title: Syntheses of prostaglandin E2 and E-cadherin and gene expression of beta-defensin-2 by human gingival epithelial cells in response to Actinobacillus actinomycetemcomitans.
abstract: The interaction between epithelial cells and microorganisms is the most important step in bacterial infections. Actinobacillus actinomycetemcomitans was suggested to play a significant role in the initiation of periodontitis because of its bacteriological characteristics. Prostaglandins (PG) mediate the inflammatory response. Human beta-defensin-2 (hBD-2) is an antimicrobial peptide and contributes to innate immunity. E-cadherin is responsible for an epithelial intercellular junction. In this study, we investigated the syntheses of PGE2 and E-cadherin and the expression of hBD-2 in human gingival epithelial cells (HGEC) following exposure to A. actinomycetemcomitans. The levels of PGE2 and cyclooxygenase-2, which are responsible for an increase in PGE2, were increased depending on bacteria exposure time. hBD-2 mRNA was induced by A. actinomycetemcomitans, while HGEC exposed to A. actinomycetemcomitans showed a decrease in E-cadherin levels. Etodolac, a selective cyclooxygenase-2 inhibitor reinforced the increase in hBD-2 mRNA levels by A. actinomycetemcomitans. Furthermore, the etodolac suppressed the decrease in E-cadherin levels. Thus, endogenous PGE2 is involved in the hBD-2 and E-cadherin responses of HGEC to A. actinomycetemcomitans. These findings suggest that the inflammatory and antimicrobial response of gingival epithelial cells to A. actinomycetemcomitans is involved in the initiation of periodontal inflammation. A. actinomycetemcomitans may destroy the mechanical epithelial barrier by destroying E-cadherin.
authors.affiliation: Department of Periodontal Medicine, Division of Frontier Medical Science, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Noguchi
authors.forename: Hideki
authors.initials: H
authors.lastname: Shiba
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Komatsuzawa
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Mizuno
authors.forename: Yuushi
authors.initials: Y
authors.lastname: Uchida
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Ouhara
authors.forename: Ryuji
authors.initials: R
authors.lastname: Asakawa
authors.forename: Seiji
authors.initials: S
authors.lastname: Kudo
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kawaguchi
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Sugai
authors.forename: Hidemi
authors.initials: H
authors.lastname: Kurihara
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000502:physiology*; D015820:Cadherins / Q000096:biosynthesis*; D002478:Cells, Cultured; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000096:biosynthesis*; D004847:Epithelial Cells / Q000382:microbiology / Q000473:pathology; D005786:Gene Expression Regulation / Q000276:immunology; D005881:Gingiva / Q000382:microbiology* / Q000473:pathology; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D008565:Membrane Proteins; D010518:Periodontitis; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D023083:beta-Defensins / Q000235:genetics*
chemical_list: D015820:Cadherins; C106641:DEFB4A protein, human; D007527:Isoenzymes; D008565:Membrane Proteins; D012333:RNA, Messenger; D023083:beta-Defensins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone