title: A glycoprotein from Porphyra yezoensis produces anti-inflammatory effects in liposaccharide-stimulated macrophages via the TLR4 signaling pathway.
abstract: The purpose of this study was to investigate the antioxidant and anti-inflammatory effects of a glycoprotein isolated from the alga Porphyra yezoensis in LPS-stimulated RAW 264.7 mouse macrophages. First, we extracted a novel material with antioxidant activity from P. yezoensis, confirmed by SDS-PAGE to be a glycoprotein, which we named P. yezoensis glycoprotein (PGP). PGP inhibited the production of NO and ROS and expression of iNOS, COX-2, TNF-α and IL-1β, which are involved in the pathogenesis of many inflammation-associated human diseases, including septic shock, hemorrhagic shock and rheumatoid arthritis. Next, we determined the mechanisms behind the antioxidant and anti-inflammatory activities of PGP. We focused on the Toll-like receptor 4 (TLR4) signaling pathway because it is well-known to induce the pro-inflammatory proteins that trigger MAPK and NF-κB activation in lipopolysaccharide (LPS)-induced oxidative events. PGP treatment reduced the formation of the TLR4-IRAK4 and TLR4-TRIF binding complexes in response to LPS. Moreover, it inhibited LPS-induced activation and nuclear translocation of NF-κB by abrogating IκB phosphorylation. PGP also suppressed the phosphorylation of ERK1/2 and JNK in a dose-dependent manner. These results suggest that PGP exerts its anti-inflammatory effects by modulating TLR4 signaling and thus inhibiting the activation of NF-κB and MAP kinases.
authors.affiliation: Faculty of Food Science and Biotechnology, Pukyong National University, Nam-gu, Busan, Republic of Korea.
authors.forename: Eun-Soon
authors.initials: ES
authors.lastname: Shin
authors.forename: Hye-Jung
authors.initials: HJ
authors.lastname: Hwang
authors.forename: In-Hye
authors.initials: IH
authors.lastname: Kim
authors.forename: Taek-Jeong
authors.initials: TJ
authors.lastname: Nam
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D015153:Blotting, Western; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000494:pharmacology*; D047468:Immunoprecipitation; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism*; D051379:Mice; D044664:Porphyra / Q000737:chemistry*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D051197:Toll-Like Receptor 4 / Q000378:metabolism*
chemical_list: D000893:Anti-Inflammatory Agents; D006023:Glycoproteins; D008070:Lipopolysaccharides; D017382:Reactive Oxygen Species; D051197:Toll-Like Receptor 4