Effect of Actinobacillus actinomycetemcomitans protease on the proliferation of gingival epithelial cells.
OBJECTIVE
Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) has been implicated as an important pathogen in periodontal disease. The aim of this report is to examine the effect of in vitro application of A. actinomycetemcomitans protease on the cell growth, DNA synthesis, and fibronectin level of human gingival epithelial cells.


METHODS
A. actinomycetemcomitans protease was isolated from the culture supernatant of A. actinomycetemcomitans. Human gingival epithelial cells were incubated in the presence or absence of A. actinomycetemcomitans protease (0.01, 0.1, or I U) for 48 h. The proliferation of cells were tested with the MTT assay and the BrdU assay. The fibronectin level was examined by flow cytometric analysis.


RESULTS
The cell growth rate, DNA synthesis rate, and fibronectin level of the gingival epithelial cells that had been incubated with protease, were lower than the respective values in the untreated gingival epithelial cells; as the dose of A. actinomycetemcomitans protease increased, the cell growth rate, DNA synthesis rate, and fibronectin level of the gingival epithelial cells decreased. A. actinomycetemcomitans protease may inhibit the proliferation of human gingival epithelial cells.


CONCLUSIONS
This protease may play a key role as a major virulence factor in the development of periodontal disease.
Wang
P L
PL
Department of Pharmacology, Osaka Dental University, Hirakata, Japan. wang@cc.osaka-dent.ac.jp
Azuma
Y
Y
Shinohara
M
M
Ohura
K
K
D016976:Aggregatibacter actinomycetemcomitans / Q000201:enzymology* / Q000472:pathogenicity; D001426:Bacterial Proteins; D001973:Bromodeoxyuridine; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003124:Colorimetry; D004396:Coloring Agents; D003546:Cysteine Endopeptidases; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects; D005353:Fibronectins / Q000032:analysis / Q000187:drug effects; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D005881:Gingiva / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D013223:Statistics as Topic; D013778:Tetrazolium Salts; D013844:Thiazoles; D014357:Trypsin / Q000008:administration & dosage / Q000494:pharmacology*; D014774:Virulence
D001426:Bacterial Proteins; D004396:Coloring Agents; D005353:Fibronectins; D005456:Fluorescent Dyes; D013778:Tetrazolium Salts; D013844:Thiazoles; D004247:DNA; D014357:Trypsin; D003546:Cysteine Endopeptidases; C078912:prtT protein, Porphyromonas gingivalis; C022616:thiazolyl blue; D001973:Bromodeoxyuridine; D016650:Fluorescein-5-isothiocyanate