Involvement of Runx1 in the down-regulation of fetal liver kinase-1 expression during transition of endothelial cells to hematopoietic cells
Involvement of Runx1 in the down-regulation of fetal liver kinase-1 expression during transition of endothelial cells to hematopoietic cells
复制标题
DOI：
10.1182/blood-2004-12-4872
复制
发表时间：
2005-09-15
期刊：
影响因子：
20.3
通讯作者：
Nishikawa, SI
中科院分区：
文献类型：
--
作者：
Hirai, H;Samokhvalov, IM;Nishikawa, SI
在小鼠早期胚胎发生过程中，胎肝激酶-1 (Flk-1)（一种血管内皮生长因子受体）和 Runx1（一种 runt 结构域转录因子）在造血谱系的生成中发挥先决作用。 Flk-1 表达在从中胚层到内皮细胞的连续阶段中得以维持，并在新生造血细胞中下调，而 Runx1（Runt 相关转录因子 1）在造血细胞从头产生的胚胎位点以及几乎所有造血器官中表达。在这里，我们发现 Runx1 在造血内皮细胞发育成造血细胞的过程中抑制 Flk-1。我们在 Runx1 基因座中建立了携带 Venus 基因（黄色荧光蛋白的修饰版本）的胚胎干细胞克隆，并将其在 0139 细胞上培养。 Flk-1(+) 细胞在第 3.5 天出现，Runx1(+) 细胞在第 4.5 天首次从 Flk-1(+) 部分出现。 Flk-1(+)Runx1(+)细胞在进一步孵育后迅速停止表达Flk-1，并最终产生CD45(+)或TER119(+)细胞。 Runx1 抑制内皮细胞系中的 Flk-1 启动子转录活性，这种抑制需要 Runx1 蛋白的完整 DNA 结合和反式激活结构域。 Runx1 对内源性 Flk-1 的抑制活性也通过在胚胎干细胞分化培养物中过表达 Runx1 得到证实。这些结果为了解 Runx1 在造血细胞谱系发育过程中的作用提供了新的见解。
During early mouse embryogenesis, fetal liver kinase-1 (Flk-1), a receptor for vascular endothelial growth factor, and Runx1, a runt domain transcription factor, have prerequisite roles in the generation of hematopoietic lineages. Flk-1 expression is maintained in successive stages from mesodermal to endothelial cells and is down-regulated in nascent hematopoietic cells, whereas Runx1 (Runt-related transcription factor 1) is expressed in embryonic sites of hematopoietic cell de novo generation and in practically all hematopoietic organs. Here we show that Runx1 represses Flk-1 during the development of hemogenic endothelial cells into hematopoietic cells. We established embryonic stem cell clones carrying the Venus gene, a modified version of yellow fluorescence protein, in the Runx1 locus and cultured them on 0139 cells. Flk-1(+) cells appeared on day 3.5, and Runx1(+) cells first appeared from the Flk-1(+) fraction on day 4.5. The Flk-1(+)Runx1(+) cells rapidly stopped expressing Flk-1 with further incubation and eventually gave rise to CD45(+) or TER119(+) cells. Runx1 repressed Flk-1 promoter transcriptional activity in an endothelial cell line, and this repression required intact DNA-binding and transactivating domains of Runx1 protein. The repressor activity of Runx1 on endogenous Flk-1 was also confirmed by overexpressing Runx1 in embryonic stem cell differentiation cultures. These results provide novel insight into the role of Runx1 during the development of hematopoietic cell lineages.