[Activation of tumor necrosis factor receptor-associated factor 6 in anti-β2GPI/β2GPI-induced tissue factor expression on THP-1 cells]

To investigate whether tumor necrosis factor receptor-associated factor 6 (TRAF6) is involved in anti-β2GPI/β2GPI-induced tissue factor (TF) expression on THP-1 cells.The total RNA was extracted and the protein lysates were collected from THP-1 cells stimulated with anti-β2GPI/β2GPI complex. And then the TF expression on THP-1 cells was detected by real-time quatitative PCR (RT-qPCR) and TF activity kit. TRAF6 mRNA and its protein expression were investigated by RT-qPCR and Western blotting, respectively. The proteasome inhibitor, MG-132, was used for inhibitory assays, in order to demonstrate the effect of anti-β2GPI/β2GPI complex on THP-1 cells.The TF expression (both mRNA and activity) on THP-1 cells was significantly up-regulated with the treatment of anti-β2GPI/β2GPI complex (100 mg/L), compared with untreated cells(P0.05). The TRAF6 mRNA and protein levels in THP-1 cells were also significantly increased with the treatment of anti-β2GPI/β2GPI complex. The expression of TRAF6 was shown in a time-dependent manner, with the maximal level at 15 minutes (mRNA) and 30 minutes (protein) respectively. All the stimulating effects of anti-β2GPI/β2GPI complex (100 mg/L) on THP-1 cells were inhibited by MG-132 (5 μmol/L).TRAF6 is up-regulated and contributes to TF expression on THP-1 cells induced with anti-β2GPI/β2GPI complex.