FUNCTION OF THE HEMOCHROMATOSIS PROTEIN

血色素沉着蛋白的功能

基本信息

批准号：
7582359
负责人：
CAROLINE ENNS
金额：
$ 40.82万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-03-01 至 2010-07-14
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7582359
关键词：
Address Affect Arthritis Binding Cardiac Myocytes Cardiomyopathies Cell Line Cells Chimera organism Couples Diabetes Mellitus Disease Enterocytes European Fc Receptor Ferritin Gene Expression Genes Goals HT29 Cells Hela Cells Hemochromatosis Hepatic Hepatocyte Hereditary hemochromatosis Homeostasis Human Inborn Genetic Diseases Inherited Intestines Iron Iron Overload Kupffer Cells Liver Liver Cirrhosis Malignant Epithelial Cell Mediating Microarray Analysis Molecular Mus Mutation Organ Peptides Proteins Publishing Regulation Research Personnel SLC11A2 gene Signal Transduction Site-Directed Mutagenesis Staging Testing Tissues Transferrin Work absorption base cell type design domain mapping established cell line hepcidin high throughput screening human TFRC protein iron metabolism monocyte programs protein complex research study uptake

项目摘要

DESCRIPTION (provided by applicant): Hereditary hemochromatosis (HH) is the most common inherited disorder in people of Northern European descent. Over 83% of the cases of HH result from a single mutation of a Cys to Tyr in the HH protein, HFE. This mutation causes a recessive disease resulting in an accumulation of iron in selected tissues. Iron overload damages these organs leading to cirrhosis of the liver, diabetes, cardiomyopathy, and arthritis. The mechanism by which HFE influences iron homeostasis in cells and in the body remains elusive. Lack of functional HFE in humans produces the opposite effects in different cell types in the body. In the early stages of the disease, Kupffer cells in the liver and enterocytes in the intestine cells are iron depleted and have low intracellular ferritin levels, whereas hepatocytes in the liver are iron overloaded and have high intracellular iron levels. Whether these are direct or indirect effects of HFE function is not known. In order to address this question and to understand the molecular mechanisms by which HFE influences iron homeostasis, cell lines have been developed that when transfected with HFE show either increases or decreases in iron levels. The aims of this proposal are focused on finding the basis of the opposite effects of HFE function in different cell types. The hypothesis that HFE alters iron homeostasis by interacting different proteins in different cell lines will be tested. Chimeric HFE proteins will be made to define the domains of HFE responsible for the alterations in iron homeostasis and site-directed mutagenesis will be used for finer mapping of the domains. The HFE protein complex could be directly regulating intracellular iron levels or signaling independently of intracellular iron levels. New genes that functionally couple to HFE will be identified in a high throughput screen. The hypothesis that HFE alters gene expression in an iron-dependent manner will be tested by microarray analysis of cells expressing and not expressing HFE. Finally, the hypothesis that HFE acts to regulate iron homeostasis in hepatocytes solely through controlling intracellular iron levels will be tested using a hepatic cell line and orimary hepatocytes. The long term goal of this work is to understand the function of HFE.

描述（由申请人提供）：遗传性血色素沉着症（HH）是北欧血统中最常见的遗传疾病。超过83％的HH病例是由Cys在HH蛋白HFE中的Tyr的单个突变引起的。该突变导致隐性疾病，导致铁中铁的积累。铁超负荷会损害这些器官，导致肝硬化，糖尿病，心肌病和关节炎。 HFE影响细胞和体内铁稳态的机制仍然难以捉摸。人类缺乏功能性HFE会在体内不同细胞类型中产生相反的作用。在疾病的早期阶段，肝脏中的库普弗细胞和肠细胞中的肠细胞耗尽，细胞内铁蛋白水平较低，而肝脏中的肝细胞是铁的过载，并且具有高细胞内铁水平。这些是HFE功能的直接效应还是间接影响。为了解决这个问题并了解HFE影响铁稳态的分子机制，已经开发出细胞系，当用HFE转染的HFE显示时，铁水平的增加或降低。该提案的目的集中在寻找不同细胞类型中HFE功能相反影响的基础。 HFE通过在不同细胞系中相互作用的不同蛋白质来改变铁稳态的假说将被测试。将制作嵌合HFE蛋白来定义负责铁稳态改变的HFE域，并将定向诱变的变化用于更细化的域。 HFE蛋白复合物可以直接调节细胞内铁水平或信号，而独立于细胞内铁水平。在功能上将与HFE的新基因将在高吞吐量屏幕中识别。 HFE以铁依赖性方式改变基因表达的假说将通过对表达和不表达HFE的细胞的微阵列分析来检验。最后，仅通过控制细胞内铁水平来调节肝细胞中的铁稳态的假设将使用肝细胞系和甲状腺素肝细胞进行测试。这项工作的长期目标是了解HFE的功能。