Notch信号通路在骨髓间充质干细胞向肝细胞分化过程中的动态表达特征

Dynamic expression characteristics of Notch signal in bone marrow-derived mesenchymal stem cells during the process of differentiation into hepatocytes

目的探寻Notch信号通路对BM-MSCs向肝细胞分化的影响机制。方法诱导BM-MSCs分化成肝细胞。当BM-MSCs分化至第0、7、11、21天时,反向斑点杂交实验检测Notch信号通路中的关键基因的mRNA表达水平。建立加入Jagged1上调信号通路的对照组RT-PCR技术绘制出BM-MSCs分化状态分子表达谱与正常情况下对比。结果 BM-MSCs分化进行至第21天,反向斑点杂交检测到的关键基因的mRNA表达水平低于第0、7、11天。加入Jagged1后Notch信号通路被激活,导致下游基因Hes1和Hey1的被表达。BM-MSCs分化过程中Albumin未被检测到。结论本研究的结果表明Notch信号通路在BMMSCs分化成肝细胞过程进行调控是必需的,但是分化必须在信号通路下调的情况下才能进行下去。

Objective To explore the effect of Notch signaling in bone marrow-derived mesenchymal stem cells during the process of differentiation into hepatocytes. Methods An induction system under which BM-MSCs can differentiate into hepatocytes was established. On days 0, 7, 11 and 21 day during the differentiation direction, nine key genes in Notch pathway were selected as target genes and determined in BM-MSCs using technique reverse dot blot hybridization. The results of reverse dot blot hybridization showed that the effect of Notch signaling in BM-MSCs during the process of differentiation into hepatocytes. At the same time,the results of RT-PCR analysis reveals the differentiation status of BM-MSCs. Results On the 21th day when the differentiation direction was determined in BM-MSCs, the mRNA level of nine key genes was significantly lower than that on days 0, 7, and 11. In the further experiments, down-regulation of Notch signaling was shown to be critical for BM-MSCs to differentiate into hepatocytes, as increased Jaggedl resulted in up-regulated Notch activation, leading to higher levels of expression of Hesl and Heyl, which completely blocked Albumin expresion in BM-MSCs. Conclusion These results in our study showed that Notch signaling in BM-MSCs was necessary to initiate differentiation into hepatocytes, but must be down-regulated for the differentiation to proceed continuously.