MicroRNAs regulating erythroid development

调节红细胞发育的 MicroRNA

• 批准号: 8010060
• 负责人: CURT I CIVIN
• 金额: $ 10万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-20 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8010060
• 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 的 3'UTR 中的位点结合，并（主要）抑制翻译成蛋白质。由于 microRNA 的结合并不依赖于与其靶序列的完全互补性，因此 microRNA 可以结合并阻断许多不同 mRNA 的蛋白质翻译，从而充当强大的调节开关。我们分析了造血干祖细胞 (HSPC) 中的 microRNA 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，提出某些 HSPC 表达的 microRNA (HE-microRNA) 调节造血作用。在此生物信息学基础上，我们制定了一个 microRNA 控制造血的模型，其中许多指定造血分化的基因由早期 HSPC 表达，但受到 HE-microRNA 的控制。对于造血过程中重要的几种靶标 mRNA，我们通过实验证明 HE-microRNA 实际上会减少翻译。 Mir-155 有效减少正常人 HSPC 的骨髓生成和红细胞生成，而 mir-16 选择性抑制红细胞生成。这些发现支持我们的假设，基于预测的目标 mRNA，即 (a) mir-155 可能在红系定型之前的大约共同骨髓前体 (CMP) 阶段调节发育，而 (b) mir-16 可能会阻止该阶段的发育双能巨核细胞-红系祖细胞（MEP）。因此，这 2 个 microRNA 可以作为分析红系发育早期事件的工具，并为扩展这些罕见的祖细胞提供潜力。更详细的 microRNA 表达和影响红细胞生成的分子靶标模型应该为研究红细胞发育和功能提供额外的分子工具。由于我们研究的细胞包括罕见的成体干细胞和各个阶段的祖细胞，因此我们在目标 1 中建议将 HSPC 的 microRNA 谱扩展到更高度纯化的原代人类和小鼠红系祖细胞亚群。此外，我们还将分析 NIH 批准的人胚胎干细胞 (hESC) 红系发育过程中的 microRNA 表达。在目标 2 中，我们将确定选定的个体 microRNA 是否通过实验抑制红系祖细胞的发育。在目标 3 中，我们将通过鉴定其合成被每种功能活性 microRNA 抑制的蛋白质来研究 microRNA 促红细胞生成作用的分子机制。该项目将研究称为 microRNA 的新型调节分子的作用，这种分子似乎在控制红细胞形成方面发挥着新颖而有效的作用。了解这些 microRNA 的作用可能为红细胞发育的扩展和控制提供新的工具。