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Karimi E, Tondkar P, Sotoudeh G, Qorbani M, Rafiee M, Koohdani F. A personalised diet study: The interaction between ApoA2 -265T > C polymorphism and dietary inflammatory index on oxidative and inflammatory markers and lipid profile in patients with type 2 diabetes mellitus: A cross-sectional study. Int J Clin Pract 2021; 75:e14178. [PMID: 33759320 DOI: 10.1111/ijcp.14178] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/15/2021] [Accepted: 03/22/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND This study aimed to investigate the interaction between dietary inflammatory index (DII) and apolipoproteinA2 265T > C (ApoA2 -265T > C) polymorphism on inflammatory and oxidative markers and lipid profile in type 2 diabetes mellitus (T2DM) patients. METHODS In this cross-sectional study, 157 patients with T2DM were recruited. A food-frequency questionnaire was used for DII calculation. Inflammatory, oxidative and lipid biomarkers were measured. Real-time polymerase chain reaction (PCR) method was used for ApoA2 genotyping determination. RESULTS In the current study, serum 8-iso-PGF2α and CRP were significantly higher, and serum SOD activity was significantly lower in subjects with CC genotype than TT homozygous in both crude and adjusted (for DII and AAs intake) models. Also, C-allele carriers compared with people with TT genotype had lower PTX3 in both models. In addition, serum TG level was significantly higher in TC genotype than TT homozygous in adjusted model. Moreover, subjects with CC homozygous and high DII level had significantly higher 8-iso-PGF2α level compared to those with TT genotype and low DII (reference group) in adjusted (for BMI, age, sexuality and AAs intake) model. Our results also showed that in TC genotypes with low DII and CC homozygous with both low and high DII, PTX3 concentrations were significantly lower than the reference group. In addition, CC carriers with low DII had significantly higher CRP level compared to the reference group. Moreover, our results reported significant higher TG in TC genotype with low DII and also higher total cholesterol level in CC genotype with low DII than the reference group. CONCLUSION These findings indicate that CC genotype might predict higher inflammatory and oxidative status level compared to T allele carriers. An inflammatory diet may accelerate oxidative stress in subjects with CC genotype. However, the association between APOA2 -265T > C polymorphism and inflammation and lipid profile is presented less modifiable by DII.
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Affiliation(s)
- Elmira Karimi
- Department of Community Nutrition, School of Nutritional Sciences and Dietetic, Tehran University of Medical Sciences, Tehran, Iran
| | - Pourya Tondkar
- Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetic, Tehran University of Medical Sciences, Tehran, Iran
| | - Gity Sotoudeh
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Mostafa Qorbani
- Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran
- Chronic Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoumeh Rafiee
- Department of Clinical Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Fariba Koohdani
- Diabetes Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
- Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, International Campus, Tehran University of Medical Sciences, Tehran, Iran
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2
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Yetukuri L, Huopaniemi I, Koivuniemi A, Maranghi M, Hiukka A, Nygren H, Kaski S, Taskinen MR, Vattulainen I, Jauhiainen M, Orešič M. High density lipoprotein structural changes and drug response in lipidomic profiles following the long-term fenofibrate therapy in the FIELD substudy. PLoS One 2011; 6:e23589. [PMID: 21887280 PMCID: PMC3160907 DOI: 10.1371/journal.pone.0023589] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 07/20/2011] [Indexed: 11/26/2022] Open
Abstract
In a recent FIELD study the fenofibrate therapy surprisingly failed to achieve significant benefit over placebo in the primary endpoint of coronary heart disease events. Increased levels of atherogenic homocysteine were observed in some patients assigned to fenofibrate therapy but the molecular mechanisms behind this are poorly understood. Herein we investigated HDL lipidomic profiles associated with fenofibrate treatment and the drug-induced Hcy levels in the FIELD substudy. We found that fenofibrate leads to complex HDL compositional changes including increased apoA-II, diminishment of lysophosphatidylcholines and increase of sphingomyelins. Ethanolamine plasmalogens were diminished only in a subgroup of fenofibrate-treated patients with elevated homocysteine levels. Finally we performed molecular dynamics simulations to qualitatively reconstitute HDL particles in silico. We found that increased number of apoA-II excludes neutral lipids from HDL surface and apoA-II is more deeply buried in the lipid matrix than apoA-I. In conclusion, a detailed molecular characterization of HDL may provide surrogates for predictors of drug response and thus help identify the patients who might benefit from fenofibrate treatment.
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Affiliation(s)
| | - Ilkka Huopaniemi
- Aalto University School of Science, Department of Information and Computer Science, Helsinki Institute for Information Technology, Espoo, Finland
| | | | - Marianna Maranghi
- Department of Internal Medicine and Medical Specialties, Sapienza University, Rome, Italy
- Division of Cardiology, Department of Medicine, University of Helsinki, Helsinki, Finland
| | - Anne Hiukka
- Division of Cardiology, Department of Medicine, University of Helsinki, Helsinki, Finland
| | - Heli Nygren
- Technical Research Centre of Finland, Espoo, Finland
| | - Samuel Kaski
- Aalto University School of Science, Department of Information and Computer Science, Helsinki Institute for Information Technology, Espoo, Finland
| | - Marja-Riitta Taskinen
- Division of Cardiology, Department of Medicine, University of Helsinki, Helsinki, Finland
| | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology, Tampere, Finland
- Department of Applied Physics, Aalto University School of Science and Technology, Espoo, Finland
- MEMPHYS – Center for Biomembrane Physics, University of Southern Denmark, Odense, Denmark
| | - Matti Jauhiainen
- National Institute for Health and Welfare, Helsinki, Finland
- Institute for Molecular Medicine Finland, Helsinki, Finland
| | - Matej Orešič
- Technical Research Centre of Finland, Espoo, Finland
- Institute for Molecular Medicine Finland, Helsinki, Finland
- * E-mail:
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3
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Baker PW, Rye KA, Gamble JR, Vadas MA, Barter PJ. Phospholipid composition of reconstituted high density lipoproteins influences their ability to inhibit endothelial cell adhesion molecule expression. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)33434-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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4
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Wang WQ, Merriam DL, Moses AS, Francis GA. Enhanced cholesterol efflux by tyrosyl radical-oxidized high density lipoprotein is mediated by apolipoprotein AI-AII heterodimers. J Biol Chem 1998; 273:17391-8. [PMID: 9651324 DOI: 10.1074/jbc.273.28.17391] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myeloperoxidase secreted by phagocytes in the artery wall may be a catalyst for lipoprotein oxidation. High density lipoprotein (HDL) oxidized by peroxidase-generated tyrosyl radical has a markedly enhanced ability to deplete cultured cells of cholesterol. We have investigated the structural modifications in tyrosylated HDL responsible for this effect. Spherical reconstituted HDL (rHDL) containing the whole apolipoprotein (apo) fraction of tyrosylated HDL reproduced the ability of intact tyrosylated HDL to enhance cholesterol efflux from cholesterol-loaded human fibroblasts when reconstituted with the whole lipid fraction of either HDL or tyrosylated HDL. Free apoAI or apoAII showed no increased capacity to induce cholesterol efflux from cholesterol-loaded fibroblasts following oxidation by tyrosyl radical, either in their lipid-free forms or in rHDL. The product of oxidation of a mixture of apoAI and apoAII (1:1 molar ratio) by tyrosyl radical, however, reproduced the enhanced ability of tyrosylated HDL to induce cholesterol efflux when reconstituted with the whole lipid fraction of HDL. HDL containing only apoAI or apoAII showed no enhanced ability to promote cholesterol efflux following oxidation by tyrosyl radical, whereas HDL containing both apoAI and apoAII did. rHDL containing apoAI-apoAIImonomer and apoAI-(apoAII)2 heterodimers showed a markedly increased ability to prevent the accumulation of LDL-derived cholesterol mass by sterol-depleted fibroblasts compared with other apolipoprotein species of tyrosylated HDL. These results indicate a novel product of HDL oxidation, apoAI-apoAII heterodimers, with a markedly enhanced capacity to deplete cells of the regulatory pool of free cholesterol and total cholesterol mass. The recent observation of tyrosyl radical-oxidized LDL in vivo suggests that a similar modification of HDL would significantly enhance its ability to deplete peripheral cells of cholesterol in the first step of reverse cholesterol transport.
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Affiliation(s)
- W Q Wang
- Lipid and Lipoprotein Research Group and the Department of Medicine, University of Alberta, Edmonton, Alberta T6G 2S2, Canada
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5
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Pussinen PJ, Jauhiainen M, Ehnholm C. ApoA-II/apoA-I molar ratio in the HDL particle influences phospholipid transfer protein-mediated HDL interconversion. J Lipid Res 1997. [DOI: 10.1016/s0022-2275(20)37271-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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6
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Su Z, Luo ZH, Niu XL, Guo ZG. High density lipoproteins increase cytoplasmic free calcium in bovine aortic endothelial cells. JOURNAL OF LIPID MEDIATORS AND CELL SIGNALLING 1996; 15:5-15. [PMID: 9029370 DOI: 10.1016/s0929-7855(96)00449-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This study examined the influence of human high density lipoproteins (HDL) on the intracellular free calcium of cultured bovine aortic endothelial cells (BAECs). Intracellular Ca2+ concentration ([Ca2+]i) was determined by a fluorescent calcium indicator, Fura-2. It was found that, in the presence of 1 mmol/L extracellular calcium, HDL resulted in a biphasic elevation of [Ca2+]i in BAECs, consisting of an initial, transient component followed by a lower, but more sustained component. Doses of HDL from 25 to 200 micrograms protein/ml induced marked concentration-dependent elevations of [Ca2+]i in BAECs. The sustained component was abolished by deprivation of extracellular calcium or by pretreatment of endothelial cells with a calcium influx blocker, NiCl2, HDL-induced elevation of [Ca2+]i was attenuated in a concentration-dependent way by an inhibitor of calcium release, tetracaine. Repeated applications of HDL (100 micrograms protein/ml) markedly blunted the initial peak component of the calcium transient of BAECs. These results demonstrate that both intracellular and extracellular calcium pools are responsible for the biphasic elevation of [Ca2+]i induced by HDL in cultured BAECs.
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Affiliation(s)
- Z Su
- Research Section of Pharmacology, Hunan Medical University, Changsha, People's Republic of China
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7
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Lagrost L, Dengremont C, Athias A, de Geitere C, Fruchart JC, Lallemant C, Gambert P, Castro G. Modulation of cholesterol efflux from Fu5AH hepatoma cells by the apolipoprotein content of high density lipoprotein particles. Particles containing various proportions of apolipoproteins A-I and A-II. J Biol Chem 1995; 270:13004-9. [PMID: 7768892 DOI: 10.1074/jbc.270.22.13004] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The influence of apolipoproteins (apo) A-I and A-II on the ability of high density lipoproteins (HDL) to remove cholesterol from cultured Fu5AH rat hepatoma cells was studied independently on alterations in the overall structure and lipid composition of the lipoprotein particles. To this end, apoA-I was progressively replaced by apoA-II in ultracentrifugally isolated HDL3 without inducing changes in other remaining lipoprotein components. As apoA-II was progressively substituted for apoA-I in HDL3 (A-II:A-I+A-II percentage mass: 29.5, 47.6, 71.5, 97.4, and 98.9%), the rate of cholesterol efflux from Fu5AH hepatoma gradually and significantly decreased after 2 or 4 h of incubation at 37 degrees C (cholesterol efflux: 30.4 +/- 0.8, 24.1 +/- 1.0, 19.8 +/- 1.2, 15.7 +/- 1.4, and 13.4 +/- 1.3%/2h, respectively; 38.4 +/- 1.5, 29.2 +/- 0.9, 27.0 +/- 0.2, 20.4 +/- 0.4, and 17.5 +/- 1.0%/4h, respectively) (p < 0.01 with all A-II-enriched HDL3 fractions as compared with non-enriched homologues). In agreement with data obtained with total HDL3, increasing the A-II:A-I+A-II percentage mass in HDL3 particles containing initially only apoA-I (HDL3-A-I) progressively reduced cellular cholesterol efflux. After 2 h of incubation, cholesterol efflux correlated negatively with A-II:A-I+A-II percentage mass (r = -0.86; p < 0.0001; n = 20), but not with either free cholesterol:phospholipid ratio, A-I+A-II:total lipid ratio or mean size of HDL3. As determined by using Spearman rank correlation analysis, the A-II:A-I+A-II% mass ratio correlated negatively with the apparent maximal efflux (Vmax(efflux)) (rho = -0.68; p < 0.05, n = 10), but not with the HDL3 concentration required to obtain 50% of maximal efflux (Km(efflux)) (rho = -0.08; not significant, n = 10). It was concluded that the apoA-I and apoA-II content of HDL3 is one determinant of its ability to promote cholesterol efflux from Fu5AH rat hepatoma cells.
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Affiliation(s)
- L Lagrost
- Laboratoire de Biochimie des Lipoprotéines, INSERM CJF 93-10, Faculté de Médecine, Dijon, France
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8
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Herold G, Hesse U, Wisst F, Fahr C, Fahr M, Rogler G, Geerling I, Stange EF. HDL3-mediated cholesterol efflux from cultured enterocytes: the role of apoproteins A-I and A-II. Lipids 1994; 29:735-45. [PMID: 7869853 DOI: 10.1007/bf02536694] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
High density lipoproteins (HDL) were recently demonstrated in an enterocyte model (CaCo-2 cells) to mediate reverse cholesterol transport by retroendocytosis. The present study was carried out to define the role of the major HDL apoproteins (apo) A-I and apo A-II in this pathway. HDL3 was fractionated by heparin affinity chromatography into the two main fractions containing either apo A-I only (fraction A) or both apo A-I and apo A-II (fraction B). In addition, liposomes were reconstituted from purified apo A-I or apo A-II and dimyristoyl phosphatidylcholine. The cell binding properties and cholesterol efflux potential were studied in the lipoprotein fractions and the liposomes. Both fractions exhibited similar maximal binding capacities of 4427 (A) and 5041 (B) ng/mg cell protein, but their dissociation constants differed (40.5 and 167.7 micrograms/mL, respectively). Fraction A induced cholesterol efflux and stimulated cholesterol synthesis more than did fraction B. Fraction A mobilized both cellular free and esterified cholesterol, whereas fraction B preferentially mobilized cholesteryl esters. Liposomes, containing either apo A-I or apo A-II, showed specific binding, endocytosis and endosomal transport, and were released as intact particles. Apo A-I liposomes also mediated cholesterol efflux. In conclusion, there is evidence that the HDL3 subfractions A and B, as well as reconstituted liposomes containing either apo A-I or apo A-II, were specifically bound and entered a retroendocytosis pathway which was directly linked to cholesterol efflux. Quantitatively, the apo A-I subfraction appeared to play the dominant role in normal enterocytes. The apo A-II content of fraction B was related to the mobilization of cholesteryl esters.
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Affiliation(s)
- G Herold
- Department of Internal Medicine I, University of Ulm, Germany
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9
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Comparative effects of purified apolipoproteins A-I, A-II, and A-IV on cholesteryl ester transfer protein activity. J Lipid Res 1994. [DOI: 10.1016/s0022-2275(20)40111-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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10
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Lagrost L, Perségol L, Lallemant C, Gambert P. Influence of apolipoprotein composition of high density lipoprotein particles on cholesteryl ester transfer protein activity. Particles containing various proportions of apolipoproteins AI and AII. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)41847-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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11
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Vadiveloo PK, Allan CM, Murray BJ, Fidge NH. Interaction of apolipoprotein AII with the putative high-density lipoprotein receptor. Biochemistry 1993; 32:9480-5. [PMID: 8396433 DOI: 10.1021/bi00087a028] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
There is strong evidence to indicate that binding of HDL by cells is due to recognition of apoproteins residing on the surface of the lipoprotein by the putative HDL receptor(s). Although both of the major HDL apoproteins, AI and AII, are recognized by the putative receptor, the nature of the binding interaction and the domains of the apoproteins involved are largely unknown. Previous data from this laboratory led to the proposal of a model to explain how HDL particles containing AII interacted with the HDL receptor in a different manner as compared to HDL particles which contain apoAI but not apoAII [Vadiveloo, P. K., & Fidge, N. H. (1992) Biochem. J. 284, 145-151]. The model predicted that each chain of the apoAII homodimer contained a binding domain capable of interacting with the HDL receptor. This model was tested in the current study by preparing apoAII monomers, complexing them with phospholipid, and determining the ability of these complexes to bind to putative HDL receptors in rat liver plasma membranes (RLPM) and bovine aortic endothelial cell membranes (BAECM) by ligand blotting. The data showed that these complexes were bound by HB1 and HB2 from RLPM, and to the 110-kDa HDL binding protein from BAECM, providing critical evidence to support the model. Further investigation into the binding interaction revealed that apoAII complexed with phospholipid (apoAII-PC) bound more than delipidated apoAII, which bound more than delipidated apoAII monomers. Thus, optimum binding required the presence of lipid.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- P K Vadiveloo
- Baker Medical Research Institute, Melbourne, Victoria, Australia
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12
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Zannis VI, Kardassis D, Zanni EE. Genetic mutations affecting human lipoproteins, their receptors, and their enzymes. ADVANCES IN HUMAN GENETICS 1993; 21:145-319. [PMID: 8391199 DOI: 10.1007/978-1-4615-3010-7_3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- V I Zannis
- Department of Medicine, Housman Medical Research Center, Boston University Medical Center, Massachusetts 02118
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13
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Lee M, Lindstedt LK, Kovanen PT. Mast cell-mediated inhibition of reverse cholesterol transport. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1992; 12:1329-35. [PMID: 1420092 DOI: 10.1161/01.atv.12.11.1329] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Net cholesterol efflux from cholesterol-loaded macrophages, i.e., foam cells, was induced by incubating the foam cells with high density lipoprotein3 (HDL3). However, when the incubation system included rat serosal mast cells stimulated to trigger exocytosis of their cytoplasmic secretory granules, the ability of HDL3 to induce cholesterol efflux was largely lost. This loss was found to be due to the proteolytic action of chymase, the neutral protease of the granules, which degraded the apolipoproteins of HDL3, so rendering them unable to mediate cholesterol efflux from the foam cells. The observation defines a novel cell-dependent mechanism that blocks the initial steps of reverse cholesterol transport and suggests a role for mast cell chymase in cellular accumulation of cholesterol, an early stage in atherogenesis.
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Affiliation(s)
- M Lee
- Wihuri Research Institute, Helsinki, Finland
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14
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Vadiveloo PK, Fidge NH. The role of apoproteins AI and AII in binding of high-density lipoprotein3 to membranes derived from bovine aortic endothelial cells. Biochem J 1992; 284 ( Pt 1):145-51. [PMID: 1599393 PMCID: PMC1132709 DOI: 10.1042/bj2840145] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Although binding of high-density lipoproteins (HDL) to a variety of cells in culture has been widely reported, the mechanism of this binding has yet to be fully elucidated. The aim of the current studies was to explore the roles of apoproteins (apo) AI and AII in HDL3 binding to membranes derived from bovine aortic endothelial cells. Binding studies showed that HDL3 (which contains both apo AI and apo AII) and AII-HDL3 (which contain only apo AII) bound to membranes with similar affinity (44 +/- 6 and 41 +/- 9 micrograms/ml respectively) and capacity (673 +/- 97 and 969 +/- 101 ng bound/mg of membrane protein respectively). In contrast with these results, HDL3 [AI w/o AII] (which contain apo AI, but not apo AII) bound to the membranes with a significantly higher capacity (2228 +/- 206 ng bound/mg of membrane protein) and lower affinity (65 +/- 3 micrograms/ml) as compared with HDL3 or AII-HDL3. Therefore, although both apo AI and apo AII appear capable of facilitating HDL3 binding, the mechanisms involved probably differ. A model which fits the data postulates that a common receptor exists which binds both apo AI and apo AII, and that a particle containing AII can occupy up to four receptors (partly owing to each AII molecule containing two binding domains), whereas an HDL3 [AI w/o AII] particle can occupy only one.
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Affiliation(s)
- P K Vadiveloo
- Baker Medical Research Institute, Prahran, Victoria, Australia
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15
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Gillett MP, Owen JS. Comparison of the cytolytic effects in vitro on Trypanosoma brucei brucei of plasma, high density lipoproteins, and apolipoprotein A-I from hosts both susceptible (cattle and sheep) and resistant (human and baboon) to infection. J Lipid Res 1992. [DOI: 10.1016/s0022-2275(20)41617-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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16
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Myers DE, Fidge NH, Stanton H, Larkins RG. The effects of low density lipoprotein and high density lipoprotein on phosphoinositide hydrolysis in bovine aortic endothelial cells. Atherosclerosis 1992; 92:9-16. [PMID: 1315550 DOI: 10.1016/0021-9150(92)90004-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Low density lipoprotein (LDL) and high density lipoprotein (HDL3) were tested for their ability to induce inositol phospholipid turnover and inositol phosphate production in bovine aortic endothelial cells (BAEC). The production of inositol phosphates following hydrolysis of the phosphoinositides was demonstrated by two methods; release of [3H]inositol phosphates after labelling with [3H]myo-inositol and by a direct binding assay for inositol 1,4,5-trisphosphate (InsP3). Acute exposure to LDL induced InsP3 release at low concentrations of the lipoprotein within the physiological range of LDL in tissues. HDL3 did not cause any release of the inositol phosphates. Pre-incubation of BAEC with HDL3 suppressed bradykinin- and LDL-induced inositol phosphate production in BAEC in a concentration-dependent manner. It is concluded that LDL acutely stimulates phosphoinositide breakdown and that pre-incubation of cells with HDL3 inhibits this effect. The mechanism responsible for these effects remains to be elucidated.
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Affiliation(s)
- D E Myers
- Department of Medicine, University of Melbourne, Royal Melbourne Hospital, Victoria, Australia
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17
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Bond HM, Morrone G, Venuta S, Howell KE. Characterization and purification of proteins which bind high-density lipoprotein. A putative cell-surface receptor. Biochem J 1991; 279 ( Pt 3):633-41. [PMID: 1659384 PMCID: PMC1151492 DOI: 10.1042/bj2790633] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
High-density lipoprotein (HDL) is shown by ligand blotting to bind membrane-associated polypeptides with sizes of 60, 100 and 210 kDa. Binding was concentration-dependent and competed by excess unlabelled HDL. All the major apolipoproteins of HDL, apoA-I, apoA-II and apoA-IV, bound independently. The 100 kDa and 210 kDa HDL-binding activities were purified from membranes of Hep3B tumour cells by ion-exchange chromatography and gel filtration. The binding activities at 100 kDa and 210 kDa co-purified. After treatment with disulphide-reducing reagent, the 210 kDa band was no longer present and an increase was observed in the amount and binding ability of the 100 kDa polypeptide. The 100 kDa binding protein labelled at the cell surface with 125I could be immunoprecipitated after cross-linking to cell-surface-bound HDL. It is proposed that this HDL-binding activity, a putative cell-surface receptor for HDL, exists totally or in part as a high-molecular-mass complex composed of 100 kDa subunits.
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Affiliation(s)
- H M Bond
- Department of Biochemistry and Medical Biotechnology, 2nd Medical School, Naples, Italy
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18
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Holian O, Kumar R, Attar B. Apoprotein A-1 is a cofactor independent substrate of protein kinase C. Biochem Biophys Res Commun 1991; 179:599-604. [PMID: 1909124 DOI: 10.1016/0006-291x(91)91413-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Apoprotein A-1 (apo A-1), the predominant protein constituent of high density lipoproteins (HDL), was phosphorylated by protein kinase C (PKC). Optimal phosphorylation of lipid-free apo A-1 occurs in the absence of calcium, phosphatidyl serine (PS), and diolein (DO). However, HDL-bound apo A-1 was not phosphorylated by PKC. Furthermore, addition of either native or reconstituted HDL particles to lipid-free apo A-1 resulted in a concentration-dependent inhibition of phosphorylation. It appears that the phosphorylatable sites on apo A-1 are involved in hydrophobic interaction with the lipids of HDL. Apo A-1 is a novel substrate of PKC because it does not require calcium and lipid cofactors for optimal phosphorylation.
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Affiliation(s)
- O Holian
- Department of Surgery, University of Illinois College of Medicine, Chicago 60680
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