构建芯片技术探讨人参皂苷Rg1促进人神经干细胞分化的机制

目的:采用基因芯片技术筛选出人参皂苷Rg1促进NSCs分化的主要分子靶点。方法:通过基因芯片技术,观察Rg1诱导人神经干细胞(neural stem cells,NSCs)向神经元分化7 d时靶基因表达,通过数据演算筛选出Rg1促进NSCs分化的最主要的靶基因和信号转导途径,然后采用Western blot和免疫组化的方法对其中的ERK信号分子进行验证。结果:在Rg1诱导NSCs分化第7天时,获得差异基因675个,其中显著上调的基因255个,显著下调的基因420个;MAPK(丝裂原活化蛋白激酶)通路中的ERK1/2(细胞外信号调节蛋白激酶)信号分子与NSCs分化直接相关。经Western blot和免疫组化证实,在Rg1诱导NSCs分化中,ERK1/2蛋白明显上调,磷酸化水平也明显增强,此作用能够被PD98059(ERK1/2阻断剂)所阻断,同时PD98059也可以明显阻断NSCs的分化。结论:ERK1/2是人参皂苷Rg1促进NSCs分化的重要分子靶点。基因芯片筛选出的差异表达基因可能为研究Rg1促进NSCs分化的分子机制提供线索。

Study on mechanism of ginsenoside Rg1-induced human neural stem cells differentiation by genechip

Objective: The molecular targets of ginsenoside Rg₁-induced neural stem cells(NSCs) differentiation were screened by genechip. Method: 7^th day following ginsenoside Rg₁ induced human neural stem cells to neurons the gene expression was observed by genechip. The purpose gene and signal transduction pathways were selected by the data calculations, and then confirmed by western blot and immunohistochemical method. Result: 7^th day following Rg₁-induced NSCs differentiation, there were about 675 different genes, 255 genes of which were up-regulated and 420 genes down-regulated obviously. Meanwhile the ERK1/2 (extracellular signal-regulated protein kinase) in MAPK (mitogen-activated protein kinase) pathway was related with the NSCs differentiation. The Western blot and immunohistochemistry detection confirmed that ERK 1/2 protein and its phosphorylation were significantly increased, which can be blocked by PD98059 (ERK1 / 2 inhibitor). In addition, differentiation rate of NSCs was also decreased obviously in ginsenoside Rg₁-induced differentiated NSCs when ERK blocker PD98059 was used. Conclusion: ERK1/2 is an important molecular target in ginsenoside Rg₁-induced NSC differentiation. The selected differentially expressed genes by genechip may provide new clues to study of ginsenoside Rg₁-induced NSCs differentiation.