• Kasekarn Kasevayuth D.D.S., Ph.D.
• Katarzyna Anna Podyma-Inoue M.Sc., Ph.D.
• Masaki Yanagishita M.D., Ph.D.

Objective The progression of chronic periodontitis depends partly on a direct invasion ability of
Porphyromonas gingivalis (P. gingivalis) against host cell supporting tissue and/or degradation of host
extracellular matrix by the inflammatory response elicited by the bacteria. The aim of this study was to
investigate the stimulation of host cells by lipopolysaccharides from P. gingivalis (Pg-LPS) using a
human gingival epithelial cell line, Ca9-22, as a model system for the latter mechanism.

Materials and methods In this study, we treated Ca9-22 cells with various concentrations (0, 0.1, 1
and 10 μg/mL) of Pg-LPS for 24h and extracted the mRNA. We investigated mRNA expression of
heparanase, a heparan sulfate degrading enzyme, as a marker of host cell inflammatory response,
Toll-like receptor (TLR) 2 and TLR4 expression at the mRNA level using reverse transcriptase
polymerase chain reaction (RT-PCR) analysis.

Results Ca9-22 cells grew as well as control even in the highest concentration of Pg-LPS.
The detection of heparanase, TLR2 and TLR4 mRNA transcripts showed no statistically significant
difference at all concentrations of Pg-LPS.

Conclusion There was no difference in expression levels of heparanase, TLR2 and TLR4 transcripts
at all concentrations of Pg-LPS tested. Protein level of heparanase should be investigated in further
experiment.

(CU Dent J. 2013;36:143-52)