title: The novel neutrophil differentiation marker phosphatidylglucoside mediates neutrophil apoptosis.
abstract: A new type of glycolipid, phosphatidylglucoside (PtdGlc), was identified as a component of raft-like membrane domains of the human leukemia cell line HL-60. In this study, we show that PtdGlc forms functional domains that are different from those produced by lactosylceramide (LacCer)-enriched lipid rafts. These rafts initiate neutrophil apoptosis. Neutrophils are the only type of human peripheral blood leukocyte or monocyte-derived dendritic cell to express large amounts of PtdGlc on their cell surfaces. PtdGlc was not colocalized with LacCer. Anti-PtdGlc IgM DIM21 did not induce neutrophil chemotaxis or superoxide generation, whereas anti-LacCer IgM T5A7 induced these activities. DIM21, but not T5A7, significantly induced neutrophil apoptosis. DIM21-induced apoptosis was inhibited by specific inhibitors of cysteine-containing aspartate-specific proteases (caspases)-8, -9, and -3 but not by the Src family kinase inhibitor PP1, PIP(3) kinase inhibitor LY294002, NADPH oxidase inhibitor diphenyleneiodonium, superoxide dismutase, or catalase. PtdGlc was colocalized with Fas on the neutrophil plasma membrane. DIM21 and the agonist anti-Fas Ab DX2 induced the formation of large Fas-colocalized clusters of PtdGlc on the plasma membrane. Furthermore, the antagonistic anti-Fas Ab ZB4 significantly inhibited DIM21-induced neutrophil apoptosis. These results suggest that PtdGlc is specifically expressed on neutrophils and mediates apoptosis of these cells, and that the Fas-associated death signal may be involved in PtdGlc-mediated apoptosis.
authors: Institute for Environmental and Gender-Specific Medicine, Juntendo University School of Medicine, Urayasu-shi, 279-0021 Chiba, Japan.
authors: Katsunari
authors: K
authors: Kina
authors: Hiromi
authors: H
authors: Masuda
authors: Hitoshi
authors: H
authors: Nakayama
authors: Yasuko
authors: Y
authors: Nagatsuka
authors: Takuji
authors: T
authors: Nabetani
authors: Yoshio
authors: Y
authors: Hirabayashi
authors: Yasue
authors: Y
authors: Takahashi
authors: Kazunori
authors: K
authors: Shimada
authors: Hiroyuki
authors: H
authors: Daida
authors: Hideoki
authors: H
authors: Ogawa
authors: Kenji
authors: K
authors: Takamori
authors: Kazuhisa
authors: K
authors: Iwabuchi
mesh_terms: D000943:Antigens, Differentiation / Q000032:analysis / Q000378:metabolism; D017209:Apoptosis / Q000502:physiology*; D002465:Cell Movement; D002469:Cell Separation; D002851:Chromatography, High Pressure Liquid; D053222:Fas Ligand Protein / Q000378:metabolism; D005434:Flow Cytometry; D020404:Glycerophospholipids / Q000378:metabolism*; D018922:HL-60 Cells; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D013058:Mass Spectrometry; D021962:Membrane Microdomains / Q000737:chemistry / Q000378:metabolism*; D009504:Neutrophils / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000943:Antigens, Differentiation; D053222:Fas Ligand Protein; D020404:Glycerophospholipids; C429823:phosphatidylglucose