Institute for Transfusion Medicine, University Hospital Essen, Virchowstraße 179, 45147 Essen, Germany.
Institute for Transfusion Medicine, University Hospital Essen, Virchowstraße 179, 45147 Essen, Germany; Department of Bone Marrow Transplantation, University Hospital Essen, Hufelandstraße 55, 45147 Essen, Germany.
Stem Cell Reports. 2018 Mar 13;10(3):875-889. doi: 10.1016/j.stemcr.2018.01.009. Epub 2018 Feb 15.
Generation of hematopoietic stem cells (HSCs) from pluripotent stem cells, in vitro, holds great promise for regenerative therapies. Primarily, this has been achieved in mouse cells by overexpression of the homeotic selector protein HOXB4. The exact cellular stage at which HOXB4 promotes hematopoietic development, in vitro, is not yet known. However, its identification is a prerequisite to unambiguously identify the molecular circuits controlling hematopoiesis, since the activity of HOX proteins is highly cell and context dependent. To identify that stage, we retrovirally expressed HOXB4 in differentiating mouse embryonic stem cells (ESCs). Through the use of Runx1 ESCs containing a doxycycline-inducible Runx1 coding sequence, we uncovered that HOXB4 promoted the formation of hemogenic endothelium cells without altering endothelial cell development. Whole-transcriptome analysis revealed that its expression mediated the upregulation of transcription of core transcription factors necessary for hematopoiesis, culminating in the formation of blood progenitors upon initiation of Runx1 expression.
体外多能干细胞向造血干细胞的生成在再生疗法中具有巨大的应用前景。主要是通过过表达同源盒蛋白 HOXB4 在鼠细胞中实现的。然而，HOXB4 促进体外造血发育的确切细胞阶段尚不清楚。但是，明确鉴定控制造血的分子回路是必不可少的，因为 HOX 蛋白的活性高度依赖于细胞和上下文。为了鉴定该阶段，我们通过逆转录病毒在分化的小鼠胚胎干细胞（ESCs）中表达 HOXB4。通过使用含有强力霉素诱导的 Runx1 编码序列的 Runx1 ESCs，我们发现 HOXB4 促进了造血内皮细胞的形成，而不改变内皮细胞的发育。全转录组分析表明，其表达介导了造血所必需的核心转录因子的转录上调，最终在启动 Runx1 表达时形成血液祖细胞。
