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知道在此过程中策划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，被认为使用RNA干扰途径的元素将转录后下调蛋白质编码基因的表达。从造血分化过程中MiRNA在扮演重要的调节作用的假设开始，Lodish和Bartel Labs与小鼠骨髓中的大约100个不同的miRNA进行了协作。其中包括五个称为“造血miRNA”的miRNA，因为它们在造血细胞谱系中高度或优先表达。五个中的三个也源自与染色体断裂点或以前与白血病相关的畸变相关的基因座。初步研究表明，骨髓祖细胞中这些miRNA之一的异位表达调节细胞培养和移植小鼠中的造血分化。 该提案的实验集中于造血miRNA，其长期的长期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节事件。具体目的是：1）检查造血过程中miRNA表达改变的后果。 2）确定造血miRNA的调节靶标，并检查破坏这些靶标miRNA调节的后果。 3）鉴定额外的造血miRNA。这些实验包括在造血干细胞和谱系祖细胞中的造血miRNA的异位表达，miRNA基因的敲除，对预测的miRNA调节靶标的VIVO验证，对靶基因的体内替代基因与mirna connecute and imirnectim and symaim and symak and symape and hemape and symape and symak and themape and symate and themape and symate symate and symate symate and。他们试图将miRNA放置在造血干细胞维持以及淋巴样和髓样分化所需的特定基因调节途径中。他们还将解决有关miRNA调控的更基本问题，例如miRNA对表达的组合控制以及脊椎动物mRNA中功能性miRNA互补位点的特征。因此，这些实验将提供重要的见解，以理解miRNA在哺乳动物中的作用，以及它们的功能障碍如何有助于血液学和其他人类疾病。