UCP2 in the pathogenesis of steatohepatitis

UCP2在脂肪性肝炎发病机制中的作用

• 批准号: 6894228
• 负责人: GYORGY BAFFY
• 金额: $ 11.89万
• 依托单位: RHODE ISLAND HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-15 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6894228
• 关键词: apoptosis; cytochrome c; cytokine; endotoxins; free radical oxygen; genetically modified animals; hepatitis; laboratory mouse; lipid disorder; liver cells; liver disorder; membrane permeability; membrane proteins; mitochondria; molecular pathology; tissue /cell culture; tumor necrosis factor alpha

DESCRIPTION (provided by applicant) A research program is described to study the role of uncoupling protein-2 (UCP2) in the pathogenesis of steatohepatitis (SH). SH evolves from fatty liver, a prevalent condition among patients with obesity, diabetes, and alcohol abuse. The predictors and biochemical mechanisms of this progression are poorly defined, but reactive oxygen species (ROS) and endotoxin-mediated cytokine release appear to have a major role. UCP2 is a mitochondrial inner membrane protein emerging as a potential regulator of mitochondrial ROS production. Expression of liver UCP2 is markedly increased in animal models of obesity, alcohol intake, and endotoxin exposure. We hypothesize that induction of UCP2 in the liver is a defensive mechanism and it may involve both parenchymal hepatocytes and Kupffer cells. UCP2-/- mice generated in the mentor's laboratory will provide a powerful tool to test this hypothesis. First, steatosis will be induced in UCP2-/-mice by crossbreeding with ob/obmice, high-fat feeding, and ethanol feeding. UCP2-/- mice will also be challenged by in vivo treatment with endotoxin, TNF-alpha, and anti-Fas antibody. UCP2-/- mice are expected to show accelerated liver injury under these conditions. Adenovirus-mediated gene transfer will be used to rescue UCP2 functions in vivo. The cellular mechanisms of UCP2 action will then be studied in vitro in cultured parenchymal hepatocytes and Kupffer cells. Apoptosis and ROS production will be detected in hepatocytes from UCP2-/- and wild type mice by fatty acids, ethanol, and ceramide. SOD mimetics and scavenger compounds will be used to revert the action of absent UCP2. The effect of UCP2 on various steps of apoptosis will be investigated (mitochondrial permeability transition opening, Bid translocation): The ability of Kupffer cells to generate ROS and release cytokines in the absence of UCP2 will be assessed. Finally, Cre/lox recombinase system will be used to create tissue-specific UCP2 knockout mice. Mice with a loxP-modified UCP2 allele will be created and bred with mice expressing an albumin promoter-driven Cre to obtain hepatocyte-specific UCP2 knockouts. Breeding of UCP2/loxP mice with mice expressing a lysozyme promoter-driven Cre will result in Kupffer cell/macrophage-specific UCP2 knockouts. Generation of Cre/lox system for tissue-specific UCP2 expression will provide a great learning potential for the applicant. The research facilities of the mentor's laboratory will provide an excellent environment to accomplish these aims. Knowledge of the biochemical actions and genetic regulation of UCP2 in the liver will advance our understanding about the role of UCP2 and the pathophysiology of SH.

描述（由申请人提供） 一项研究计划描述了研究解偶联蛋白-2的作用 （UCP 2）在脂肪性肝炎（SH）发病机制中的作用。SH由脂肪 肝脏是肥胖、糖尿病和酗酒患者的常见疾病 虐待这种进展的预测因素和生化机制很差 但活性氧（ROS）和内毒素介导的细胞因子 释放似乎起着重要作用。UCP 2是线粒体内膜 作为线粒体ROS产生的潜在调节剂出现的蛋白质。 肝脏UCP 2的表达在肥胖动物模型中显著增加， 酒精摄入和内毒素暴露我们假设UCP 2的诱导 肝脏中的免疫是一种防御机制，它可能涉及两个实质 肝细胞和枯否细胞。UCP 2-/-小鼠在导师的 实验室将提供一个强有力的工具来检验这一假设。第一、 通过与ob/ob小鼠杂交在UCP 2-/-小鼠中诱导脂肪变性， 高脂肪喂养和乙醇喂养。UCP 2-/-小鼠还将通过以下方法进行攻击： 用内毒素、TNF-α和抗Fas抗体进行体内处理。UCP2-/- 预期小鼠在这些条件下显示加速的肝损伤。 腺病毒介导的基因转移将被用于拯救UCP 2的功能， vivo.然后将在体外研究UCP 2作用的细胞机制。 培养的实质肝细胞和枯否细胞。细胞凋亡与ROS 将通过以下方法在来自UCP 2-/-和野生型小鼠的肝细胞中检测产生 脂肪酸、乙醇和神经酰胺。SOD模拟物和清除剂化合物将 用于恢复不存在的UCP 2的作用。UCP 2对各种 将研究细胞凋亡的步骤（线粒体通透性转换 开放，Bid易位）：枯否细胞产生ROS和 将评估在不存在UCP 2的情况下细胞因子的释放。最后，Cre/lox 重组酶系统将用于产生组织特异性UCP 2敲除小鼠。 将产生具有loxP修饰的UCP 2等位基因的小鼠，并与小鼠繁殖 表达白蛋白启动子驱动的Cre以获得肝细胞特异性UCP 2 击倒对手。用表达溶菌酶的小鼠培育UCP 2/loxP小鼠 启动子驱动的Cre将导致枯否细胞/巨噬细胞特异性UCP 2 击倒对手。构建组织特异性表达UCP 2的Cre/lox系统 将为申请人提供巨大的学习潜力。研究 导师实验室的设施将提供良好的环境， 实现这些目标。了解生物化学作用和遗传 UCP 2在肝脏中的调节将促进我们对UCP 2在肝脏中的作用的理解。 和SH的病理生理学。

项目成果

Uncoupling protein-2 modulates the lipid metabolic response to fasting in mice.

• DOI: 10.1152/ajpgi.00016.2008
• 发表时间: 2008-04
• 期刊: American journal of physiology. Gastrointestinal and liver physiology
• 作者: Anthony R Sheets;P. Fülöp;Zoltán Derdák;Andrea Kassai;E. Sabo;N. Mark;G. Paragh;J. Wands;G. Baff

Kupffer cells in non-alcoholic fatty liver disease: the emerging view.

• DOI: 10.1016/j.jhep.2009.03.008
• 发表时间: 2009-07
• 期刊: Journal of hepatology
• 影响因子: 25.7
• 作者: Baffy G