m6A Epitranscriptomics in Toxicant Associated Steatohepatitis

m6A 表观转录组学在中毒性相关脂肪性肝炎中的应用

基本信息

批准号：
10220036
负责人：
Matthew C Cave
金额：
$ 28.86万
依托单位：
UNIVERSITY OF LOUISVILLE
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-20 至 2023-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10220036
关键词：
Address Adenosine Adipose tissue Affect Alternative Splicing Animal Model Antibodies Aryl Hydrocarbon Receptor Attenuated Biological Markers C57BL/6 Mouse Cessation of life Cirrhosis Data Diet Dioxygenases Disease Dose Environmental Exposure Environmental Pollutants Environmental Pollution Enzymes Epidermal Growth Factor Euthanasia Event Exposure to Fatty Liver Fatty acid glycerol esters Female Fibrosis Functional disorder Future Genes Goals Health Hepatic Hepatocyte High Fat Diet Histology Homeostasis Human Hypertriglyceridemia Immunoprecipitation Inflammation Knockout Mice Liver Liver Extract Liver diseases Measures Mediating Messenger RNA Metabolic Diseases Methyltransferase MicroRNAs Modeling Modification Mus Necrosis Nuclear Receptors Nutrient Nutritional Outcome Pathology Pathway Analysis Play Polychlorinated Biphenyls Positioning Attribute Primary carcinoma of the liver cells Protein Methyltransferases Proteins Proteome RNA RNA Splicing Reader Receptor Inhibition Regulation Reporting Role Sampling Sex Differences Signal Pathway Signal Transduction Steatohepatitis Stress Testing Therapeutic Intervention Time Transcript Translations Untranslated RNA Western Blotting base bioaccumulation circulating microRNA cohort constitutive androstane receptor epitranscriptome epitranscriptomics human subject in vivo knock-down lipid metabolism liver function liver transplantation mRNA sequencing male methyl group mortality non-alcoholic fatty liver disease overexpression pregnane X receptor protein complex protein expression receptor response sex sexual dimorphism targeted treatment toxicant transcriptome transcriptome sequencing virtual western diet

项目摘要

Project Summary/Abstract Exposure to persistent environmental contaminants including polychlorinated biphenyls (PCBs) contributes to metabolic diseases including toxicant-associated steatohepatitis (TASH), a form of nonalcoholic fatty liver disease (NAFLD). PCBs have been positively associated with TASH, hepatocellular cancer, altered liver enzymes, and mortality in human cohorts. A complete understanding of the mechanisms by which PCBs act as a 1st ‘hit’ in combination with a high fat ‘Western diet’ (HFD) as a 2nd ‘hit’ to increase triglyceride accumulation, fibrosis, and inflammation in the liver (hallmarks of TASH) remains elusive. Further, although liver sexual dimorphism is well-established and sex-specific differences in human health outcomes after PCB exposure have been reported, there are few mechanistic studies addressing these differences. N(6)-methyladenosine (m6A) is the most common dynamic modification of transcribed RNAs. The regulation and role of m6A in liver epitranscriptomics and the impact of PCB exposure is unknown. This application addresses RFA-ES-19-002 by investigating the role of altered m6A and its writers, readers, and erasers in TASH in vivo, using an established PCB exposure model. Preliminary RNA-seq data show that liver from HFD + Aroclor 1260 (PCB) exposed male C57BL/6J mice have reduced transcript levels of the m6A methyltransferase complex protein Rbm15 and altered levels of the m6A readers Ythdf1 and Ythdc1/2. Whether these HFD + Aroclor 1260-induced changes are also occur in females and how they affect the m6A epitranscriptome and hepatocyte homeostasis or liver function is unknown. We recently reported increased PCB-induced hepatic inflammation and altered lipid metabolism in female vs. male mice. The goal of this exploratory study is to determine the impact of PCB +/- HFD exposure in vivo on the hepatic m6A epitranscriptome in male and female mice. We will test the hypothesis that altered m6A levels of specific transcripts play a role in TASH in vivo. Integrated analysis will identify m6A epitranscriptome- mediated changes in signaling pathways regulating TASH pathophysiology. This goal will be achieved by 1) Identification of m6A-mediated transcriptome changes in HFD, Aroclor 1260 (a mixture of non-dioxin-like (NDL) PCB subtypes that best mimics the PCB bioaccumulation in human adipose tissue), and HFD + Aroclor 1260 – exposed male and female mouse liver; 2) Determination if HFD, Aroclor 1260, or HFD + Aroclor 1260 exposure alter the expression of the writers, readers, and erasers of m6A in mouse liver. Integrated analysis will identify m6A epitranscriptome-mediated changes in signaling pathways regulating TASH pathophysiology that may be targets for therapeutic intervention. In the future, knockdown or overexpression of key proteins identified in this study will confirm their role in the observed m6A changes and in downstream signaling.

项目概要/摘要接触包括多氯联苯 (PCB) 在内的持久性环境污染物会导致代谢性疾病，包括毒物相关脂肪性肝炎 (TASH)，一种非酒精性脂肪肝 PCB 与 TASH、肝细胞癌、肝脏改变呈正相关。全面了解 PCB 的作用机制。第一次“打击”与高脂肪“西方饮食”（HFD）相结合作为第二次“打击”，以增加甘油三酯的积累，肝脏纤维化和炎症（TASH 的标志）仍然难以捉摸。二态性是公认的，接触 PCB 后人类健康结果存在性别差异据报道，解决这些差异的机制研究很少。转录 RNA 最常见的动态修饰 m6A 在肝脏中的调节和作用。表观转录组学和 PCB 暴露的影响尚不清楚，本申请通过以下方式解决 RFA-ES-19-002。使用已建立的方法研究改变的 m6A 及其写入器、读取器和擦除器在体内 TASH 中的作用 PCB 暴露模型。初步 RNA-seq 数据显示，HFD + Aroclor 1260 (PCB) 暴露的男性肝脏 C57BL/6J 小鼠 m6A 甲基转移酶复合体蛋白 Rbm15 的转录水平降低，并发生改变 m6A 阅读器 Ythdf1 和 Ythdc1/2 的水平是否也由 HFD + Aroclor 1260 引起。发生在女性中以及它们如何影响 m6A 表观转录组和肝细胞稳态或肝功能我们最近报道了 PCB 引起的肝脏炎症增加和脂质代谢改变。这项探索性研究的目的是确定 PCB +/- HFD 暴露对雌性小鼠和雄性小鼠的影响。我们将测试改变 m6A 的假设。特定转录本的水平在体内 TASH 中发挥作用综合分析将鉴定 m6A 表观转录组。调节 TASH 病理生理学的信号通路介导的变化可通过以下方式实现：1) 鉴定 HFD 中 m6A 介导的转录组变化，Aroclor 1260（非二恶英类 (NDL) 混合物）最能模拟人体脂肪组织中 PCB 生物累积的 PCB 亚型）以及 HFD + Aroclor 1260 – 暴露的雄性和雌性小鼠肝脏；2) 确定 HFD、Aroclor 1260 或 HFD + Aroclor 1260 暴露改变小鼠肝脏中 m6A 的书写者、阅读者和擦除者的表达综合分析将确定。 m6A 表观转录组介导的信号通路变化调节 TASH 病理生理学，可能是未来治疗干预的目标是敲低或过度表达本研究中确定的关键蛋白。研究将证实它们在观察到的 m6A 变化和下游信号传导中的作用。