Western blot assay

Well-grown cells were treated with ox-LDL. Total protein extraction was performed via RIPA buffer (Pierce, Rockford, USA). Protein was segregated by SDS-PAGE after quantification, and then transferred onto a PVDF membrane (Millipore, Billerica, MA, USA). The blots were incubated with primary antibodies against tumor necrosis factor α (TNF-α) (1 : 200, Abcam, Cambridge, United Kingdom), cleaved caspase-3 (1 : 1000, Abcam), cleaved PARP (1 : 1000, Abcam), or GAPDH (1 : 2000, Abcam, UK), and then added with secondary antibody (1 : 5000, Abcam). Finally, the signal was detected via an ECL Plus Detection kit (Pierce).