Transporter Expression in Response to Hepatotoxicants

对肝毒物反应的转运蛋白表达

• 批准号: 8287089
• 负责人: Jose E Manautou
• 金额: $ 30.87万
• 依托单位: UNIVERSITY OF CONNECTICUT STORRS
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-30 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8287089
• 关键词: ABCC1 gene; Accounting; Acetaminophen; Acute; Acute Liver Failure; Bioinformatics; Biological; Biological Assay; Cell Proliferation; Cell Survival; Cells; Chemicals; Computer Simulation; Data; Dose; EMSA; ES01; Excretory function; Exposure to; Funding; Gene Expression; Genes; Genetic Transcription; Goals; Health; Hepatic; Hepatobiliary; Hepatocyte; Hepatotoxicity; Human; In Vitro; Injury; Injury to Liver; Investigation; Knock-out; Knowledge; Kupffer Cells; Lead; Liver; Liver diseases; Mediating; Messenger RNA; Mission; Molecular; Molecular Biology; Mus; National Institute of Diabetes and Digestive and Kidney Diseases; Natural regeneration; Non-Prescription Drugs; Nuclear; Oxidative Stress; Paracrine Communication; Patients; Pharmaceutical Preparations; Play; Predisposition; Property; Proteins; Recovery; Regulation; Reporter Genes; Reporting; Research; Resistance; Resistance development; Risk; Role; Scanning; Signal Pathway; Small Interfering RNA; Specimen; Structure; Testing; Toxic effect; Transcriptional Regulation; Transfection; United States; Wild Type Mouse; acetaminophen overdose; acute liver disease; chromatin immunoprecipitation; cytotoxic; cytotoxicity; design; drug induced liver disease; hepatotoxin; metabolomics; novel; novel therapeutic intervention; paracrine; promoter; protein expression; research study; response; tert-Butylhydroperoxide; tissue repair; toxicant; transcription factor; transcriptomics; uptake

ABSTRACT Although knowledge on acetaminophen (APAP) hepatotoxicity has advanced significantly during the last three decades, the precise mechanism of toxicity remains unknown. Even less is known about a phenomenon known as autoprotection, in which the liver adapts to sub-toxic APAP exposure, resulting in resistance to subsequent toxic APAP dosing. Our long-term goal is to understand the role of MRP (ABCC) transporters in APAP-induced hepatotoxicity. During the current funding cycle we determined that the efflux transporter Mrp4 is the most significantly induced MRP during APAP hepatotoxicity. Our data also show a strong relationship between liver Mrp4 induction and development of resistance to APAP toxicity. Therefore, the hypothesis for this competing renewal is that "Mrp4 induction is a compensatory response to drug-induced liver injury that confers resistance to subsequent toxicant challenge". To test this hypothesis, three specific research aims have been formulated. First, we will analyze the role of Mrp4 in APAP hepatotoxicity by examining the susceptibility of Mrp4-/- mice to APAP. A complementary in vitro approach is to examine the susceptibility of stably transfected immortalized human hepatocytes overexpresing Mrp4 cells (hMRP4-HC04) to APAP cytotoxicity. Then, we will determine the functional consequences of Mrp4 induction using metabolomic approaches to identify endogenous molecules transported by MRP4 with paracrine functions promoting heightened cellular defenses and compensatory cell proliferation. Lastly, transcriptional regulation of MRP4 gene expression in response to oxidative stress will be examined using molecular biological approaches and bioinformatics. Characterization of the transcription activity of mouse and human Mrp4/MRP4 gene promoter and its proximal regions will be carried out. Additional investigations will determine the effects of two transcription factors (NFR1 and HES-1) in MRP4 gene expression. Altered liver MRP4 expression may be essential for cell survival during periods of recovery and regeneration from drug-induced liver injury. This adaptation may mediate more efficient hepatobiliary excretion of cytotoxic intermediates and/or enhance the export of endogenous substrates for paracrine signaling to adjacent hepatocytes and non-parenchymal cells to promote survival and tissue repair. An increased knowledge of MRP4 regulation is expected to lead to better treatments of specific liver disorders and reduce the risk of drug liver injury. !

抽象的 尽管对乙酰氨基酚（APAP）肝毒性的知识已提高 在过去的三十年中，显着的毒性仍然存在 未知。关于一种称为自动保护的现象，甚至不知道 肝脏适应亚毒性APAP暴露，导致对随后的有毒 APAP给药。我们的长期目标是了解MRP（ABCC）转运蛋白的作用 在APAP诱导的肝毒性中。在当前的资金周期中，我们确定 排出转运蛋白MRP4是APAP期间最显着诱导的MRP 肝毒性。我们的数据还显示了肝脏MRP4诱导之间的牢固关系 和对APAP毒性的抵抗力的发展。因此，为此的假设 竞争的更新是“ MRP4诱导是对药物诱导的补偿性反应 肝脏损伤赋予对随后的毒物挑战的抵抗力”。 假设，已经制定了三个具体的研究目标。首先，我们将分析 MRP4在APAP肝毒性中的作用，通过检查MRP4 - / - 小鼠的敏感性 APAP。一种互补的体外方法是检查稳定的敏感性 转染的永生的人肝细胞过多地说明了MRP4细胞（HMRP4-HC04） 为了APAP细胞毒性。然后，我们将确定MRP4的功能后果 使用代谢组方法鉴定运输的内源分子的诱导 由MRP4具有旁分泌功能，促进了增强的细胞防御能力和 补偿性细胞增殖。最后，MRP4基因的转录调控 响应氧化应激的表达将使用分子生物学检查 方法和生物信息学。小鼠转录活性的表征 人类MRP4/MRP4基因启动子及其近端区域将进行。 其他调查将确定两个转录因子的影响（NFR1和 HES-1）在MRP4基因表达中。肝脏MRP4表达改变可能是必不可少的 在药物诱导的肝损伤中恢复和再生期间的细胞存活。 这种适应可能介导细胞毒性的更有效的肝胆管排泄 中间体和/或增强旁分泌的内源性底物的出口 向相邻的肝细胞和非副质细胞发出信号，以促进生存和 组织修复。预计对MRP4法规的了解将导致更好 特定肝病的治疗方法并降低了肝损伤的风险。 呢