Abstract:

Objective  To observe the effect of insulin-like growth factor-1(IGF-1) on the differentiation of neural stem cells(NSCs)  cultured in vitro into neurons, and to explore its relationship with PI3K/Akt signaling pathway. Methods  Neonatal hippocampus tissues were isolated from C57BL/6J mice to obtain NSCs cultures. The NSCs were treated with IGF-1 and the inhibitor(LY294002) at final concentrations of 100ng/mL and 50μmol/L, respectively. The NSCs were divided into four groups: IGF-1 group, normal control group, LY group and IGF-1+LY group. βⅢ Tubulin immunofluorescence staining was used to detect the differentiation of NSCs into neurons and DAPI nuclear staining was applied to quantify cell numbers; p-Akt immunofluorescnce staining was adopted to detect the expression of phosphorylated Akt (p-Akt) in each group; Western blotting was used to detect the expressions of Akt and p-Akt proteins, followed by the comparison among each group. Results  IGF-1 could promote the differentiation of NSCs into neurons and the differentiation rate was significantly higher than that of normal control group， LY group and IGF-1+LY group（all P<0.05）; immunofluorescence staining Results   showed that the expression level of p-Akt in IGF-1 group was significantly higher than those of normal control group， LY group and IGF-1+LY group（all P<0.05）;  Western blotting Results   showed that IGF-1 promoted the phosphorylation of Akt, while  LY294002 inhibited Akt phosphorylation.  Conclusion  IGF-1 induces Akt hosphorylation via activating PI3K/Akt signaling pathway and promotes NSCs differentiating into neurons.

Key words: Mice, C57BL/6J, Insulin-like growth factor-1, Differentiation, PI3K/Akt singal pathway, Neural stem cells