Fig. 4

Osteopontin (OPN) promoted neural stem cell (NSC) migration via CXCR4 signaling. A modified Boyden chamber trans-well migration assay was used to assess the effects of OPN on NSC migration, measuring the optical density of migrating cells, corresponding to their number. Growing NSC in the presence of 10 μg/ml OPN for 48 h significantly increased their migration, while concentrations of 5 and 20 μg/ml did not have an effect. The positive effect of OPN on NSC migration was completely blocked by treatment with AMD 3100, indicating that the effect was mediated through CXCR4 receptor signaling. Fetal calf serum (FCS) served as positive control; its migration-promoting effect was unaffected by CXCR4 blockage. AMD 3100 alone did not affect NSC migration (values displayed as means ± SEM; *p < 0.05)