血管内皮生长因子促进少突胶质前体细胞增殖及其机制的初步研究

Mechanism of vascular endothelial growth factor promoting in vitro proliferation of oligodendrocyte precursor cells

目的观察不同浓度血管内皮生长因子(vascular endothelial growth factor,VEGF)对少突胶质前体细胞(oli-godendrocyte precursor cells,OPCs)增殖的影响,探索VEGF促进OPCs体外增殖与Notch信号通道上相关蛋白的关系。方法分离纯化培养OPCs,MTT法检测不同浓度VEGF(50、100、200 ng/ml)促进OPCs增殖的作用以及加入Notch通路γ-分泌酶抑制剂DAPT(VEGF 100 ng/ml+DAPT50μmol/ml)后OPCs增殖变化情况,RT-PCR、Western blot技术检测VEGF处理OPCs后Notch信号通道上Notch-1、Hes-1的基因表达和蛋白表达情况。结果 50、100、200 ng/ml VEGF处理组的细胞增殖率分别为(107±2)%、(124±2)%、(142±7)%,与空白对照组相比差异具有统计学意义(P<0.05);VEGF+DAPT处理组的增殖率下降至(103±4)%(P<0.05)。RT-PCR及Western blot分析显示VEGF处理OPCs后,Notch-1、Hes-1蛋白在基因水平和蛋白水平表达均增加(P<0.05),γ-分泌酶抑制剂DAPT能抑制其表达(P<0.05)。结论 VEGF对OPCs具有促进增殖的作用,其促增殖作用与Nocth信号通路相关蛋白有关。

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 100 ng/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.