HUMAN HEPATOCYTE GROWTH FACTORS

理解这一顺序背后的细胞和分子机制 而补偿性肝再生的精确度对于 对肝癌发生和毒理学的认识和干预 以及肝细胞移植策略的发展和 基因疗法。越来越多的证据表明，对损害的反应 正常的肝脏是通过激活和抑制 多种细胞因子在肝脏内而不是体外的活性 荷尔蒙。这一有序过程的功能障碍会导致进展 变得恶毒。成纤维细胞生长因子家族的14个配体，它们的酪氨酸 激酶受体(FGF-R)(四个基因，16个剪接变体导致 100个以上的异构体)及其硫酸乙酰肝素蛋白多糖- 肝脏内的受体参与瞬时调节 实质细胞和非实质细胞的生长和功能 导致肝癌的功能障碍。这个续建项目将 肝组织中成纤维细胞生长因子-13(FHF-13)表达的意义 肝癌。成纤维细胞生长因子和成纤维细胞生长因子受体特异性硫酸肝素蛋白多糖 FGFR信号转导复合体的亚基将从 肝细胞，其蛋白质核心的特征和编码的cdna将 经成纤维细胞生长因子和成纤维细胞生长因子受体亲和层析鉴定。乱交 FGFR之间的二聚化和功能相互作用 将使用嵌合体确定肝细胞中的同种异型 用转化生长因子β细胞内激酶构建胞外结构域。 四种FGFR胞内蛋白激酶结构域及其亚结构域对血管内皮生长因子表达的影响 有丝分裂、抑制细胞生长和肝细胞表型 使用胞外结构域和嵌合结构确定 细胞内的激酶域。变异体NH2末端的作用 肝脏主要成纤维细胞生长因子多肽-1及其蛋白水解性修饰 将会被确定。小鼠肝脏的基因靶向将是 用来分析FGFR1、2、3、4和成纤维细胞生长因子-1的功能作用 静息和再生肝细胞表型及其对 肝癌的发展(与S.Thorgeirsson博士和 J.Martin博士)。结果表明，FGFR 1、2、3、4和 它们的变种将与时间和细胞表型相关 原代肝细胞培养标记罕见的移行细胞相关类型 成熟的肝细胞和胆管细胞系。一个统一的 提出了项目所基于的假设，具体是 FGFR和辅助因子HSPG与成熟表型相关 而过渡类型的特征是特定的共表达 FGFR和HSPG亚型。

Understanding the cellular and molecular mechanisms underlying the order and precision of compensatory liver regeneration is essential for understanding and intervention in liver carcinogenesis and toxicology as well as development of strategies for liver cell transplantation and gene therapy. Increasing evidence indicates that response to damage by the normal liver is orchestrated by activation and repression of the activity of multiple cytokines within the liver rather than external hormones. Dysfunction of this ordered process results in progression to malignancy. The FGF family of fourteen ligands, their tyrosine kinase receptors (FGF-R) (four genes, 16 splice variants resulting in greater than 100 isoforms) and their heparan sulfate proteoglycan co- receptors within liver are involved in the transient regulation of growth and function in both parenchymal and non-parenchymal cells and the dysfunction leading to hepatoma. This continuation project will characterize significance of expression of FHF-13 (FGF-13) in liver and hepatomas. FGF and FGFR specific heparan sulfate proteoglycan (HSPG) subunits of the FGFR signal transduction complex will be isolated from liver cells, characterized and cDNA coding for their protein cores will be identified by FGF and FGFR affinity chromatography. The promiscuity (or lack of it) of dimerization and functional interaction between FGFR isotypes will be determined in liver cells by using chimeric constructions of ectodomain with the TFG beta intracellular kinases. Impact of the four FGFR intracellular kinase domains and subdomains on mitogenesis, inhibition of cell growth and phenotype of liver cells will be determined using chimeric constructions of ectodomain and intracellular kinase domains. The role of the variant NH2-terminus of the major liver FGF polypeptide, FGF-1, and its proteolytic modification will be determined. Gene targeting to the liver in mice will be employed to dissect the functional role of FGFR1,2,3,4 and FGF-1, on resting and regenerating liver cell phenotypes as well as effect on development of hepatomas (collaborations with Dr. S. Thorgeirsson and Dr. J. Martin). From the results, the expression of FGFR 1,2,3,4 and their variants will be correlated with time and cell phenotypes in primary liver cell culture to mark rare transitional cell types related to mature hepatocytes and bile ductule cell lineages. A unifying hypothesis is presented on which the project is based in which specific FGFR and co-factor HSPG are associated with the mature phenotypes whereas transitional types are characterized by specific co-expression of FGFR and HSPG isoforms.