Abstract
Introduction
Early immunopathogenic mechanisms behind pulp infection–induced furcal inflammation
have not been well understood. To address the immunopathology of the pulp infection–induced
furcal region of the periodontal ligament (PDL), we performed immunohistochemical
and quantitative gene expression analyses for toll-like receptors (TLRs) in the furcal
PDL of rat molars subjected to unsealed or sealed pulpotomy.
Methods
Furcal inflammation in rat molars was generated by making unsealed pulpotomies that
were exposed to the oral environment for 24 hours. Pulpotomized teeth sealed with
a temporary filling material and untreated normal teeth served as controls. Gene expression
was analyzed with laser capture real-time polymerase chain reaction for TLR-2, TLR-4,
and antigen presenting cell (APC)-related molecules (class II MHC, CD83, and CD86).
Immunohistochemistry for TLR-2 and TLR-4 was also performed.
Results
Messenger RNA expression levels of TLRs and the APC-related molecules in the furcal
periodontal ligament were significantly up-regulated in teeth with unsealed pulpotomy.
Immunohistochemistry for unsealed pulpotomized teeth revealed that TLRs-expressing
cells were predominantly distributed within the PDL beneath the furcal dentin.
Conclusions
These results suggested the involvement of innate immune mechanisms involving TLRs
and resulting activation of APCs in the early pathogenesis of pulp infection-induced
furcal inflammation.
Key Words
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Article info
Publication history
Published online: December 07, 2009
Footnotes
Supported by Grants-in-Aid for Scientific Research (No. 19209059 to H.S., No. 18791395 to M.K., No. 18390504 to M.S., No. 20390483 to T. O., and No. 21592411 to T. K.) from the Japan Society for the Promotion of Sciences.
Identification
Copyright
© 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
