. Promoter regions containing functional polymorphisms that regulate HDL cholesterol in baboons were conserved among primates but not retained between primates and rodents. Phylogenetic analyses examined the relationships and potential evolutionary origins of the vertebrate LIPG gene subfamily with other neutral triglyceride lipase gene families, LIPC and LPL. It is apparent that the triglyceride lipase ancestral gene for the vertebrate LIPG gene predated the appearance of fish during vertebrate evolution >500 million years ago.
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Affiliation(s)
- Roger S Holmes
- Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, TX 78227, USA.
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Abstract
PURPOSE OF REVIEW There are strong epidemiologic connections between plasma triglycerides and atherosclerosis. We will consider to what extent this goes back to derangements of the lipoprotein lipase (LPL) system. The roles of hepatic lipase and endothelial lipase will also be touched upon. RECENT FINDINGS Understanding of LPL action has taken major steps with the discovery of lipase maturation factor 1 as a specific endoplasmic reticulum chaperon needed for proper folding of the lipases, glycosylphosphatidylinositol-anchored HDL-binding protein 1 as an endothelial cell protein needed for transport and binding of LPL and some angiopoietin-like proteins that can modulate LPL activity. Studies of genetic variants continue to support the important roles of the lipases in lipoprotein metabolism and in atherosclerosis. CONCLUSION There are several ways by which derangement of the lipases may contribute to atherogenesis. Lipase actions are major determinants of plasma lipoprotein patterns. LPL activity must be modulated in relation to the physiological situation (feeding, fasting, exercise, etc.). Fatty acids and monoglycerides generated must be efficiently removed so that they do not endanger the integrity of the endothelium, cause lipotoxic reactions or both. In addition, the lipases may cause binding and endocytosis of lipoprotein particles in the artery wall.
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Affiliation(s)
- Gunilla Olivecrona
- Department of Medical Biosciences, Section on Physiological Chemistry, Umeå University, Umeå, Sweden.
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29
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Huang J, Qian HY, Li ZZ, Zhang JM, Wang S, Tao Y, Gao YL, Yin CQ, Que B, Sun T, Zhao ZY, Li Z. Role of endothelial lipase in atherosclerosis. Transl Res 2010; 156:1-6. [PMID: 20621031 DOI: 10.1016/j.trsl.2010.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Revised: 04/22/2010] [Accepted: 05/01/2010] [Indexed: 11/16/2022]
Abstract
Endothelial lipase, which is a newly identified member of the lipase family, plays an important role in high-density lipoprotein metabolism, which catalyzes the hydrolysis of high-density lipoprotein phospholipids and facilitates the clearance of high-density lipoprotein from the circulation. In addition, inflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1beta), upregulate endothelial lipase expression, and endothelial lipase also affects the expression of cytokines, which in turn play an important role in atherogenesis. Endothelial lipase expression has been associated with macrophages within human atherosclerotic lesions. However, an important challenge is to determine how endothelial lipase alters the progression of atherosclerosis. Although few data are available from human studies, it seems that plasma endothelial lipase levels in individuals with atherosclerosis might be higher than that measured in healthy individuals. Therefore, we believe that endothelial lipase might be a promising marker for atherosclerosis in clinical settings in the future.
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Affiliation(s)
- Ji Huang
- Emergency Center of Heart, Lung and Blood Vessel Diseases, Beijing Anzhen Hospital, Capital University of Medical Sciences & Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing 100029, P. R. China
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Liu J, Afroza H, Rader DJ, Jin W. Angiopoietin-like protein 3 inhibits lipoprotein lipase activity through enhancing its cleavage by proprotein convertases. J Biol Chem 2010; 285:27561-70. [PMID: 20581395 DOI: 10.1074/jbc.m110.144279] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lipoprotein lipase (LPL)-mediated lipolysis of triglycerides is the first and rate-limiting step in chylomicron/very low density lipoprotein clearance at the luminal surface of the capillaries. Angiopoietin-like protein 3 (ANGPTL3) is shown to inhibit LPL activity and plays important roles in modulating lipoprotein metabolism in vivo. However, the mechanism by which it inhibits LPL activity remains poorly understood. Using cell-based analysis of the interaction between ANGPTL3, furin, proprotein convertase subtilisin/kexin type 5 (PCSK5), paired amino acid converting enzyme-4 (PACE4), and LPL, we demonstrated that the cleavage of LPL by proprotein convertases is an inactivation process, similar to that seen for endothelial lipase cleavage. At physiological concentrations and in the presence of cells, ANGPTL3 is a potent inhibitor of LPL. This action is due to the fact that ANGPTL3 can enhance LPL cleavage by endogenous furin and PACE4 but not by PCSK5. This effect is specific to LPL but not endothelial lipase. Both N- and C-terminal domains of LPL are required for ANGPTL3-enhanced cleavage, and the N-terminal domain of ANGPTL3 is sufficient to exert its effect on LPL cleavage. Moreover, ANGPTL3 enhances LPL cleavage in the presence of either heparan sulfate proteoglycans or glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1). By enhancing LPL cleavage, ANGPTL3 dissociates LPL from the cell surface, inhibiting both the catalytic and noncatalytic functions of LPL. Taken together, our data provide a molecular connection between ANGPTL3, LPL, and proprotein convertases, which may represent a rapid signal communication among different metabolically active tissues to maintain energy homeostasis. These novel findings provide a new paradigm of specific protease-substrate interaction and further improve our knowledge of LPL biology.
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Affiliation(s)
- Jun Liu
- Translational Medicine and Therapeutics and Cardiovascular Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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Krintel C, Klint C, Lindvall H, Mörgelin M, Holm C. Quarternary structure and enzymological properties of the different hormone-sensitive lipase (HSL) isoforms. PLoS One 2010; 5:e11193. [PMID: 20567594 PMCID: PMC2887374 DOI: 10.1371/journal.pone.0011193] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 05/26/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Hormone-sensitive lipase (HSL) is a key enzyme in the mobilization of energy in the form of fatty acids from intracellular stores of neutral lipids. The enzyme has been shown to exist in different isoforms with different molecular masses (84 kDa, 89 kDa and 117 kDa) expressed in a tissue-dependent manner, where the predominant 84 kDa form in adipocytes is the most extensively studied. METHODOLOGY/PRINCIPAL FINDINGS In this study we employed negative stain electron microscopy (EM) to analyze the quarternary structure of the different HSL isoforms. The results show that all three isoforms adopt a head-to-head homodimeric organization, where each monomer contains two structural domains. We also used enzymatic assays to show that despite the variation in the size of the N-terminal domain all three isoforms exhibit similar enzymological properties with regard to psychrotolerance and protein kinase A (PKA)-mediated phosphorylation and activation. CONCLUSIONS/SIGNIFICANCE We present the first data on the quaternary structure and domain organization of the three HSL isoforms. We conclude that despite large differences in the size of the N-terminal, non-catalytic domain all three HSL isoforms exhibit the same three-dimensional architecture. Furthermore, the three HSL isoforms are very similar with regard to two unique enzymological characteristics of HSL, i.e., cold adaptation and PKA-mediated activation.
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Affiliation(s)
- Christian Krintel
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Division of Diabetes, Metabolism and Endocrinology, Department of Molecular Biophysics, Lund University, Lund, Sweden
| | - Cecilia Klint
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Håkan Lindvall
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Matthias Mörgelin
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Cecilia Holm
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- * E-mail:
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Abstract
PURPOSE OF REVIEW Lipase maturation factor 1 (LMF1) is a membrane-bound protein located in the endoplasmic reticulum. It is essential to the folding and assembly (i.e., maturation) of a selected group of lipases that include lipoprotein lipase, hepatic lipase and endothelial lipase. The purpose of this review is to examine recent studies that have begun to elucidate the structure and function of LMF1 and to place it in the context of lipase folding and assembly. RECENT FINDINGS Recent studies identified mutations in LMF1 that cause combined lipase deficiency and hypertriglyceridemia in humans. These mutations result in the truncation of a large, evolutionarily conserved domain (DUF1222), which is essential for interaction with lipases and their attainment of enzymatic activity. The structural complexity of LMF1 has been further characterized by solving its topology in the endoplasmic reticulum membrane. Recent studies indicate that in addition to lipoprotein lipase and hepatic lipase, the maturation of endothelial lipase is also dependent on LMF1. Based on its apparent specificity for dimeric lipases, LMF1 is proposed to play an essential role in the assembly and/or stabilization of head-to-tail lipase homodimers. SUMMARY LMF1 functions in the maturation of a selected group of secreted lipases that assemble into homodimers in the endoplasmic reticulum. These dimeric lipases include lipoprotein lipase, hepatic lipase and endothelial lipase, all of which contribute significantly to plasma triglyceride and high-density lipoprotein cholesterol levels in humans. Future studies involving genetically engineered mouse models will be required to fully elucidate the role of LMF1 in normal physiology and diseases.
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Affiliation(s)
- Mark H. Doolittle
- Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, and VA Greater Los Angeles Healthcare System, 11301 Wilshire Blvd., Bldg. 113, Rm. 312, Los Angeles, CA 90073, USA, Tel.: 661-433-6349, Fax: 310-268-4981,
| | - Nicole Ehrhardt
- Medical Genetics Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA, Tel.: 310-423-3862, Fax: 310-423-0299,
| | - Miklós Péterfy
- Medical Genetics Institute, Cedars-Sinai Medical Center, and Department of Medicine, David Geffen School of Medicine, University of California at Los Angeles, 8700 Beverly Blvd., Los Angeles, CA 90048, USA, Tel.: 310-478-3711 x42153, Fax: 310-268-4981,
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34
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Kojima Y, Ishida T, Sun L, Yasuda T, Toh R, Rikitake Y, Fukuda A, Kume N, Koshiyama H, Taniguchi A, Hirata KI. Pitavastatin decreases the expression of endothelial lipase both in vitro and in vivo. Cardiovasc Res 2010; 87:385-93. [PMID: 20045866 DOI: 10.1093/cvr/cvp419] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
AIMS In addition to their cholesterol-lowering effect, statins increase high-density lipoprotein cholesterol (HDL-C) levels. Endothelial lipase (EL) is a regulator of plasma HDL-C levels. In the present study, the effects of statins on EL expression were investigated. METHODS AND RESULTS The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor pitavastatin suppressed basal and cytokine-treated EL expression in endothelial cells. Concomitant treatment with mevalonate or geranylgeranyl pyrophosphate completely reversed the inhibitory effect of pitavastatin, suggesting that geranylgeranylated proteins are involved in the inhibition of EL expression by statins. Inhibition of RhoA activity by overexpression of a dominant-negative mutant of RhoA or a Rho kinase inhibitor decreased EL levels. Pitavastatin reduced phospholipase activities of endothelial cells, and concomitant treatment with mevalonate reversed its inhibitory effect. Pitavastatin reduced RhoA activity and EL expression in mouse tissues. Furthermore, plasma EL concentrations in human subjects were measured by enzyme-linked immunosorbent assays. Plasma EL levels were negatively associated with plasma HDL levels in 237 patients with cardiovascular diseases, and pitavastatin treatment reduced plasma EL levels and increased HDL-C levels in 48 patients with hypercholesterolaemia. CONCLUSION These findings suggest that statins can reduce EL expression in vitro and in vivo via inhibition of RhoA activity. The inhibition of EL expression in the vessel wall may contribute to the anti-atherogenic effects of statins.
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Affiliation(s)
- Yoko Kojima
- Division of Cardiovascular Medicine, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Japan
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35
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Yasuda T, Ishida T, Rader DJ. Update on the Role of Endothelial Lipase in High-Density Lipoprotein Metabolism, Reverse Cholesterol Transport, and Atherosclerosis. Circ J 2010; 74:2263-70. [DOI: 10.1253/circj.cj-10-0934] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tomoyuki Yasuda
- Institute for Translational Medicine and Therapeutics and Cardiovascular Institute, University of Pennsylvania School of Medicine
- Division of Cardiovascular Medicine, Kobe University Graduate school of Medicine
| | - Tatsuro Ishida
- Division of Cardiovascular Medicine, Kobe University Graduate school of Medicine
| | - Daniel J. Rader
- Institute for Translational Medicine and Therapeutics and Cardiovascular Institute, University of Pennsylvania School of Medicine
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36
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Abstract
Lipases are acyl hydrolases that represent a diverse group of enzymes present in organisms ranging from prokaryotes to humans. This article focuses on an evolutionarily related family of extracellular lipases that include lipoprotein lipase, hepatic lipase and endothelial lipase. As newly synthesized proteins, these lipases undergo a series of co- and post-translational maturation steps occurring in the endoplasmic reticulum, including glycosylation and glycan processing, and protein folding and subunit assembly. This article identifies and discusses mechanisms that direct early and late events in lipase folding and assembly. Lipase maturation employs the two general chaperone systems operating in the endoplasmic reticulum, as well as a recently identified lipase-specific chaperone termed lipase maturation factor 1. We propose that the two general chaperone systems act in a coordinated manner early in lipase maturation in order to help create partially folded monomers; lipase maturation factor 1 then facilitates final monomer folding and subunit assembly into fully functional homodimers. Once maturation is complete, the lipases exit the endoplasmic reticulum and are secreted to extracellular sites, where they carry out a number of functions related to lipoprotein and lipid metabolism.
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Affiliation(s)
- Mark H Doolittle
- VA Greater Los Angeles, Healthcare System, 11301 Wilshire Blvd, Bldg 113, Rm 312, Los Angeles, CA 90073, USA, Tel.: +1 661 433 6349
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