J Korean Acad Periodontol.  2003 Dec;33(4):585-597. 10.5051/jkape.2003.33.4.585.

Effects of Porphyromonas gingivalis extracts on the function of mouse calvarial primary osteoblastic cells

• Yun JH
• Choi SH
• Cho KS
• Chai JK
• Kim CK
• Kim CS

• KMID: 1999780
• DOI: http://doi.org/10.5051/jkape.2003.33.4.585

Abstract

Porphyromonas gingivalis has been implicated as an important periodontophathic bacterium in the etiology and progression of periodontal diseases. It has been reported that P.gingivalis may mediate periodontal destruction not only directly through its virulence factors, but also indirectly by inducing complex host mediated inflammatory reponses. The purpose of this study was to evaluate the effects of P.gingivalis on the bone formation and resorption by osteoblasts. For this purpose, after determining the concentration below which sonicated P.gingivalis extracts (SPEs) have no cytotoxicity on mouse calvarial primary osteoblastic (POB) cells, we investigated the effects of SPEs on the alkaline phosphatase (ALP) activity, matrix metalloproteinase (MMP) expression (MMP-2, -9, 13), and prostaglandin E2 (PGE2) release in POB cells by treament with SPEs below that concentration. The results were as follows; 1. SPEs showed no cytotoxic effect on POB cells up to a concentration of 1 microgram/ml. 2. The treatment with SPEs reduced ALP activity in a dose-dependent manner in POB cells. In addition, when we investigated the effect of SPEs (1 microgram/ml) on ALP activity for different exposure periods, statistically significant inhibition of ALP activity was shown at 2 days of exposure, and further significant inhibition occurred by extending the periods of exposure. 3. The treatment with SPEs stimulated the gene expression of MMP-9 in POB cells. 4. The pre-treatment with SPEs increased the amount of PGE2 released in POB cells. In summary, the present study shows that P.gingivalis could inhibit osteogenesis and stimulate bone resorption not only by reducing ALP activity but also by increasing MMP-9 mRNA expression in osteoblasts, possibly through an endogenous PGE2 pathway. In addition, our results suggest that if P.gingivalis affects osteoblasts in early differentiation stage, such effects by P.ingivalis could be irreversible.

Keyword

Porphyromonas gingivalis; osteoblast; alkaline phosphatase; matrix matalloproteinase; prostaglandin E2

MeSH Terms

Alkaline Phosphatase
Animals
Bone Resorption
Dinoprostone
Gene Expression
Mice*
Osteoblasts*
Osteogenesis
Periodontal Diseases
Porphyromonas gingivalis*
Porphyromonas*
RNA, Messenger
Virulence Factors
Alkaline Phosphatase
Dinoprostone
RNA, Messenger
Virulence Factors