Objective        To observe the effect of dendritic cells (DCs) on neural stem/progenitor cells (NSPCs) differentiation in vitro

and to explore the possible mechanism of neurotrophin-3 (NT-3) in NSPCs differentiation regulated by DCs.       Methods      Primary NSPCs and DCs generated from SD rats were separately cultured and then co-cultured by using transwell chambers

respectively. There are five experimental groups including a NSPCs group

a DCs group

a NSPCs/DCs group

a NSPCs+NT-3 group and a NSPCs/DCs+anti-NT-3 group. After incubation for 24

48 and 72 h

ELISA was used to detect the NT-3 content in cell supernatant of each group. After 7 d

fluorescence immunocytochemistry was used to detect NSPCs differentiation

and Western blot assay was used to detect the expression of phosphorylated extracellular signal-regulated protein kinases (p-ERK1/2) of NSPCs.       Results       The ELISA results showed that the NT-3 content in the cell supernatant of the NSPCs/DCs group was significantly increased compared with the NSPCs group

DCs group and NSPCs/DCs+anti-NT-3 group (P0.05). Seven days after induction of differentiation

the proportions of β-tubulin-Ⅲ-positive cells in the NSPCs/DCs group and NSPCs+NT-3 group were significantly higher than those of the NSPCs group and NSPCs/DCs+anti-NT-3 group (P0.05)

while the proportions of glial fibrillary acidic protein (GFAP)-positive cells in the NSPCs/DCs group and NSPCs+NT-3 group were significantly lower than those of the NSPCs group and NSPCs/DCs+anti-NT-3 group (P0.05). The Western blotting results showed that the levels of p-ERK1/2 in the NSPCs/DCs group and NSPCs+NT-3 group were significantly higher than those in the NSPCs group

DCs group and NSPCs/DCs+anti-NT-3 group (P0.05).       Conclusion       Co-culture of DCs and NSPCs can significantly promote NSPCs to differentiate into neurons. Activation of MEK-ERK signaling pathway may contribute to the differentiation of NSPCs into neurons

which is mediated by increased NT-3 binding to its specific receptor TrkC in co-culture system.