title: Toll like receptor 5 ligand induces monocyte chemoattractant protein-1 in mouse osteoblastic cells.
abstract: Flagellin, the ligand of Toll like receptor 5, is the major subunit of bacterial flagella. Flagellin stimulates various cells to release chemokines. Monocyte chemoattractant protein-1 (MCP-1) is a member of the CC chemokine family that is involved in monocyte infiltration in inflammatory diseases. It has been reported that serum MCP-1 levels increase proportionally with the severity of periodontal disease. Inflammatory mediators induce MCP-1 production in various cells, including osteoblasts. However, it remains unclear whether MCP-1 is released from osteoblasts in response to flagellin. In the present study, we investigated the effects of flagellin on the expression of MCP-1 in the mouse osteoblastic cell line, MC3T3-E1 (E1) cells. Flagellin markedly increased MCP-1 mRNA level in a dose-dependent manner. The effect of flagellin on MCP-1 mRNA expression in E1 cells was transient, with a peak at 1 h. Concomitant with MCP-1 mRNA expression, MCP-1 protein levels were clearly elevated at 3 h after flagellin exposure. In addition, we revealed that JNK and MEK-ERK1/2 are involved in flagellin-induced MCP-1 expression in E1 cells. These results indicated that bacterial flagellin may play an important role in the progression of periodontitis. Results of further studies will provide more clues to the prevention of periodontal diseases.
authors.affiliation: Comprehensive Conservative Dentistry, Hokkaido University Hospital, Kita 14 Nishi 5, Kita-ku, Sapporo 060-8648, Japan.
authors.forename: Kimiya
authors.initials: K
authors.lastname: Nakamura
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Deyama
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Suzuki
authors.forename: Manabu
authors.initials: M
authors.lastname: Morita
mesh_terms: D000818:Animals; D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism*; D005408:Flagellin / Q000494:pharmacology*; D051379:Mice; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism*; D010510:Periodontal Diseases / Q000188:drug therapy; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction; D051198:Toll-Like Receptor 5 / Q000378:metabolism
chemical_list: C491768:Ccl2 protein, mouse; D018932:Chemokine CCL2; D012333:RNA, Messenger; D051198:Toll-Like Receptor 5; D005408:Flagellin