Lysophosphatidylcholine Exhibits Selective Cytotoxicity, Accompanied by ROS Formation, in RAW 264.7 Macrophages
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Lysophosphatidylcholine (lysoPtdCho) is a component of oxidized low density lipoprotein, and is involved in the pathogenesis of atherosclerosis and inflammation. We studied the effects of lysoPtdCho on cytotoxicity, reactive oxygen species (ROS) production, activation of the extracellular signal-regulated kinase (ERK), mitogen-activated protein kinases and pro-inflammatory gene expression in RAW 264.7 murine macrophage cells. When cells were exposed to lysoPtdCho with various acyl chains in a culture medium containing 10% fetal bovine serum, only 1-linoleoyl (C18:2) lysoPtdCho showed a remarkable cytotoxicity, reaching the highest level at 24 h, and elicited ROS production, suggesting that oxidative stress might be implicated in the cytotoxicity of 1-linoleoyl (C18:2) lysoPtdCho. Presumably in support of this, antioxidants such as magnolol or trolox prevented 1-linoleoyl (C18:2) lysoPtdCho-induced cytotoxicity as well as ROS production, although only partially. Furthermore, the phosphorylation of ERK 1/2 and the expression of pro-inflammatory cytokines such as IL-1β, CCL2 and CCL5 were augmented by 1-linoleoyl (C18:2) lysoPtdCho. Meanwhile, there was no structural importance of the acyl chain for the cytotoxic action of lysoPtdCho during 10 min incubation in serum-free media. Taken together, it is suggested that in a serum-containing medium, 1-linoleoyl (C18:2) lysoPtdCho can cause a significant cytotoxicity through ROS production, probably accompanied by activation of ERK and induction of related inflammatory cytokines, in RAW 264.7 cells.
KeywordsDelayed cytotoxicity Lysophosphatidylcholine Macrophage Inflammation NADPH oxidase Atherosclerosis Cytokines Extracellular signal-regulated kinase Antioxidants
Reactive oxygen species
Fetal bovine serum
Extracellular signal-regulated kinase
Chemotactic cytokines ligand
This work was financially supported by a Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2007-531-C00067), Korea.
- 6.Ojala PJ, Hermansson M, Tolvanen M, Polvenen K, Hirvonen T, Impola U, Jauhiainen M, Somerharju P, Parkkinen J (2006) Identification of alpha-1 acid glycoprotein as a lysophospholipid binding protein: a complementary role to albumin in the scavenging of lysophosphatidylcholine. Biochemistry 45:14021–14031PubMedCrossRefGoogle Scholar
- 7.Kugiyama K, Sakamoto T, Misumi I, Sugiyama S, Ohgushi M, Ogawa H, Horiguchi M, Yasue H (1993) Transferable lipids in oxidized low-density lipoprotein stimulate plasminogen activator inhibitor-1 and inhibit tissue-type plasminogen activator release from endothelial cells. Circ Res 73:335–343PubMedGoogle Scholar
- 9.Silliman CC, Elzi DJ, Ambruso DR, Musters RJ, Hamiel C, Harbeck RJ, Bjornsen AJ, Wyman TH, Kelher M, England KM, McLaughlin-Malaxecheberria N, Barnett CC, Aiboshi J, Bannerjee A (2003) Lysophosphatidylcholines prime the NADPH oxidase and stimulate multiple neutrophil functions through changes in cytosolic calcium. J Leukoc Biol 73:511–524PubMedCrossRefGoogle Scholar
- 12.Yamakawa T, Eguchi S, Yamakawa Y, Motley ED, Numaguchi K, Utsunomiya H, Inagami T (1998) Lysophosphatidylcholine stimulates MAP kinase activity in rat vascular smooth muscle cells. Hypertension 31:258–263Google Scholar
- 15.Lauber K, Bohn E, Krober SM, Xiao YJ, Blumenthal SG, Lindemann RK, Marini P, Wiedig C, Zobywalski A, Baksh S, Xu Y, Autenrieth IB, Schulze-Osthoff K, Belka C, Stuhler G, Wesselborg S (2003) Apoptotic cells induce migration of phagocytes via caspase-3-mediated release of a lipid attraction signal. Cell 113:717–730PubMedCrossRefGoogle Scholar
- 25.Watanabe N, Zmijewski JW, Takabe W, Umezu-Goto M, Le Goffe C, Sekine A, Landar A, Watanabe A, Aoki J, Arai H, Kodama T, Murphy MP, Kalyanaraman R, Darley-Usmar VM, Noguchi N (2006) Activation of mitogen-activated protein kinases by lysophosphatidylcholine-induced mitochondrial reactive oxygen species generation in endothelial cells. Am J Pathol 168:1737–1748PubMedCrossRefGoogle Scholar
- 26.Komatsu D, Kato M, Nakayama J, Miyagawa S, Kamata T (2008) NADPH oxidase 1 plays a critical mediating role in oncogenic Ras-induced vascular endothelial growth factor expression. Oncogene 102:1–9Google Scholar