Expression of beta-defensin-2 in human gingival epithelial cells in response to challenge with Porphyromonas gingivalis in vitro.
OBJECTIVE
Human beta-defensin-2 (hBD-2) is an antimicrobial peptide that is produced by epithelial cells after stimulation with microorganisms and inflammatory mediators. Compared with gram-positive bacteria, gram-negative bacteria, which are typically detected in the periodontal pockets in periodontitis, elicit a stronger antibacterial peptide response of hBD-2 by epithelial cells. The purpose of this study was to investigate the expression of hBD-2 and relationships between it and inflammatory mediators in human gingival epithelial cells (HGEC) in response to challenge with Porphyromonas gingivalis in vitro.


METHODS
mRNA expression of hBD-2 in HGEC stimulated with or without P. gingivalis was assessed using a semiquantitative reverse transcription-polymerase chain reaction. Primary cultured HGEC were activated by live P. gingivalis, and inflammatory cytokine production was examined using an enzyme-linked immunosorbent assay.


RESULTS
The level of hBD-2 mRNA in HGEC treated with P. gingivalis increased with exposure time. After 48 h, the mRNA in P. gingivalis was significantly increased compared with that in control HGEC. The interleukin-8 production rate was much greater in stimulated HGEC than in the control HGEC, almost always showing a significant difference after 3 h. The production of interleukin-1beta was not increased as much as that of interleukin-8.


CONCLUSIONS
These findings suggest that the expression of hBD-2 in HGEC is P. gingivalis-dependently induced and is likely to be connected with the initial stage of the inflammatory response.
Taguchi
Y
Y
Graduate School of Dentistry (Periodontology), Osaka Dental University, Osaka, Japan. taguchi@stu.osaka-dent.ac.jp
Imai
H
H
D002478:Cells, Cultured; D004846:Epithelial Attachment / Q000378:metabolism / Q000382:microbiology*; D005881:Gingiva / Q000166:cytology / Q000378:metabolism / Q000382:microbiology*; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D016209:Interleukin-8 / Q000096:biosynthesis; D015603:Keratinocytes / Q000378:metabolism / Q000382:microbiology; D010514:Periodontal Pocket / Q000378:metabolism* / Q000382:microbiology*; D016966:Porphyromonas gingivalis; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation; D023083:beta-Defensins / Q000096:biosynthesis*
C106641:DEFB4A protein, human; D007375:Interleukin-1; D016209:Interleukin-8; D012333:RNA, Messenger; D023083:beta-Defensins