title: Structural characteristics and in vitro macrophage activation of acetyl fucoidan from Cladosiphon okamuranus.
abstract: We investigated a structural characteristics of acetyl fucoidan (CAF) isolated from commercially cultured Cladosiphon okamuranus. The CAF-induced macrophage activation and its signaling pathways in murine macrophage cell line, RAW 264.7 were also investigated. From the results of methylation analysis, CAF consisted of alpha-1-->3 linked L: -fucosyl residues and substituted sulfate and acetyl groups at C-4 on the main chain. CAF induced production of nitric oxide (NO), tumor necrosis factor-alpha and interleukin-6 in RAW 264.7 cells. Sulfate and acetyl groups of CAF involved in CAF-induced NO production. Neutralizing anti-Toll-like receptor 4 (TLR4), anti-CD14 and anti-scavenger receptor class A (SRA) but not anti-complement receptor type 3 monoclonal antibodies decreased CAF-induced NO production. The results of immunoblot analysis indicated that CAF activated mitogen-activated protein kinases (MAPKs) such as p38 MAPK, extracellular signal-regulated kinase (ERK)1/2 and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK). SB203580 (p38 MAPK inhibitor) and SP600125 (SAPK/JNK inhibitor), but not U0126 (MAPK/ERK kinase 1/2 inhibitor) decreased CAF-induced NO production. The results suggested that CAF induced macrophage activation through membrane receptors TLR4, CD14 and SRA, and MAPK signaling pathways.
authors.affiliation: The United Graduate School of Agricultural Sciences, Kagoshima University, 1-21-24, Korimoto, Kagoshima 890-0065, Japan. k5939532@kadai.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Teruya
authors.forename: Hideki
authors.initials: H
authors.lastname: Tatemoto
authors.forename: Teruko
authors.initials: T
authors.lastname: Konishi
authors.forename: Masakuni
authors.initials: M
authors.lastname: Tako
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000818:Animals; D002236:Carbohydrate Conformation; D004731:Endotoxins; D015850:Interleukin-6 / Q000096:biosynthesis; D018950:Lipopolysaccharide Receptors / Q000378:metabolism; D008262:Macrophage Activation / Q000187:drug effects*; D016177:Macrophage-1 Antigen / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects / Q000201:enzymology; D008745:Methylation / Q000187:drug effects; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D000459:Phaeophyceae / Q000737:chemistry*; D010766:Phosphorylation / Q000187:drug effects; D011112:Polymyxin B / Q000494:pharmacology; D011134:Polysaccharides / Q000737:chemistry* / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051117:Scavenger Receptors, Class A / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D013997:Time Factors; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D004731:Endotoxins; D015850:Interleukin-6; D018950:Lipopolysaccharide Receptors; D016177:Macrophage-1 Antigen; D011134:Polysaccharides; D047428:Protein Kinase Inhibitors; D051117:Scavenger Receptors, Class A; D013431:Sulfates; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; C547517:acetyl fucoidan; D009569:Nitric Oxide; C007789:fucoidan; D020928:Mitogen-Activated Protein Kinases; D011112:Polymyxin B