Objective    To observe the effects of vascular endothelial growth factor (VEGF) with different concentrations on the proliferation of oligodendrocyte precursor cells (OPCs)

and to study the relationship between the promotion effect of VEGF on OPCs in vitro proliferation and relevant proteins in Notch signaling pathway.     Methods    OPCs were isolated

purified

and cultured. The influences of VEGF with different concentrations (50

100

and 200 ng/ml) and Notch signaling pathway γ-secretase inhibitor DAPT on OPCs proliferation were detected with MTT assay. The influences of VEGF on the expression of Notch-1 and Hes-1 in Notch signaling pathway at mRNA level and protein level were detected with RT-PCR and Western blotting.     Results    OPCs treated with 50

100

and 200 ng/ml VEGF had proliferation rates of (107±2)%

(124±2)%

and (142±7)%

respectively

which were significantly different from the proliferation rate (100%) of untreated OPCs (P0.05). After γ-secretase inhibitor addition

the proliferation rate of OPCs treated with 100ng/ml VEGF decreased to (103±4)%. RT-PCR and Western blot results showed that the expression of Notch-1 and Hes-1 in OPCs treated with VEGF was significantly higher than those in the untreated OPCs (P0.05)

and lower than those in OPCs treated with VEGF and γ-secretase inhibitor (P0.05).     Conclusion    VEGF can directly promote the proliferation of OPCs

associated with proteins in Notch signaling pathway.