Oleanolic Acid Inhibiting the Differentiation of Neural Stem Cells into Astrocyte by Down-Regulating JAK/STAT Signaling Pathway.

To investigate the effect of oleanolic acid (OA) on the differentiation of neural stem cells (NSCs) induced by A[Formula: see text] via regulating the JAK/STAT signaling pathway, a neurotoxicity cell model involving the induction of NSCs by soluble A[Formula: see text] (5 [Formula: see text]M) was used. The WST-1 method and immunofluorescence tests were used respectively to detect the activity of cell model and the expression of GFAP[Formula: see text]/DAPI and Tubulin[Formula: see text]/DAPI. Western blotting and real-time PCR analyses were used to observe the effects of OA on NSCs differentiation by examining key targets of the JAK/STAT signal transduction pathway. Compared with normal NSCs, A[Formula: see text]-induced NSCs had down-regulated expression of Ngn1 and up-regulated STAT3 expression and phosphorylation, and inhibited neuronal differentiation. OA treatment effectively inhibited the A[Formula: see text]-induced activation of JAK/STAT signaling, with a significant increase in Ngn1 expression and a significant decrease in p-STAT3/STAT3. These results indicate that OA could inhibit the excessive differentiation of NSCs into astrocytes by down-regulating JAK/STAT signaling which might retard the progress of AD.