Regulation of HNF4 in Hepatic Failure in Cirrhosis

HNF4 在肝硬化肝衰竭中的调控

• 批准号: 8698412
• 负责人: Ira J. Fox
• 金额: $ 59.51万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-15 至 2017-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8698412
• 关键词: Adult; Alcohols; Animals; CCL4 gene; Cell Aging; Cells; Cessation of life; ChIP-seq; Characteristics; Child; Chromatin; Chronic; Cirrhosis; Cirrhotic hepatocyte; Defect; Down-Regulation; ETS1 gene; EZH2 gene; Etiology; Exhibits; Failure; Functional disorder; Gene Expression; Gene Expression Profile; Genes; Hepatic; Hepatitis B Virus; Hepatitis C virus; Hepatocyte; Human; IL6 gene; Immune; Infection; Injury; Lead; Liver; Liver Cirrhosis; Liver Failure; Liver Regeneration; Liver diseases; MADH4 gene; Mental Depression; Metabolic; Modeling; Mus; NR4A1 gene; Natural regeneration; Nuclear Receptors; Patients; Phenotype; Public Health; Rattus; Recombinants; Regulation; Repression; Rodent; Series; Signal Pathway; Signal Transduction Pathway; Staging; TNF gene; TNFRSF5 gene; Telomerase; Telomere Shortening; Time; Transcriptional Activation; Transplantation; United States; Virus; adeno-associated viral vector; chronic liver disease; clinical efficacy; genome-wide; human HNF4A protein; improved; improved functioning; liver function; liver injury; loss of function; p65; promoter; public health relevance; repaired; restoration; transcription factor; transcriptome sequencing

DESCRIPTION (provided by applicant): The cause of liver failure in cirrhosis is not well understood, as the liver is capable of regeneration and functions normally despite loss of more than half of its hepatocytes. Hepatic failure in cirrhosis therefore results from additional dysfunction of the remaining hepatocytes. Our Preliminary Studies showed that primary hepatocytes derived from cirrhotic livers with decompensated function exhibit numerous alterations in gene expression and proliferative capacity. Yet, despite critical shortening of telomeres and loss of telomerase activity, these hepatocytes can eventually recover their capacity for regeneration and function after transfer into a normal liver. Our transcriptome analysis demonstrated that progression to hepatocyte failure was associated with down regulation of transcription factor HNF4¿ and suppression of its regulatory network. Since HNF4¿ deficiency could explain the depression of downstream effectors, mature hepatocyte-specific genes, and general hepatic function, we studied end-stage cirrhotic hepatocytes in culture and found that HNF4¿ expression, restored via AAV transduction, dramatically and immediately corrected the phenotype. Next, AAV-HNF4¿ was given IV to rodents with decompensated cirrhosis. Their hepatocyte function improved to almost normal levels within 2 weeks and survival was prolonged from ~2 weeks to more than 100 days! Thus, disruption of HNF4¿ transcriptional activation appears to be the mechanism responsible for hepatic failure in advanced cirrhosis. We therefore hypothesize that restoration of HNF4¿ will effectively treat cirrhotic patients with end-stage liver failure by correcting the metabolic defects and reversing the hepatocyte replicative senescence. In these studies we will use a recombinant AAV vector that encodes HNF4¿ driven from an inducible promoter to determine whether short term treatment with HNF4¿ can lead to sustained normalization of hepatic function and survival. In addition, we will assess the utility of HNF4¿-AAV treatment during continuing injury with CCL4 to determine the potential clinical efficacy of such therapy. To determine the mechanism of HNF4¿ downregulation in decompensated cirrhosis, we will perform a genome-wide ChIP-Seq analysis of isolated hepatocytes and whole liver. Finally, we will determine the extent to which human end-stage cirrhotic livers share the same characteristics as those identified in our rodent studies, and will determine the extent that restoration of HNF4¿ expression can normalize human hepatocytes derived from these end-stage livers.

描述（由适用提供）：肝硬化中肝衰竭的原因尚不清楚，因为肝脏能够再生和功能通常希望丧失其一半以上的肝细胞。因此，肝硬化中的肝衰竭是由于其余肝细胞的其他功能障碍引起的。我们的初步研究表明，源自肝硬化的原发性肝细胞具有代偿功能的作用，暴露了基因表达和增殖能力的许多改变。然而，尽管端粒的严重缩短和端粒酶活性的丧失，但这些肝细胞最终可以恢复其转移到正常肝脏后再生和功能的能力。我们的转录组分析表明，向肝细胞衰竭的进展与转录因子HNF4的调节及其调节网络的抑制有关。由于HNF4缺乏可以解释下游作用的抑郁，成熟的肝细胞特异性基因和一般的肝功能，因此我们研究了培养中终末期肝硬化肝细胞，发现HNF4表达是通过AAV转导，很大程度上恢复的，并立即恢复了现象型。接下来，AAV-HNF4`他们的肝细胞功能在2周内提高到几乎正常水平，生存率从〜2周延长到超过100天！这是HNF4€转录激活的破坏似乎是导致晚期肝硬化肝炎衰竭的机制。因此，我们假设恢复HNF4¿将通过纠正代谢缺陷并逆转肝细胞复制感应感，有效地治疗肝硬化患者。在这些研究中，我们将使用编码从诱导启动子驱动的HNF4的重组AAV载体来确定用HNF4驱动的短期治疗是否会导致肝功能和生存的持续正常化。此外，我们将评估CCL4持续损伤期间HNF4�-AAV治疗的效用，以确定这种疗法的潜在临床效率。为了确定肝硬化代偿性肝硬化的下调的机理，我们将对分离的肝细胞和整个肝脏进行全基因组芯片seq分析。最后，我们将确定人类终末期肝硬化的特征与啮齿动物研究中发现的特征相同，并将确定HNF4¿表达的恢复可以使人类肝细胞从这些终阶段得出的恢复。