Figure 5

Methamphetamine-mediated induction of σ-1R involves CREB activation. (A to C) Effect of methamphetamine on the total level of CREB in whole cell lysates (A), nuclear (B), as well as cytoplasmic (C) fractions. (D) Pretreatment of astrocytes with σ-1R antagonist-BD1047 (10 μM), Src inhibitor-PP2 (10 μM), or MEK1/2 (U0126, 10 μM) significantly inhibited methamphetamine-mediated translocation of CREB into the nucleus. Representative immunoblots and the densitometric analysis of CREB/Histone H3 from three separate experiments are presented. (E) Pretreatment of primary rat astrocytes with Src inhibitor-PP2 (10 μM), MEK1/2 (U0126, 10 μM), or the PKA inhibitor-H89 (10 μM), resulted in inhibition of methamphetamine-mediated expression of σ-1R. Representative immunoblots and the densitometric analysis of σ-1R/GAPDH from the three separate experiments are presented. All the data are presented as mean ± SD of three individual experiments. *P < 0.05 and **P < 0.01 versus control group; #P < 0.05 versus methamphetamine-treated group. (F) Illustration of the consensus binding site of CREB to the σ-1R promoter. (G) ChIP assay demonstrating methamphetamine-mediated binding of CREB to the σ-1R promoter.