Fig. 9.
TGF-β1 increases glutamate uptake in a concentration- and time-dependent manner in astrocytes. (a) Treatment of astrocytes for 24 h with TGF-β1 (2, 4, 8 ng/mL) increased glutamate uptake. (b) TGF-β1 at 4 ng/mL increased glutamate uptake most effectively after 24 h treatment in astrocytes. (c) Pre-treatment with TGF-β1 (18 h) prior to Mn treatment (6 h) reversed the Mn-induced glutamate uptake inhibition in astrocytes. (d) SB431542 (a TGFR inhibitor, 20 μM) abolished the E2/TX-induced enhancement of glutamate uptake (###p < 0.01 vs. control; *p < 0.05, **p < 0.01, ***p < 0.001 vs. control (a,b,d), or the Mn treatment (c), #p < 0.05; Tukey's test following anova). Data are expressed as the mean ± SEM (n = 4).