Regulation of mammalian iron homeostasis by iron and transferrin

铁和转铁蛋白对哺乳动物铁稳态的调节

• 批准号: 8532426
• 负责人: Thomas Benedict Bartnikas
• 金额: $ 24.9万
• 依托单位: BROWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2015-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8532426
• 关键词: Anabolism; Anemia; Binding; Binding Proteins; Biological Assay; Bone Marrow; Carrier Proteins; Cell Line; Cells; Defect; Diet; Disease; Erythroid; Erythropoiesis; Funding; Gene Expression; Gene Expression Regulation; Goals; Health; Hepatocyte; Homeostasis; Hormones; Human; In Transferrin; Instruction; Iron; Lead; Liver; Mammalian Cell; Manganese; Measures; Mediating; Mentors; Metabolism; Metals; Modeling; Mus; Pathway interactions; Peptides; Phase; Play; Progress Reports; Recycling; Regulation; Research; Resistance; Role; SLC11A2 gene; Serum; Severities; Testing; Tissues; Transferrin; Transferrin-Binding Proteins; Work; absorption; cDNA Library; design; diferric transferrin; hepcidin; in vivo; interest; macrophage; metal metabolism; metal transporting protein 1; mutant; novel; peptide hormone; research study; small hairpin RNA; trend

PROJECT SUMMARY (See instructions); As iron (Fe)-related disorders are prevalent world-wide, understanding Fe homeostasis is critical to understanding human health. Fe homeostasis is regulated by hepcidin, a largely liver-derived peptide that inhibits dietary Fe absorption and macrophage Fe recycling. Hepcidin expression Is inhibited and stimulated respectively by increased erythropoietic drive and Fe overload. The first objective of this K99/R00 application was to determine the effect of transferrin (TF) on hepcidin expression in vivo. This objective has been completed. Studies during the K99 phase demonstrated that TF, an abundant serum metal-binding protein essential for Fe delivery to bone marrow for erythropoiesis, regulates hepcidin expression dependently and Independently of TF's role In erythropoiesis. These studies also demonstrated that TF Is essential for the stimulation of hepcidin expression by Fe overload; this stimulation is a likely target ofthe unidentified factor that mediates suppression of hepcidin expression by increased erythropoietic drive. The second objective of this K99/R00 application, to be completed during the ROO phase, is to identify commonalities and divergences between cellular manganese (Mn) and Fe homeostasis as a means to further dissect Fe homeostasis. I will identify the means by which TF saturated with Fe, Mn and other metals similarly and differentially regulate hepatocyte gene expression and determine if TF plays a role In cellular Fe and Mn efflux. The third objective, also to be completed during the ROO phase, is to identify novel factors required for cellular metal homeostasis. As high Mn levels are toxic to many cell lines, I will alter cellular gene expression with shRNA and cDNA libraries, select for cells resistant to high Mn levels and Identify mutant lines of interest by 54Mn and 55Fe transport assays. From these two objectives, I will establish an Independent focus divergent from my mentor's, the role of Iron in hematologic disorders. This proposal reflects the overall trend in my research the study of mammalian metal homeostasis and its relation to human health and disease¿and will lead to a paradigm of metal homeostasis from which novel treatments for metal-related disorders can be designed.

项目总结（见说明）; 由于铁（Fe）相关疾病在世界范围内普遍存在，因此了解Fe稳态对了解人类健康至关重要。铁稳态由铁调素调节，铁调素是一种主要来自肝脏的肽，可抑制膳食铁吸收和巨噬细胞铁再循环。铁调素的表达分别被增加的红细胞生成驱动和铁超载抑制和刺激。该K99/R 00应用的第一个目的是确定转铁蛋白（TF）对体内铁调素表达的影响。这一目标已经完成。在K99期的研究表明，TF，一个丰富的血清金属结合蛋白的铁输送到骨髓红细胞生成所必需的，调节铁调素表达依赖性和独立的TF的作用在红细胞生成。这些研究还表明，TF是铁超载刺激铁调素表达所必需的;这种刺激可能是通过增加红细胞生成驱动介导铁调素表达抑制的未知因子的靶点。该K99/R 00应用程序的第二个目标将在ROO阶段完成，是识别细胞锰（Mn）和铁稳态之间的共性和差异，作为进一步剖析铁稳态的手段。我将确定的方法，其中TF饱和铁，锰和其他金属类似和差异调节肝细胞基因表达，并确定TF是否在细胞铁和锰流出的作用。第三个目标，也要在ROO阶段完成，是确定细胞金属稳态所需的新因素。由于高Mn水平对许多细胞系是有毒的，我将用shRNA和cDNA文库改变细胞基因表达，选择对高Mn水平有抗性的细胞，并通过54 Mn和55 Fe转运测定鉴定感兴趣的突变株。从这两个目标，我将建立一个独立的重点不同于我的导师的，铁在血液系统疾病中的作用。这一提议反映了我研究的总体趋势，即哺乳动物金属稳态及其与人类健康和疾病的关系，并将导致金属稳态的范式，从而可以设计出金属相关疾病的新治疗方法。