The Fetal Hepatocyte Phenotype and Cell-Based Therapy for Liver Disease

胎儿肝细胞表型和肝病细胞治疗

• 批准号: 8608214
• 负责人: Philip A. Gruppuso
• 金额: $ 36.01万
• 依托单位: RHODE ISLAND HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8608214
• 关键词: 1-Phosphatidylinositol 3-Kinase; Accounting; Adult; Advanced Development; Area; Artificial Liver; Behavior; Biogenesis; Biological; Biology; Cell Cycle; Cell Cycle Progression; Cell Lineage; Cell Therapy; Cells; Characteristics; Chromatin Structure; Development; Device or Instrument Development; Disease; Embryo; Endothelial Cells; Engraftment; Epigenetic Process; Event; Fetal Development; Fetal Liver; Fetus; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genome; Goals; Growth; Health; Hepatic; Hepatocarcinogenesis; Hepatocyte; Histones; Human; In Vitro; Injury; Laboratories; Leucine; Life; Liver; Liver diseases; Location; MAPK3 gene; Metabolic; Metabolic Diseases; Metabolism; Methods; Mitogens; Molecular; Newborn Infant; Nutrient; Pathway interactions; Peptide Hydrolases; Perinatal; Phenotype; Physiology; Population; Post-Translational Protein Processing; Pregnancy; Process; Rattus; Recovery; Regulation; Resistance; Ribosomes; Rodent; Role; Signal Pathway; Signal Transduction; Sirolimus; Testing; Translations; Transplantation; Variant; base; bile ductular; carcinogenesis; cell behavior; cell type; cholangiocyte; epigenetic marker; fetal; fetus cell; in vivo; inhibitor/antagonist; injured; innovation; insight; liver cell proliferation; liver function; liver injury; mature animal; multipotent cell; novel; postnatal; public health relevance

Growth and functional differentiation of the liver are critical to late gestation fetal metabolism, the perinatal transition and metabolic adaptation by the newborn. The biology of fetal liver development also has implications for regulation of fetal somatic growth, hepatic carcinogenesis, and cell-based therapy for liver disease. Our laboratory has long focused on late gestation liver development in the rodent. In doing so, we have identified a fetal hepatocyte phenotype that is defined by the signaling pathways that regulate fetal hepatocyte growth, proliferation and gene expression. More recently, we demonstrated the ability of late gestation fetal rat liver cells possessing a key hepatocyte marker, leucine amino peptidase (LAP), to repopulate an injured adult liver. This is a capacity not shared by adult rat hepatocytes. The present proposal is based on the central hypothesis that histone variants and histone posttranslational modifications (PTMs), acting through effects on chromatin structure, account for the signaling phenotype of late gestation fetal rat hepatocytes and the persistence of this phenotype following transplantation into the adult liver microenvironment. The long term goal of the project is to identify genetic and epigenetic mechanisms that account for the novel characteristics of fetal liver cells, thereby applying an understanding of fetal liver development to the development of cell-based therapy for liver disease. This goal will be pursued through three Specific Aims. Specific Aim 1 is to identify a fetal hepatocyte epigenetic signature by examining chromatin structure, histone variants and histone PTMs in liver during late fetal versus adult life. Specific Aim 2 is to characterize the functional relationship between histone variants, histone PTMs, chromatin structure and regulation of key growth-regulating genes in liver during the fetal to adult transition. This aim will test the hypothesis that specific histone variants and PTMs are associated with developmental changes in critical growth-regulating genes. In Specific Aim 3, we will assess the role of the epigenetic signature identified in Aims 1 and 2 in defining and maintaining the ability of late gestation fetal rat liver cells to repopulate an injured adult rat liver. This aim will test the hypothesis that a fetal hepatic epigenetic signature is characteristic of a subpopulation of fetal hepatocytes that possess both hepatocyte and bile ductular markers, and that this epigenetic signature is present both before transplantation and after engraftment. Completion of these aims will provide insight into molecular mechanisms that determine cell behavior in the developing liver while advancing the development of cell-based therapy for liver disease. The project is innovative in a number of aspects. We will generate new information regarding the epigenetic regulation of gene expression during liver development. In doing so, we will characterize a previously unidentified, multipotent cell population in fetal liver that can repopulate an injured adult liver. Finally, we will use innovative methods throughout these studies, thus advancing the ability to study epigenetic regulation in the context of mammalian developmental physiology.

肝脏的生长和功能分化对于妊娠晚期胎儿代谢、围产期胎儿代谢至关重要。 新生儿的过渡和代谢适应。胎儿肝脏发育的生物学也有 对胎儿体细胞生长调节、肝癌发生和基于细胞的肝脏治疗的影响 疾病。我们的实验室长期以来一直专注于啮齿动物妊娠晚期肝脏的发育。这样做，我们 已经确定了胎儿肝细胞表型，该表型由调节胎儿的信号通路定义 肝细胞生长、增殖和基因表达。最近，我们展示了后期的能力 妊娠胎鼠肝细胞具有关键的肝细胞标记物亮氨酸氨基肽酶（LAP）， 重新填充受伤的成人肝脏。这是成年大鼠肝细胞不具备的能力。目前的建议是 基于组蛋白变异和组蛋白翻译后修饰（PTM）的中心假设， 通过影响染色质结构发挥作用，解释妊娠晚期胎鼠的信号传导表型 肝细胞以及移植到成人肝脏后这种表型的持续存在 微环境。该项目的长期目标是确定遗传和表观遗传机制 解释胎儿肝细胞的新特征，从而应用对胎儿肝脏的理解 发展到基于细胞的肝病疗法的发展。这一目标将通过 三个具体目标。具体目标 1 是通过检查来识别胎儿肝细胞表观遗传特征 胎儿晚期与成年期间肝脏中的染色质结构、组蛋白变异和组蛋白 PTM。具体目标 图2是表征组蛋白变体、组蛋白PTM、染色质结构和 在胎儿到成人的过渡过程中肝脏中关键生长调节基因的调节。这个目标将考验 假设特定组蛋白变体和 PTM 与关键发育变化相关 生长调节基因。在具体目标 3 中，我们将评估表观遗传特征的作用 目标 1 和 2 确定并维持妊娠晚期胎鼠肝细胞重新填充受损细胞的能力 成年大鼠肝脏。这一目标将检验胎儿肝脏表观遗传特征是胎儿肝脏特征的假设。 具有肝细胞和胆管标记物的胎儿肝细胞亚群，并且这 表观遗传特征在移植前和植入后都存在。完成这些目标将 深入了解决定肝脏发育过程中细胞行为的分子机制 肝病细胞疗法的发展。该项目在多个方面都有创新。我们 将产生有关肝脏发育过程中基因表达的表观遗传调控的新信息。 在此过程中，我们将描述胎儿肝脏中先前未识别的多能细胞群，该细胞群可以 重新填充受伤的成人肝脏。最后，我们将在整个研究中使用创新方法，从而 提高在哺乳动物发育生理学背景下研究表观遗传调控的能力。