[Ox-LDL/β2GPI/anti-β2GPI antibody complex promotes apoptosis and inflammatory factors expression in RAW264.7 cells]

Objective To investigate the effects of ox-LDL/β2GPI/anti-β2GPI antibody complex on apoptosis and inflammatory factors expression in RAW264.7 cells and its mechanism. Methods RAW264.7 cells were treated with medium, ox-LDL, β2GPI/aβ2GPI antibody complex, ox-LDL/β2GPI complex, ox-LDL/aβ2GPI antibody complex, and ox-LDL/β2GPI/aβ2GPI antibody complex separately. The role of signaling pathways was investigated by TLR4 inhibitor TAK-242 and mTOR inhibitor rapamycin. Finally, cells were stimulated with different concentrations of TNF-α. The apoptosis was detected by Annexin V-FITC/PI double labeling. The mRNA expressions of TNF-α and IL-1β were detected by real-time quantitative PCR, and the protein expressions of TNF-α, IL-1β, and apoptosis-related proteins cleaved-caspase-3 (c-caspase-3) and Bcl2 were detected by Western blot. Results Ox-LDL/β2GPI/aβ2GPI antibody complex promoted RAW264.7 cells' apoptosis, with a decrease in protein Bcl2 and an increase in protein cleaved-caspase-3, and enhanced the level of inflammatory factors, while apoptosis and the expression of inflammatory factors were partially reduced when macrophages had been pre-treated with inhibitors. TNF-α up-regulated apoptosis in RAW264.7 cells at 100 ng/mL and 200 ng/mL. Conclusion Ox-LDL/β2GPI/aβ2GPI antibody complex induces apoptosis in RAW264.7 cells by increasing the expression of inflammatory factors. TLR4 and mTOR pathways are involved in the process.