Fig. 2.

PolyI:C accelerates cell death through the inhibition of TGF‐β signaling. Effect of forced expression of constitutively active Smad3 (caSmad3) on polyI:C‐induced cell death. Hs578T cells expressing HA (control) or caSmad3 were transfected with polyI:C (1 μg·mL⁻¹). Twelve hours after transfection, cells were starved with serum‐free culture media and then stimulated with TGF‐β (1 ng·mL⁻¹) or left untreated. After 36 h of starvation, the cells were analyzed with the following experiment. (A) Phase‐contrast micrographic images of the Hs578T cells demonstrating the effect of polyI:C transfection and expression of caSmad3. Scale bars, 200 μm. (B, C) Flow cytometric analysis of polyI:C‐transfected Hs578T cells stained with annexin V‐APC and PI. The percentage of annexin V‐positive and PI‐positive cells in forward scatter (FSC)‐gated and side scatter (SSC)‐gated cells are shown. Representative data (B) and mean values (C) of four biological replicate samples are shown. Error bars indicate the SD. ***P < 0.001 by the Tukey–Kramer test.