CDX2调控Wnt/β-catenin信号通路促进hiPSCs向肝祖细胞分化的机制研究

我们发现人诱导多能干细胞（hiPSCs）向肝祖细胞（HPCs）分化，可较向成熟肝细胞分化缩短培养周期、提升细胞活力，但其分化效能仍需提高。最近表明，CDX2及其靶向的Wnt/β-catenin信号通路可能在hiPSCs向HPCs分化中起到核心调控作用。我们前期及预实验发现，激活CDX2或抑制Wnt/β-catenin后可促进hiPSCs定向分化为HPCs，但进一步效果及机制未明。为此，本项目拟在前期基础上：1.应用CDX2精准调控Wnt/β-catenin信号，促进hiPSCs向HPCs诱导分化；2.在上述过程中，阐明CDX2在hiPSCs分化特定阶段-定向内胚层向HPCs分化阶段，通过靶向Wnt8b等降低Wnt/β-catenin信号进而促进HPCs分化的机制。本项目旨在获得一种高效合理的HPCs分化方法用于肝功能替代治疗，并促进干细胞分化和肝脏发育机制的完善更新。

With the advantages of short culture cycle and high cell viability, the differentiation of human induced pluripotent stem cells (hiPSCs) into liver progenitor cells (HPCs) is more utilitarian, when compared to the differentiation of hiPSCs into mature hepatocytes. However, two major problems (low differentiation efficiency and bidirectional differentiation) need to be solved ungently. Recent studies proved that CDX2 and its targeted Wnt/β-catenin signaling pathway may play an important role in regulating the differentiation of hiPSCs into HPCs. In our previous studies, the activation of CDX2 or inhibition of Wnt/β-catenin can promote the differentiation of hiPSCs into HPCs, but its underlying mechanism are still unknown. Hence, we will explore the items as following: 1. The precise regulation of CDX2 through Wnt/β-catenin signaling pathway will be applied to improve the differentiation efficiency of HPCs during the differentiation of hiPSCs into HPCs. 2. To clarify the role of CDX2, and to illustrate the underlying mechanism on how CDX2 regulates Wnt/β-catenin and the downstream pathways by targeting Wnt8b during the specific stage of the differentiation of hiPSCs (hiPSC-derived definitive endoderm into HPCs). In this proposal, we aim to explore an efficient and feasible method on HPCs differentiation for liver function replacement therapy, and to illustrate the underlying mechanism on stem cell differentiation and liver development.