title: Mitogen-activated protein kinases and phosphatidylinositol 3-kinase are involved in Prevotella intermedia-induced proinflammatory cytokines expression in human periodontal ligament cells.
abstract: Chronic periodontitis is an inflammatory disease affecting periodontal connective tissues and alveolar bone. Proinflammatory mediators induced by periodontal pathogens play vital roles in the initiation and progression of the disease. In this study, we examined whether Prevotella intermedia induces proinflammatory cytokines expression in human periodontal ligament cells (hPDLs). The mRNA expression and protein production were determined by reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbant assay (ELISA) respectively. P. intermedia treatment dose- and time-dependently increased IL-6, IL-8 and M-CSF, but not IL-1beta and TNF-alpha mRNA expression and protein secretion. Preincubation of hPDLs with extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 kinase and phosphatidylinositol 3-kinase (PI3K) inhibitors PD98059, SP600125, SB203580 and LY294002 resulted in significant reduction in P. intermedia-induced IL-6, IL-8 and M-CSF expression. Blocking the synthesis of prostaglandin E(2) (PGE(2)) by indomethacin also abolished the stimulatory effects of P. intermedia on cytokines expression. Our results indicate that P. intermedia induces proinflammatory cytokines through MAPKs and PI3K signaling pathways, and PGE(2) is involved in the P. intermedia-induced proinflammatory cytokines upregulation.
authors.affiliation: Department of Oral Biology, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China. jchsmg@fmmu.edu.cn
authors.forename: Su-Min
authors.initials: SM
authors.lastname: Guan
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: He
authors.forename: Jun-Zheng
authors.initials: JZ
authors.lastname: Wu
mesh_terms: D016866:Bacteroidaceae Infections / Q000276:immunology / Q000382:microbiology*; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis*; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010513:Periodontal Ligament / Q000276:immunology / Q000382:microbiology; D010518:Periodontitis / Q000276:immunology* / Q000382:microbiology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D018713:Prevotella intermedia; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D015854:Up-Regulation
chemical_list: D016207:Cytokines; D020928:Mitogen-Activated Protein Kinases; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors