A Global Transcriptome Analysis Reveals Molecular Hallmarks of Neural Stem Cell Death, Survival, and Differentiation in Response to Partial FGF-2 and EGF Deprivation
Figure 2
The effect of growth factor addition on neurosphere size, proliferation and the expression of cell differentiation markers in aOBSC neurospheres.
The aOBSCs (prepared from 7- and 15-month old mice) were grown as neurospheres, to which FGF-2/EGF was added at different intervals. After 7 days in culture, BrdU (5 µM) was added for 30 minutes and the neurospheres were collected on matrigel, fixed and immunostained, and then stained with DAPI. Representative images of neurospheres grown in cultures supplemented with growth factors daily (A, D, G), every 2 days (B, E, H) and every 4 days (C, F, I), and immunostained with BrdU (A–C), GFAP (D–F) and TuJ1 (G–I). Bar graphs show the average number of DAPI+ cells per confocal plane of each neurosphere (J), and the percentage of BrdU+ (L), GFAP+ (M) and TuJ1+ cells (N). Line graphs show the distribution of neurosphere number versus volume (K). The results represent the mean ± SEM of 15–30 neurospheres from 2 different cell cultures. *P<0.05, **P<0.01 and ***P<0.001 (One way ANOVA followed by post hoc analysis using Bonferronís test). The 32% reduction in DAPI+ cell number in the C2 versus the Ctr condition (J) was statistically significant when the two average means were compared using the Student´s t test (P<0.01). Scale bars (I) = 77.51 µm and 39.0 µm (inserts).