FIGURE 2.

Effects of ATF-3 knockdown on the protective effects of metformin against LPS-induced inflammation. ATF-3 siRNA (100 nm) was transfected into primary macrophages, and the extent of ATF-3 knockdown was determined by RT-PCR (left panel) and Western blotting (right panel) (A). Then the cells were treated with 2 mm metformin (M) for 20 h followed by LPS (L) for 4 h. Levels of TNF-α and IL-6 in the culture media were determined by ELISA (B). Results are expressed as means ± S.E. (error bars) of three independent experiments performed in triplicate. *, p < 0.05 versus LPS alone; #, p < 0.05 versus control siRNA. Con, control.