Fig. 5

Methamphetamine-induced HMGB1 mediates activation of astrocytes. Methamphetamine (150 μM) increased the expression of GFAP in C6 cells (a) and primary human astrocytes (b). c Pretreatment of C6 cells with the σ-1R antagonist (BD1047; 10 μM), the Src inhibitor (PP2; 10 μM), the ERK inhibitor (U0126; 10 μM), or the Ikk-2 inhibitor (SC514; 10 μM) significantly reversed the increased GFAP expression induced by methamphetamine. d Transfection of primary human astrocytes with siRNA σ-1R, Src, ERK and NF-κB p65 resulted in attenuation of methamphetamine-induced GFAP expression. e Transfection of C6 cells with HMGB1 siRNA successfully decreased the expression of HMGB1 (upper panel). Knockdown of HMGB1 expression significantly inhibited the activation of C6 cells as determined by GFAP expression using western blot (lower panel). f–g Fluorescent intensity of GFAP was quantified in five areas using Image J software (f). Representative image of GFAP staining in C6 cells transfected with siRNA control or HMGB1 followed by treatment with or without methamphetamine (g). Scale bars all indicate 50 μm. All the data are mean ± SD of three individual experiments. *p < 0.05 and **p < 0.01 compared with control group; #p < 0.05 compared with methamphetamine-treated group in C6 cells or primary human astrocytes