ABSTRACT
Lipopolysaccharide is a potent virulence factor of Porphyromonas gingivalis and has been implicated predominant pathogen in the development and progression of periodontal diseases. The aim of this study was to determine the effect of Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) on cementoblasts. Cementoblast (OCCM-30) were evaluated proliferation using real-time cell analyzer. In addition, total RNA was isolated at 8, 16, 24 and 72 h from 1000 ng/mL Pg-LPS treated OCCM-30 cells and mRNA expressions of pro/anti-inflammatory cytokine mediators, extracellular matrix enzymes and their tissue inhibitors and of oxidative stress enzymes were studied by real-time polymerase chain reaction. Proliferation analysis indicated that Pg-LPS slightly decreased proliferation of OCCM-30. Pg-LPS had a time-dependent impact on the expression of cytokines and enzymes. There was statistically significant up-regulation of IL-1ß and IL-10 in response to Pg-LPS at 8, 16, 24, 72 h but IL-6 expression was reduced compared to control at 8 h. While IL-8 and IL-17 expressions were determined higher than control group at 16 and 24 h, their expressions were decreased compared to control groups at 72 h (p < 0.01). While MMP-1, MMP-2, MMP-3, TIMP-1, TIMP-2 expressions increased, MMP-9 expression reduced at time-points. Also, a time-dependent up-regulation in mRNA levels for oxidative stress enzymes was detected. These results indicated that up-regulation in the transcripts of inflammation-associated cytokines and degradation enzymes were noted in the cementoblasts exposed to Pg-LPS. Cementoblasts infected with the virulence factors of periodontopathogens might also involve to the induction of inflammation and degradation of the periodontal tissues.
