Genetic regulation of ductular reaction in liver injury and regeneration

肝损伤和再生中导管反应的基因调控

• 批准号: 10595652
• 负责人: Adam David Gracz
• 金额: $ 39.97万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10595652
• 关键词: Acute; Adult; Alleles; Biliary; Binding; Biological Assay; Cartilage; Cell Differentiation process; Cell Proliferation; Cells; Cholestasis; Chromatin; Chronic; Data; Development; Duct (organ) structure; Enhancers; Epigenetic Process; Epithelial Cell Proliferation; Epithelial Cells; Epithelium; Equilibrium; Esophagus; Exhibits; Functional disorder; Gene Expression; Genes; Genetic; Genetic Transcription; Genome; Genomic approach; Genomics; Goals; Hair follicle structure; Hepatocyte; Heterogeneity; Homeostasis; Human; Hybrids; Impairment; In Vitro; Injury; Intrahepatic bile duct; Knockout Mice; Knowledge; Liver; Liver Failure; Liver Regeneration; Liver diseases; Maps; Mediating; Modeling; Mus; Natural regeneration; Organoids; Phenotype; Play; Population; Process; Proliferating; Reaction; Regenerative Medicine; Regenerative capacity; Regulation; Reporting; Role; Specific qualifier value; Testing; Tissues; Transgenes; end stage liver disease; functional genomics; gene regulatory network; genome-wide; in vivo; in vivo Model; injury and repair; insight; intrahepatic; liver function; liver injury; liver transplantation; mouse model; multiple omics; novel therapeutics; regenerative; repaired; response; severe injury; stem cell function; stem cells; targeted treatment; therapeutic target; tissue regeneration; transcription factor; transcriptome sequencing; transcriptomics; transdifferentiation

PROJECT SUMMARY The liver exhibits remarkable capacity for regeneration, but chronic injury or severe acute damage can overwhelm compensatory responses and result in liver failure. The need for transplantable livers regularly exceeds the donor pool, necessitating the development of new regenerative medicine-based therapies and a deeper understanding of the liver’s endogenous repair mechanisms. This proposal seeks a mechanistic understanding of gene regulatory networks underlying ductular reaction (DR), a damage response associated with a broad range of liver injury and disease. DR is defined by the proliferative expansion of biliary epithelial cells (BECs) and can involve context-dependent lineage conversion between mature hepatocytes and BECs that contributes to tissue regeneration. The genetic regulation of DR remains poorly understood, including how BECs balance proliferation and phenotypic plasticity. Sox9 is a transcription factor required for stem/progenitor cell function in a number of epithelial tissues and has been shown to establish cellular identity through genome-wide effects on the chromatin landscape. In the liver, Sox9 is required for timing of BEC specification in development and is broadly expressed in adult BECs. Our lab recently used a Sox9EGFP transgene to study BEC heterogeneity and showed that Sox9 is expressed at distinct levels in subpopulations of BECs and peribiliary hybrid hepatocytes (HybHeps) during homeostasis and cholestasis. New findings from our lab also demonstrate abnormalities in BECs of adult Sox9 knockout mice. The central hypothesis of this proposal is that Sox9 functions as a master regulator of DR, by inhibiting proliferation and promoting BEC identity. The following specific aims will test this hypothesis: Aim 1A will determine the role of Sox9 in damage induced BEC proliferation, through the use of the Sox9EGFP allele and (1) combined BEC/hepatocyte or (2) BEC-specific Sox9 knockout mouse models. Aim 1B will determine the role of Sox9 in bi-directional BEC-to-hepatocyte plasticity, through complementary in vivo lineage tracing and in vitro organoid assays. Aim 2A will map the chromatin regulatory landscape of DR, by integrating transcriptomics and chromatin assays in BEC subpopulations during liver injury. Aim 2B will determine the genomic regulatory impact of Sox9 in DR by applying single cell multi-omics to BEC- specific Sox9 knockout mouse models. The data generated in this project will provide fundamental mechanistic insight into genetic regulation of DR and identify regulatory nodes for therapeutic targeting to enhance regeneration in end stage liver disease.

项目摘要 肝脏具有显着的再生能力，但是慢性损伤或严重急性损害可以 压倒性补偿性反应并导致肝衰竭。需要定期进行移植生命 超过供体池，这是开发新的基于再生医学疗法的必要条件 对肝脏内源性修复机制的更深入了解。该建议寻求机械 了解导管反应（DR）的基因调节网络，这是与损伤响应相关的 具有广泛的肝损伤和疾病。 DR由胆道上皮的扩散器扩展来定义 细胞（BEC），并且可以涉及成熟肝细胞和BEC之间的上下文依赖性谱系转化 有助于组织再生。 DR的遗传调节仍然很了解，包括BEC 平衡增殖和表型可塑性。 Sox9是茎/祖细胞所需的转录因子 在许多上皮组织中的功能，已证明可以通过全基因组建立细胞身份 对染色质景观的影响。在肝脏中，SOX9是开发中BEC规范时期所必需的 并在成人BEC中广泛表达。我们的实验室最近使用Sox9EGFP转换来研究BEC异质性 并表明Sox9在BEC和Peribilariary杂种的亚群中以不同的水平表达 稳态和胆汁淤积期间的肝细胞（Hybheps）。我们实验室的新发现也证明了 成人Sox9基因敲除小鼠的BEC异常。该提议的中心假设是Sox9功能 作为DR的主要监管者，通过抑制增殖并促进BEC身份。以下特定目标 将检验以下假设：AIM 1A将通过 使用Sox9EGFP等位基因和（1）BEC/HEPATOCYTE或（2）BEC特定的Sox9敲除鼠标 AIM 1B将通过 完全体内谱系跟踪和体外器官分析。 AIM 2A将映射染色质调节 DR的景观，通过在肝损伤过程中将转录组学和染色质分析整合在BEC亚群中。 AIM 2B将通过将单个细胞多词应用于Bec- 特定的SOX9敲除鼠标模型。该项目中产生的数据将提供基本的机理 深入了解DR的遗传调节并确定热靶向的调节节点以增强 末期肝病的再生。