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Jayedi A, Rashidy-Pour A, Parohan M, Zargar MS, Shab-Bidar S. Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies. Adv Nutr 2018; 9:701-716. [PMID: 30239557 PMCID: PMC6247336 DOI: 10.1093/advances/nmy040] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The associations of various dietary or circulating antioxidants with the risk of all-cause mortality in the general population have not been established yet. A systematic search was performed in PubMed and Scopus, from their inception up to October 2017. Prospective observational studies reporting risk estimates of all-cause mortality in relation to dietary intake and/or circulating concentrations of antioxidants were included. Random-effects meta-analyses were conducted. Forty-one prospective observational studies (total n = 507,251) involving 73,965 cases of all-cause mortality were included. The RRs of all-cause mortality for the highest compared with the lowest category of circulating antioxidant concentrations were as follows: total carotenes, 0.60 (95% CI: 0.46, 0.74); vitamin C, 0.61 (95% CI: 0.53, 0.69); selenium, 0.62 (95% CI: 0.45, 0.79); β-carotene, 0.63 (95% CI: 0.57, 0.70); α-carotene, 0.68 (95% CI: 0.58, 0.78); total carotenoids, 0.68 (95% CI: 0.56, 0.80); lycopene, 0.75 (95% CI: 0.54, 0.97); and α-tocopherol, 0.84 (95% CI: 0.77, 0.91). The RRs for dietary intakes were: total carotenoids, 0.76 (95% CI: 0.66, 0.85); total antioxidant capacity, 0.77 (95% CI: 0.73, 0.81); selenium, 0.79 (95% CI: 0.73, 0.85); α-carotene, 0.79 (95% CI: 0.63, 0.94); β-carotene, 0.82 (95% CI: 0.77, 0.86); vitamin C, 0.88 (95% CI: 0.83, 0.94); and total carotenes, 0.89 (95% CI: 0.81, 0.97). A nonsignificant inverse association was found for dietary zinc, zeaxanthin, lutein, and vitamin E. The nonlinear dose-response meta-analyses demonstrated a linear inverse association in the analyses of dietary β-carotene and total antioxidant capacity, as well as in the analyses of circulating α-carotene, β-carotene, selenium, vitamin C, and total carotenoids. The association appeared to be U-shaped in the analyses of serum lycopene and dietary vitamin C. The present study indicates that adherence to a diet with high antioxidant properties may reduce the risk of all-cause mortality. Our results confirm current recommendations that promote higher intake of antioxidant-rich foods such as fruit and vegetables.
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Affiliation(s)
- Ahmad Jayedi
- Food (salt) Safety Research Center, Semnan, Iran
| | - Ali Rashidy-Pour
- Laboratory of Learning and Memory, Research Center of Physiology, Semnan, Iran
- Department of Physiology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Mohammad Parohan
- Departments of Cellular and Molecular Nutrition, School of Nutritional Science and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahdieh Sadat Zargar
- Nursing Care Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Sakineh Shab-Bidar
- Departments of Community Nutrition, School of Nutritional Science and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
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2
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Aviram M, Presser D. Oxidized low-density lipoprotein reduces plasma coagulationin vitro. Scandinavian Journal of Clinical and Laboratory Investigation 2018. [DOI: 10.1080/00365513.1991.11978684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- M. Aviram
- Lipid Research Laboratory and Rambam Medical Center, Haifa, Israel
- Emergency Test Laboratory, Rambam Medical Center, Haifa, Israel
| | - D. Presser
- Emergency Test Laboratory, Rambam Medical Center, Haifa, Israel
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3
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Batt KV, Avella M, Moore EH, Jackson B, Suckling KE, Botham KM. Differential Effects of Low-Density Lipoprotein and Chylomicron Remnants on Lipid Accumulation in Human Macrophages. Exp Biol Med (Maywood) 2016; 229:528-37. [PMID: 15169972 DOI: 10.1177/153537020422900611] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The effects of low-density lipoprotein (LDL) and chylomicron remnants on lipid accumulation in human monocyte–derived macrophages (HMDMs) and in macrophages derived from the human monocyte cell line THP-1 were compared. The HMDMs or THP-1 macrophages were incubated with LDL, oxidized LDL (oxLDL), chylomicron remnant–like particles (CMR-LPs), or oxidized CMR-LPs (oxCMR-LPs), and the amount and type of lipid accumulated were determined. As expected, the lipid content of both cell types was increased markedly by oxLDL but not LDL, and this was due to a rise in cholesterol, cholesteryl ester (CE), and triacylglycerol (TG) levels. In contrast, both CMR-LPs and oxCMR-LPs caused a considerable increase in cellular lipid in HMDMs and THP-1 macrophages, but in this case there was a greater rise in the TG than in the cholesterol or CE content. Lipid accumulation in response to oxLDL, CMR-LPs, and oxCMR-LPs was prevented by the ACAT inhibitor CI976 in HMDMs but not in THP-1 macrophages, where TG levels remained markedly elevated. The rate of incorporation of [3H]oleate into CE and TG in THP-1 macrophages was increased by oxLDL, CMR-LPs, and oxCMR-LPs, but incorporation into TG was increased to a greater extent with CMR-LPs and oxCMR-LPs compared with oxLDL. These results demonstrate that both CMR-LPs and oxCMR-LPs cause lipid accumulation in human macrophages comparable to that seen with oxLDL and that oxidation of the remnant particles does not enhance this effect. They also demonstrate that a greater proportion of the lipid accumulated in response to CMR-LPs compared with oxLDL is TG rather than cholesterol or CE and that this is associated with a higher rate of TG synthesis. This study, therefore, provides further evidence to suggest that chylomicron remnants have a role in foam cell formation that is distinct from that of oxLDL.
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Affiliation(s)
- Kelly V Batt
- Department of Veterinary Basic Sciences, The Royal Veterinary College, London NW1 0TU, England
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Kraehling JR, Chidlow JH, Rajagopal C, Sugiyama MG, Fowler JW, Lee MY, Zhang X, Ramírez CM, Park EJ, Tao B, Chen K, Kuruvilla L, Larriveé B, Folta-Stogniew E, Ola R, Rotllan N, Zhou W, Nagle MW, Herz J, Williams KJ, Eichmann A, Lee WL, Fernández-Hernando C, Sessa WC. Genome-wide RNAi screen reveals ALK1 mediates LDL uptake and transcytosis in endothelial cells. Nat Commun 2016; 7:13516. [PMID: 27869117 PMCID: PMC5121336 DOI: 10.1038/ncomms13516] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 10/11/2016] [Indexed: 12/31/2022] Open
Abstract
In humans and animals lacking functional LDL receptor (LDLR), LDL from plasma still readily traverses the endothelium. To identify the pathways of LDL uptake, a genome-wide RNAi screen was performed in endothelial cells and cross-referenced with GWAS-data sets. Here we show that the activin-like kinase 1 (ALK1) mediates LDL uptake into endothelial cells. ALK1 binds LDL with lower affinity than LDLR and saturates only at hypercholesterolemic concentrations. ALK1 mediates uptake of LDL into endothelial cells via an unusual endocytic pathway that diverts the ligand from lysosomal degradation and promotes LDL transcytosis. The endothelium-specific genetic ablation of Alk1 in Ldlr-KO animals leads to less LDL uptake into the aortic endothelium, showing its physiological role in endothelial lipoprotein metabolism. In summary, identification of pathways mediating LDLR-independent uptake of LDL may provide unique opportunities to block the initiation of LDL accumulation in the vessel wall or augment hepatic LDLR-dependent clearance of LDL. Atherosclerosis is caused by low-density lipoprotein (LDL) buildup in the vessel wall, a process thought to be mediated by LDL receptor alone. Here, the authors show that the endothelium can uptake LDL via ALK1, a TGFβ signalling receptor, suggesting new therapies for blocking LDL accumulation in the vessel wall.
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Affiliation(s)
- Jan R Kraehling
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - John H Chidlow
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Chitra Rajagopal
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Michael G Sugiyama
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada M5B 1W8.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Joseph W Fowler
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Monica Y Lee
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Xinbo Zhang
- Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Department of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Cristina M Ramírez
- Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Department of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Eon Joo Park
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Bo Tao
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Keyang Chen
- Division of Endocrinology, Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
| | - Leena Kuruvilla
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Bruno Larriveé
- Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06511, USA
| | - Ewa Folta-Stogniew
- W.M. Keck Biotechnology Resource Laboratory, Yale University School of Medicine, New Haven, Connecticut 06511, USA
| | - Roxana Ola
- Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06511, USA
| | - Noemi Rotllan
- Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Department of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Wenping Zhou
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - Michael W Nagle
- Human Genetics &Computational Biomedicine, Pfizer Worldwide Research and Development, Cambridge, Massachusetts 02139, USA
| | - Joachim Herz
- Departments of Molecular Genetics, Neuroscience, Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Kevin Jon Williams
- Division of Endocrinology, Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.,Department of Molecular and Clinical Medicine, Sahlgrenska Academy of the University of Gothenburg, Göteborg 41345, Sweden
| | - Anne Eichmann
- Cardiovascular Research Center, Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06511, USA
| | - Warren L Lee
- Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario, Canada M5B 1W8.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8.,Departments of Biochemistry and Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Carlos Fernández-Hernando
- Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Department of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | - William C Sessa
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.,Vascular Biology and Therapeutics Program (VBT), Yale University School of Medicine, New Haven, Connecticut 06520, USA
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Arora S, Patra SK, Saini R. HDL—A molecule with a multi-faceted role in coronary artery disease. Clin Chim Acta 2016; 452:66-81. [DOI: 10.1016/j.cca.2015.10.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 10/13/2015] [Accepted: 10/22/2015] [Indexed: 01/18/2023]
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6
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Lipofuscin and lipid oxidation in human coronary endothelium. Cardiovasc Pathol 2015; 7:75-85. [PMID: 25990066 DOI: 10.1016/s1054-8807(97)00076-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/1997] [Accepted: 08/05/1997] [Indexed: 11/22/2022] Open
Abstract
Coronary artery endothelium was studied in 13 human hearts removed in the course of heart transplants. Plasma cholesterol ranged from 60 to 240 mg/dl (median 151). In all cases, abundant endothelial lipid and lipofuscin droplets were found, with images of transition between the two types; ultrastructural evidence indicated that lipofuscin derived both by fusion of smaller lipofuscin droplets as well as by oxidation of lipid droplets. There was no evidence of lipofuscin generation by autophagocytosis as seen in other organs. It is concluded that endothelial lipofuscin is not "wear-and-tear pigment" but a byproduct of lipid oxidation, a process normally carried out by the endothelial cells. In the endothelium of human veins, lipofuscin granules were much smaller and rare; this points to a biological difference between arterial and venous endothelium.
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Gómez-Vidales V, Granados-Oliveros G, Nieto-Camacho A, Reyes-Solís M, Jiménez-Estrada M. Cacalol and cacalol acetate as photoproducers of singlet oxygen and as free radical scavengers, evaluated by EPR spectroscopy and TBARS. RSC Adv 2014. [DOI: 10.1039/c3ra42848f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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8
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Karppi J, Laukkanen JA, Mäkikallio TH, Ronkainen K, Kurl S. Low β-carotene concentrations increase the risk of cardiovascular disease mortality among Finnish men with risk factors. Nutr Metab Cardiovasc Dis 2012; 22:921-928. [PMID: 22494809 DOI: 10.1016/j.numecd.2012.01.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 01/18/2012] [Accepted: 01/18/2012] [Indexed: 11/26/2022]
Abstract
BACKGROUND & AIMS Healthy diet rich in fruits and vegetables is an important factor in prevention of cardiovascular diseases (CVD). Some previous epidemiological studies have suggested that dietary and serum carotenoids are associated with decreased CVD mortality, but the results have been inconsistent. We assessed relations between the concentrations of serum carotenoids and CVD mortality among Eastern Finnish men. METHODS & RESULTS The study population consisted of 1031 Eastern Finnish men aged 46-65 years in the Kuopio Ischaemic Heart Disease Risk Factor (KIHD) cohort. Subjects were classified quartiles according to concentrations of carotenoids and subgroups according to risk factors. Hazard ratios of serum lycopene, α-carotene and β-carotene were estimated by the Cox proportional hazard model after adjusting for potential confounding factors. During the median 15.9-year follow-up, 122 deaths from CVDs, were identified among the cohort subjects. Low serum concentrations of β-carotene were strongly related to an increased CVD mortality risk after adjustment for confounders. For β-carotene, the hazard ratio (95% confidence interval) for the lowest versus highest quartile was 2.23 (1.26-3.93; P=0.006). However, the strongest risk of CVD mortality was observed among smokers with lowest levels of β-carotene (HR=3.15, 95%, CI: 1.19-8.33; P=0.020). Other carotenoids and the sum of carotenoids were not significantly related to increased risk of CVD mortality. CONCLUSIONS Low concentrations of serum β-carotene concentrations may increase the risk for CVD mortality among Eastern Finnish men; thus elevated serum concentrations of β-carotene may have clinical and public health relevance.
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Affiliation(s)
- J Karppi
- University of Eastern Finland, Department of Medicine, Institute of Public Health and Clinical Nutrition, FI-70211 Kuopio, Finland.
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9
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Eder K, Kirchgessner M. Effect of dietary fats on susceptibility of low-density lipoproteins to lipid peroxidation in pigs. J Anim Physiol Anim Nutr (Berl) 2011. [DOI: 10.1111/j.1439-0396.1997.tb00739.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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10
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Podrez EA. Anti-oxidant properties of high-density lipoprotein and atherosclerosis. Clin Exp Pharmacol Physiol 2010; 37:719-25. [PMID: 20374263 DOI: 10.1111/j.1440-1681.2010.05380.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
1. High-density lipoprotein (HDL) is one of the major carriers of cholesterol in the blood. It attracts particular attention because, in contrast with other lipoproteins, many physiological functions of HDL influence the cardiovascular system in favourable ways unless HDL is modified pathologically. 2. The best known function of HDL is the capacity to promote cellular cholesterol efflux from peripheral cells and deliver cholesterol to the liver for excretion, thereby playing a key role in reverse cholesterol transport. The functions of HDL that have recently attracted attention include anti-inflammatory and anti-oxidant activities. High anti-oxidant and anti-inflammatory activities of HDL are associated with protection from cardiovascular disease. 3. Atheroprotective activities, as well as a functional deficiency of HDL, ultimately depend on the protein and lipid composition of HDL. Conversely, these activities are compromised in many pathological states associated with inflammation. 4. The focus of the present review is on the anti-oxidant and anti-inflammatory functions of HDL and its individual components in relation to protection from atherosclerosis.
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Affiliation(s)
- Eugene A Podrez
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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12
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Vincent AM, Hinder LM, Pop-Busui R, Feldman EL. Hyperlipidemia: a new therapeutic target for diabetic neuropathy. J Peripher Nerv Syst 2009; 14:257-67. [PMID: 20021567 PMCID: PMC4239691 DOI: 10.1111/j.1529-8027.2009.00237.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Emerging data establish dyslipidemia as a significant contributor to the development of diabetic neuropathy. In this review, we discuss how separate metabolic imbalances, including hyperglycemia and hyperlipidemia, converge on mechanisms leading to oxidative stress in dorsal root ganglia (DRG) sensory neurons. We conclude with suggestions for novel therapeutic strategies to prevent or reverse diabetes-induced nerve degeneration.
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Affiliation(s)
- Andrea M Vincent
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.
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13
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McIntyre TM, Prescott SM, Stafforini DM. The emerging roles of PAF acetylhydrolase. J Lipid Res 2008; 50 Suppl:S255-9. [PMID: 18838739 DOI: 10.1194/jlr.r800024-jlr200] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Platelet-activating factor (PAF), a phospholipid autacoid with potent effects throughout the innate immune system, is selectively degraded by two small families of PAF acetylhydrolases (PAF-AHs). These Ca2+-independent phospholipases A2 display remarkable specificity for the length of the sn-2 residue, but this selectivity is lost as the residue gains oxygen functions. Two of the PAF-AHs therefore are specific oxidized phospholipid phospholipases that reduce inflammation, but also remove oxidatively truncated phospholipids that induce apoptosis. The roles of these enzymes are manifold, and their separate and combined functions are now being addressed in model systems and clinical studies.
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Affiliation(s)
- Thomas M McIntyre
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic College of Medicine of Case Western Reserve University, Cleveland, OH 44195, USA.
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14
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Duthie GG, Wahle KWJ, James WPT. Oxidants, Antioxidants and Cardiovascular Disease. Nutr Res Rev 2007; 2:51-62. [DOI: 10.1079/nrr19890007] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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15
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Ito Y, Kurata M, Suzuki K, Hamajima N, Hishida H, Aoki K. Cardiovascular disease mortality and serum carotenoid levels: a Japanese population-based follow-up study. J Epidemiol 2006; 16:154-60. [PMID: 16837766 PMCID: PMC7603911 DOI: 10.2188/jea.16.154] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Some observational epidemiologic studies suggest that dietary and serum carotenoids are associated with reduced cardiovascular disease mortality. METHODS Three thousand and sixty-one subjects (1,190 males and 1,871 females), aged 39 to 80 years, were recruited from residents of Hokkaido, Japan who had attended comprehensive health check-up programs from 1988 through 1995. Serum levels of α-carotene, β-carotene, and lycopene were separately determined by high-performance liquid chromatography. Serum levels of total carotene consisted of the sum of α-carotene, β-carotene, and lycopene levels. Each serum level of α-carotene, β-carotene, lycopene, total carotene, triglyceride, and alanine transaminase (ALT) activity was transformed logarithmically. The hazard ratios of serum α- and β-carotenes, lycopene, and total carotene values were estimated by the Cox proportional hazard model after adjusting for sex, age, and other potential confounding factors. RESULTS During the 11.9-year follow-up period, 80 deaths (49 males and 31 females) from cardiovascular disease, 40 deaths from heart disease, and 37 deaths from stroke were identified among the cohort subjects. High serum values of carotenoids such as α- and β-carotenes, and lycopene were found to be significantly associated with low hazard ratios for cardiovascular disease mortality. However, a significant inverse association between high serum lycopene value and the risk for stroke mortality was not always observed. CONCLUSIONS High serum levels of total carotene, comprising α- and β-carotenes and lycopene, may reduce the risk for cardiovascular disease mortality among the Japanese population.
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Affiliation(s)
- Yoshinori Ito
- Department of Preventive Medicine/Biostatistics and Medical Decision Making, Nagoya University Graduate School of Medicine, Japan.
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16
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Aneja R, Katyal A, Chandra R. Stimulation of lipid peroxidation and impairment of glutathione-dependent defense system in wistar rats treated with cryptopine, a rare non-narcotic opium alkaloid. Eur J Drug Metab Pharmacokinet 2004; 29:31-6. [PMID: 15151168 DOI: 10.1007/bf03190571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The present study was designed to evaluate the effect of repeated oral administration of cryptopine at differential dosing regimens (50, 100, 150, 200 mg/kg bwt) in vivo on lipid peroxide measures, glutathione levels (GSH) and activity of glutathione S-transferase (GST) and glutathione reductase (GR) in the liver, spleen, kidney and lung of Male Wistar rats after a 5 day treatment period. In all the tissues examined, we observed an increase in lipid peroxidation and a decline in glutathione content and activity of glutathione S-transferase and glutathione reductase in a dose-dependent manner. The decrease in GSH content did not definitively correlate with a concomitant increase of lipid peroxidation in all the tissues. Our results ensemble that the enhancement of lipid peroxidation in the tissues investigated is a consequence of depletion of glutathione to certain critical levels and impairment of the glutathione-dependent enzyme systems viz. GST and GR. Our study potentiates that decreased levels of GSH may lead to lipid peroxidation, one of the key events in cellular damage. The inhibition of GST also suggests that the detoxification of the alkaloid could be suppressed following acute exposures. Conclusively, it appears that cryptopine in vivo disturbs the cellular defense system, so that it tips in the direction of autoxidative lipid peroxidation, producing cytotoxicity.
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Affiliation(s)
- Ritu Aneja
- Department of Chemistry, University of Delhi, Delhi, India
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17
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Baer JT, Ayres SA. Estrogen levels and lipid peroxidation following exercise. PREVENTIVE CARDIOLOGY 2002; 4:85-87. [PMID: 11828205 DOI: 10.1111/j.1520-037x.2001.00528.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recent large-scale clinical trials have confirmed that estrogens are powerful antioxidants that effectively prevent lipid peroxidation. In particular, estrogen decreases oxidative modification of low-density lipoprotein both in vitro and in vivo. Estrogen levels fluctuate during the menstrual cycle and during perimenopause, and they are permanently depressed at menopause. Thus, it is of interest to evaluate the lipid peroxidation response under conditions of low estrogen status. It is of additional interest to evaluate lipid peroxidation under such conditions in response to situations that augment free radical production, such as exercise. Aerobic exercise, and more recently anaerobic exercise regimens, are reported to variably affect free radical production and lipid peroxidation. In addition to the exercising woman's estrogen status and menstrual history, other factors to consider when evaluating an exercising woman's risk for increased lipid peroxidation include the intensity of exercise and/or the woman's fitness level as well as her current dietary antioxidant status. (c) 2001 by CHF, Inc.
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Affiliation(s)
- J T Baer
- Department of Health and Sport Science, University of Dayton, Dayton, OH 45469
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18
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Hsu HC, Chiang YY, Chen WJ, Lee YT. Water-soluble hexasulfobutyl [60] fullerene inhibits plasma lipid peroxidation by direct association with lipoproteins. J Cardiovasc Pharmacol 2000; 36:423-7. [PMID: 11026641 DOI: 10.1097/00005344-200010000-00002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Free radicals can induce lipid peroxidation, leading to the formation of atherosclerosis. A new class of water-soluble C60 derivative, hexasulfobutyl [60] fullerene [C60-(CH2CH2CH2CH2SO3Na)6; (FC4S)], comprising six sulfobutyl functional groups covalently bound on a C60 cage, is a potent free radical scavenger. This study sought to define the effect of FC4S in protecting plasma from peroxidation. At concentrations of 10-100 microM, FC4S efficiently protected plasma against Cu2+-induced oxidation, as shown by maintenance of apoprotein B integrity and decrease in oxidative products levels, conjugated diene, and thiobarbituric acid-reactive substances. Addition of FC4S to both plasma and isolated lipoproteins, including very low density, low-density, and high-density lipoproteins, resulted in an increased mobility of the lipoprotein on agarose gel electrophoresis. This was attributed to FC4S associating with the lipoproteins because of the negative charge of the sulfonate groups after hydrolysis in the electrophoretic buffer. When lipoprotein was oxidized by 2,2-azobis (2,4-dimethyl-valeronitrile), which produces peroxyl radicals within lipoprotein, but not in the aqueous phase, the FC4S still efficiently inhibited lipoprotein oxidation. These data substantiate that FC4S acts efficiently in protecting plasma lipid from oxidation by associating with lipoprotein to scavenge free radicals in both the aqueous and lipophilic phases.
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Affiliation(s)
- H C Hsu
- Department of Internal Medicine (Cardiology), National Taiwan University, Taipei.
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19
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Macrophage receptors responsible for distinct recognition of low density lipoprotein containing pyrrole or pyridinium adducts: models of oxidized low density lipoprotein. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)33458-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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20
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Menéndez R, Más R, Amor AM, Fernández JC, González RM. Effects of policosanol on the susceptibility of low-density lipoprotein isolated from hypercholesterolemic patients at high coronary risk to in vitro copper-mediated lipid peroxidation: a randomized, double-blind pilot study. Curr Ther Res Clin Exp 2000. [DOI: 10.1016/s0011-393x(00)88013-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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21
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Shishino K, Murase M, Makino H, Saheki S. Glycated apolipoprotein A-I assay by combination of affinity chromatography and latex immunoagglutination. Ann Clin Biochem 2000; 37 ( Pt 4):498-506. [PMID: 10902867 DOI: 10.1177/000456320003700411] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The degree of glycation of plasma apolipoprotein A-I was measured by a combination of gel filtration, boronate affinity chromatography and latex immunoagglutination. The plasma concentrations of apolipoprotein A-I determined by this combination method (y) correlated well with those determined by turbidimetric immunoassay (x) (y=1.12x + 1.9, r=0.964). The inter- and intra-assay coefficients of variation in the glycated apolipoprotein A-I assay were 4.1-5.0% and 4.0-4.4%, respectively. Interference from plasma glucose at concentrations up to 55.1 mmol/L was eliminated by gel filtration. Labile glycated apolipoprotein A-I did not interfere with the measurement of glycated apolipoprotein A-I. Reference values for glycated apolipoprotein A-I were determined to be 2.4-4.0% (n=140), with no significant difference between men and women. The mean concentration of plasma glycated apolipoprotein A-I in patients with uncontrolled diabetes mellitus (5.11%) was significantly higher than in normal subjects (3.12%, P<0.001). The method is simple, rapid and highly sensitive for determination of the glycation level of plasma apolipoprotein A-I.
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Affiliation(s)
- K Shishino
- Department of Clinical Laboratory Medicine and Central Laboratory, School of Medicine, Ehime University, Onsen-Gun, Japan.
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22
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Tsuzuki D, Sumino K, Yokoyama M. Analysis of 7-ketocholesterol in low density lipoprotein and fatty acid composition in erythrocyte membranes of patients on maintenance hemodialysis and healthy controls. Clin Chim Acta 2000; 295:155-68. [PMID: 10767401 DOI: 10.1016/s0009-8981(00)00199-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We established a method to quantify 7-ketocholesterol (7-KC) in low density lipoprotein by using the heparin-citrate method and gas chromatography-mass spectrometry. We examined the concentration of 7-ketocholesterol in LDL using this method to assess the pathological conditions in uremic patients with hemodialysis and healthy controls. We also examined the fatty acid composition in erythrocyte membranes to estimate the modification of biological membranes. We showed that the concentrations of 7-KC/cholesterol in LDL were significantly increased in hemodialysis patients compared to healthy controls (3.68+/-0.45 vs. 2.41+/-0.19, P<0.05) and the ratio of polyunsaturated fatty acids to saturated fatty acids in erythrocyte membranes was significantly decreased in hemodialysis patients compared to healthy controls (0.499+/-0.014 vs. 0.655+/-0. 017, P<0.001). There was no significant difference in 7-KC concentration in LDL or fatty acid composition in erythrocyte membranes between pre- and post-intervention of hemodialysis. We concluded that hemodialysis patients are under oxidative stress, which modifies LDL and erythrocyte membranes and we speculated these modifications may participate in the process of atherosclerosis. We believe that the method to quantify 7-KC in this study is concise and reliable and may be used to investigate various diseases.
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Affiliation(s)
- D Tsuzuki
- Department of Public Health, Kobe University, School of Medicine, 7-5-1 Kusunoki-cho Chuo-ku Kobe, Hyogo, Japan.
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23
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Abstract
High-density lipoprotein (HDL) exists within the brain and is highly vulnerable to oxidative modifications. The focus of the present study was to determine the effect of HDL and oxidized HDL (oxHDL) upon neurons, astrocytes, and microglia. Administration of highly oxidized HDL, but not native, minimally, or moderately modified HDL resulted in a dose- and time-dependent increase in oxidative stress and death of cultured rat embryonic neurons. Astrocyte and microglia cultures treated with highly oxidized HDL displayed increased reactive oxygen species formation but no toxicity. Application of oxHDL exacerbated oxidative stress and neuron death induced by beta-amyloid peptide. Studies using pharmacological inhibitors implicate the involvement of calcium and reactive oxygen species in oxHDL-induced neuronal loss. Neural cells expressing increased levels of BCL-2 had decreased levels of oxidative stress and neuron death following exposure to oxHDL. Together, these data demonstrate that oxHDL increases oxidative stress in neurons, astrocytes, and microglia which ultimately culminate in neuron death.
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Affiliation(s)
- J N Keller
- Department of Biochemistry, Sanders-Brown Center on Aging, Lexington, Kentucky, 40536, USA
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24
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Keller JN, Hanni KB, Markesbery WR. Oxidized low-density lipoprotein induces neuronal death: implications for calcium, reactive oxygen species, and caspases. J Neurochem 1999; 72:2601-9. [PMID: 10349872 DOI: 10.1046/j.1471-4159.1999.0722601.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Low-density lipoprotein (LDL) exists within the brain and is highly vulnerable to oxidative modifications. Once formed, oxidized LDL (oxLDL) is capable of eliciting cytotoxicity, differentiation, and inflammation in nonneuronal cells. Although oxLDL has been studied primarily for its role in the development of atherosclerosis, recent studies have identified a possible role for it in neurological disorders associated with oxidative stress. In the present study application of oxLDL, but not LDL, resulted in a dose- and time-dependent death of cultured rat embryonic neurons. Studies using pharmacological inhibitors implicate the involvement of calcium, reactive oxygen species, and caspases in oxLDL-induced neuronal death. Coapplication of oxLDL with either amyloid beta-peptide or glutamate, agents that enhance oxidative stress, resulted in increased neuronal death. Taken together, these data demonstrate that oxLDL induces neuronal death and implicate a possible role for oxLDL in conditions associated with increased levels of reactive oxygen species, including Alzheimer's disease.
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Affiliation(s)
- J N Keller
- Sanders-Brown Center on Aging, University of Kentucky, Lexington 40536-0230, USA
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25
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Kanwar R, Balasubramanian D. Structure and stability of the dityrosine-linked dimer of gammaB-crystallin. Exp Eye Res 1999; 68:773-84. [PMID: 10375441 DOI: 10.1006/exer.1999.0669] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Oxidative damage to proteins leads to a variety of modifications such as racemization, carbonyl compound formation, new fluorophores, aggregation, crosslinking and insolubility, several of which are markers of pathogenesis. A particular modification that has been associated with abnormal and pathological situations is the dityrosine crosslink in proteins, thought to be responsible for the reduced solubility and elasticity of proteins, and plaque formation. Dityrosine crosslinking has been suspected to occur in the crystallins of the eye lens during cataract. We focus attention here on the generation, structure and conformational stability of such a dityrosine-linked protein of the eye lens. We find this crosslink to be readily generated photodynamically in the presence of sensitizers. Among the crystallins, crosslinking occurs most readily in the gamma-crystallins under these conditions. We have isolated, purified and studied the properties of the dityrosine-linked dimer of the eye lens protein gammaB-crystallin. While the dityrosine crosslink does not alter the secondary structure of the protein, it changes the tertiary structure in a subtle manner. This alteration destabilizes the dimer, which denatures more readily than the parent monomer, and also makes it precipitate more readily, a point of relevance to cataractogenesis of the eye lens. Comparison of these results with those reported on other dityrosine-dimerized proteins suggests that while the conformation of these proteins might not be altered in a major manner upon dityrosine linkage, the dimer is structurally less stable and displays reduced solubility, both of which are of pathological importance.
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Affiliation(s)
- R Kanwar
- Centre for Cellular and Molecular Biology, Hyderabad, 500 007, India
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26
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Keller JN, Hanni KB, Gabbita SP, Friebe V, Mattson MP, Kindy MS. Oxidized lipoproteins increase reactive oxygen species formation in microglia and astrocyte cell lines. Brain Res 1999; 830:10-5. [PMID: 10350554 DOI: 10.1016/s0006-8993(99)01272-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Lipoproteins exist in the central nervous system and surrounding vasculature possibly mediating effects upon cells in the brain during times of oxidative stress or compromised blood-brain barrier. The focus of the present study was to determine the effect of unmodified and oxidatively modified lipoproteins on astrocytes and microglia. Application of oxidized low-density lipoprotein resulted in an increase in DCF fluorescence, which was inhibited by pretreatment with antioxidants, consistent with the formation of reactive oxygen species (ROS). Low-density at concentrations below 20 microg/ml likewise increased ROS formation. Because ROS are associated with numerous astrocyte and microglia activities including proliferation, activation, and cytokine production it is possible that lipoproteins may mediate such effects on glial cells in the central nervous system.
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Affiliation(s)
- J N Keller
- Sanders-Brown Center on Aging, University of Kentucky, 101 Sanders-Brown Building, Lexington, KY, 40536-0230, USA.
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27
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Keller JN, Hanni KB, Pedersen WA, Cashman NR, Mattson MP, Gabbita SP, Friebe V, Markesbery WR. Opposing actions of native and oxidized lipoprotein on motor neuron-like cells. Exp Neurol 1999; 157:202-10. [PMID: 10222123 DOI: 10.1006/exnr.1999.7043] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Lipoproteins are present in the central nervous system and surrounding vasculature and possibly mediate effects relevant to neuronal physiology and pathology. To determine the effects of lipoproteins on motor neurons, native low density lipoproteins (LDL) and oxidized LDL (oxLDL) were applied to a motor neuron cell line. Oxidized LDL, but not native LDL, resulted in a dose- and time-dependent increase in reactive oxygen species and neuron death. Oxidized LDL-induced toxicity was attenuated by a calcium chelator, antioxidants, caspase inhibitors, and inhibitors of macromolecular synthesis. In addition to being nontoxic, application of native LDL attenuated reactive oxygen species formation and neuron loss following glucose deprivation injury. Together, these data demonstrate a possible neuroprotective role for unmodified lipoproteins and suggest oxidized lipoproteins may amplify oxidative stress and neuron loss.
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Affiliation(s)
- J N Keller
- Departments of Neurology and Pathology, University of Kentucky, Lexington, Kentucky 40536, USA
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28
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Ayres S, Baer J, Subbiah MT. Exercised-induced increase in lipid peroxidation parameters in amenorrheic female athletes. Fertil Steril 1998; 69:73-7. [PMID: 9457937 DOI: 10.1016/s0015-0282(97)00428-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To determine plasma lipid peroxidation parameters in eumenorrheic and amenorrheic athletes and to evaluate differences in their response to exercise-induced oxidative stress. In female athletes, intense physical exercise has been shown to be associated with an increased occurrence of menstrual dysfunction with lower levels of E2. Recently, a protective role has been demonstrated for estrogens as free radical scavengers. DESIGN Comparison of eumenorrheic and amenorrheic athletes before and after an acute bout of exercise. SETTING Academic Research Environment. PATIENT(S) Seven eumenorrheic (normally menstruating) and seven amenorrheic (<3 menses/year) female athletes aged 18 to 35 years participating in regular training. MAIN OUTCOME MEASURE(S) Plasma and low-density lipoprotein oxidation parameters, plasma E2 and vitamin E levels, and creatine kinase activity. RESULT(S) Both the amenorrheic and eumenorrheic athletes demonstrated a significant decrease in the lag time of conjugated diene formation after exercise (P < 0.01), with greater magnitude of change occurring in the amenorrheic athletes (P < 0.05). In addition, postexercise samples from amenorrheic (but not eumenorrhic) athletes showed a significant (P < 0.01) increase in oxysterol formation as compared to baseline values. Amenorrheic athletes also demonstrated a significantly higher baseline creatine kinase activity and a nonsignificant (P = 0.04) trend of an increase in creatine kinase activity after exercise. CONCLUSION(S) The results of this study shows that amenorrheic female athletes demonstrate an increased potential for lipid peroxidation after exercise. This could be related to lower plasma E2 levels in this group, considering the strong free radical scavenging ability of estrogens identified recently.
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Affiliation(s)
- S Ayres
- Department of Internal Medicine, University of Cincinnati Medical Center, Ohio 45267-0540, USA
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29
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McKinney KA, Duell PB, Wheaton DL, Hess DL, Patton PE, Spies HG, Burry KA. Differential effects of subcutaneous estrogen and progesterone on low-density lipoprotein size and susceptibility to oxidation in postmenopausal rhesus monkeys. Fertil Steril 1997; 68:525-30. [PMID: 9314927 DOI: 10.1016/s0015-0282(97)00237-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To study the differential effects of subcutaneous E2 alone or in combination with P on the susceptibility of low-density lipoprotein (LDL) cholesterol to oxidation in naturally postmenopausal diet-controlled rhesus monkeys. DESIGN Prospective, longitudinal controlled study. SETTING Oregon Health Sciences University, Portland, Oregon, and Oregon Regional Primate Research Center, Beaverton, Oregon. PATIENT(S) Five naturally postmenopausal rhesus monkeys. INTERVENTION(S) Estradiol was administered subcutaneously for the first 4 weeks, followed by E2 plus P for 4 weeks, followed by a third 4-week washout period. MAIN OUTCOME MEASURE(S) Changes in plasma lipoprotein levels and oxidation of LDL and serum concentrations of E2 and P. RESULT(S) Levels of LDL cholesterol fell after 4 weeks of treatment with E2, compared with baseline. The lag time to half maximal light absorbancy after 4 weeks of E2 treatment was significantly increased compared with baseline. The maximal absorbance values and the slope of the propagation phase after 4 weeks of treatment with E2 were decreased compared with baseline. After 4 weeks of combined E2 and P treatment, all values were comparable to baseline. CONCLUSION(S) These results suggest that subcutaneous E2 therapy appears to enhance LDL resistance to oxidation and that this effect is attenuated by the addition of the P.
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Affiliation(s)
- K A McKinney
- Department of Obstetrics and Gynecology, Oregon Health Sciences University, Portland, USA
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30
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Sugawa M, Ikeda S, Kushima Y, Takashima Y, Cynshi O. Oxidized low density lipoprotein caused CNS neuron cell death. Brain Res 1997; 761:165-72. [PMID: 9247081 DOI: 10.1016/s0006-8993(97)00468-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Death induced by oxidized low density lipoproteins (oxLDL) to embryonic CNS neuronal and neuroblastoma cells was investigated. Cell damage and viability were evaluated by LDH leakage and the MTT method, respectively. Dose- and time-dependent degeneration of neurons occurred after oxLDL (1-100 microg/ml) treatment but was absent after native low density lipoproteins (LDL). This degeneration was mediated, in part, by apoptosis because increased TUNEL and Hoechst dye-positive staining was observed. These effects occurred in the absence of microglia. However, DNA degradation was not detected. The cytotoxicity was attenuated by pre-treatment with antioxidants. These results suggest that oxidation by oxLDL may be important in neurocytotoxicity in the brain.
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Affiliation(s)
- M Sugawa
- Fuji-Gotemba Research Laboratories Chugai Pharmaceutical Co. Ltd., Gotemba-shi, Shizuoka, Japan.
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31
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Leeuwenburgh C, Rasmussen JE, Hsu FF, Mueller DM, Pennathur S, Heinecke JW. Mass spectrometric quantification of markers for protein oxidation by tyrosyl radical, copper, and hydroxyl radical in low density lipoprotein isolated from human atherosclerotic plaques. J Biol Chem 1997; 272:3520-6. [PMID: 9013599 DOI: 10.1074/jbc.272.6.3520] [Citation(s) in RCA: 298] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Lipoprotein oxidation has been implicated in the pathogenesis of atherosclerosis. However, the physiologically relevant pathways mediating oxidative damage have not yet been identified. Three potential mechanisms are tyrosyl radical, hydroxyl radical, and redox active metal ions. Tyrosyl radical forms o,o'-dityrosine cross-links in proteins. The highly reactive hydroxyl radical oxidizes phenylalanine residues to o-tyrosine and m-tyrosine. Metal ions oxidize low density lipoprotein (LDL) by poorly understood pathways. To explore the involvement of tyrosyl radical, hydroxyl radical, and metal ions in atherosclerosis, we developed a highly sensitive and quantitative method for measuring levels of o, o'-dityrosine, o-tyrosine, and m-tyrosine in proteins, lipoproteins, and tissue, using stable isotope dilution gas chromatography-mass spectrometry. We showed that o,o'-dityrosine was selectively produced in LDL oxidized with tyrosyl radical. Both o-tyrosine and o, o'-dityrosine were major products when LDL was oxidized with hydroxyl radical. Only o-tyrosine was formed in LDL oxidized with copper. Similar profiles of oxidation products were observed in bovine serum albumin oxidized with the three different systems. Applying these findings to LDL isolated from human atherosclerotic lesions, we detected a 100-fold increase in o,o'-dityrosine levels compared to those in circulating LDL. In striking contrast, levels of o-tyrosine and m-tyrosine were not elevated in LDL isolated from atherosclerotic tissue. Analysis of fatty streaks revealed a similar pattern of oxidation products; compared with normal aortic tissue, there was a selective increase in o,o'-dityrosine with no change in o-tyrosine. The detection of a selective increase of o,o'-dityrosine in LDL isolated from vascular lesions is consistent with the hypothesis that oxidative damage in human atherosclerosis is mediated in part by tyrosyl radical. In contrast, these observations do not support a role for free metal ions as catalysts of LDL oxidation in the artery wall.
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Affiliation(s)
- C Leeuwenburgh
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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32
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Haylett AK, McNair FI, McGarvey D, Dodd NJ, Forbes E, Truscott TG, Moore JV. Singlet oxygen and superoxide characteristics of a series of novel asymmetric photosensitizers. Cancer Lett 1997; 112:233-8. [PMID: 9066733 DOI: 10.1016/s0304-3835(96)04577-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The singlet oxygen quantum yields and superoxide quantum yields for a series of novel compounds based on an asymmetrical protoporphyrin molecule have been examined. Electron spin resonance was used to measure superoxide yield and time resolved luminescence for singlet oxygen. A comparison between these results and previously published cell survival data was carried out. A broad association was found between singlet oxygen quantum yield and clonogenic cell kill.
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Affiliation(s)
- A K Haylett
- Department of Experimental Radiation Oncology, Paterson Institute for Cancer Research, Manchester, UK
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33
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Chang YH, Abdalla DS, Sevanian A. Characterization of cholesterol oxidation products formed by oxidative modification of low density lipoprotein. Free Radic Biol Med 1997; 23:202-14. [PMID: 9199882 DOI: 10.1016/s0891-5849(96)00626-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Oxidative modification of LDL is evidenced by alterations in both the protein and lipid components of the particle. Progressive oxidation of the apoprotein is associated with loss of specific amino acids and a gradual increase in electronegativity. Electronegative LDL has been isolated from human plasma (LDL-) by several groups using liquid chromatographic techniques and appears to be oxidized based on increased lipid peroxide levels and cholesterol oxidation products (ChOx). Formation of LDL- also takes place following Cu(2+)-induced oxidation. Cu(2+)-induced oxidation caused a small fraction of the normal unoxidized LDL (n-LDL) to convert to LDL-during the oxidative lag phase while minimal increases in conjugated dienes were apparent. After the lag phase, there was a further increase in LDL-, a rapid accumulation of conjugated dienes, and another more electronegative particle was formed (LDL2-). By the end of the lag phase, approximately 30% and 12% of the total LDL converted to LDL- and LDL2-, respectively. Nearly 40% of the total ChOx formed was present by the end of the lag period, accompanied by small increases in conjugated dienes. The major products accumulating during this time were 7-ketocholesterol, cholesterol-beta-epoxide and 7-alpha-hydroxycholesterol. Accumulation of predominated during the subsequent propagation phase. At the end of propagation phase there was a six fold increase in conjugated dienes and total ChOx increased eight-fold. It appears that a subpopulation of LDL rapidly converts to LDL-, representing a mildly oxidized but oxidant sensitive LDL population. Oxidation of cholesterol accompanies these early events in LDL oxidation with formation of specific ChOx.
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Affiliation(s)
- Y H Chang
- University of São Paulo, Faculdade de Ciências Farmacêuticas, Brazil
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34
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Pico I, Myara I, Pech-Amsellem MA, Vedie B, Chappey B, Moatti N. Oxidative modification of low-density lipoprotein by the human hepatoma cell line HepG2. Free Radic Res 1996; 25:321-36. [PMID: 8889496 DOI: 10.3109/10715769609149055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The human hepatoblastoma cell line HepG2 is a liver model commonly used for lipid metabolism studies. Numerous cell types have been found to oxidize low-density lipoprotein (LDL) but, to our knowledge, the effects of HepG2 cells on LDL have not been investigated. We found that LDL is modified by HepG2 cells through a peroxidative mechanism, as judged by an increase in TBARS content (which was prevented in the presence of the antioxidants vitamin E, 2,6-di-tertbutyl-cresol and probucol), increased degradation by J774 macrophages, decreased internalization by MRC5 fibroblasts, and aggregation of apo B. Aspirin and allopurinol, which inhibit cyclooxygenase and xanthine-oxidase activities, respectively, had no effect on HepG2-induced LDL modification, and neither did catalase, which dismutates hydrogen peroxide; or mannitol, which scavenges hydroxyl radicals. In contrast, superoxide dismutase, a superoxide anion scavenger, and glutamate and threonine, which alter cellular cystine uptake, prevented LDL modifications, as did the removal of cysteine/cystine from the culture medium. Oxidation of LDL by HepG2 cells might thus involve superoxide anion production and/or thiol metabolism.
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Affiliation(s)
- I Pico
- Laboratoire de Biochimie Appliquée des Sciences Pharmaceutiques et Biologiques, Châtenay-Malabry, France
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35
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Yuan C, Mei Z, Liu S, Yi L. PSK protects macrophages from lipoperoxide accumulation and foam cell formation caused by oxidatively modified low-density lipoprotein. Atherosclerosis 1996; 124:171-81. [PMID: 8830930 DOI: 10.1016/0021-9150(96)05835-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In previous works, it has been evidenced that lipoperoxidative injury to macrophages caused by oxidatively modified low-density lipoprotein (O-LDL) plays an important role in foam cell formation, and that PSK, a protein bound polysaccharide extracted from the class Basidiomycetes Coriolus Versicolor, can protect macrophages from lipoperoxidative injury induced by tert-butyl hydroperoxide (tbOOH). In this paper PSK protection of macrophages from lipoperoxide (LPO) accumulation and foam cell formation caused by O-LDL and its action mechanism were further studied. The LPO accumulation was determined by using ACAS 570. Dynamic assay of the LPO level in eight single cells after adding O-LDL or determination of the average LPO content in a lot of cells incubated in advance with O-LDL for 12 h, both indicated that O-LDL might induce LPO accumulation in macrophages and the effects of O-LDL could be prevented by PSK. O-LDL might cause the changes of morphological structure in macrophages and the transformation of macrophages into foam cells, and the effects could also be prevented by PSK. The determination of selenium-dependent glutathione peroxidase (SeGSHPx) activities and mRNA contents of macrophages and changes of SeGSHPx activity and mRNA content after incubation with tbOOH showed that PSK might increase the SeGSHPx activity of macrophage and the enhanced SeGSHPx activity may occur at the level of gene transcription.
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Affiliation(s)
- C Yuan
- Research Laboratory of Free Radical Medicine, First Military Medical University, Guangzhou, China
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36
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Chajès V, Sattler W, Stultschnig M, Kostner GM. Photometric evaluation of lipid peroxidation products in human plasma and copper oxidized low density lipoproteins: correlation of different oxidation parameters. Atherosclerosis 1996; 121:193-203. [PMID: 9125294 DOI: 10.1016/0021-9150(95)05719-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Despite considerable methodological advances, ideal parameters relating to the in vitro assessment of lipoprotein oxidizability are lacking. In this study, some of the more common parameters of lipid peroxidation were measured in 30 plasma samples. The following parameters were determined: conjugated dienes (method 1), reaction of lipid hydroperoxides with a methylene blue derivative (method 2), oxidation of iodide to triiodide (method 3) and an iodometric assay based on the same chemistry but modified to correct for unspecific interferences (method 4). Alpha-Tocopherol in plasma was assayed by high-pressure liquid chromatography. In addition, LDL was isolated from plasma and the susceptibility of individual LDL preparations towards copper-initiated oxidation was characterized. The amount of lipid hydroperoxides found in fresh plasma samples obtained from apparently healthy humans was dependent on the method used for the assessment. Lipid hydroperoxides measured by method 2 were: 8.6 +/- 5.8 mu M, by method 3: 5.8 +/- 1.9 mu M and by method 4: 4.2 +/- 2.7 mu M. Mean values of conjugated dienes (method 1) were 84.6 +/- 20.9 mu M; The content of alpha-tocopherol in plasma was 23.6 +/- 3.9 mu M. Despite the differences in absolute values, a statistically significant correlation was found between values obtained by methods 1, 2 and 3, but not by method 4. An inverse relationship has been observed between the lipid hydroperoxide content in plasma obtained with method 4 and two parameters of LDL oxidation (diene concentration, rate of diene formation) but not with the lag time. Our data suggest that--among the photometric methods evaluated--method 4 might be the most specific for the measurement of plasma (and lipoprotein associated) lipid hydroperoxides.
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Affiliation(s)
- V Chajès
- Institute of Medical Biochemistry, Karl-Franzens-University of Graz, Graz, Austria
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37
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Marquez LA, Dunford HB. Kinetics of oxidation of tyrosine and dityrosine by myeloperoxidase compounds I and II. Implications for lipoprotein peroxidation studies. J Biol Chem 1995; 270:30434-40. [PMID: 8530471 DOI: 10.1074/jbc.270.51.30434] [Citation(s) in RCA: 194] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The oxidation of lipoproteins is considered to play a key role in atherogenesis, and tyrosyl radicals have been implicated in the oxidation reaction. Tyrosyl radicals are generated in a system containing myeloperoxidase, H2O2, and tyrosine, but details of this enzyme-catalyzed reaction have not been explored. We have performed transient spectral and kinetic measurements to study the oxidation of tyrosine by the myeloperoxidase intermediates, compounds I and II, using both sequential mixing and single-mixing stopped-flow techniques. The one-electron reduction of compound I to compound II by tyrosine has a second order rate constant of (7.7 +/- 0.1) x 10(5) M-1 s-1. Compound II is then reduced by tyrosine to native enzyme with a second order rate constant of (1.57 +/- 0.06) x 10(4) M-1 s-1. Our study further revealed that, compared with horseradish peroxidase, thyroid peroxidase, and lactoperoxidase, myeloperoxidase is the most efficient catalyst of tyrosine oxidation at physiological pH. The second order rate constant for the myeloperoxidase compound I reaction with tyrosine is comparable with that of its compound I reaction with chloride: (4.7 +/- 0.1) x 10(6) M-1 s-1. Thus, although chloride is considered the major myeloperoxidase substrate, tyrosine is able to compete effectively for compound I. Steady state inhibition studies demonstrate that chloride binds very weakly to the tyrosine binding site of the enzyme. Coupling of tyrosyl radicals yields dityrosine, a highly fluorescent stable compound that had been identified as a possible marker for lipoprotein oxidation. We present spectral and kinetic data showing that dityrosine is further oxidized by both myeloperoxidase compounds I and II. The second order rate constants we determined for dityrosine oxidation are (1.12 +/- 0.01) x 10(5) M-1 s-1 for compound I and (7.5 +/- 0.3) x 10(2) M-1 s-1 for compound II. Therefore, caution must be exercised when using dityrosine as a quantitative index of lipoprotein oxidation, particularly in the presence of myeloperoxidase and H2O2.
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Affiliation(s)
- L A Marquez
- Department of Chemistry, University of Alberta, Edmonton, Canada
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38
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Jürgens G, Fell A, Ledinski G, Chen Q, Paltauf F. Delay of copper-catalyzed oxidation of low density lipoprotein by in vitro enrichment with choline or ethanolamine plasmalogens. Chem Phys Lipids 1995; 77:25-31. [PMID: 7586089 DOI: 10.1016/0009-3084(95)02451-n] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Low density lipoprotein (LDL) isolated from human serum of different donors was enriched with plasmalogens and their diacyl analogs in order to investigate a possible effect of these phospholipids on the rate of lipid peroxidation in this lipoprotein. LDL was incubated with either vesicles of choline plasmalogen or phosphatidylcholine in presence of lipoprotein- deficient serum, or with liposomes of ethanolamine plasmalogen or phosphatidylethanolamine together with the non-specific phospholipid transfer protein isolated from beef liver. After re-isolation of LDL by ultracentrifugation, a dose-dependent incorporation of the exogenous phospholipids was obtained. Enrichment of LDL with choline plasmalogen resulted in a delay of the copper-catalyzed oxidation of LDL from five different donors. LDL from two donors was also enriched with diacylglycerophosphocholine which led to a delay of oxidation, but the protective effect was smaller than with choline plasmalogen. Enrichment of LDL from two additional donors with ethanolamine plasmalogen resulted in the strongest protection against oxidation, whereas, diacylglycerophospho-ethanolamine had little effect. The delay of the copper-catalyzed LDL oxidation may be due to a direct antioxidative action of the plasmalogens, which are partially degraded during the lag phase of oxidation, or to an indirect effect caused by alteration of the LDL surface in the presence of an excess of glycerophospholipids.
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Affiliation(s)
- G Jürgens
- Institut für Medizinische Biochemie, Karl-Franzens Universität Graz, Austria
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39
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Hayam I, Cogan U, Mokady S. Dietary oxidized oil and the activity of antioxidant enzymes and lipoprotein peroxidation in rats. Nutr Res 1995. [DOI: 10.1016/0271-5317(95)00065-q] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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40
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Abstract
Superoxide production by macrophages and leukocytes may have an important role in atherogenesis. Whether lipoproteins modulate the superoxide production of these cells is not clear. Therefore, the effect of lipoproteins on the production of superoxide by rat peritoneal macrophages was tested. VLDL and LDL inhibited digitonin-stimulated superoxide production in a dose-dependent manner. Maximum inhibition was observed at 10 micrograms ml-1 of VLDL protein and 50 micrograms ml-1 of LDL protein respectively. In contrast, HDL (40 micrograms protein ml-1) enhanced digitonin-stimulated superoxide production (by 47 per cent). Macrophage superoxide production induced by arachidonic acid was enhanced by both VLDL (130 per cent) and HDL (84 per cent), whereas LDL had no effect. The lipoproteins had no effect on macrophage superoxide stimulated by other agonists such as phorbol myristate 13-acetate, sodium fluoride or the calcium ionophore, A23187. The effect of lipoproteins was also tested on human polymorphonuclear leukocyte superoxide generation, stimulated by digitonin and PMA. Ten micrograms of VLDL, 50 micrograms of LDL and 50 micrograms of HDL proteins ml-1, inhibited digitonin-induced superoxide production by 50, 100 and 33 per cent respectively. Lipoproteins had no effect on PMA stimulated superoxide generation by human polymorphonuclear leukocytes. The stimulatory and inhibitory effects of lipoproteins on macrophage and neutrophil superoxide generation could be important in the understanding of oxidation-mediated development of atherosclerosis.
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Affiliation(s)
- P F Mohan
- Department of Pediatrics, Schneider Children's Hospital, Long Island Jewish Medical Center, New Hyde Park, New York 11042, USA
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41
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Dansa-Petretski M, Ribeiro JM, Atella GC, Masuda H, Oliveira PL. Antioxidant role of Rhodnius prolixus heme-binding protein. Protection against heme-induced lipid peroxidation. J Biol Chem 1995; 270:10893-6. [PMID: 7738029 DOI: 10.1074/jbc.270.18.10893] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Heme in aqueous solutions actively promotes free radical reactions leading to degradation of biological molecules. The blood-sucking insect Rhodnius prolixus has a heme-binding protein (RHBP) in its hemolymph (Oliveira, P.L., Kawooya, J.K., Ribeiro, J.M.C., Meyer, T., Poorman, R., Alves, E.W., Walker, F., Padovan, G.J., and Masuda, H. (1994) J. Biol. Chem. 270, 10897-10901. Here we show that this protein inhibits heme-dependent peroxidation of both linolenic acid liposomes and lipophorin, the main lipoprotein of insect hemolymph. The oxidized lipophorin is functionally impaired, being defective both in its capacity to be loaded with phospholipids from the fat body as well as in its ability to deliver phospholipids to the growing oocytes. RHBP prevents the heme-induced oxidative damage to lipophorin. It is proposed that in vivo RHBP binds the heme derived from digestion of blood hemoglobin, suppressing the generation of activated oxygen species and protecting the insect against oxidative stress throughout the feeding cycle.
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Affiliation(s)
- M Dansa-Petretski
- Departamento de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Brasil
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42
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Hammer A, Kager G, Dohr G, Rabl H, Ghassempur I, Jürgens G. Generation, characterization, and histochemical application of monoclonal antibodies selectively recognizing oxidatively modified apoB-containing serum lipoproteins. Arterioscler Thromb Vasc Biol 1995; 15:704-13. [PMID: 7749884 DOI: 10.1161/01.atv.15.5.704] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To investigate either the role oxidized LDL plays in atherosclerosis or structural changes on the surface of oxidized LDL, monoclonal antibodies (mAbs) are an important tool. After immunizing mice with Cu(2+)-oxidized LDL (oxLDL) and fusion of splenocytes, hybridoma supernatants were screened and cloned. Two mAbs, OB/04 and OB/09 (IgG and IgM), were further characterized. In solid-phase fluorescence immunoassays and Western blot analysis both mAbs reacted with oxLDL, LDL oxidized by a free radical-generating azo compound, or oxVLDL but not with native LDL, acetylated LDL, oxHDL3, azo-oxidized HDL3, or HDL3 modified with malondialdehyde (MDA). In competitive immunoassays with LDL modified by oxidized fatty acid-derived aldehydes, mAb OB/09 strongly reacted with MDA-LDL or MDA-VLDL and LDL modified with 4-hydroxyhexenal followed by 4-hydroxynonenal but not with 4-hydroxyoctenal or hepta-2,4-dienal. mAb OB/04 had a weak affinity for LDL after modification with these aldehydes except for MDA-LDL. LDL modified with arachidonic acid oxidation products (AAOPs) was also recognized by this mAb. However, albumin modified either by the aldehydes applied or by AAOPs did not react with either mAb. Thus, the data indicate that each of the mAbs recognizes a different epitope that is expressed only on apoB-containing lipoproteins upon oxidative modification. An immunostaining with mAb OB/04 was obtained in areas rich in macrophages and in connective tissue of a human atherosclerotic lesion.
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Affiliation(s)
- A Hammer
- Institute for Medical Biochemistry, Medical Faculty, Karl-Franzens Universität Graz, Austria
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43
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Hahn M, Tang M, Subbiah MT. Cholest-3,5-dien-7-one formation in peroxidized human plasma as an indicator of lipoprotein cholesterol peroxidation potential. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1255:341-3. [PMID: 7734451 DOI: 10.1016/0005-2760(95)00004-v] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Lipoprotein peroxidation susceptibility is routinely evaluated using products of unsaturated fatty acids as markers (e.g., malonaldehyde). The significance and factors influencing peroxidation of cholesterol moiety of lipoproteins are relatively unknown due to lack of a reliable marker product which can be measured easily. Under the influence of Cu2+ ions, the major product of lipoprotein cholesterol peroxidation (isolated after saponification) was cholest-3-5-dien-7-one (CSD). Apart from gas-liquid chromatography, this compound lends itself for measurement by alternative methods. Due to lack of the 3 beta-hydroxyl group, CSD was separated from the rest of the oxysterols and cholesterol by passing through digitonin-coated silica-gel G and its concentration was determined by absorption at 283 nm. The recovery of CSD by this method exceeded by 87%. The formation of CSD was also sensitive to vitamin E and therefore could be used as an index of lipoprotein cholesterol susceptibility to peroxidation.
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Affiliation(s)
- M Hahn
- Department of Internal Medicine, University of Cincinnati Medical Center, University Hospital, OH 45267-0540, USA
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44
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Bowry VW, Mohr D, Cleary J, Stocker R. Prevention of tocopherol-mediated peroxidation in ubiquinol-10-free human low density lipoprotein. J Biol Chem 1995; 270:5756-63. [PMID: 7890704 DOI: 10.1074/jbc.270.11.5756] [Citation(s) in RCA: 170] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Oxidation of low density lipoprotein (LDL) may be involved in the development of atherosclerosis. It has recently been shown that alpha-tocopherol (alpha-TOH) can act either as an antioxidant or prooxidant for isolated low density lipoprotein (LDL). In the absence of an effective co-antioxidant, alpha-TOH is a prooxidant and this activity is evidently due to reaction of the alpha-tocopheroxyl radical (alpha-TO.) with the LDL's polyunsaturated lipids (Bowry, V. B., and Stocker, R. (1993) J. Am. Chem. Soc. 115, 6029-6045). Herein we examined the effectiveness of selected natural and synthetic radical scavengers as co-antioxidants for inhibiting peroxyl radical-induced peroxidation in LDL that is devoid of ubiquinol-10 (an effective endogenous co-antioxidant) but still contains most of its natural complement of alpha-TOH. Various quinols, catechols, and aminophenols, as well as ascorbate, 6-palmityl ascorbate, and bilirubin, were very effective co-antioxidants under our test conditions, whereas ordinary phenolic antioxidants, including short-tailed alpha-TOH homologues, were less effective. Reduced glutathione, urate, and Probucol were ineffective. These findings confirm that the prooxidant activity of alpha-TOH in LDL relies heavily on the segregation of water-insoluble radicals (particularly alpha-TO.) into individual LDL particles, since it was those compounds that are expected to either irreversibly reduce alpha-TO. or accelerate the diffusion of radicals between particles which most effectively inhibited the tocopherol-mediated phase of peroxidation. Theoretical and practical implications of these findings are discussed, as is their relevance to the "LDL oxidation" hypothesis of atherogenesis.
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Affiliation(s)
- V W Bowry
- Biochemistry Group, Heart Research Institute, Sydney, New South Wales, Australia
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45
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Abstract
Changes in the plasma lipid levels were investigated among rats fed an atherosclerotic-promoting diet containing 0.5% cholesterol and rats fed the same diet with added vitamin C (ascorbic acid), vitamin E (a-tocopherol) and vitamins C + E from one to seven weeks. Total cholesterol (TC) and triglycerides (TG) were significantly increased in rats fed a hyperlipidemic diet from the third week to the seventh week, whereas high density lipoprotein cholesterol (HDL-C) was not affected. Rats supplemented with 5 mg vitamin C, 5 mg vitamin E or 5 mg vitamin C + 5 mg vitamin E per day for four to seven weeks showed significant decrease in the concentration of TC and TG. HDL-C was only affected at the seventh week with vitamin C alone, whereas it was significantly increased with vitamin E alone and vitamins C + E at five to seven weeks. However, supplementation of vitamins C, E or C + E for less than four weeks has no significant effect on plasma lipid concentrations. The antioxidant effect of vitamins C and E is probably a time-dependent process that significantly lowers plasma lipids between week four and week seven following administration of these vitamins. It is therefore suggested that the incidence of coronary heart disease (CHD) may be reduced in lowering plasma lipid levels by dietary supplementation of vitamins C or E.
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Affiliation(s)
- S M Khoja
- Department of Biochemistry, Faculty of Science and Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
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46
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Ozdemirler G, Aykaç G, Uysal M, Oz H. Liver lipid peroxidation and glutathione-related defence enzyme systems in mice treated with paracetamol. J Appl Toxicol 1994; 14:297-9. [PMID: 7963244 DOI: 10.1002/jat.2550140410] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Glutathione levels were found to be decreased while lipid peroxide levels were increased in total liver homogenates 6 h following paracetamol treatment (500 mg kg-1 i.p.). Furthermore, it has been determined that cytosolic glutathione S-transferase (GST) activity was decreased and glutathione peroxidase (GSH-Px) activity remained unchanged. On the other hand, a decrease in liver microsomal lipid peroxide levels and an increase in GST and GSH-Px activity has been observed. We concluded that decreased lipid peroxide levels in microsomes could be a consequence of increased GSH-Px and GST enzyme activities. In this way, these glutathione-related defence enzyme systems may play an important role in protecting microsomes from lipid peroxidation.
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Affiliation(s)
- G Ozdemirler
- Department of Biochemistry, Istanbul Faculty of Medicine, University of Istanbul, Capa, Turkey
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47
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Wiegel D, Richter O, Arnold K. Partitioning of chemically modified low-density lipoprotein in aqueous polymer two-phase systems. J Chromatogr A 1994; 668:107-16. [PMID: 7516242 DOI: 10.1016/0021-9673(94)80098-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Aqueous polyethylene glycol (PEG)-dextran two-phase systems containing 10 mM Tris.HCl (pH 7.4) were used for the partitioning of chemically modified low-density lipoprotein (LDL). Anionic modification connected with an increase in the negative surface charge of lipoproteins favours the accumulation of modified LDL in the top phase. The partition coefficient increases depending on the extent of modification. Cationic modification yields lower values for the partition coefficient. Positively charged LDL favours a bottom-phase accumulation. With weakly charged and nearly neutral particles, the Van der Waals interaction between polymer and particle preponderates over electrostatic interactions, leading to a favoured accumulation of LDL in the PEG-rich top phase. Results of measurements of the relative electrophoretic mobility and the determination of free amino groups are in agreement with the calculated values of the partition coefficient. Because the partitioning of LDL is accompanied by aggregation at the interface, experimental techniques have to be carefully standardized. Subtle differences in the surface properties of modified LDL can be detected.
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Affiliation(s)
- D Wiegel
- University of Leipzig, School of Medicine, Institute of Medical Physics and Biophysics, Germany
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48
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Shoukry MI, el-Khatim MS, Gumaa KA. Effect of LDL and serum from diabetic subjects on DNA synthesis in HIT-cells in culture. Acta Diabetol 1994; 31:40-2. [PMID: 8043896 DOI: 10.1007/bf00580759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The effect of lipoprotein-deficient serum (LPDS) with and without added low-density lipoprotein (LDL), isolated from diabetic subjects, on the replication of SV40-transformed islet cells (HIT cells) was investigated. Whole serum as well as LPDS preparations stimulated DNA synthesis maximally when added to the culture medium at a final concentration of 0.1%. The addition of LDL at 25 and 175 micrograms protein/ml medium did not cause further stimulation. On the contrary, the higher concentrations resulted in a significant inhibition. These results suggest that previously observed stimulation of DNA synthesis in smooth muscle cells by LDL from diabetic subjects is most likely due to the presence of growth factors in the serum of these patients and not to LDL per se.
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Affiliation(s)
- M I Shoukry
- Department of Biochemistry, Faculty of Medicine, Kuwait University
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49
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Dousset N, Ferretti G, Taus M, Valdiguiè P, Curatola G. Fluorescence analysis of lipoprotein peroxidation. Methods Enzymol 1994; 233:459-69. [PMID: 8015481 DOI: 10.1016/s0076-6879(94)33052-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- N Dousset
- Laboratory of Biochemistry, CHU Rangueil, Toulouse, France
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50
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Tsuda T, Sugaya A, Liu YZ, Katoh K, Tanaka H, Kawazura H, Sugaya E, Kusai M, Kohno M. Radical scavenger effect of Boschniakia rossica. JOURNAL OF ETHNOPHARMACOLOGY 1994; 41:85-90. [PMID: 8170164 DOI: 10.1016/0378-8741(94)90062-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To elucidate the mechanism of the invigorating and antisenile action of the dried herb of Boschniakia rossica (Boschniakiae Herba), the free radical scavenging activity of its 50% ethanol extract (BR) was examined using an electron spin resonance spectrometer. The scavenging activity of plasma from Fisher-334 rats with continuous administration of BR was also examined. The concentrations showing 50% inhibition of the free radical of BR on the 1,1-diphenyl-2-picrylhydrazil (DPPH) radical, superoxide radical and hydroxyl radical were 0.003%, 0.06% and 9.67%, respectively. Plasma from the rats with BR administered clearly showed higher free radical scavenging activity compared with that of normal control rats. These findings suggest that Boschniakia rossica has strong free radical scavenging activity and consequently it has inhibitory effects on the disorders caused by free radical production in living tissue.
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Affiliation(s)
- T Tsuda
- Faculty of Pharmaceutical Sciences, Josai University, Saitama-ken, Japan
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