‘Profile’ analysis of oxygenated sterols in plasma and serum

Brooks, C. J. W.; McKenna, Ruth; Cole, William R.; Maclachlan, John T.; Lawrie, T. D. V.

doi:10.1042/bst0110700

Cited by 61 publications

(19 citation statements)

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“…On the other hand, POPs were not discovered until 1983, when α and β-epoxydes of sitosterol were quantified in the plasma of a patient with Waldenström´s macroglobulinaemia (Brooks et al, 1983). Later, other oxysterols, mainly epoxysitosterols, were identified in phytosterolemic patients, but not in healthy volunteers (Plat et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Oxysterols: A world to explore

Otaegui-Arrazola

Menéndez-Carreño

Ansorena

et al. 2010

Food and Chemical Toxicology

202

185

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Oxysterols (oxidized derivatives of cholesterol an phytosterols) can be generated in the human organism through different oxidation processes, some requiring enzymes.Furthermore, oxysterols are also present in food due to lipid oxidation reactions caused by heating treatments, contact with oxygen, exposure to sunlight, etc., and they could be absorbed from the diet, at different rates depending on their side chain lenght.In the organism, oxysterols can follow different routes: secreted into the intestinal lumen, esterified and distributed by lipoproteins to different tissues or degraded, maily in the liver. Cholesterol oxidation products (COPs) have shown citotoxicity, apoptotic and pro-inflammatory effects and they have also been linked with chronic diseases including atherosclerotic and neurodegenerative processess. In the case of phytosterols oxidation products (POPs), the evidences for toxic effects need more research. Nevertheless, current knowledge suggest their relation to cytotoxic and proapoptotic effects, although at higher concentrations than COPs.Recently, new beneficial biological activities of oxysterols are being under research. Whereas COPs are associated with cholesterol homeostasis mediated by different mechanisms, the implication of POPs is not clear yet.Available literature on sources of oxysterols in the organism, metabolism, toxicity and potential benefitial effects of these compounds are reviewed in this paper.2

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Section: Introductionmentioning

confidence: 99%

Oxysterols: A world to explore

Otaegui-Arrazola

Menéndez-Carreño

Ansorena

et al. 2010

Food and Chemical Toxicology

202

185

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“…The lipids were subjected to mild saponification with alcoholic KOH (26), and then derived to CH and oxysterols trimethylsilyl ethers (TMSi) with N , O -Bis-TMS-trifluoroacetamide-trimethylchlorosilane (5:1, v/v; Tokyo Kasei Kogyo) as described detail in the literature (27).…”

Section: Samples Preparation For Lipid Analysis By Gc and Gc/msmentioning

confidence: 99%

Ethanolamine plasmalogens prevent the oxidation of cholesterol by reducing the oxidizability of cholesterol in phospholipid bilayers

Maeba

Ueta

2003

Journal of Lipid Research

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The aims of the present study are to establish an appropriate system for assessing the oxidizability of cholesterol (CH) in phospholipid (PL) bilayers, and to explore the effect of ethanolamine plasmalogens on the oxidizability of CH with the system, through comparing with those of choline plasmalogens, phosphatidylethanolamine, and antioxidant ␣ -tocopherol (Toc). Investigation of the effects of oxidants, vesicle lamellar forms, saturation level, and constituent ratio of PLs in vesicles on CH oxidation revealed the suitability of a system comprising unilamellar vesicles and the watersoluble radical initiator 2,2'-azobis (2-amidino-propane) dihydrochloride (AAPH). As CH oxidation in the system was found to follow the rate law for autoxidation without significant interference from oxidizable PLs, the oxidizability of CH in PL bilayers could be experimentally determined from the equation

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“…9 More specifically, a number of in vivo and in vitro studies have suggested a determinant role of oxysterols in inducing cytotoxicity in the vascular wall. 10 -14 In addition, increased levels of oxysterols were reported in hypercholesterolemic human plasma, [15][16][17] in the arterial wall from hypercholesterolemic rabbits, 18 and in atheromatous plaques from hypercholesterolemic patients. 19 The mode of cell death, ie, apoptosis versus necrosis, mediated by oxysterols in the cells of the vascular wall was only recently addressed.…”

mentioning

confidence: 99%

Characterization and Comparison of the Mode of Cell Death, Apoptosis Versus Necrosis, Induced by 7β-Hydroxycholesterol and 7-Ketocholesterol in the Cells of the Vascular Wall

Lizard

Monier

Cordelet

et al. 1999

ATVB

182

125

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Abstract-Oxidized low density lipoproteins (LDLs) play a central role in atherosclerosis, and their toxicity is due, at least in part, to the formation of oxysterols that have been shown to induce apoptosis in various cell types. As 7␤-hydroxycholesterol and 7-ketocholesterol are the major oxysterols found in oxidized LDLs, we have investigated and compared the mode of cell death, apoptosis versus necrosis, that they induce in the cells of the vascular wall, ie, endothelial cells, smooth muscle cells, and fibroblasts. To this end, human vascular endothelial cells from umbilical cord veins (HUVECs), human artery smooth muscle cells, A7R5 rat smooth muscle cells, MRC5 human fibroblasts, and human fibroblasts isolated from umbilical cord veins were taken at confluence and incubated for 48 hours with 7␤-hydroxycholesterol or 7-ketocholesterol (concentration range, 5 to 80 g/mL). In all cells, both 7␤-hydroxycholesterol and 7-ketocholesterol exhibited toxic effects characterized by a loss of cell adhesion and an increased permeability to propidium iodide. In oxysterol-treated endothelial and smooth muscle cells, typical features of apoptosis were revealed: condensed and/or fragmented nuclei were detected by fluorescence microscopy after staining with Hoechst 33342, oligonucleosomal DNA fragments were visualized in situ in the cell nuclei by the TdT-mediated dUTP-biotin nick-end labeling (TUNEL) method, and internucleosomal DNA fragmentation was found on agarose gel. In contrast, in oxysterol-treated fibroblasts, fragmented and/or condensed nuclei were never revealed, and no DNA fragmentation was observed either by the TUNEL method or by DNA analysis on agarose gel, indicating that these oxysterols induced necrosis in these cells but not apoptosis. In addition, acetylated Asp-Glu-Val-L-aspartic acid aldehyde (an inhibitor of Asp-Glu-Val-L-aspartic acid-sensitive caspases) prevented 7␤-hydroxycholesterol-and 7-ketocholesterol-induced cell death in HUVECs and smooth muscle cells but not in fibroblasts. Thus, 7␤-hydroxycholesterol and 7-ketocholesterol have dual cytotoxic effects on the cells of the vascular wall by their ability to induce apoptosis in endothelial and smooth muscle cells and necrosis in fibroblasts. (Arterioscler Thromb Vasc Biol.

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‘Profile’ analysis of oxygenated sterols in plasma and serum

Cited by 61 publications

References 0 publications

Oxysterols: A world to explore

Oxysterols: A world to explore

Ethanolamine plasmalogens prevent the oxidation of cholesterol by reducing the oxidizability of cholesterol in phospholipid bilayers

Characterization and Comparison of the Mode of Cell Death, Apoptosis Versus Necrosis, Induced by 7β-Hydroxycholesterol and 7-Ketocholesterol in the Cells of the Vascular Wall

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