Figure 2. TLR4 is required for S100A9-induced cellular senescence. (A) Cells were pretreated with CLI-095 (1 μg/ml) for 2 h and then treated with rhS100A9 for 72h. Senescent cells were counted and presented in graphs (40 × magnification). The expression of p53, p21, and p16 was measured using qPCR and western blot. (B) The RNAi efficiency of TLR4 was assayed utilizing qPCR. (C) TLR4 was knocked down, and cells were treated with rhS100A9 for 72h. Senescent cells were counted and presented in graphs (40 × magnification). Next, p53, p21, and p16 levels were measured utilizing qPCR and western blot. Data are expressed as mean ± SD from three experiments. *P<0.05, **P<0.01, and ***P<0.001.