title: Phospholipase D1 is required for lipopolysaccharide-induced tumor necrosis factor-α expression and production through S6K1/JNK/c-Jun pathway in Raw 264.7 cells.
abstract: The purpose of this study was to identify the role of phospholipase D1 (PLD1) in lipopolysaccharide (LPS)-induced tumor necrosis factor-α (TNF-α) expression and production. LPS-induced TNF-α expression and production were TLR4 (Toll-like receptor 4)/Myd88 dependent in Raw 264.7 cells. LPS enhanced PLD activation, which was attenuated by TLR4 inhibitor (Polymixin B) or knockdown of Myd88 with siRNA treatment. To investigate the role of PLD in LPS-induced TNF-α expression and production, we transfected PLD1 and PLD2 siRNAs to Raw 264.7 cells, respectively. Interestingly, only knockdown of PLD1 decreased TNF-α expression but not PLD2. Next, we investigated the S6K1-JNK-c-Jun signaling pathway in LPS-induced TNF-α expression mechanism. Knockdown of PLD1 also decreased phosphorylation of S6K1, JNK and c-Jun induced by LPS. Furthermore, we found that activated c-Jun63/73 bound to TNF-α promoter and turned on TNF-α expression. Taken together, our results demonstrate that PLD1 is activated by LPS/TLR4/Myd88 pathway and regulates TNF-α expression and production through S6K1/JNK/c-Jun in Raw 264.7 cells.
authors.affiliation: Biomedical Research Institute and Department of Biochemistry & Molecular Biology, College of Medicine, Hanyang University, Seoul 133-791, Republic of Korea.
authors.forename: Cheong-Hae
authors.initials: CH
authors.lastname: Oh
authors.affiliation: Biomedical Research Institute and Department of Biochemistry & Molecular Biology, College of Medicine, Hanyang University, Seoul 133-791, Republic of Korea.
authors.forename: Shin-Young
authors.initials: SY
authors.lastname: Park
authors.affiliation: Biomedical Research Institute and Department of Biochemistry & Molecular Biology, College of Medicine, Hanyang University, Seoul 133-791, Republic of Korea. Electronic address: jshan@hanyang.ac.kr.
authors.forename: Joong-Soo
authors.initials: JS
authors.lastname: Han
mesh_terms: D000818:Animals; D002460:Cell Line; D004789:Enzyme Activation / Q000187:drug effects; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D053594:Myeloid Differentiation Factor 88 / Q000378:metabolism; D010739:Phospholipase D / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism*; D038744:Ribosomal Protein S6 Kinases, 90-kDa / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D008070:Lipopolysaccharides; D053594:Myeloid Differentiation Factor 88; D016755:Proto-Oncogene Proteins c-jun; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D038744:Ribosomal Protein S6 Kinases, 90-kDa; C512964:Rps6ka1 protein, mouse; D048031:JNK Mitogen-Activated Protein Kinases; D010739:Phospholipase D; C106801:phospholipase D1
keywords: Lipopolysaccharide; Phospholipase D1; TLR4; TNF-α; c-Jun