Expression of toll-like receptor 2 and 4 in dental pulp.
Toll-like receptors (TLRs) are important factors in innate immune responses because they mediate signals from bacterial cell wall components during inflammatory reactions. However, the role of TLR in dental pulp, which is bounded by hard tissues, is little understood. The present study investigated the expression of TLR-2 and TLR-4 in experimentally inflamed pulp by quantitative real-time polymerase chain reaction and immunohistochemistry. Total RNA isolated from pulp tissue from 0 to 72 hours after bacterial dentinal infection. The TLR-2 messenger RNA (mRNA) level was 30-fold higher than the TLR-4 mRNA level at 9 hours. The TLR-2 mRNA level in pulp began to increase by 3 hours after bacterial infection, reaching a maximum level after 9 hours and gradually decreasing from 9 to 72 hours. Numerous TLR-2- and CD64-positive cells detected on macrophage and dendritic-like cells, TLR-4-positive cells detected a little in the pulp at 9 hours. These results suggest that TLR-2 may be mainly regulated during the early stage of pulp inflammation triggered by bacterial infection.
Mutoh
Noriko
N
Department of Maxillofacial Diagnostic Science, Division of Pathology, Kanagawa Dental College, Kanagawa, Japan.
Tani-Ishii
Nobuyuki
N
Tsukinoki
Keiichi
K
Chieda
Keiko
K
Watanabe
Kiyoko
K
D000818:Animals; D001424:Bacterial Infections / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D003782:Dental Pulp / Q000276:immunology* / Q000382:microbiology; D003789:Dental Pulp Exposure / Q000382:microbiology; D003804:Dentin / Q000382:microbiology; D004195:Disease Models, Animal; D005260:Female; D007113:Immunity, Innate / Q000276:immunology; D007150:Immunohistochemistry; D008264:Macrophages / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009804:Odontoblasts / Q000276:immunology; D011671:Pulpitis / Q000276:immunology / Q000382:microbiology; D012333:RNA, Messenger / Q000032:analysis; D017452:Receptors, IgG / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D051195:Toll-Like Receptor 2 / Q000032:analysis*; D051197:Toll-Like Receptor 4 / Q000032:analysis*
D012333:RNA, Messenger; D017452:Receptors, IgG; C493486:Tlr2 protein, mouse; C493487:Tlr4 protein, mouse; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4