Oral bacterial extracts facilitate early osteogenic/dentinogenic differentiation in human dental pulp–derived cells
Received 5 February 2009; received in revised form 10 August 2009; accepted 14 August 2009.
Objectives
Bacterial metabolites demineralize dental hard tissues, and soluble factors lead to tertiary dentinogenesis in the area of the dentin-pulp complex. However, it is unclear whether the oral bacteria are directly involved in the differentiation of dental pulp cells. In this study, we evaluated the effect of oral bacterial extracts on cellular differentiation in human dental pulp–derived cells (hDPC).
Study design
The hDPC were obtained from third molar teeth, and the cells were subcultured. The sonicated extracts were obtained from Porphyromonas gingivalis (gram-negative) and Streptococcus mutans (gram-positive). The effect of bacterial extracts on cellular growth and differentiation in hDPC were tested.
Results
Alkaline phosphatase activity and bone sialoprotein (BSP) gene expression were increased in hDPC exposed to low concentrations of both sonicated extracts, whereas the activity was decreased upon exposure to high concentrations of sonicated extracts from P. gingivalis.
Conclusion
This is the first evidence that oral bacteria have a positive effect on cellular differentiation in hPDC.
aResearch Associate, Division of Stem Sell Engineering, Institute of Medical Science, University of Tokyo, Tokyo, Japan
bTechnical Assistant, Division of Stem Sell Engineering, Institute of Medical Science, University of Tokyo, Tokyo, Japan
cAssistant Professor, Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan
dTechnical Assistant, Department of Microbiology, Tokyo Dental College, Chiba, Japan
eResearch Associate, Division of Stem Sell Engineering, Institute of Medical Science, University of Tokyo, Tokyo, Japan
fStudent, Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan
gAssociate Professor, Department of Oral and Maxillofacial Surgery, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan
hProfessor, Department of Microbiology, Tokyo Dental College, Chiba, Japan
iAssistant Professor, Division of Stem Sell Engineering, Institute of Medical Science, University of Tokyo, and Department of Anatomy, Nihon University School of Dentistry, Tokyo, Japan
Reprint requests: Masaki J. Honda, DDS, PhD, Assistant Professor, Department of Anatomy, School of Dentistry, Nihon University, 1-8-13, Kanda-surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
Supported by Grant-in-Aid for Scientific Research (B) (19390511 and 21390528) and Exploratory Research (20659305).
ABSTRACT