Role of TRAF6 in inflammatory responses of human osteoblast ⁃like cells with Enterococcus faecalis

Abstract

Objective Explore the role and status of tumor necrosis factor receptor⁃associated factor 6 (TRAF6) in the inflammatory response of human osteoblast⁃like cells MG63 which was triggered by Enterococcus faecalis (E. faeca⁃ lis) and its lipoteichoic acid (LTA). Methods SiRNA technology was applied to silence the TRAF6 gene of MG63 cells, Using E.faecelis and its LTA to stimulate the silence MG63 cells with different hours. After that, using real⁃time PCR technology to detect toll⁃like receptor 2 (TLR2) and TRAF6 gene expression and using ELISA assay to detect pro⁃ inflammatory cytokines interleukin⁃1β and TNF⁃alpha expression levels. Results When MG63 cells was infected by E. faecalis, its LTA, TLR2 and TRAF6 gene level has increased to varying degrees (P < 0.05); interleukin⁃1β and TNF⁃ alpha expression was significantly higher (P < 0.05). When TRAF6 gene of MG63 cells was silenced by siRNA, pro⁃in⁃ flammatory cytokines interleukin ⁃ 1β, interleukin ⁃6, interleukin ⁃8 and TNF ⁃alpha expression decreased significantly (P < 0.05). Conclusion E. faecalis and its toxic components is identified by MG63 cells mainly through TLR2 recep⁃ tors. The major virulence factor in periapical infections caused by E. faecalis is LTA.

Keywords

• E. faecalis
• LTA
• TLR2
• Human osteoblast⁃like cells
• TRAF6