title: Up-regulation of NOD1 and NOD2 through TLR4 and TNF-alpha in LPS-treated murine macrophages.
abstract: NOD1 (Card4) and NOD2 (Card15) are thought to be responsible for cytoplasmic defense against bacterial entry. To gain further knowledge about how their expressions are regulated in murine macrophages, we investigated the expression of NOD1 and NOD2 mRNAs after stimulation with various endotoxins, lipopolysaccharide, lipoteichoic acid and peptidoglycan. In macrophage RAW264.7 cells, the first and second rises in NOD1 and NOD2 mRNAs were observed at 2 hr and at 8-12 hr after endotoxin treatment. Increases in NOD1 and NOD2 mRNAs at 2 hr in lipopolysaccharide-treated RAW264.7 cells were reduced with the use of NF-kappaB inhibitor, caffeic acid phenethyl ester. In RAW264.7 cells, lipopolysaccharide-induced increases in NOD1 and NOD2 mRNAs were inhibited with anti-TLR4 antibody, and partially reduced in peritoneal macrophages obtained from TLR4-deficient mice. Furthermore, NOD1 and NOD2 mRNA expressions in RAW264.7 cells were increased by the treatment with proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), or IL-6. In TNF-alpha deficient macrophages, the expression of NOD molecules was minimal at 12 hr, and the second rise in NOD mRNA seen in lipopolysaccharide-treated RAW264.7 cells was inhibited with anti-TNF-alpha, but not with anti-IL-1beta or anti-IL-6 antibody. These observations suggest that immediate response of NODs to endotoxins could result from NF-kappaB activation via TLR signaling, whereas the second rise in NOD mRNAs might have resulted from TNF-alpha production possibly through NF-kappaB, TLR, and/or NOD signalings.
authors.affiliation: Laboratory of Animal Breeding, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Kazuto
authors.initials: K
authors.lastname: Isuzugawa
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Murase
authors.forename: Misa
authors.initials: M
authors.lastname: Imai
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Masateru
authors.initials: M
authors.lastname: Iizuka
authors.forename: Shizuo
authors.initials: S
authors.lastname: Akira
authors.forename: George M
authors.initials: GM
authors.lastname: Bahr
authors.forename: Ei-Ichi
authors.initials: E
authors.lastname: Momotani
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hori
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ozaki
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Imakawa
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004306:Dose-Response Relationship, Immunologic; D008070:Lipopolysaccharides / Q000494:pharmacology; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000378:metabolism / Q000502:physiology; D053474:Nod1 Signaling Adaptor Protein / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D051197:Toll-Like Receptor 4 / Q000276:immunology / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000502:physiology*; D015854:Up-Regulation
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D008070:Lipopolysaccharides; D016328:NF-kappa B; D053474:Nod1 Signaling Adaptor Protein; C507873:Nod1 protein, mouse; D053473:Nod2 Signaling Adaptor Protein; C495945:Nod2 protein, mouse; D012333:RNA, Messenger; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha