ETYA suppresses CCL2/MCP-1 expression by inducing MKP-1 expression in brain microglia. (A - C) Primary microglia were stimulated with 10 U/ml IFN-γ for 2 h or 12 h in the presence of ETYA or WY-14643. MKP-1 protein expression and JNK phosphorylation were analyzed by Western blotting (A), and MKP-1 and CCL2/MCP-1 transcript levels and protein release were examined by qRT-PCR (B) and ELISA (C). (D - G) Rat microglia were transfected with a siRNA duplex specific for MKP-1 (D and E) or PPAR-α (F and G). After 48 h, cells were stimulated with IFN-γ for 2 h in the presence or absence of ETYA. MKP-1 protein and JNK phosphorylation were analyzed by Western blotting (D and F), and MKP-1 and CCL2/MCP-1 transcript levels were examined by RT-PCR (E and G). Values are means ± SDs of three independent experiments. *p < 0.05, **p < 0.01, NS; non significant.