Oxidized phosphatidylserine

Phosphatidylcholine (PC) is the main phospholipid in all mammalian cells (40-50%) and lipoproteins. As a consequence, most oxidized phospholipids detected in mammalian tissues contain a choline head group. In addition to oxidized PC (oxPC), oxidized phosphatidylserine (oxPS) and phosphatidy-lethanolamine (oxPE) have been detected. The latter was found in the retina, which is a tissue containing high amounts of phosphatidylethanolamine (Gugiu et ah, 2006), while OxPS was reported to be present on the surface of apoptotic cells (Kagan et ah, 2002 Matsura et ah, 2005). 

Borisenko, G G, Iverson, S L, Ahlberg, S, Kagan, V E, and Fadeel, B, Milk fat globule epidermal growth factor 8 (MFG-E8) binds to oxidized phosphatidylserine Implications for macrophage clearance of apoptotic cells. Cell Death Differ 11 (2004) 943-945. 

Greenberg, M E, Sun, M, Zhang, R, Febbraio, M, Silverstein, R, and Hazen, S L, Oxidized phosphatidylserine-CD36 interactions play an essential role in macrophage-dependent phagocytosis of apoptotic cells, J. Exp. Med. 203 (2006) 2613-2625. 

Matsura, T, Togawa, A, Kai, M, Nishida, T, Nakada, J, Ishibe, Y, Kojo, S, Yamamoto, Y, and Yamada, K, The presence of oxidized phosphatidylserine on Fas-mediated apoptotic cell surface, Biochim. Biophys. Acta - Molecular and Cell Biology of Lipids 1736 (2005) 181-188. 

Greenberg, M. E. et aL Oxidized phosphatidylserine-CD36 interactions play an essential role in macrophage-dependent phagocytosis of apoptotic ceUs. 203,... 

OxPL/apoB OxPL on apolipoprotein B-lOO OxPS oxidized phosphatidylserine... 

Minami M, Kume N, Shimaoka T, et al. Expression of scavenger receptor for phosphatidylserine and oxidized lipoprotein (SR-PSOX) in human atheroma. Ann N Y Acad Sci 2001 947 373-376. 

Fabisiak, J.P., Tyuiin, V.A., Tyurina, Y.Y., Sedlov, A., Lazo, J.S., and Kagan, V.E., 2000, Nitric oxide dissociates lipid oxidation from apoptosis and phosphatidylserine externalization during oxidative stress. Biochemistry 39 127-138. 

Ramprasad, M.P., Fischer, W., Witztum, J.L., Sambrano, G.R., Quehenberger, O., and Steinberg, D., 1995, The 94- to 97-kDa mouse macrophage membrane protein that recognizes oxidized low density lipoprotein and phosphatidylserine-rich liposomes is identical to macrosiaUn, the mouse homologue of human CD68, Proc. Natl. Acad. Sci. U.S.A. 92 9580-9584. 

Studies carried out with complete cells in vivo, cell membranes and other cell fractions point to the selective oxidation of phosphatidylserine (26) to a hydroperoxide (PS-OOH) on oxidative stress caused by toxic agents such as H2O2, t-BuOOH and cumyl hydroperoxide (27). Formation of PS-OOH is observed during apoptosis. These phenomena are important because of the cytotoxic effects of various peroxides used in commercial products coming into direct contact with the human body, as is the case of epidermal keratinocytes in contact with cosmetic formulations" ". The toxic effects of f-BuOOH are associated with vasoconstriction and damage to the vascular smooth muscles ". Global determination methods for primary lipid oxidation products are discussed in Section IV.B. 

Essentially three approaches can be used in the isolation of phosphatidylserine from a total lipid sample. These include thin-layer silica gel chromatography, aluminum oxide chromatography, and high-performance (high-pressure) liquid chromatography. The merits of these techniques are discussed as follows. 

Fabisiak, J.P., Kagan, V.E., Ritov, V.B., and Laso, J.S., 1997, Bcl-2 inhibits selective oxidation and externalization of phosphatidylserine during paraquat-induced apoptosis, Am. J. Physiol. (CellPhysiol.) 212 C675-C684. 

One of the earliest events of apoptosis is oxidative damage of the contacts between cytosceleton and membrane bilayer. Among cytosceletal proteins annexins is the family of proteins responsible for such contacts, while phosphatidylserine is involved from membrane bilayer site. After interruption of these contacts phosphatidylserine is disengaged and migrates from the inner (normal location) to the outer side of the bilayer (initiation of apoptosis). Thus, appearance of phosphatidylserine on the outer side of the membrane is a sign that apoptosis begins. Addition of fluorescent labeled annexin V (usually, FITS labeled annexin V) allows to mark the cells with phosphatidylserine located... 

SR-PSOX Scavenger receptor for phosphatidylserine and oxidized lipoprotein... 

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