MicorRNAs and hematopoietic differentiation

MicorRNA 和造血分化

• 批准号: 6911633
• 负责人: Harvey F Lodish
• 金额: $ 79.94万
• 依托单位: WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6911633
• 关键词: RNA; RNA interference; antisense nucleic acid; bioinformatics; bone marrow transplantation; cell differentiation; computational biology; gene expression; gene targeting; genetic transduction; genetically modified animals; growth factor; hematopoiesis; hematopoietic stem cells; laboratory mouse; lymphocyte; molecular biology; molecular cloning; myeloid stem cell; phenotype; tissue /cell culture; transcription factor

DESCRIPTION (provided by applicant): Understanding and manipulating hematopoietic differentiation requires knowing the regulatory circuitry that orchestrates the programs of gene expression during this process. One class of gene regulatory molecules are the microRNAs (miRNAs) - tiny endogenous RNAs, about 22 nucleotides in length, that are thought to use the elements of the RNA-interference pathway to post transcriptionally down-regulate the expression of protein-coding genes. Starting with the hypothesis that miRNAs are playing important regulatory roles during hematopoietic differentiation, the Lodish and Bartel labs have collaborated to clone about 100 different miRNAs from mouse bone marrow. These include five miRNAs referred to as "hematopoietic miRNAs", because they are highly or preferentially expressed in hematopoietic cell lineages. Three of the five also derive from loci associated with chromosomal breakpoints or aberrations previously linked to leukemias. Preliminary studies show that ectopic expression of one of these miRNAs in bone marrow progenitors modulates hematopoietic differentiation both in cell culture and in transplanted mice. The experiments of this proposal focus on the hematopoietic miRNAs with the broad, long-term objective of understanding the gene regulatory events needed for hematopoietic stem cell and progenitor maintenance and differentiation. The specific aims are: 1) To examine the consequences of altered miRNA expression during hematopoiesis. 2) To identify the regulatory targets of hematopoietic miRNAs and examine the consequences of disrupting miRNA regulation of these targets. 3) To identify additional hematopoietic miRNAs. These experiments include the ectopic expression of hematopoietic miRNAs in hematopoietic stem cells and lineage-committed progenitors, knock-outs of miRNA genes, in vitro validation of predicted miRNA regulatory targets, in vivo substitution of target genes with versions unresponsive to miRNA regulation, cloning of additional miRNAs from hematopoietic tissues, and further expression analyses. They seek to place miRNAs within specific gene regulatory pathways needed for hematopoietic stem cell maintenance and lymphoid and myeloid differentiation. They will also address more fundamental issues regarding miRNA regulation, such as the combinatorial control of expression by miRNAs and the features of functional miRNA complementary sites within vertebrate mRNAs. Thus, these experiments will provide important insights for understanding the action of miRNAs in mammals and how their dysfunction might contribute to both hematological and other human diseases.

描述（由申请人提供）：理解和操纵造血分化需要了解在此过程中协调基因表达程序的调节电路。一类基因调节分子是 microRNA (miRNA)——微小的内源性 RNA，长度约为 22 个核苷酸，被认为利用 RNA 干扰途径的元件来转录后下调蛋白质编码基因的表达。 Lodish 和 Bartel 实验室基于 miRNA 在造血分化过程中发挥重要调节作用的假设，合作从小鼠骨髓中克隆了约 100 种不同的 miRNA。其中包括五种被称为“造血 miRNA”的 miRNA，因为它们在造血细胞谱系中高度或优先表达。五个基因中的三个也源自与染色体断点或畸变相关的位点，这些基因位点先前与白血病有关。初步研究表明，这些 miRNA 之一在骨髓祖细胞中的异位表达可调节细胞培养物和移植小鼠的造血分化。 本提案的实验重点关注造血 miRNA，其广泛、长期的目标是了解造血干细胞和祖细胞维持和分化所需的基因调控事件。具体目标是： 1) 检查造血过程中 miRNA 表达改变的后果。 2) 确定造血 miRNA 的调节靶点并检查破坏这些靶点的 miRNA 调节的后果。 3) 鉴定其他造血 miRNA。这些实验包括造血干细胞和谱系定型祖细胞中造血 miRNA 的异位表达、miRNA 基因的敲除、预测 miRNA 调节靶点的体外验证、体内用对 miRNA 调节无反应的版本替换靶基因、克隆来自造血组织的其他 miRNA 以及进一步的表达分析。他们试图将 miRNA 置于造血干细胞维持以及淋巴和骨髓分化所需的特定基因调控途径中。他们还将解决有关 miRNA 调控的更基本问题，例如 miRNA 表达的组合控制以及脊椎动物 mRNA 内功能性 miRNA 互补位点的特征。因此，这些实验将为理解 miRNA 在哺乳动物中的作用以及它们的功能障碍如何导致血液学和其他人类疾病提供重要的见解。