title: The presence of oxidized phosphatidylserine on Fas-mediated apoptotic cell surface.
abstract: A growing body of evidence suggests that phosphatidylserine (PS) oxidation is linked with its transmembrane migration from the inner to the outer leaflet of the plasma membrane during apoptosis. However, there is no direct evidence for the presence of oxidized PS (PSox) on the surface of cells undergoing apoptosis. The present study was performed to detect PSox externalized to the cell surface after Fas engagement in Jurkat cells. Treatment of Jurkat cells with anti-Fas antibody induced caspase-3 activation, chromatin condensation, PS externalization, generation of reactive oxygen species, intracellular glutathione depletion, disruption of mitochondrial transmembrane potential and release of cytochrome c from mitochondria. To determine externalized PS and phosphatidylethanolamine (PE), Jurkat cells were treated with anti-Fas antibody and then labeled with membrane-impermeable fluorescamine, a probe for visualizing lipids that contain primary amino groups. Their total lipids were extracted and subjected to two-dimensional high-performance thin-layer chromatography (HPTLC). The HPTLC plate was sprayed with N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride to detect phospholipid hydroperoxides. PSox was present in small amounts within but not on the surface of normal cells. Treatment with anti-Fas antibody increased PSox within the cells and caused PSox to appear on the cell surface. In contrast, PE on the surface of Fas-ligated cells was not oxidized. Thus, the present study demonstrates for the first time the presence of PSox both within and on the surface of apoptotic cells.
authors.affiliation: Division of Medical Biochemistry, Department of Pathophysiological and Therapeutic Science, Tottori University Faculty of Medicine, 86 Nishi-cho, Yonago 683-8503, Japan. tmatsura@grape.med.tottori-u.ac.jp
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Matsura
authors.forename: Aki
authors.initials: A
authors.lastname: Togawa
authors.forename: Masachika
authors.initials: M
authors.lastname: Kai
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nishida
authors.forename: Junya
authors.initials: J
authors.lastname: Nakada
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ishibe
authors.forename: Shosuke
authors.initials: S
authors.lastname: Kojo
authors.forename: Yorihiro
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamada
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D045304:Cytochromes c / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010718:Phosphatidylserines / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000276:immunology / Q000502:physiology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D019014:fas Receptor
chemical_list: D000911:Antibodies, Monoclonal; C491901:FAS protein, human; D010718:Phosphatidylserines; D017382:Reactive Oxygen Species; D018124:Receptors, Tumor Necrosis Factor; D019014:fas Receptor; D045304:Cytochromes c; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D005978:Glutathione