title: Stimulatory effect of the sulfated polysaccharide ascophyllan on the respiratory burst in RAW264.7 macrophages.
abstract: In this study, we investigated the bioactivity of ascophyllan in terms of reactive oxygen species (ROS) generation. In RAW264.7 cells, we found that ascophyllan induced ROS generation in a concentration-dependent manner, but with bell-shaped profile. Immunoblot analysis demonstrated that ascophyllan promoted the translocation of cytosolic subunits (p67(phox) and p47(phox)) of NADPH oxidase to the plasma membrane. Among mitogen activated protein (MAP) kinase inhibitors tested, JNK inhibitor showed the most potent inhibitory effect on ascophyllan-induced ROS production. Consistently, significant level of phosphorylated JNK MAP kinase was detected in ascophyllan-treated RAW264.7 cells. Our findings suggest for the first time that ascophyllan can stimulate macrophages to produce ROS through the activations of NADPH oxidase and JNK MAP kinase.
authors.affiliation: Graduate School of Science and Technology, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, Nagasaki 852-8521, Japan.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Wang
authors.forename: Zedong
authors.initials: Z
authors.lastname: Jiang
authors.forename: Daekyung
authors.initials: D
authors.lastname: Kim
authors.forename: Mikinori
authors.initials: M
authors.lastname: Ueno
authors.forename: Takasi
authors.initials: T
authors.lastname: Okimura
authors.forename: Kenichi
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Oda
mesh_terms: D000818:Animals; D002460:Cell Line; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D048670:MAP Kinase Kinase 4 / Q000037:antagonists & inhibitors / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D019255:NADPH Oxidases / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011134:Polysaccharides / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D021381:Protein Transport / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016897:Respiratory Burst / Q000187:drug effects*
chemical_list: D010750:Phosphoproteins; D011134:Polysaccharides; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; C058519:ascophyllin; C079789:neutrophil cytosol factor 67K; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D048049:Extracellular Signal-Regulated MAP Kinases; D048670:MAP Kinase Kinase 4