Oxidized phospholipids

Megli and Sabatini [55] studied the phospholipid bilayers after lipoperoxidation. Phospholipids were oxidized, and the oxidized phospholipid species were separated by PLC and estimated by EPR. It was shown that the early stages of lipoperoxidation brought about disordering of the phospholipid bilayer interior rather than fluidity alterations and that prolonged oxidation may result in a loss of structural and chemical properties of the bilayer until the structure no longer holds. 

Historically, the target analytes in clinical mass spectrometric applications were small, volatile compounds that could be analyzed by GC-MS (see Chapter 4). With time, new chemical preparation techniques and derivatization schemes broadened the scope of these metabolites to include fatty acids, amino acids, intermediates of glucose oxidation, phospholipids, steroids, neurogenic amines, nucleic acids, etc. The molecular weights (molar masses) after derivatization were less than 1000 Da, a mass range easily within the limits of most conventional mass spectrometers. 

Boullier, A., GUlotte, K.L., Horkko, S., Green, S.R., Friedman, P., Dennis, E.A., Witzmm, J.L., Steinberg, D., and Quehenberger, O., 2000, The binding of oxidized low density lipoprotein to mouse CD36 in mediated in part by oxidized phospholipids that are associated with both the lipid and protein moieties of the hpoprotein, J. Biol. Chem. 275 9163-9169. 

Lee, H., Shi, W., Tontonoz, P., Wang, S., Subbanagouder, G., Hedrick, C.C., Hama, S., Borromeo, C., Evans, R.M., Berliner, J.A., and Nagy, L, 2000, Role for peroxisome prohferator-activated receptor [alpha] in oxidized phospholipid-induced synthesis of monocyte chematachc protein-1 and interleukin-8 by endothehal cehs, Circ. Res. 87 516-521. 

Subbanagounder, G., Leitinger, N., Schwenke, D.C., Wong, J.W., Lee, H.R., Watson, A.D., FauU, K.F., Fogelman, A.M., and Berliner, J.A., 2000, Determination of bioactivity of oxidized phospholipids Specific oxidized fatty acyl groups at the sn-2 position, Arterioscler. Thromb. Vase. Biol. 20 2248-2254. 

Phospholipid classes (see Section V.B.3) may be separated from one another by HPLC-UVD, measuring at 210 nm. Oxidized phospholipids, including hydroperoxide and hydroxy derivatives, can be detected by the same method measuring the signal at 234 nm. This was applied for assessment of the oxidation of phosphohpids in human erythrocite membranes catalyzed by soybean lipoxydase in the presence of various modifiers ... 

Oxidized phospholipid was produced by Irradiation of pure phospholipid dissolved In decane at 254 nm In the ambient atmosphere. 

All experiments using lipid membranes employed equal weight ratios of the phospholipid or oxidized phospholipid, and one of the steroids. For the trough experiments, 2 mg of phospholipid and 2 mg of steroid were dissolved In a total of 5 ml of solvent. Hexane was used as the solvent In most Instances, but sma1 1 quantities of chloroform were necessary as a secondary solvent for complete dissolution of the steroid dlol and trlol species. Approximately 0.1 ml of solution was slowly spread on the aqueous sub-phase (consisting of pure water or 0.1 M KC1) In the trough, and the solvent was allowed to completely evaporate before compression experiments were Initiated. Compression was performed slowly In all cases to allow surface equilibration and each sample solution was Investigated at least four times to ensure reproducibility. 

A second important series of experiments dealt with membrane chemistry composed of 5-cho1esten-3B-o1 (cholesterol) and partially oxidized phospholipid. The ultraviolet radiation Induced oxidation led to formation of hydroperoxide moieties at the unsaturated sites on some of the phospholipid acyl chains listed In Table II. The Cjg 2 chain was chosen as a reactive representative... 

Figure 2. Relationships between A) phospholipid-steroid ELM Arrhenius energy barrier and monolayer average molecular area measurements as a function of steroids a-g (see Table II), and B) BLM Arrhenius energy barrier and monolayer average molecular area measurements for oxidized phospholipid-cholesterol compositions.

Furnkranz A. and Leitinger N. (2004). Regulation of inflammatory responses by oxidized phospholipids structure-function relationships. Curr. Pharmaceut. Design 10 915-921. 

Leitinger N. (2003). Oxidized phospholipids as modulators of inflammation in atherosclerosis. Curr. Opin. Lipidol. 14 421 130. 

Leitinger N., Watson A. D., Faull K. F., Fogelman A. M., and Berliner J. A. (1997). Monocyte binding to endothelial cells induced by oxidized phospholipids present in minimally oxidized low density lipoprotein is inhibited by a platelet activating factor receptor antagonist. Adv. Exp. Med. Biol. 433 379-382. 

Yeh M, Leitinger N, de Martin R, Onai N, Matsushima K, Vora DK, Berliner JA, Reddy ST. Increased transcription of IL-8 in endothelial cells is differentially regulated by TNF-alpha and oxidized phospholipids. Arterioscler Thromb Vase Biol 2001 21 1585-1591. 

Delerive, P., Furman, C., Teissier, E., Fruchart, J., Duriez, P., and Staels, B. (2000). Oxidized phospholipids activate PPARalpha in a phospholipase A2-dependent manner. FEBS Lett. 471,... 

A total synthesis of the ester of 2-lysophosphatydylcholine HOT-PC (86) has been devised to facilitate identification of this oxidized phospholipid. ... 

Catala, A. (2009). Lipid peroxidation of membrane phospholipids generates hydroxy-aUcenals and oxidized phospholipids active in physiological and/or pathological conditions. Chemistry and Physics of Lipids, 157, 1—11. 

Horkko S, Bird DA, Miller E, et al. (1999) Monoclonal autoantibodies specific for oxidized phospholipids or oxidized phospholipid-protein adducts inhibit macrophage uptake of oxidized low-density lipoproteins. J Clin Invest 103 117-128... 

Nonas, S., Miller, I., Kawkitinarong, K., Chatchavalvanich, S., Gorshkova, I., Bochkov, V.N., Leitinger, N., Natarajan, V., Garcia, J.G., and Birukov, K.G. (2006). Oxidized phospholipids reduce vascular leak and inflammation in rat model of acute lung injury. Am J Respir Crit Care Med 173, 1130-8. 

Brame, C.J., Boutaud, O., Davies, S.S., Yang, T., Oates, J.A., Roden, D., and Roberts, L.J. Modification of proteins by isoketal-containing oxidized phospholipids. J Biol Chem 279 (2004) 13447-13451. 

Moumtzi, A., Trenker, M., Flicker, K., Zenzmaier, E., Saf, R., Hermetter, A. Import and fate of fluorescent analogs of oxidized phospholipids in vascular smooth muscle cells. J Lipid Res 48 (2007) 565-582. 

Abstract Since the discovery of oxidized phospholipids (OxPL) and their implication as modulators of inflammation in cardiovascular disease, roles for these lipid oxidation products have been suggested in many other disease settings. Lipid oxidation products accumulate in inflamed and oxidatively damaged tissue, where they are derived from oxidative modification of lipoproteins, but also from membranes of cells undergoing apoptosis. Thus, increased oxidative stress as well as decreased clearance of apoptotic cells has been implied to contribute to accumulation of OxPL in chronically inflamed tissues. 

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