Studies on mechanisms for apoptosis and carcinogenessis, and stam cell transplantation in hereditary liver diseases.

遗传性酪氨酸血症是一种由富马酰乙酸水解酶（FAH）缺乏引起的遗传病。患者表现出严重的内脏损伤。FAH缺乏的小鼠是新生儿死亡的，这阻碍了阐明疾病过程机制的努力。Fah-/- hpd -/-双突变体的使用为酪氨酸血症的研究提供了新的机会。使用模型的研究揭示了该疾病内脏损伤的基本特征。(1)利用基因芯片分析双突变体匀浆处理后基因表达的变化。本实验比较了双突变体和III型小鼠（HPD-/-）肝脏中的基因表达模式。对感兴趣的rna进行实时定量RT-PCR分析，碳水化合物、脂肪酸相关代谢酶的表达减少最为突出。这些结果提示HT1患者的代谢异常和凝血因子异常是与肝细胞内FAA积累有关的特异性事件，而不是一般肝损害的一个方面。(2)我们研究了受损唾液腺中存在内胚层祖细胞的可能性。在本实验中，我们使用FAH缺陷小鼠作为供体进行细胞移植。在脾内注射从受损唾液腺中提取的细胞后，供体细胞在肝脏中找到。最后，我们分离出在I型胶原包被培养皿上增殖的上皮样细胞。(3)祖细胞同时表达a6b1整合素和细胞质层粘连蛋白。神经祖细胞标记物巢蛋白、造血干细胞标记物CD34和肝卵圆细胞标记物如白蛋白、蛋白（AFP）和细胞角蛋白19在该细胞中呈阴性。当细胞经门静脉移植到肝脏时，细胞被整合到肝小梁中并产生白蛋白。(4)当SGP-1细胞在I型胶原包被培养皿上形成簇时，它们分化为内胚层谱系，并出现两种主要类型的簇。一组由肝细胞样细胞类型（肝簇）组成，另一组由胰岛样细胞类型（胰腺簇）组成。肝细胞簇含有AFP和/或白蛋白阳性的细胞，胰腺细胞簇含有胰高血糖素和/或胰岛素阳性的细胞。这些细胞是组织干细胞，能够分化为内胚层细胞，包括肝细胞样细胞和胰岛细胞样细胞。少

Hreditary tyrosinemia typelis a genetic disease caused by deficiency of fumarylacetoacetate hydrolase (FAH). The patients show severe visceral injuries. Mice with FAH deficiency are neonatal leathal and this hampered the efforts to elucidate the mechanisms of disease process. The use of Fah-/-Hpd-/- double mutants provided new opportunity for studies on tyrosinemias. The studies using the models revealed essential features of visceral injury in this disease.(1) We analyzed altered expression of genes after the administration of homogentisate in the double mutants by using gene chips. In thisexperiment gene expression patterns in the livers of double mutants and III mice (HPD-/-) were compared. The RNAs interested were analyzed by real-time quantitative RT-PCR Reduction of expression of metabolic enzymes related to carbohydrate, fatty acids are prominent. These results imply that in the patients with HT1, abnormality of metabolisms and blood coagulation factors are specific events relat … More ed to accumulation of FAA in hepatocytes but not one aspect of general liver damage.(2) we investigated possibility for the presence of endodermal progenitor cells in the damaged salivary gland. For this experiments we used FAH deficient mice as a donor for cell transplantations. After intrasplenic injection of cells prepared from damaged salivary glands, the donor cells were found the liver. Finally we isolated epithelium like cells which proliferate on type I collagen-coated dishes.(3) The progenitor cell expresses both a6b1 integrin and cytoplasmic laminin. Neural progenitor marker nestin, hematopoietic stem cell marker CD34, and hepatic oval cell markers such as albumin, afetoprotein (AFP) and cytokeratin 19 are negative in this cell. When the cells were transplanted into the liver via portal vein, cells wereintegrated into hepatic trabecula and produced albumin.(4) When SGP-1 cells formed clusters on type I collagen-coated dishes, they differentiated into endodermal lineage and two major types of clusters appeared. One consisted of hepatocyte-like cell type (hepatic cluster) and the other consisted of islet-like cell type of the pancreas (pancreatic cluster). The hepatic clusters contained cells positive for AFP and/or albumin, and the cells in the pancreatic clusters are positive for glucagon and/or insulin. These cells aretissue stem cells and able to differentiate into endodermal lineageincluding hepatocyte-like cells and islet-like cells. Less