BDNF peptides B-5, B-4, and B-3 are neurogenic and neurotrophic.

<p>(A–C) Peptide B-5 induces the expression of the neuronal markers β-III-tubulin, MAP2, NFM, and NeuN in E18 primary hippocampal cell cultures. Representative confocal images illustrating double immunolabeling of β–III-tubulin (green) and MAP2 (red) and NFM (green) and NeuN (red) in cells treated for 5 days with (A) Peptide B-5 at 1 µM, (B) with BDNF, 20 ng/ml (0.79 nM) for 5 days, and,(C) vehicle only (control, C). TOPRO-3 (blue) was used to stain the nuclei. Magnification bar = 10 µm. The bottom panel shows the level of fluorescence intensity using Image J software to measure the level of expression. (D, E) BDNF peptides (B-5, B-4, and B-3) induce the expression of neuronal markers in E18 primary hippocampal neurons. (D) Representative Western blots showing an increase in the expression of the neuronal markers PSD95, NeuN, NFM, and MAP-2 in cells treated with the peptides (B5, B-4 and B-3) at concentrations of 0.1 µM and 1 µM or BDNF at concentrations of 20 or 100 ng/ml (0.79 or 3.95 nM respectively). GPADH was used as a loading control. (E) Quantification of the Western blots of neuronal markers shown in D. The integrated density value of the bands in Western blots was determined using densitometry (Fuji software, Multi Gauge, Version 3.0), and data was normalized to GAPDH and to control (medium treated cells for 5 days, C 5d). Data are shown as mean ± standard deviation, n = 3. 10% SDS-PAGE gels. *<i>p</i><0.05, **<i>p</i><0.01, ***<i>p</i><0.001. One-way ANOVA/post-hoc test/Student’s <i>t</i> test.