title: Comparison of inhibitory effects of polyanions on nitric oxide production by macrophages stimulated with LPS.
abstract: In this paper, we investigated the inhibitory mechanism of the production of nitric oxide (NO) by polyanions and liposomes composed of phosphatidylserine (PS-liposomes) focusing on cytokine production and mitogen activated protein kinase (MAP kinase) activation. NO production by macrophages was inhibited by treatment with oxidized lipoprotein (OxLDL), maleylated bovine serum albumin (mBSA), and heparin. No inhibitory effect was exhibited by poly-cytidilic acid (PolyC). To clarify the mechanism of the inhibitory effect of polyanions on NO production, we evaluated the productions of transforming growth factor-beta (TGF-beta) and interleukin (IL)-10 which are known to be anti-inflammatory cytokines. TGF-beta was produced when macrophages were treated with OxLDL as was the case with PS-liposomes. No increase in TGF-beta production was observed for mBSA, heparin, and PolyC. On the other hand, significant production of IL-10 was observed using mBSA. Extracellular signal-regulated kinase (ERK), a member of the MAP kinase superfamily, was activated when macrophages were treated with OxLDL as well as PS-liposomes. In the case of mBSA, the activation of ERK and c-Jun N-terminal kinase (JNK) was observed. No activation of p38 MAP kinase was observed using any of the polyanions. Although heparin had an inhibitory effect on NO production by macrophages, no activation of MAP kinase or production of TGF-beta and IL-10 was observed. The inhibitory effect of these ligands on NO production may be regulated via different signaling pathways.
authors.affiliation: School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Otsuka
authors.forename: Seishi
authors.initials: S
authors.lastname: Tsuchiya
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Aramaki
mesh_terms: D000818:Animals; D015153:Blotting, Western; D016207:Cytokines / Q000378:metabolism; D004731:Endotoxins / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D066298:In Vitro Techniques; D016753:Interleukin-10 / Q000096:biosynthesis; D008024:Ligands; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008074:Lipoproteins / Q000378:metabolism; D008081:Liposomes; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis*; D009573:Nitrites / Q000378:metabolism; D010084:Oxidation-Reduction; D000071228:Polyelectrolytes; D011108:Polymers / Q000494:pharmacology*; D012710:Serum Albumin, Bovine / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000096:biosynthesis
chemical_list: D016207:Cytokines; D004731:Endotoxins; D016753:Interleukin-10; D008024:Ligands; D008070:Lipopolysaccharides; D008074:Lipoproteins; D008081:Liposomes; D020928:Mitogen-Activated Protein Kinases; D009569:Nitric Oxide; D009573:Nitrites; D000071228:Polyelectrolytes; D011108:Polymers; D012710:Serum Albumin, Bovine; D016212:Transforming Growth Factor beta; C044101:endotoxin, Escherichia coli