MicroRNAs regulating erythroid development

调节红细胞发育的 MicroRNA

• 批准号: 7862406
• 负责人: CURT I CIVIN
• 金额: $ 22.28万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7862406
• 关键词: 3' Untranslated Regions; Abbreviations; Adult; Affect; Applications Grants; Binding; Bioinformatics; Biology; Bone Marrow; CD34 gene; Cell Line; Cell physiology; Cells; Common Lymphoid Progenitor; Data; Development; Electronics; Embryo; Erythrocytes; Erythroid; Erythroid Cells; Erythroid Progenitor Cells; Erythropoiesis; Event; Figs - dietary; Genes; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Human; Individual; Lead; Longitudinal Studies; Luciferases; Mediating; Megakaryocytes; Messenger RNA; MicroRNAs; Modeling; Molecular; Molecular Target; Multipotent Stem Cells; Mus; Myelogenous; Myelopoiesis; Oranges; Pathway interactions; Play; Proteins; Publishing; Regulation; Reporting; Role; Site; Specific qualifier value; Staging; Stem cells; Thermodynamics; Translational Repression; Translations; adult stem cell; base; cellular development; clinical application; granulocyte; human embryonic stem cell; mRNA Expression; macrophage; novel; peripheral blood; progenitor; research and development; stem; tool; translation assay

DESCRIPTION (provided by applicant): MicroRNAs bind to sites in target mRNAs' 3'UTR and (principally) inhibit translation to protein. Since binding of microRNAs does not depend on full complementarity with their target sequences, microRNAs can bind to and block protein translation of many different mRNAs, and thereby serve as powerful regulatory switches. We profiled microRNA expression in hematopoietic stem-progenitor cells (HSPCs) and combined this data with human HSPC mRNA expression and thermodynamic microRNA-mRNA target predictions to propose that certain HSPC-expressed microRNAs (HE-microRNAs) regulate hematopoiesis. On this bioinformatic basis, we formulated a model for microRNA control of hematopoiesis in which many genes specifying hematopoietic differentiation are expressed by early HSPCs, but held in check by HE-microRNAs. For several target mRNAs important in hematopoiesis, we demonstrated experimentally that translation is actually decreased by HE- microRNAs. Mir-155 potently reduced both myelopoiesis and erythropoiesis of normal human HSPCs, and mir-16 selectively inhibited erythropoiesis. These findings supported our hypotheses, based on predicted target mRNAs, that (a) mir-155 may regulate development at approximately the common myeloid precursor (CMP) stage prior to erythroid commitment, while (b) mir-16 may block development at the stage of a bipotent megakaryocyte-erythroid progenitor (MEP). Thus, these 2 microRNAs may serve as tools to dissect the very early events of erythroid development and offer potential to expand these rare progenitors. A more detailed model of microRNA expression and molecular targets affecting erythropoiesis should provide additional molecular tools for studying erythroid development and function. Since the cells that we studied included rare adult stem cells and various stages of progenitors, we propose in Aim 1 to expand our microRNA profiles of HSPCs to more highly purified subsets of primary human and mouse erythroid progenitors. In addition, we will profile microRNA expression during erythroid development from NIH-approved human embryonic stem cells (hESCs). In Aim 2, we will determine if selected individual microRNAs experimentally inhibit development of erythroid progenitors. In Aim 3, we will study the molecular mechanisms of the microRNA's erythropoietic effects by identifying proteins whose synthesis is inhibited by each functionally-active microRNA. This project will investigate the effects of new regulatory molecules called microRNAs, which appear to play novel, potent roles in control of red blood cell formation. Understanding the actions of these microRNAs may provide new tools, for both expansion and control of red blood cell development.

描述（由申请人提供）：microRNA与靶mRNA 3'UTR中的位点结合，（主要）抑制转化为蛋白质。由于microRNA的结合并不取决于其目标序列的完全互补性，因此microRNA可以与许多不同mRNA的蛋白质翻译结合并阻止蛋白质翻译，从而充当强大的调节开关。我们在造血干燥蛋白细胞（HSPC）中介绍了microRNA的表达，并将这些数据与人类HSPC mRNA表达和热力学microRNA-MRNA靶标预测相结合，以提出某些HSPC表达的MicroRNA（He-MicroRNAS）调节造血性造血。在这种生物信息学的基础上，我们制定了一个模型，用于造血对造血的模型，其中许多指定造血分化的基因由早期的HSPC表达，但由He-Micrornas检查。对于造血中重要的几种靶标mRNA，我们在实验上证明了he-microRNA实际上降低了翻译。 miR-155有效地降低了正常人HSPC的骨髓和红细胞生成，而miR-16有选择地抑制红细胞生成。这些发现支持了我们的假设，基于预测的靶标mRNA，（a）miR-155可能在红毛细血管 - 巨核细胞 - 毛细血管 - 毛状细胞 - 毛细血管 - 毛细血管 - 毛细血管 - 毛细血管 - 毛细血管阶段（MiR-16）之前大约调节大约骨髓前体（CMP）阶段的发育。因此，这2个microRNA可以作为剖析红斑发育的早期事件的工具，并提供了扩展这些罕见祖细胞的潜力。一个更详细的影响促红细胞生成的microRNA表达和分子靶标的模型应提供其他分子工具来研究红细胞发育和功能。由于我们研究的细胞包括罕见的成年干细胞和祖细胞的各个阶段，因此我们在AIM 1中提出，将HSPC的microRNA谱扩大到更高度纯化的原代人和小鼠红细胞祖细胞的子集。此外，我们将在NIH批准的人类胚胎干细胞（HESC）中介绍红细胞发育过程中的microRNA表达。在AIM 2中，我们将确定是否在实验上选择单个microRNA会抑制红细胞祖细胞的发展。在AIM 3中，我们将通过鉴定每种功能激活的microRNA抑制合成的蛋白质来研究microRNA促红细胞生成作用的分子机制。该项目将研究称为microRNA的新调节分子的影响，这些分子似乎在控制红细胞形成中起着新颖而有效的作用。了解这些microRNA的作用可能会提供新的工具，以扩展和控制红细胞发育。