Human hepatocyte metaplasia in injured humanized mouse livers

The goal of this experiment was to test whether human hepatocytes could give rise to biliary-like progenitor cells in an in vivo context. Here Fah-/- Il2ry-/- Rag2-/-NOD mouse livers were humanized with human hepatocytes. Only hepatocytes engraft in the Fah-/- mouse at detectable levels in this model. Then animals were given chronic liver injury with 0.1% ddc. After injury we measured human-specific transcripts to determine whether the phenotype of the human cells had changed. Specifically, we evaluated the relative levels of human biliary duct markers such as Spp1, Sox9, Krt7, etc. and hepatocyte markers such as Alb, Ttr, Fah, etc. 3 DDC treated chimeras and 6 untreated chimeras are included. Additional controls include a normal human liver biopsy, FACS sorted primary intrahepatic human bile duct cells, mouse hepatocytes, and mouse intrahepatic biliary cells in ddc treated animal.

本实验的核心目标为验证人类肝细胞在体内环境中能否分化为胆管样祖细胞。本研究使用人类肝细胞对Fah基因敲除（Fah-/-）、Il2ry基因敲除（Il2ry-/-）、重组激活基因2敲除（Rag2-/-）的NOD小鼠肝脏进行人源化改造。在该模型中，仅人类肝细胞可在Fah-/-小鼠肝脏中达到可检测的嵌合水平。随后对小鼠给予0.1%的DDC以构建慢性肝损伤模型。造模完成后，我们通过检测人类特异性转录本，以分析人类细胞的表型是否发生改变。具体而言，我们评估了人类胆管细胞标志物（如Spp1、Sox9、Krt7等）以及肝细胞标志物（如Alb、Ttr、Fah等）的相对表达水平。本研究共纳入3只DDC处理的嵌合小鼠与6只未处理的嵌合小鼠。额外对照样本包括正常人肝活检组织、经荧光激活细胞分选（FACS）分离的原代人肝内胆管细胞、小鼠肝细胞以及DDC处理小鼠体内的小鼠肝内胆管细胞。