Cocaine-mediated induction of MCP-1 expression involves MAPKs and PI3K/Akt cell-signaling pathways. (A) Western blot analysis of time-dependent activation of ERK, JNK, and p38 by cocaine. (B) Inhibition of the ERK and JNK pathways by MEK1/2 (U0126) and JNK inhibitor (SP600125) resulted in amelioration of cocaine-mediated induction of MCP-1. (C) Time-dependent activation of Akt in cocaine-treated BV-2 cells. (D) Pretreatment with PI3K inhibitor (LY294002) resulted in inhibition of cocaine-mediated induction of MCP-1 expression. (E) Transduction with DN-Akt and not WT-Akt resulted in abrogation of cocaine-mediated induction of MCP-1. All the data are presented as means ± SD of 4 individual experiments. **P < .01 versus control group; ##P < .01 versus cocaine-treated group.