Bcl2 enhances induced hematopoietic differentiation of murine embryonic stem cells
Bcl2 enhances induced hematopoietic differentiation of murine embryonic stem cells
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DOI：
10.1016/j.exphem.2007.09.004
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发表时间：
2008-02-01
影响因子：
2.6
通讯作者：
May, W. Stratford
中科院分区：
文献类型：
--
作者：
Wang, Yan-Yi;Deng, Xingming;May, W. Stratford
bcl 2是一种有效的抗凋亡基因，可以增加成人骨髓造血祖细胞对致死辐射的抵抗力，从而保持其分化能力。然而，Bcl 2对在不存在毒性应激的情况下诱导经历造血分化的鼠胚胎干（ES）细胞的作用尚不清楚。为了测试这一点，使用了可以在导致Bcl 2上调的两步过程中被诱导经历造血分化的鼠CCE-ES细胞。当作为单细胞在甲基纤维素中铺板时，Bcl 2的上调先于造血拟胚体（EB）的形成及其进一步分化成造血集落形成单位。检查稳定表达Bcl 2 siRNA质粒以“敲低”内源表达的ES细胞或表达野生型（WT）Bcl 2或磷酸化模拟Bcl 2突变体的细胞。表达Bcl 2 siRNA的ES细胞或表达显性阴性、非磷酸化Bcl 2的ES细胞与表达WT或磷酸化模拟Bcl 2的细胞相比，显示出显著降低的形成造血EB和集落形成单位的能力，而表达WT或磷酸化模拟Bcl 2的细胞显示出增加的能力。Bcl 2对ES细胞诱导造血分化的作用不是由于细胞凋亡减少或细胞数量减少。相反，Bcl 2-通过上调p27来增强ES细胞的造血分化，这导致细胞周期阻滞在G（1）/ Go。因此，p27的siRNA沉默以类似于Bcl 2“沉默”或非磷酸化Bcl 2表达的方式恢复Bcl 2的增强表型。除了Bcl 2对体细胞的抗凋亡和细胞周期阻滞作用外，Bcl 12还可用于增强小鼠ES细胞的诱导造血细胞分化。这些发现可能与从ES细胞来源扩大造血干/祖细胞数量用于干细胞移植应用具有潜在的相关性。(C)2008 ISEH -血液学和干细胞学会。爱思唯尔公司出版
Bcl2 is a potent antiapoptotic gene that can increase resistance of adult bone marrow hematopoietic progenitor cells to lethal irradiation, and thereby preserve their ability to differentiate. However, the effect of Bcl2 on murine embryonic stem (ES) cells induced to undergo hematopoietic differentiation in the absence of a toxic stress is not known. To test this, murine CCE-ES cells that can be induced to undergo hematopoietic differentiation in a two-step process that results in upregulation of Bcl2 were used. Upregulation of Bcl2 precedes formation of hematopoietic embryoid bodies (EB) and their further differentiation into hematopoietic colony-forming units, when plated as single cells in methylcellulose. ES cells stably expressing a Bcl2 siRNA plasmid to "knock-down" endogenous expression or cells expressing wildtype (WT) Bcl2 or phosphomimetic Bcl2 mutants were examined. ES cells expressing the Bcl2 siRNA or those expressing a dominant-negative, nonphosphorylatable Bcl2 display a strikingly reduced capacity to form hematopoietic EBs and colony-forming units compared to cells expressing WT or phosphomimetic Bcl2 that demonstrate an increased capacity. Bcl2's effect on induced-hematopoietic differentiation of ES cells does not result from either decreased apoptosis or a reduced number of cells. Rather, Bcl2-enhances hematopoietic differentiation of ES cells by upregulating p27, which results in retardation of the cell cycle at G(1)/ Go. Thus siRNA silencing of p27 reverts Bcl2's enhancement phenotype in a manner similar to that of Bcl2 "silencing" or expression of a nonphosphorylable Bcl2. In addition to Bcl2's well-described antiapoptotic and cell-cycle retardant effect on somatic cells, Bc12 may also function to enhance induced hematopoietic cell differentiation of murine ES cells. These findings may have potential relevance for expanding hematopoietic stem/progenitor cell numbers from an ES cell source for stem cell transplantation applications. (C) 2008 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc.