血清和无血清诱导方法分化小鼠胚胎干细胞为定形内胚层的比较

Serum and non-serum method-induced differentiation of mouse embryonic stem cells into definitive endoderm

目的比较两种方法(血清诱导方法和无血清诱导方法)诱导小鼠胚胎干细胞分化为定形内胚层细胞的效率。方法利用血清诱导法和无血清诱导法分别诱导分化小鼠胚胎干细胞,根据定形内胚层表面标记蛋白(Cxcr4、c-Kit和E-cadherin)的表达,通过流式细胞术分析定形内胚层诱导的时间及效率,并利用RT-PCR检测两种方法诱导的定形内胚层基因表达谱;同时利用荧光定量PCR检测无血清诱导过程中内胚层基因的表达情况;利用流式细胞术分选Cxcr4和c-Kit双阳性细胞进行定形内胚层基因表达的鉴定。结果血清诱导法和无血清诱导法都能够将胚胎干细胞诱导分化为定形内胚层,其中无血清组的诱导效率高于血清组,高达74.19%,并且在诱导的第4天就能到达峰值。结论建立了高效快捷的诱导胚胎干细胞分化为定形内胚层细胞的方法,为进一步向肝、胰等组织细胞诱导打下了基础。

Objective To compare the efficiencies of two methods （serum and non-serum） in inducing mouse embryonic stem cell differentiation into definitive endoderm cells. Methods The serum and non-serum methods were used to induce differentiation of mouse embryonic stem cells into definitive endoderm cells. Fluorescence activated cell sorter （FACS） was used to analyze the inducing time and efficiency of definitive endoderm using their surface protein marks （Cxcr4, c-Kit and Ecadherin）. Meanwhile, RT-PCR was used to analyze the gene profile of definitive endoderm induced by the two methods. Realtime PCR was used to analyze the gene expression in definitive endoderm during the induction course in the non-serum group. The Cxcr4 and c-Kit double positive definitive endoderm cells were sorted by flow cytometry and gene profile was characterized by RT-PCR. Results Definitive endoderm cells were induced from mouse embryonic stem cells by both serum and non-serum methods. However, the efficiency of non-serum group （74.19 %） was higher than that in the serum group, and the induction outcome reached a climax at the 4th day of induction. Conclusion We have established a highly efficient method to induce differentiation of mouse embryonic stem cells into definitive endoderm, which lays a foundation for further differentiation into liver and pancreatic cells.