scholarly journals Low-density lipoprotein is the major carrier of lipid hydroperoxides in plasma. Relevance to determination of total plasma lipid hydroperoxide concentrations

1996 ◽  
Vol 313 (3) ◽  
pp. 781-786 ◽  
Author(s):  
Jaffar NOUROOZ-ZADEH ◽  
Jarad TAJADDINI-SARMADI ◽  
K. L. Eddie LING ◽  
Simon P. WOLFF
Keyword(s):  
Total Lipid ◽  
Xylenol Orange ◽  
Low Density Lipoprotein ◽  
Lipid Hydroperoxide ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
Ldl Oxidation ◽  
Lipid Hydroperoxides ◽  
Very Low Density Lipoprotein ◽  
Low Density

High-density lipoprotein (HDL) has been proposed as the principal carrier of hydroperoxides in plasma, based upon data gathered with an HPLC-chemiluminescence technique. To test this hypothesis we have measured total lipid hydroperoxides in native plasma using the ferrous oxidation in Xylenol Orange (FOX) assay and then fractionated plasma into very-low-density lipoprotein, low-density lipoprotein (LDL) and HDL fractions. Hydroperoxides were found to accumulate principally (more than 65%) in LDL, as judged by hydroperoxide content per amount of protein or cholesterol, or expressed as a proportion of total hydroperoxide in plasma. Plasma was also incubated at 37 °C in the presence and absence of 2,2´-azo-bis-(2-amidinopropane) hydrochloride (AAPH), an azo-initiator of lipid peroxidation. The majority of hydroperoxides generated in plasma were recovered in the LDL fraction. Furthermore, when isolated lipoproteins were subject to oxidation initiated by AAPH, very-low-density lipoprotein and LDL showed the greatest propensity for hydroperoxide accumulation, whereas HDL seemed relatively resistant. Estimates for plasma and LDL peroxidation based upon techniques which measure total lipid hydroperoxides suggest that levels of hydroperoxides in plasma and LDL are far higher than that those estimates generated by ostensibly more selective techniques. Higher levels of hydroperoxides in LDL than those reported by HPLC-chemiluminescence also seem in greater accordance with other available data concerning LDL oxidation.

scholarly journals Estrogen Deficiency after Menopause Does Not Result in Male Very-Low-Density Lipoprotein Metabolism Phenotype

2010 ◽  
Vol 95 (7) ◽  
pp. 3377-3384 ◽  
Author(s):  
Faidon Magkos ◽  
Elisa Fabbrini ◽  
B. Selma Mohammed ◽  
Bruce W. Patterson ◽  
Samuel Klein ◽  
...  
Keyword(s):  
Postmenopausal Women ◽  
Low Density Lipoprotein ◽  
Plasma Lipid ◽  
Lipoprotein Metabolism ◽  
Density Lipoprotein ◽  
Premenopausal Women ◽  
Reproductive Hormones ◽  
Secretion Rate ◽  
Very Low Density Lipoprotein ◽  
Low Density

Context: Sex differences in lipid metabolism result in a less proatherogenic plasma lipid profile in premenopausal women than men. The mechanisms responsible for this are unclear but are thought to be related to differences in the sex hormone milieu in men and women. Objective: Our objective was to evaluate the effect of endogenous sex hormones on very-low-density lipoprotein (VLDL) triglyceride (TG) and apolipoprotein B-100 (apoB-100) metabolism. Experimental Design and Main Outcome Measures: We measured basal VLDL-TG and VLDL-apoB-100 concentrations and kinetics by using stable isotope-labeled tracers. Setting and Participants: Eight premenopausal women [age, 43 ± 8 yr; body mass index (BMI), 35 ± 4 kg/m2; mean ± sd], eight postmenopausal women (age, 55 ± 4 yr; BMI, 34 ± 4 kg/m2), and eight men (age, 41 ± 13 yr; BMI, 34 ± 4 kg/m2) were studied at Washington University School of Medicine, St. Louis, MO. Results: VLDL-TG secretion rate was approximately double (P < 0.05) in postmenopausal women and men compared with premenopausal women but not different in postmenopausal women and men. The secretion rate of VLDL-apoB-100 was not different in pre- and postmenopausal women but was greater (P < 0.05) in men than in women. Conclusions: Endogenous ovarian sex steroids are responsible for sexual dimorphism in VLDL-TG secretion, whereas VLDL-apoB-100 secretion is not regulated by female reproductive hormones.

scholarly journals Detection of new epitopes formed upon oxidation of low-density lipoprotein, lipoprotein (a) and very-low-density lipoprotein. Use of an antiserum against 4-hydroxynonenal-modified low-density lipoprotein

1990 ◽  
Vol 265 (2) ◽  
pp. 605-608 ◽  
Author(s):  
G Jürgens ◽  
A Ashy ◽  
H Esterbauer
Keyword(s):  
Unsaturated Fatty Acids ◽  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Oxidative Modification ◽  
Lipid Hydroperoxides ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Dependent Manner ◽  
Lipoprotein A

4-Hydroxynonenal (HNE) is a major aldehydic propagation product formed during peroxidation of unsaturated fatty acids. The aldehyde was used to modify freshly prepared human low-density lipoprotein (LDL). A polyclonal antiserum was raised in the rabbit and absorbed with freshly prepared LDL. The antiserum did not react with human LDL, but reacted with CuCl2-oxidized LDL and in a dose-dependent manner with LDL, modified with 1, 2 and 3 mM-HNE, in the double-diffusion analysis. LDL treated with 4 mM of hexanal or hepta-2,4-dienal or 4-hydroxyhexenal or malonaldehyde (4 or 20 mM) did not react with the antiserum. However, LDL modified with 4 mM-4-hydroxyoctenal showed a very weak reaction. Lipoprotein (a) and very-low-density lipoprotein were revealed for the first time to undergo oxidative modification initiated by CuCl2. This was evidenced by the generation of lipid hydroperoxides and thiobarbituric acid-reactive substances, as well as by a marked increase in the electrophoretic mobility. After oxidation these two lipoproteins also reacted positively with the antiserum against HNE-modified LDL.

scholarly journals Decomposition of lipid hydroperoxides enhances the uptake of low density lipoprotein by macrophages.

1999 ◽  
Vol 46 (1) ◽  
pp. 31-42 ◽  
Author(s):  
A V Babiy ◽  
J M Gebicki
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Lipid Hydroperoxide ◽  
Significant Proportion ◽  
Density Lipoprotein ◽  
Scavenger Receptors ◽  
Lipid Hydroperoxides ◽  
Strictly Anaerobic ◽  
Low Density ◽  
Apo B

This study examined the roles of low-density lipoprotein (LDL) lipid oxidation and peroxide breakdown in its conversion to a form rapidly taken up by mouse peritoneal macrophages. Oxidation of the LDL without decomposition of the hydroperoxide groups was performed by exposure to gamma radiation in air-saturated solutions. Virtually complete decomposition of the hydroperoxides was achieved by treatment of the irradiated LDL with Cu2+ under strictly anaerobic conditions. No uncontrolled LDL uptake by macrophages occurred when the lipoprotein contained less than 150 hydroperoxide groups per particle. More extensively oxidized LDL was taken up and degraded by mouse macrophages significantly faster than the native lipoprotein. The uptake was greatly enhanced by treatment of the oxidized LDL with Cu2+. A significant proportion of the LDL containing intact or copper-decomposed LDL hydroperoxide groups accumulated within the macrophages without further degradation. Treatment of the radiation-oxidized LDL with Cu2+ was accompanied by aggregation of the particles. Competition studies showed that the oxidized LDL was taken up by macrophages via both the LDL and the scavenger receptors, whereas the copper-treated lipoprotein entered the cells only by the scavenger pathway. Phagocytosis also played an important role in the metabolism of all forms of the extensively modified LDL. Our results suggest that minimally-oxidized LDL is not recognized by the macrophage scavenger receptors unless the lipid hydroperoxide groups are decomposed to products able to derivatize the apo B protein.

Lipoprotein Profiles in a Family with Two Mutants of Apolipoprotein E: Possible Association with Hypertriglyceridaemia but Not with Dysbetalipoproteinaemia

1994 ◽  
Vol 86 (3) ◽  
pp. 323-329 ◽  
Author(s):  
Shui-Ping Zhao ◽  
Arn M. J. M. Van den Maagdenberg ◽  
Ton F. F. P. Vroom ◽  
Ferdinand M. Van't Hooft ◽  
Jan A. Gevers Leuven ◽  
...  
Keyword(s):  
Apolipoprotein E ◽  
Plasma Cholesterol ◽  
Low Density Lipoprotein ◽  
Family Members ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
Molar Ratio ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Profiles

1. The plasma lipoprotein profiles of eight members of a Dutch pedigree spanning three generations where two rare apolipoprotein E mutants, APOE*3(Cys-112→Arg; Arg-251→Gly) and APOE*2(Val-236 →Glu), segregate were analysed to determine whether the APOE mutants were associated with dyslipidaemia. 2. The proband, a 51-year-old Caucasian male, was a carrier of APOE*3(Cys-112→Arg; Arg-251→Gly) and his spouse was a carrier of APOE*2(Val-236→Glu). Four other family members were carriers of one or both of the mutant APOE genes. 3. The plasma cholesterol and triacylglycerol concentrations were markedly elevated in the proband and were classified as type IV hyperlipoproteinaemia. The plasma triacylglycerol concentration was moderately increased in a sister, who was a carrier of APOE*3(Cys-112→Arg; Arg-251→Gly), and in the son, who was a compound heterozygote for both mutant APOE alleles. Normal plasma lipid levels were observed in all other family members. In the plasma samples of the proband and his family members β-very-low-density lipoprotein was not detectable and the molar ratio of very-low-density lipoprotein-cholesterol to very-low-density lipoprotein-triacylglycerol was less than 0.9. The concentration of intermediate-density lipoprotein was within normal limits. 4. None of the family members carrying APOE*3-(Cys-112→Arg; Arg-251→Gly) and/or APOE*2(Val-236→Glu) exhibited lipoprotein abnormalities characteristic of familial dysbetalipoproteinaemia, although three family members carrying APOE*3-(Cys-112→Arg; Arg-251→Gly) showed hypertriglyceridaemia.

Effects of lactic acid bacteria on low-density lipoprotein susceptibility to oxidation and aortic fatty lesion formation in hyperlipidemic hamsters

2015 ◽  
Vol 6 (3) ◽  
pp. 287-293 ◽  
Author(s):  
M. Ito ◽  
K. Oishi ◽  
Y. Yoshida ◽  
T. Okumura ◽  
T. Sato ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Low Density Lipoprotein ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
Streptococcus Thermophilus ◽  
Ldl Oxidation ◽  
Low Density ◽  
Lag Times

We investigated the effects of Streptococcus thermophilus YIT 2001, a strain of lactic acid bacteria, on the susceptibility of low-density lipoprotein (LDL) to oxidation and the formation of aortic fatty lesions in hyperlipidemic hamsters. S. thermophilus YIT 2001 had the highest in vitro antioxidative activity against LDL oxidation among the 79 strains of lactic acid bacteria and bifidobacteria tested, which was about twice that of S. thermophilus YIT 2084. The lag time of LDL oxidation in the YIT 2001 feeding group was significantly longer than in controls, but was unchanged in the YIT 2084 group. After the feeding of YIT 2001, lag times were prolonged and areas of aortic fatty lesions were dose-dependently attenuated, although there were no effects on plasma lipid levels. These results suggest that YIT 2001 has the potential to prevent the formation of aortic fatty lesions by inhibiting LDL oxidation.

Heme and lipid peroxides in hemoglobin-modified low-density lipoprotein mediate cell survival and adaptation to oxidative stress

Blood ◽  
2003 ◽  
Vol 102 (5) ◽  
pp. 1732-1739 ◽  
Author(s):  
Liana Asatryan ◽  
Ouliana Ziouzenkova ◽  
Roger Duncan ◽  
Alex Sevanian
Keyword(s):  
Oxidative Stress ◽  
Cell Survival ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipid Peroxides ◽  
Ldl Oxidation ◽  
Lipid Hydroperoxides ◽  
Low Density ◽  
Atherosclerotic Lesions ◽  
Ldl Particles

AbstractLow-density lipoprotein (LDL) oxidation mediated by a variety of catalysts in atherosclerotic lesions plays a crucial role in the genesis and evolution of atherosclerotic plaques. In this study we focused on oxidative properties of hemoglobin (Hb)–modified LDL because Hb is present in atherosclerotic lesions. Under low oxygen tensions Hb was previously found to modify apolipoprotein B100 with covalent binding of Hb fragments and formation of electronegative LDL particles (LDL–). Here we show that HbLDL is highly susceptible to oxidation, but is not cytotoxic to vascular cells, as was found for LDL– isolated from human plasma. HbLDL and LDL– have similar levels of oxidized lipid products and low uptake rates; however, the virtual absence of HbLDL-induced toxicity depends on a marked adaptive oxidative stress response. This was evidenced by a time- and dose-dependent induction of heme oxygenase (HO-1). Cell survival was significantly decreased in the presence of HO-1 inhibitor, tin protoporphyrin (SnPPIX). HO-1 induction by HbLDL increased resistance of cells to toxic doses of hemin or t-BuOOH. The high sensitivity to oxidation and HO-1 induction was largely dependent on lipid hydroperoxides and heme associated with HbLDL. Reduction of pre-existing lipid peroxides using ebselen delayed HbLDL kinetics and inhibited HO-1 induction. Moreover, heme inactivation or its degradation inhibited HO-1 induction and provided an additive inhibitory effect to ebselen. We conclude that Hb-catalyzed reactions may modulate vascular cell survival and oxidative stress adaptation due to the presence of peroxides and heme, thus providing a possible mechanism for the evolution of atherosclerotic and hemorrhagic lesions.

scholarly journals When and why a water-soluble antioxidant becomes pro-oxidant during copper-induced low-density lipoprotein oxidation: a study using uric acid

1999 ◽  
Vol 340 (1) ◽  
pp. 143-152 ◽  
Author(s):  
Marco BAGNATI ◽  
Cristina PERUGINI ◽  
Cristiana CAU ◽  
Roberta BORDONE ◽  
Emanuele ALBANO ◽  
...  
Keyword(s):  
Uric Acid ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipid Peroxides ◽  
Water Soluble ◽  
Ldl Oxidation ◽  
Lag Phase ◽  
Lipid Hydroperoxides ◽  
Low Density ◽  
Oxidant Effect

The inclusion of uric acid in the incubation medium during copper-induced low-density lipoprotein (LDL) oxidation exerted either an antioxidant or pro-oxidant effect. The pro-oxidant effect, as mirrored by an enhanced formation of conjugated dienes, lipid peroxides, thiobarbituric acid-reactive substances and increase in negative charge, occurred when uric acid was added late during the inhibitory or lag phase and during the subsequent extensive propagation phase of copper-stimulated LDL oxidation. The pro-oxidant effect of uric acid was specific for copper-induced LDL oxidation and required the presence of copper as either Cu(I) or Cu(II). In addition, it became much more evident when the copper to LDL molar ratio was below a threshold value of approx. 50. In native LDL, the shift between the antioxidant and the pro-oxidant activities was related to the availability of lipid hydroperoxides formed during the early phases of copper-promoted LDL oxidation. The artificial enrichment of isolated LDL with α-tocopherol delayed the onset of the pro-oxidant activity of uric acid and also decreased the rate of stimulated lipid peroxidation. However, previous depletion of α-tocopherol was not a prerequisite for unmasking the pro-oxidant activity of uric acid, since this became apparent even when α-tocopherol was still present in significant amounts (more than 50% of the original values) in LDL. These results suggest, irrespective of the levels of endogenous α-tocopherol, that uric acid may enhance LDL oxidation by reducing Cu(II) to Cu(I), thus making more Cu(I) available for subsequent radical decomposition of lipid peroxides and propagation reactions.

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