Regulation and function of the microRNA-144/451 cluster during megakaryocytic/erythroid differentiation

microRNA-144/451簇在巨核细胞/红细胞分化过程中的调控和功能

• 批准号: 273908699
• 负责人: Professor Dr. Jörn Lausen
• 金额: --
• 依托单位: Institut für Biomedizinische Genetik (IBMG)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/273908699?language=en
• 关键词: Regulation; function; microRNA; 144; 451

Transcription factors and microRNAs are central regulators of hematopoietic stem cell emergence during embryogenesis and regulate differentiation of hematopoietic lineages such as myelopoiesis. Transcription factors regulate gene expression by binding to specific sites in regulatory sequences of genes and recruit cofactor complexes with epigenetic functions. Transcription factors are a main target of microRNAs and often create regulatory loops, which drive and stabilize specific gene expression programs. Deregulation of gene expression caused by mutations, chromosomal translocations or epigenetic alterations of transcription factors and microRNAs are a major cause for the development of leukaemia in humans. Our preliminary data show that expression the microRNA cluster miR144/451 is directly regulated by the transcription factors Tal1, GATA1 and RUNX1. Expression of miR144/451 is upregulated during erythroid and down regulated during megakaryocytic differentiation. We found that the transcription factor binding to regulatory elements of miR144/451 changes during differentiation. Furthermore, we found that the leukemic fusion protein RUNX1/ETO binds to the miR144/451 promoter and down regulates miR144/451 expression.In this project we want to examine the transcriptional regulation of miR144/451 during megakaryocytic/erythroid differentiation with a focus on epigenetic changes at regulatory elements of miR144/451. Furthermore, we want to analyse the influence of RUNX1/ETO on miR144/451 expression to evaluate if the repressive effect of RUNX1/ETO on erythroid differentiation is partly mediated through miR144/451. In relation to these experiments we will examine the influence of miR144/451 on megakaryocytic/erythroid differentiation using primary human CD34+ cells. To examine the mechanism how miR144/451 influences differentiation we want to analyse if miR144 targets the 3-UTRs of Tal1 and/or RUNX1 and this way creates a regulatory loop. Furthermore, we want to use SILAC-based mass spectrometry to identify targets of the single microRNAs, miR144 and miR451, in a proteome wide manner. The proposed investigations will decipher the network created by miR144/451 and transcription factors, which regulates the gene expression programs at the megakaryocytic/erythoid bifurcation.

转录因子和 microRNA 是胚胎发生过程中造血干细胞出现的中心调节因子，并调节造血谱系的分化，例如骨髓生成。转录因子通过与基因调控序列中的特定位点结合来调节基因表达，并招募具有表观遗传功能的辅因子复合物。转录因子是 microRNA 的主要靶标，通常会产生调节环，驱动并稳定特定的基因表达程序。由突变、染色体易位或转录因子和 microRNA 的表观遗传改变引起的基因表达失调是人类患白血病的主要原因。我们的初步数据表明，microRNA 簇 miR144/451 的表达受转录因子 Tal1、GATA1 和 RUNX1 直接调节。 miR144/451 的表达在红细胞分化过程中上调，在巨核细胞分化过程中下调。我们发现与 miR144/451 调控元件结合的转录因子在分化过程中发生变化。 此外，我们发现白血病融合蛋白RUNX1/ETO与miR144/451启动子结合并下调miR144/451的表达。在本项目中，我们希望研究巨核细胞/红细胞分化过程中miR144/451的转录调控，重点关注miR144/451调控元件的表观遗传变化。此外，我们想要分析RUNX1/ETO对miR144/451表达的影响，以评估RUNX1/ETO对红系分化的抑制作用是否部分通过miR144/451介导。与这些实验相关，我们将使用原代人 CD34+ 细胞检查 miR144/451 对巨核细胞/红细胞分化的影响。为了研究 miR144/451 如何影响分化的机制，我们想要分析 miR144 是否靶向 Tal1 和/或 RUNX1 的 3-UTR，并且这种方式创建了一个调节环。此外，我们希望使用基于 SILAC 的质谱法以蛋白质组范围内的方式识别单个 microRNA、miR144 和 miR451 的靶标。拟议的研究将破译由 miR144/451 和转录因子创建的网络，该网络调节巨核细胞/红细胞分叉处的基因表达程序。