肝脏类器官的建立及其在移植治疗肝脏疾病中的研究

肝脏是人体至关重要的代谢器官，也具有强大再生能力。但在晚期肝病患者中，肝脏失去再生能力。肝脏移植成为唯一有效的治疗手段。由于供肝缺乏，细胞替代疗法逐步成为终末期肝病治疗的新方法。而类器官具有器官结构和功能成熟的特征，在组织修复中具有潜在优势。但满足临床移植细胞量需求且肝功能成熟的人肝脏类器官及其原位移植治疗肝病尚未实现。申请人前期将人原代肝细胞去分化为兼具肝细胞和肝前体细胞特征的双表型肝细胞（ProliHH），实现了人肝细胞扩增。本项目拟系统解析ProliHH 肝向诱导成熟的调控机制，并针对该机制优化构建肝功能成熟的肝脏类器官。同时构建严重免疫缺陷肝脏代谢疾病大鼠作为类器官原位移植模型，利用活体显微成像技术全景式解析类器官整合机制，探究人肝脏类器官移植治疗肝病的有效性和安全性，最终为临床肝脏类器官移植治疗肝病提供理论依据。

The liver is a vital organ controlling numerous metabolic functions. A remarkable feature of the liver is its outstanding regenerative capability after injury. However, in fatal liver diseases, the liver loses regeneration capability and liver transplantation is only curative therapy. Due to the shortage of donor organs，cell replacement therapy has been evaluated as a promising alterative to whole-organ transplantation. Organoids recapitulate certain structures and mature functions of their counterpart organs in vivo，having an advantage in tissue repair. However, the functional maturation of human liver organoids and their efficacy after orthotopic transplantation have not been achieved. Recently, we overcame the problem of hepatocyte expansion by dedifferentiating primary human hepatocytes to expandable bi-phenotypic cells (ProliHH), which showed partial hepatic features and expressed progenitor-associated genes. In this project, we will first reveal the underlying mechanism of hepatic rematuration of ProliHHs, and then construct liver organoids with mature hepatic functions by manipulating these key pathways. Moreover, we will develop a severely immunodeficient rat with liver metabolic disease as orthotopic transplantation model. Using intravital microscopy, we will identify the cellular mechanism of liver organoid engraftment. Finally, we will characterize the efficacy and safety of orthotopic transplantation of human liver organoids, providing a proof of concept for liver disease treatment using organoids.