Alternative human cell-based models of fatty liver disease

描述（由申请人提供）：肥胖和2型糖尿病影响着全世界数百万人的生活，大大增加了与健康相关的支出，并且似乎是无法控制的健康问题，因为发病率正在稳步上升。在肥胖和胰岛素抵抗发病率不断上升的同时，非酒精性脂肪性肝病（NAFLD）的发病率也在上升，这是一种慢性肝病，影响着高达25%的普通人群；包括很大一部分儿科病例。已经确定了几种导致NAFLD和进展为非酒精性脂肪性肝炎（NASH）的细胞内事件。然而，确切的分子机制需要进一步研究，特别是在人体系统中。原代人肝细胞是体外肝脏功能最具生理学相关性的细胞模型。然而，用于细胞基础应用的原代人肝细胞的可用性明显有限。使用原代人肝细胞的其他混杂因素包括低温保存后恢复不良、功能特征迅速丧失和培养寿命短。现有的肝癌细胞系不表达许多研究肝细胞功能所必需的蛋白质。此外，新分离的啮齿动物肝细胞在培养中表现出与人类肝细胞相似的问题，并且它们不能忠实地概括人类肝细胞中的观察结果。为了满足市场对相关的基于人类细胞的肝细胞功能模型的需求，我们开发了一种基于脂肪组织来源的成体干细胞（ASC）向肝细胞样细胞分化的替代模型。我们已经获得了重要的初步数据，表明asc来源的肝细胞具有许多原代人肝细胞的特征，并且正在开发这些细胞在细胞治疗和药物开发中的应用。作为一种额外的替代模型，我们将采用最近开发的肝细胞样细胞系HepaRG，它来源于从人类肝脏肿瘤中分离的祖细胞。该提案的目标是为使用asc来源的肝细胞和/或HepaRG作为NAFLD的模型系统提供概念验证。

DESCRIPTION (provided by applicant): Obesity and Type 2 diabetes affect the lives of millions of people worldwide, add significantly to health-related expenditures, and are seemingly unmanageable health issues, since rates of occurrence are steadily increasing. In parallel with the increasing incidence of obesity and insulin resistance, is the occurrence of non-alcoholic fatty liver disease (NAFLD), a chronic hepatic disorder affecting up to 25% of the general population; including a significant portion of pediatric cases. Several intracellular events leading to NAFLD and progression to non-alcoholic steatohepatitis (NASH) have been identified. However, the exact molecular mechanisms require further investigation, especially in human systems. Primary human hepatocytes are the most physiologically relevant cell-based model for in vitro hepatic function. However, the availability of primary human hepatocytes for cell-based applications is significantly limited. Additional confounding factors for the use of primary human hepatocytes include poor recovery from cryopreservation, rapid loss of functional characteristics, and a short lifespan in culture. Available hepatoma cell lines do not express many of the proteins necessary for the study of hepatocyte function. Additionally, freshly isolated rodent hepatocytes display similar problems as human hepatocytes in culture, and they do not faithfully recapitulate observations in human hepatocytes. In order to address the market demand for relevant human cell-based models of hepatocyte function, we have developed an alternative model based upon the differentiation of adipose tissue derived adult stem cells (ASC) to hepatocyte-like cells. We have obtained significant preliminary data suggesting that the ASC-derived hepatocytes possess many of the characteristics of primary human hepatocytes and are in the process of developing applications of these cells for use in cell therapy and drug development. As an additional alternative model, we will employ a recently developed hepatocyte-like cell line, HepaRG, which is derived from progenitor cells isolated from a human liver tumor. It is the goal of this proposal to provide proof-of-concept for the use of the ASC-derived hepatocytes and/or HepaRG as a model system(s) for NAFLD. PUBLIC HEALTH RELEVANCE: Non-alcoholic fatty liver disease (NAFLD) is a chronic hepatic disorder affecting up to 25% of the general population and can progress to non-alcoholic steatohepatitis (NASH) and liver failure. Current NAFLD models are grossly inadequate due to the limited availability and poor characteristics of human primary hepatocytes in culture. This proposal focuses on the characterization of two alternative human cell-based models for the study of NAFLD in vitro, the development and implementation of which will have a significant and immediate impact on the study of NAFLD in humans.