Kitajima Kenji, Nakajima Marino, Kanokoda Mai, Kyba Michael, Dandapat Abhijit, Tolar Jakub, Saito Megumu K, Toyoda Masashi, Umezawa Akihiro, Hara Takahiko
Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
Stem Cell Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Exp Hematol. 2016 Jan;44(1):68-74.e1-10. doi: 10.1016/j.exphem.2015.09.007. Epub 2015 Oct 23.
WNT/β-CATENIN signaling promotes the hematopoietic/endothelial differentiation of human embryonic stem cells and human induced pluripotent stem cells (hiPSCs). The transient addition of a GSK3β inhibitor (GSKi) has been found to facilitate in vitro endothelial cell differentiation from hESCs/hiPSCs. Because hematopoietic and endothelial cells are derived from common progenitors (hemogenic endothelial progenitors [HEPs]), we examined the effect of transient GSKi treatment on hematopoietic cell differentiation from hiPSCs. We found that transient GSKi treatment at the start of hiPSC differentiation induction altered the gene expression profile of the cells. Multiple CDX/HOX genes, which are expressed in the posterior mesoderm of developing embryos, were significantly upregulated by GSKi treatment. Further, inclusion of the GSKi in a serum- and stroma-free culture with chemically defined medium efficiently induced HEPs, and the HEPs gave rise to various lineages of hematopoietic and endothelial cells. Therefore, transient WNT/β-CATENIN signaling triggers activation of the CDX/HOX pathway, which in turn confers hemogenic posterior mesoderm identity to differentiating hiPSCs. These data enhance our understanding of human embryonic hematopoietic/endothelial cell development and provide a novel in vitro system for inducing the differentiation of hematopoietic cells from hiPSCs.
WNT/β-连环蛋白信号通路促进人类胚胎干细胞和人类诱导多能干细胞（hiPSC）的造血/内皮分化。已发现短暂添加GSK3β抑制剂（GSKi）有助于hESC/hiPSC在体外向内皮细胞分化。由于造血细胞和内皮细胞来源于共同祖细胞（造血内皮祖细胞[HEP]），我们研究了短暂GSKi处理对hiPSC造血细胞分化的影响。我们发现，在hiPSC分化诱导开始时进行短暂的GSKi处理会改变细胞的基因表达谱。在发育胚胎的后中胚层中表达的多个CDX/HOX基因通过GSKi处理显著上调。此外，在无血清和无基质的化学定义培养基培养中加入GSKi可有效诱导HEP，并且HEP可分化为各种造血和内皮细胞谱系。因此，短暂的WNT/β-连环蛋白信号通路触发CDX/HOX途径的激活，进而赋予分化中的hiPSC造血后中胚层特性。这些数据加深了我们对人类胚胎造血/内皮细胞发育的理解，并为诱导hiPSC分化为造血细胞提供了一种新的体外系统。
