干细胞治疗是目前终末期肝病治疗中最具潜在应用价值的治疗方案之一。然而由于肝干细胞存在的争议性，虽在国内外已有探索性尝试，仍然没有得到很好的临床治疗效果和推广。申请人前期研究识别鉴定了肝内肝干细胞以及其表面标志物CD63。进而发现小鼠肝外胆囊中也存在CD63阳性细胞，该细胞具有肝干细胞的基本特性，可大量扩增以及分化为成熟肝细胞和胆管细胞，并且可以参与损伤肝脏的再生修复。而且，申请人在人胆囊中也证明了CD63+细胞的存在，并发现该细胞表达肝干细胞标志物。然而，尚不清楚人胆囊CD63+细胞是否具有肝干细胞特性以及其是否可以达到“细胞治疗”的效果。基于肝外胆囊组织在临床上取材的相对便捷，细胞治疗的应用前景以及前期工作基础，本课题拟开展人胆囊CD63+细胞的识别鉴定以及其再殖损伤肝脏的能力，进而建立CD63+干细胞类器官并评估其对急慢性肝脏疾病模型的治疗作用，为实现“肝病胆治”的临床转化奠定基础。

The end-stage liver diseases including acute and chronic hepatic failure has a high mortality rate. Although liver transplantation is the most commonly used therapy, it is limited due to organ rejection, lack of donors and high cost. It has been proposed that the stem cells can serve as a potential source for liver regeneration therapy. However, due to the controversial of hepatic stem cells, it has not yet widely used in clinic. In our previous study, we identified the liver stem cells based on lineage trace and single cell analysis, and found that CD63 was the surface marker of hepatic stem cells. Then, we also found that CD63+ cells can be isolated form mouse gallbladder possessed the liver stem cell traits. These CD63+ cells can be stably expanded and be induced to differentiate into both functional hepatocytes and cholangiocytes in vitro. In the injured liver of fumarylacetoacetate hydrolase deficient (Fah-/-) mice, these CD63+ cells participate in the repairment of the injured liver and rescue Fah-/- mouse from the failure of liver function. Furthermore, the CD63+ cells were also found in human gallbladder and these cells expressed several stem cell markers. But it is not clear that the human gallbladder CD63+ cells can possess the characteristics of liver stem cells and the effective of liver injury repair with stem cell therapy. Based on the relatively easy obtaining of human gallbladder and the urgent needs for the research of cell therapy of liver diseases, this project intends to identify the characteristics of the human gallbladder CD63+ cells. In this research, we first detect the characteristics of proliferation and differentiation of human gallbladder CD63+ cells and the repopulative capacity in liver injury mouse model. Secondly, we want to build the stem cell organoids in 3D culture and identify the characteristics of these organoids. Finally, to achieve the stem cell therapy in clinic liver diseases, we investigate therapeutic effect of stem cells in acute and chronic animal models. This project will investigate the possibility of “the liver diseases were cured by the transplantation with the extra-heaptic biliary tree stem/progenitor cells” and will find a new breakthrough for the cell source in the cell therapy for liver disease.