Figure 3.

Western blot analysis of apoptosis-associated proteins following PCSK9 siRNA transfection. A549 cells were transfected with PCSK9 siRNA or control siRNA for 48 h prior to being subjected to protein extraction and western blot analysis with the indicated antibodies. (A) Representative western blot images and (B) quantified protein levels obtained by densitometric analysis. Protein levels relative to GAPDH (loading control) are presented. Levels of control siRNA were set at 1. Values are expressed as the mean ± standard deviation (n=3). *P<0.05, **P<0.001 vs. control siRNA. siRNA, small interfering RNA; PCSK9, proprotein convertase subtilisin/kexin type 9; c-caspase-3, cleaved caspase-3; XIAP, X-linked inhibitor of apoptosis protein.