TET1 in alcoholic liver disease progression

TET1 在酒精性肝病进展中的作用

基本信息

批准号：
10399756
负责人：
Chiung-Kuei Huang
金额：
$ 17.57万
依托单位：
TULANE UNIVERSITY OF LOUISIANA
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-01 至 2023-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10399756
关键词：
Affect Albumins Alcohol abuse Alcohol consumption Alcoholic Hepatitis Alcoholic Liver Cirrhosis Alcoholic Liver Diseases Alcohols Animals Apoptosis Apoptotic Asthma Azacitidine Catalytic Domain Cause of Death Cell Death Cessation of life Chronic Cirrhosis DNA Damage DNA Methylation DNA Sequence Data Development Diet Dioxygenases Disease Disease Progression Down-Regulation Enterobacteria phage P1 Cre recombinase Enzymes Epigenetic Process Ethanol Family Gene Expression Generations Genes Hepatic Hepatocyte Human In Vitro Knock-out Knockout Mice Knowledge Length Link Liquid substance Liver Liver Cirrhosis Liver Fibrosis LoxP-flanked allele Malignant Neoplasms Measures Mediating Modification Molecular Mus Mutation Necrosis Outcome Pathway interactions Patients Process Rattus Regulation Rodent Role Sampling Severities Therapeutic Tissues Vascular Diseases alcohol exposure chronic alcohol ingestion dietary control effective therapy improved inhibitor/antagonist knock-down liver injury member oxidation problem drinker promoter protein expression response small hairpin RNA targeted treatment therapeutic target wound healing

项目摘要

Project Summary Chronic alcohol abuse has been linked to abnormal epigenetic modifications that affect the progression of alcoholic liver disease (ALD) by influencing factors in controlling cell death in hepatocytes. One such factor is 5-hydroxymethylcytosine (5hmC), but there is currently little information as to how chronic alcohol consumption affects 5hmC's regulation of cell death. Understanding how alcohol impacts 5hmC formation and consequently cell death pathways will potentially yield therapeutic approaches towards ALD. In our preliminary studies, we found that 5hmC expression is down-regulated in the livers of rats and mice fed with an ethanol diet as well as in human ALD tissues. We further examined the expression levels of enzymes involved in the generation of 5hmC, which include methylcytosine dioxygenase TET1, TET2, and TET3 in ALD samples. It was found that TET1 is significantly down-regulated in human and rodent ALD samples. We determined that using shRNA- TET1 to knockdown TET1 in human hepatocytes significantly suppressed 5hmC formation and promoted cell death as well as the pro-apoptotic gene, HRK. Intriguingly, the treatment of the DNA methylation inhibitor, 5- Azacytidine, could replace the impact of TET1 knockdown on hepatocyte cell death, further suggesting the importance of DNA methylation in TET1-mediated hepatocyte cell death. We then analyzed how TET1 down- regulation is involved in ALD progression by using TET1 knockout mice. It was found that knockout of TET1 substantially elicited liver fibrosis, which is consequently the outcome of wound-healing in chronic liver damage. Thus, our central hypothesis is that ethanol exposure increases hepatocyte cell death to promote ALD progression by suppressing TET1-mediated 5hmC epigenetic changes. Our long-term objective is to clarify the underlying mechanisms by which TET1 modulates ALD progression, and determine if TET1 is a potential therapeutic target in ALD. Two specific aims propose to evaluate our hypothesis. In aim 1, we will examine how TET1 modulates cell death pathways in ALD progression. We will investigate the enzymatic function of TET1 in regulating cell death pathways by using TET1 catalytic domain, full length TET1, TET1 catalytic domain dead mutation, and TET1 specific inhibitor. In aim 2, we will examine the role of TET1 in ALD progression. We will evaluate the impact of TET1 down-regulation on hepatocyte cell death in wild-type (WT) and TET1 knockout (KO) mice challenged with an alcoholic liquid diet. To further determine the hepatic specific TET1 role in ALD progression, we will generate liver specific TET1 knockout mice by using albumin promoter driven Cre mouse and floxed TET1 mouse. The results will significantly advance our knowledge of the mechanisms by which TET1 modulates hepatocyte cell death and improve our understanding of pathophysiological mechanisms underlying ALD progression. We also anticipate that it will have a broad impact on the understanding of TET1 expression and its relationship to hepatocyte function in general.

项目概要慢性酒精滥用与异常的表观遗传修饰有关，从而影响疾病的进展通过影响控制肝细胞细胞死亡的因素来预防酒精性肝病（ALD）。其中一个因素是 5-羟甲基胞嘧啶（5hmC），但目前关于长期饮酒如何影响的信息很少影响 5hmC 对细胞死亡的调节。了解酒精如何影响 5hmC 的形成并因此影响细胞死亡途径可能会产生 ALD 的治疗方法。在我们的初步研究中，我们发现在喂食乙醇饮食的大鼠和小鼠的肝脏中 5hmC 表达下调在人类 ALD 组织中。我们进一步检查了参与生成的酶的表达水平 5hmC，其中包括 ALD 样品中的甲基胞嘧啶双加氧酶 TET1、TET2 和 TET3。结果发现 TET1 在人类和啮齿动物 ALD 样本中显着下调。我们确定使用shRNA- TET1在人肝细胞中敲低TET1显着抑制5hmC形成并促进细胞死亡以及促凋亡基因 HRK。有趣的是，DNA甲基化抑制剂的治疗，5- 氮胞苷可以替代 TET1 敲低对肝细胞死亡的影响，进一步表明 DNA甲基化在TET1介导的肝细胞死亡中的重要性。然后我们分析了 TET1 是如何下调的通过使用 TET1 敲除小鼠，调节参与 ALD 进展。结果发现TET1的敲除显着引起肝纤维化，这是慢性肝损伤伤口愈合的结果。因此，我们的中心假设是乙醇暴露会增加肝细胞死亡，从而促进 ALD 通过抑制 TET1 介导的 5hmC 表观遗传变化来进展。我们的长期目标是澄清 TET1 调节 ALD 进展的潜在机制，并确定 TET1 是否是潜在的 ALD 的治疗目标。提出了两个具体目标来评估我们的假设。在目标 1 中，我们将检查 TET1 如何调节 ALD 进展中的细胞死亡途径。我们将研究酶的功能 TET1通过使用TET1催化结构域调节细胞死亡途径，全长TET1，TET1催化结构域死亡突变和 TET1 特异性抑制剂。在目标 2 中，我们将研究 TET1 在 ALD 中的作用进展。我们将评估 TET1 下调对野生型 (WT) 肝细胞死亡的影响和 TET1 敲除（KO）小鼠接受含酒精流质饮食的挑战。进一步确定肝脏特异性 TET1在ALD进展中的作用，我们将通过使用白蛋白启动子来产生肝脏特异性TET1敲除小鼠驱动的 Cre 鼠标和 floxed TET1 鼠标。研究结果将显着提高我们对 TET1 调节肝细胞死亡的机制并提高我们对 ALD 进展的病理生理机制。我们还预计它将具有广泛的对 TET1 表达及其与肝细胞功能关系的总体理解产生影响。

项目成果

期刊论文数量（1）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Elevated 2-oxoglutarate antagonizes DNA damage responses in cholangiocarcinoma chemotherapy through regulating aspartate beta-hydroxylase.

升高的 2-酮戊二酸通过调节天冬氨酸 β-羟化酶拮抗胆管癌化疗中的 DNA 损伤反应。

DOI：
发表时间：
2024-01-01
期刊：
影响因子：
9.7
作者：
Nagaoka, Katsuya;Bai, Xuewei;Liu, Dan;Cao, Kevin;Mulla, Joud;Ji, Chengcheng;Chen, Hongze;Nisar, Muhammad Azhar;Bay, Amalia;Mueller, William;Hildebrand, Grace;Gao, Jin;Lu, Shaolei;Setoyama, Hiroko;Tanaka, Yasuhito;Wands, Jack R;Huang
通讯作者：
Huang