Fig. 3.

GR downregulates BDNF expression in BZ cells. a, The total BDNF transcript abundance was decreased by 30% after 3 and 4 h DEX treatment. Time course of total BDNF transcript expression under 10^-7 M DEX or vehicle treatment, time 0 is set at 1, n = 12, Mean ± SEM; * P < 0.05, ** P < 0.01vs Veh, Mann Whitney U-tests. b, Repression of BDNF mRNA expression is transcriptional. Time course assessment of total BDNF mRNA expression under DRB in the presence or absence of DEX. Note the logarithmic scale of the y-axis. Total BDNF transcript half-life time was estimated at approximately 2 h. The corresponding slopes were not significantly different with ANCOVA test (P = 0.14) (c), GR effect is inhibited by RU. RT-qPCR on common exon IX, 3 h treatment with DEX 10^-7 M and/or RU 10^-6 M (n = 12, Mean ± SEM); Veh vs DEX ***P < 0.001, RU and DEX + RU vs DEX, $ P < 0.05, $$ P < 0.01. d, Relative expression of BDNF untranslated exons containing mRNA in 4-day BZ cultures (n = 6, Mean ± SEM) as measured by RT-qPCR. The highest expressed isoform in BZ cells is exon VI-containing transcript, followed by exon VII and VIII, then exon IV, while exon I mRNA expression was negligible. e, f, g, h, GR specifically repressed exon IV and VI expression but was ineffective on exon VII and VIII expression. qPCR on exon IV, VI, VII and VIII (n = 12, Mean ± SEM) containing transcript levels in the same samples than in (c); Veh set at 1, * (P < 0.05), and ** (P < 0.001) vs Veh; $ (P < 0.05) and $$ (P < 0.01) vs Dex, Mann Whitney U-tests