title: Tumor necrosis factor-α and interleukin-1β expression pathway induced by Streptococcus mutans in macrophage cell line RAW 264.7.
abstract: Streptococcus mutans, a major etiological agent of dental caries, frequently causes systemic disease, such as subacute bacterial endocarditis, if it enters the bloodstream. In this study, the production pathways of the proinflammatory cytokines, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), induced by S. mutans in mouse macrophage were examined using a quantitative real-time polymerase chain reaction and an enzyme-linked immunosorbent assay. The S. mutans stimulated the expression of TNF-α and IL-1β mRNA at a multiplicity of infection of 1 : 100, which increased at 2 and 4 h, respectively, to 24 h. It also induced the production of high levels of the TNF-α and IL-1β proteins, which increased at 2 h and reached a peak at 4 and 24 h, respectively. Nuclear factor-κB (NF-κB) was activated and reached a maximum level 30 min after the S. mutans treatment. The expression of TNF-α and IL-1β mRNA and protein was suppressed by the treatment with pyrrolidine dithiocarbamate, an NF-κB inhibitor. The S. mutans-induced TNF-α expression was suppressed by the presence of SB203580, a p38 mitogen-activated protein (MAP) kinase inhibitor, or SP600125, a Jun N-terminal kinase (JNK) MAP kinase inhibitor. On the other hand, IL-1β expression was inhibited by extracellular signal-regulated kinase (ERK)/p38/JNK MAP kinase inhibitor pretreatment. In addition, TNF-α production was suppressed more in the Toll-like receptor 2(-/-) (TLR2(-/-)) macrophages than in the TLR4(-/-) macrophages, whereas IL-1β production was suppressed more in the TLR4(-/-) macrophages than in the TLR2(-/-) macrophages. These results show that S. mutans stimulates the production of TNF-α and IL-1β in the mouse macrophage cell line, RAW 264.7, by activating ERK/p38/JNK, and NF-κB through TLR2 and TLR4, respectively.
authors.affiliation: Department of Oral Microbiology, School of Dentistry, Pusan National University, Yangsan, South Korea.
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: K D
authors.initials: KD
authors.lastname: Kim
authors.forename: H S
authors.initials: HS
authors.lastname: Na
authors.forename: S Y
authors.initials: SY
authors.lastname: Jeong
authors.forename: H R
authors.initials: HR
authors.lastname: Park
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: J
authors.initials: J
authors.lastname: Chung
mesh_terms: D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D002460:Cell Line; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors; D007093:Imidazoles / Q000494:pharmacology; D018836:Inflammation Mediators / Q000276:immunology; D053583:Interleukin-1beta / Q000037:antagonists & inhibitors / Q000276:immunology*; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D008264:Macrophages / Q000201:enzymology / Q000276:immunology / Q000382:microbiology*; D017737:Macrophages, Peritoneal / Q000201:enzymology / Q000276:immunology / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D052002:NF-kappa B p50 Subunit / Q000037:antagonists & inhibitors / Q000276:immunology; D011725:Pyridines / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology; D060888:Real-Time Polymerase Chain Reaction; D013295:Streptococcus mutans / Q000276:immunology*; D013859:Thiocarbamates / Q000494:pharmacology; D013997:Time Factors; D051195:Toll-Like Receptor 2 / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000276:immunology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors
chemical_list: D000873:Anthracenes; D000975:Antioxidants; D004791:Enzyme Inhibitors; D007093:Imidazoles; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D052002:NF-kappa B p50 Subunit; D011725:Pyridines; D011759:Pyrrolidines; D013859:Thiocarbamates; C493486:Tlr2 protein, mouse; C493487:Tlr4 protein, mouse; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; C073701:Nfkb1 protein, mouse; C432165:pyrazolanthrone; C020972:pyrrolidine dithiocarbamic acid; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580