Effect of black-pigmented bacteria on the plasminogen-plasmin system in human pulp and osteoblastic cells.
OBJECTIVE
To date, there have been relatively few studies addressing the presence and expression of the plasminogen-plasmin system at the site of bacterial infection. The aim of the present study was to investigate the effect of black-pigmented bacteria on the expression of the plasminogen-plasmin system in human pulp and osteoblastic cells.


METHODS
The supernatants of Porphyromonas endodontalis, Porphyromonas gingivalis, and Prevotella intermedia were used to evaluate tissue-type plasminogen activator (t-PA) and type 1 plasminogen activator inhibitor (PAI-1) gene expression in human pulp and osteoblastic cells. The levels of mRNA were quantitatively measured by using reverse transcription-polymerase chain reaction.


RESULTS
In this study, black-pigmented bacteria induced not only t-PA but also PAI-1 gene expression in human pulp and osteoblastic cells. In addition, the ratio of t-PA to PAI-1 was higher in human pulp and osteoblastic cells stimulated by black-pigmented bacteria than in untreated cell cultures (P <.05).


CONCLUSIONS
A fine balance exists in the expression of components of the plasminogen-plasmin system, whereby tissue homeostasis is maintained. Black-pigmented bacteria activate the activator-inhibitor system in human pulp and osteoblastic cells through unbalance regulation of t-PA and PAI-1, which might result in an uncontrolled degradation of pulpal and periapical tissues.
Yang
Shun-Fa
SF
Institute of Biochemistry, Chung Shan Medical University, Taichung, Taiwan.
Hsieh
Yih-Shou
YS
Huang
Fu-Mei
FM
Yang
Li-Chiu
LC
Chang
Yu-Chao
YC
D000704:Analysis of Variance; D018929:Cell Culture Techniques; D017077:Culture Media, Conditioned; D003782:Dental Pulp / Q000378:metabolism*; D005341:Fibrinolysin / Q000032:analysis / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D006801:Humans; D010006:Osteoblasts / Q000378:metabolism*; D010958:Plasminogen / Q000032:analysis / Q000235:genetics; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis / Q000235:genetics*; D010960:Plasminogen Activators / Q000032:analysis / Q000235:genetics*; D017861:Porphyromonas / Q000235:genetics*; D016966:Porphyromonas gingivalis / Q000235:genetics*; D018713:Prevotella intermedia / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D010959:Tissue Plasminogen Activator / Q000032:analysis / Q000235:genetics*
D017077:Culture Media, Conditioned; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D010958:Plasminogen; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator; D005341:Fibrinolysin