Directing Embryonic Stem Cells to Hepatocytes

描述(由申请人提供)：原位肝移植(OLT)治疗肝病具有相当高的发病率和死亡率。此外，由于器官短缺，每年有数千人在没有移植的情况下死亡。因此，更安全、更方便的替代疗法将使许多需要肝移植的人受益。一种可能解决这一问题的方法是开发一种能够表达肝脏特异性基因的增殖性细胞系，这种基因可以用于细胞移植或生物人工肝。从人类胚胎干细胞(ESC)开发这样的系将提供对药理学和毒理学研究有价值的细胞，并建立一种可用于人类细胞的方法。具体目的：1)确定体外诱导胚胎干细胞分化为肝细胞的条件，并对分化后的细胞进行鉴定；2)建立人胚胎干细胞的体内潜能。方法：经验性地分析各种条件，以描述沿着肝细胞谱系分化胚胎细胞的最有效的方法。正在使用的小区的NIH代码编号是WA01。为了阐明诱导细胞增殖或肝细胞基因表达的机制，将利用肝脏特异性基因产物和生长因子反应性的分析进行特定的操作。为了确定细胞能否在移植后植入、存活和增殖，将在免疫缺陷NOD-SCID小鼠模型中进行研究。与健康相关：如果研究成功，它将提供无限来源的分化的人类肝细胞样细胞，可用于基于细胞的治疗或药理学研究。

DESCRIPTION (provided by applicant): Treatment of liver disease with orthotopic liver transplantation (OLT) carries considerable morbidity and mortality. Moreover, due to organ shortages, thousands of people die each year without getting transplanted. Therefore, safer and more convenient alternative therapies will benefit many people requiring liver transplantation. An approach that might address this problem is the development of a proliferative cell line that expresses liver-specific genes which could be employed for cell transplantation or for a bioartificial liver. Developing such a line from human embryonic stem cells (ESC) would provide cells valuable for pharmacology and toxicology studies, as well as establishing an approach that could be employed in human cells. Specific Aims: 1) to determine conditions for directing the ESC to differentiate into hepatocytes in vitro, and to characterize the differentiated cells; and 2) to establish the in vivo potential of human ESC. Methods: A variety of conditions will be empirically assayed to delineate the most effective approach to differentiate the embryonic cells along a hepatocyte lineage. The NIH code number of the cells that are being used is WA01. To delineate mechanisms aimed at inducing either proliferation or hepatocellular gene expression in the cells, specific manipulations will be utilized with assays of liver-specific gene products and growth factor responsiveness. To determine whether the cells can engraft, survive and proliferate after transplantation, studies will be conducted in immunodeficient NOD-SCID mouse models. Health Relatedness: If the studies are successfully undertaken, it will provide for the development of an unlimited source of differentiated human hepatocyte-like cells that can be employed in cell-based therapeutics or in pharmacology studies.