[Effects of intracellular Porphyromonas gingivalis on proliferation and osteogenic differentiation of human periodontal ligament cells in vitro].
OBJECTIVE
To investigate the ability of Porphyromonas gingivalis to invade human periodontal ligament cells (hPDLCs) and the effect of intracellular P. gingivalis on cell proliferation and osteogenic differentiation in vitro.


METHODS
The invasion ability of P. gingivalis in hPDLCs was tested using an antibiotic protection assay at the multiplicity of infection (MOI) of 10 and 100. The proliferation of the infected cells was detected using a CFDA-SE kit, and the cells were sorted by fluorescence-activated cell sorting (FACS) followed by alizarin red staining for detecting mineralization nodules deposition; real-time PCR was used to examine the expression of Runx2 mRNA in the cells.


RESULTS
P. gingivalis actively invaded hPDLCs, and the internalized P. gingivalis was able to resist antibiotic treatment. The cells infected by P. gingivalis exhibited no significant suppression of cell proliferation, but showed significantly lowered capacity for osteogenic differentiation, down-regulated RUNX2 mRNA expression, and reduced mineral deposition.


CONCLUSIONS
Intracellular P. gingivalis does not significantly affect the proliferation of hPDLCs but inhibits osteogenic differentiation of the cells.
Department of Stomatology, Nanfang Hospital1, College of Stomatology2, Southern Medical University, Guangzhou 510515, China. E-mail: yobecute@126.com.
Yong-Mei
YM
Tan
Jin
J
Hou
Xiao-Jun
XJ
Yang
Yue-E
YE
Liang
Yan
Y
Zhang
Wang-Hong
WH
Zhao
D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D005434:Flow Cytometry; D005452:Fluoresceins; D006801:Humans; D010012:Osteogenesis; D010513:Periodontal Ligament / Q000166:cytology* / Q000382:microbiology; D016966:Porphyromonas gingivalis; D012333:RNA, Messenger; D060888:Real-Time Polymerase Chain Reaction; D013388:Succinimides
C087165:5-(6)-carboxyfluorescein diacetate succinimidyl ester; D050659:Core Binding Factor Alpha 1 Subunit; D005452:Fluoresceins; D012333:RNA, Messenger; C493709:RUNX2 protein, human; D013388:Succinimides