Figure 6.

TAT-CPE^452-466 attenuates the activity-enhanced BDNF signaling. A, Representative images of immunoblots showing BDNF-induced phosphorylation of TrkB, Akt, and ERK1/2 in cultured hippocampal neurons under the indicated conditions. Neurons at 9 DIV pretreated with TAT-Con or TAT-CPE^452-466 for 30 min were stimulated with BDNF and glycine for 10 min. Phosphorylation and total protein levels of TrkB, Erk1/2, and Akt were assessed by immunoblotting. B, Quantitative analysis of pTrkB (two-way ANOVA with Tukey's multiple comparisons test, F_(2,12) = 3.489, Ctr-TAT-Con vs BDNF-TAT-Con, ***p = 0.0003; Ctr-TAT-Con vs Gly+BDNF-TAT-Con, ****p < 0.0001; BDNF-TAT-Con vs Gly+BDNF-TAT-Con, ^#p = 0.0112; Ctr-TAT-CPE^452-466 vs BDNF-TAT-CPE^452-466, ****p < 0.0001; Ctr-TAT-CPE^452-466 vs Gly+BDNF-TAT-CPE^452-466, ****p < 0.0001, n = 4). C, Quantitative analysis of pErk (two-way ANOVA with Tukey's multiple comparisons test, F_(2,12) = 3.146, Ctr-TAT-Con vs BDNF-TAT-Con, ***p = 0.0004; Ctr-TAT-Con vs Gly+BDNF-TAT-Con, ****p < 0.0001; BDNF-TAT-Con vs Gly+BDNF-TAT-Con, ^#p = 0.0132; Ctr-TAT-CPE^452-466 vs BDNF-TAT-CPE^452-466, ***p = 0.0001; Ctr-TAT-CPE^452-466 vs Gly+BDNF-TAT-CPE^452-466, ***p = 0.0002, n = 4). D, Quantitative analysis of pAkt (two-way ANOVA with Tukey's multiple comparisons test, F_(2,12) = 4.723, Ctr-TAT-Con vs BDNF-TAT-Con, ****p < 0.0001; Ctr-TAT-Con vs Gly+BDNF-TAT-Con, ****p < 0.0001; BDNF-TAT-Con vs Gly+BDNF-TAT-Con, ^##p = 0.0079; Ctr-TAT-CPE^452-466 vs BDNF-TAT-CPE^452-466, ****p < 0.0001; Ctr-TAT-CPE^452-466 vs Gly+BDNF-TAT-CPE^452-466, ****p < 0.0001, n = 4). pTrkB, pErk1/2, and pAkt levels were normalized to the phosphorylation levels in TAT-Con group detected without glycine pretreatment. Graphs represent mean ± SEM.