新型骨髓间充质干细胞NG2+/BmMSCs亚群向胆管细胞定向分化功能鉴定及其分子调控机制研究

背景：干细胞的组织修复和再生是当前治疗终末期器官功能障碍的研究热点，其中干细胞异质性和分化调控因素仍是需要解决的难题。我们前期预实验采用原创方法首次发现骨髓来源的新型干细胞亚群（NG2+/BmMSCs）具有独立胆管细胞分化优势，其治疗慢性肝损伤效果明显优于同体NG2-/BmMSCs 和肝脏来源的NG2+阳性细胞。尤其在严重肝损伤病理条件下NG2+/BmMSCs很可能是优越性干细胞来源。据此，本研究将证明负向调控损伤微环境中HGF信号通路调节其下游特异分子HNF3α-HNF4γ-Lgr5轴通路可启动NG2+/BmMSCs介导的慢性肝再生”这一科学假设。.主要研究内容：（1） NG2+/BmMSCs生物学特性鉴定；（2）肝损伤环境HGF信号通路调控下的胆管细胞分化和功能比较；（3）疗效评估。.重要结果：（1）证明骨髓中存在功能性胆管祖细胞功能亚群（NG2+/BmMSCs），在慢性肝损伤环境下分化为大量修复性胆管细胞并受HGF信号通路的负向调控；（2）在慢性肝损伤环境下NG2+/BmMSCs具有优于与其它组织类同干细胞的治疗效果，以此提供治疗性干细胞和提升现有BM-MSCs疗效。.关键数据：（1）获取生物学特性比较数据（NG2+/BmMSCs-NG2-/BmMSCs） ；（2）获取NG2+/BmMSCs胆管细胞功能分化和提升疗效比较数据（BmMSCs-肝脏NG2+细胞; NG2+/BmMSCs-NG2-/BmMSCs）；获取NG2+/BmMSCs在慢性肝损伤环境下干性和功能特性受慢性肝损伤微环境HGF信号通路负向调控数据；（4）从人类BM-MSCs中获取NG2+细胞功能亚群；.科学意义：证明本设想有助于丰富干细胞功能和调控机制的理论体系，并为慢性肝病干细胞疗效提升提供新的理论依据。

Stem/progenitors for tissue repair, engineer and regeneration is a hot area in the field. However, underlining of their heterogeneity and control factors for functional differentiation is still challenging. We have previously identified a NG2-expressing cells from marrow mesenchymal stem cells (NG2+/BmMSCs) that exhibite a cholagiocyte progenitor activity and have better therapeutic effect than those of NG2 negative in marrow (NG2-/BmMSCs) and liver-derived NG2- cells (NG2+SPCs) in chronic cirrhotic condition. Thus effect is negatively regulated by HGF signaling pathway and its downstream unique transcription factors. This suggests NG2-/BmMSCs might be a novel bile duct stem/progenitors and advanced functional stem cell source in chronic pathological conditions. Therefore, in this application, we hypothesized that NG2+/BmMSCs as novel cholangiocyte progenitors might initiate chronic liver regeneration through HGF/cMet-HNF3α-HNF4β-Lgr5 axis in chronic injured liver niche by differentiate into functional cholangiocytes. Demonstration of the concept will provide a new theory and improve therapeutic efficacy in the near future clinic.