Abstract: [Abstract] Objective To explore the effect and mechanism of Porphyromonas gingivalis (P.g) lipopolysaccharide (LPS) on the secretion of inflammatory cytokines in human gingival fibroblasts (HGFs). Methods  HGFs were separated and cultured. Tumor necrosis factor-α and interleukin-1β in the HGFs were examined by enzyme-linked immunosorbent assay at 6 h and 12 h after stimulation with different concentration of LPS (1 μg/ml, 10 μg/ml). Meanwhile, the expressions of TLR2, 4 were examined by real-time PCR. Analysis of variance (ANOVA) statistical analysis was performed with SPSS10.0 software package. Results   Compared with the control group (without LPS stimulation), the expression of TLR2 and secretion of inflammatory cytokine (TNF-α、IL-1β) in HGFs were enhanced obviously at 6 h, 12 h after stimulation of LPS in P.g LPS concentration- and time-dependent manner (P<0.05). The expression of TLR4 was enhanced obviously at 6h after stimulation of P.g LPS in P.g LPS concentration-dependent manner (P<0.05). However, the expression of TLR4 showed no difference between LPS-stimulated group and non-LPS-stimulated group. Conclusion    P.g LPS stimulates HGFs to secrete inflammatory cytokines mainly through TLR2, 4 at early stage. After that, the expression of TLR2 plays an important role in inflammatory reaction induced by p.g LPS in HGFs.

Key words: Human gingival fibroblast, lipopolysaccharides, Fibroblasts, gingival, toll-like receptor 2, Toll-like receptor 4, tumor necrosis factor-alpha, 白细胞介素1β