title: Role of 12/15-lipoxygenase in the expression of MCP-1 in mouse macrophages.
abstract: Monocyte chemoattractant protein (MCP)-1 plays a key role in atherosclerosis and inflammation associated with visceral adiposity by inducing mononuclear cell migration. Evidence shows that mouse peritoneal macrophages (MPM) express a 12-lipoxygenase (12/15-LO) that has been clearly linked to accelerated atherosclerosis in mouse models and increased monocyte endothelial interactions in both rodent and human cells. However, the role of 12/15-LO products in regulating MCP-1 expression in macrophages has not been clarified. In this study, we tested the role of 12/15-LO products using MPM and the mouse macrophage cell line, J774A.1 cells. We found that 12(S)-hydroxyeicosatetraenoic acid [12(S)-HETE] increased MCP-1 mRNA and protein expression in J774A.1 cells and MPM. In contrast, 12(R)-HETE, a lipid not derived from 12/15-LO, did not affect MCP-1 expression. 15(S)-HETE also increased MCP-1 mRNA expression, but the effect was less compared with 12(S)-HETE. MCP-1 mRNA expression was upregulated in a macrophage cell line stably overexpressing 12/15-LO (Plox-86 cells) and in MPM isolated from a 12/15-LO transgenic mouse. In addition, the expression of MCP-1 was downregulated in MPM isolated from 12/15-LO knockout mice. 12(S)-HETE-induced MCP-1 mRNA expression was attenuated by specific inhibitors of protein kinase C (PKC) and p38 mitogen-activated protein kinase (p38). 12(S)-HETE also directly activated NADPH oxidase activity. Two NADPH oxidase inhibitors, apocynin and diphenyleneiodonium chloride, blocked 12(S)-HETE-induced MCP-1 mRNA. Apocynin attenuated 12(S)-HETE-induced MCP-1 protein secretion. These data show that 12(S)-HETE increases MCP-1 expression by inducing PKC, p38, and NADPH oxidase activity. These results suggest a potentially important mechanism linking 12/15-LO activation to MCP-1 expression that induces inflammatory cell infiltration.
authors.affiliation: Diabetes and Hormone Center, University of Virginia, Charlottesville, Virginia, USA.
authors.forename: Yeshao
authors.initials: Y
authors.lastname: Wen
authors.forename: Jiali
authors.initials: J
authors.lastname: Gu
authors.forename: George E
authors.initials: GE
authors.lastname: Vandenhoff
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Liu
authors.forename: Jerry L
authors.initials: JL
authors.lastname: Nadler
mesh_terms: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid / Q000378:metabolism; D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D001092:Arachidonate 12-Lipoxygenase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D001093:Arachidonate 15-Lipoxygenase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008301:Maleimides / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009281:Naphthalenes / Q000494:pharmacology; D009861:Onium Compounds / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: C475064:12-15-lipoxygenase; D000098:Acetophenones; C491768:Ccl2 protein, mouse; D018932:Chemokine CCL2; D006893:Hydroxyeicosatetraenoic Acids; D007093:Imidazoles; D007211:Indoles; D008301:Maleimides; D009281:Naphthalenes; D009861:Onium Compounds; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D012333:RNA, Messenger; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; C007517:diphenyleneiodonium; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; C056165:acetovanillone; D001092:Arachidonate 12-Lipoxygenase; D001093:Arachidonate 15-Lipoxygenase; D019255:NADPH Oxidases; D011493:Protein Kinase C; D048051:p38 Mitogen-Activated Protein Kinases; C058819:calphostin C; C070515:bisindolylmaleimide I; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole