Role of FGF10 in liver organogenesis and alcohol-impaired regeneration

FGF10 在肝器官发生和酒精损伤再生中的作用

• 批准号: 7289368
• 负责人: KASPER SAONUN WANG
• 金额: $ 16.37万
• 依托单位: CHILDREN'S HOSPITAL OF LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-25 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7289368
• 关键词: Adult; Alcohol abuse; Alcoholic Liver Diseases; Alcohols; Artificial Liver; Cell Proliferation; Cell Separation; Cells; Cirrhosis; Data; Dependence; Development; Dominant-Negative Mutation; Embryo; Embryonic Development; Endoderm; Epithelium; Ethanol; Exhibits; Fibroblast Growth Factor Receptor 2; Fluorescence; Fluorescence-Activated Cell Sorting; Galactosidase; Gastrointestinal tract structure; Genes; Growth Factor; Health; Healthcare; Hepatectomy; Hepatic; Hepatic Fibrogenesis; Hepatic Stellate Cell; Hepatocyte; Hydrolysis; Immunofluorescence Immunologic; Impairment; In Vitro; Ingestion; Injury; LacZ Genes; Lead; Ligands; Liver; Liver Cirrhosis; Liver Regeneration; Liver diseases; Mediating; Mesenchymal; Mesenchyme; Mesoderm; Methods; Modeling; Molecular; Morbidity - disease rate; Mus; Mutant Strains Mice; Myofibroblast; Natural regeneration; Nuclear Translocation; Numbers; Organogenesis; Partial Hepatectomy; Pathway interactions; Pattern; Personal Satisfaction; Play; Polymerase Chain Reaction; Population; Prevention; Primitive foregut structure; Process; Protein Isoforms; Protein Overexpression; Relative (related person); Reporter; Research Personnel; Role; Signal Transduction; Societies; Sorting - Cell Movement; Staging; Stem cells; Time; Today; Transgenic Mice; Transgenic Organisms; United States; Up-Regulation; WNT Signaling Pathway; autocrine; base; cell type; cost; early embryonic stage; feeding; fetal; fibroblast growth factor 10; gain of function; in vivo; insight; intestinal crypt; liver transplantation; loss of function; mortality; mutant; novel; organ regeneration; oval cell; postnatal; problem drinker; programs; receptor; repaired; response to injury; stellate cell

DESCRIPTION (provided by applicant): This proposal focuses on the potential role of reduced FGF10 signaling in the setting of ethanol (EtOH) impaired liver regeneration. FgflO, expressed in the embryonic foregut mesoderm, normally interacts with the adjacent endoderm through Fibroblast Growth Factor Receptor 2 1Mb (FGFR2b). Absence of signaling through FGFR2b results in atresias of numerous gastrointestinal tract structures. We have preliminary evidence showing that FGF10 activates canonical WNT signaling in the developing liver through FGFR2b. Our studies indicate that Fgf 10 is expressed by activated hepatic stellate cells, which play a key role in liver fibrogenesis, and that Fgfr2b is expressed by progenitor cells, hepatoblasts prenatally and oval cells postnatally. Consistent with the observation that FGFR2b signaling is activated during liver regeneration, we have evidence that Fgf 10 expression, which is upregulated after partial hepatectomy, is reduced in the setting of ethanol-induced impaired liver regeneration. We hypothesize that ethanol suppresses signaling through the FGF10/FGFR2b, thus, impairing progenitor cell proliferation. We thus propose the following specific aims: (1) To determine the role of FGF10 signaling via FGFR2b during liver regeneration following partial hepatectomy (PH) in the absence or presence of EtOH in transgenic mice. Liver-specific induced overexpression of the dominant negative soluble FGFR2b isoform or of Fgf 10 in the setting of EtOH impaired liver regeneration following PH will be performed for loss-of-function or gain-of-function analyses, respectively. (2) To determine the identity and role of Fgf 10-expressing cells in hepatogenesis and EtOHimpaired liver regeneration. Cells expressing Fgf 10 from transgenic embryo livers and PH livers exposed to EtOH will be sorted by fluorescence activated cell sorting (FACS) and characterized by real-time PCR. (3) To determine the identity of cells undergoing FGF10-mediated canonical WNT activation. Cells with activated canonical WNT signaling will be sorted by FACS. Loss and gain-of function analyses for FgflO will be performed to determine relative levels of canonical WNT activiation. Alcohol impairs the liver's ability to repair and regenerate itself. This contributes to the development of liver cirrhosis. We postulate that the mechanism by which alcohol impairs liver regeneration may be due to impaired signaling through the FGF10/FGFR2b pathway we show normally promotes liver regeneration.

描述（由申请人提供）：该提案重点关注减少 FGF10 信号传导在乙醇 (EtOH) 损害肝再生的情况下的潜在作用。 FgflO 在胚胎前肠中胚层中表达，通常通过成纤维细胞生长因子受体 2 1Mb (FGFR2b) 与相邻内胚层相互作用。 FGFR2b 信号传导的缺失会导致许多胃肠道结构闭锁。我们有初步证据表明 FGF10 通过 FGFR2b 激活发育中肝脏中的经典 WNT 信号传导。我们的研究表明，Fgf 10 由活化的肝星状细胞表达，在肝纤维形成中发挥关键作用，而 Fgfr2b 由祖细胞、产前成肝细胞和产后卵圆细胞表达。与 FGFR2b 信号在肝再生过程中被激活的观察结果一致，我们有证据表明，部分肝切除术后上调的 Fgf 10 表达在乙醇诱导的肝再生受损的情况下降低。我们假设乙醇通过 FGF10/FGFR2b 抑制信号传导，从而损害祖细胞增殖。因此我们提出以下建议 具体目标：(1) 确定在转基因小鼠中，在存在或不存在 EtOH 的情况下，部分肝切除术 (PH) 后，FGF10 信号通过 FGFR2b 在肝脏再生过程中的作用。在 PH 后 EtOH 损害肝脏再生的情况下，将分别进行肝脏特异性诱导的显性失活可溶性 FGFR2b 亚型或 Fgf 10 的过度表达，以进行功能丧失或功能获得分析。 (2) 确定表达Fgf 10的细胞在肝发生和EtOH损伤的肝再生中的身份和作用。来自暴露于 EtOH 的转基因胚胎肝脏和 PH 肝脏的表达 Fgf 10 的细胞将通过荧光激活细胞分选 (FACS) 进行分选，并通过实时 PCR 进行表征。 (3) 确定经历 FGF10 介导的经典 WNT 激活的细胞的身份。具有激活的规范 WNT 信号传导的细胞将通过 FACS 进行分选。将进行 FgflO 功能丧失和获得功能分析以确定典型 WNT 激活的相对水平。酒精会损害肝脏的自我修复和再生能力。这有助于肝硬化的发展。我们推测，酒精损害肝再生的机制可能是由于我们显示通常促进肝再生的 FGF10/FGFR2b 通路信号传导受损。