造血干细胞是血液组织中的一部分，当它们被移植到受者时，能够产生血液组织中的全部细胞。来自IMIM(Hospital del Mar Medical Research Institute)的研究人员揭示出一种被称作β-连环蛋白(β-catenin)的蛋白在产生造血干细胞中所发挥的功能。造血干细胞被用于移植来对抗不同类型的白血病。这些研究结果将为人们在实验室中生产这些干细胞打开大门。在未来，这也将让没有合适供者的病人能够从这项发现中获利。2012年7月16日，相关研究结果在线发表在Journal of Experimental Medicine期刊上。
在这项研究中，研究人员分析了一些胚胎细胞内部产生的一系列分子反应，其中这些胚胎细胞在产生造血干细胞中发挥着作用。论文通讯作者Anna Bigas博士说，“我们的研究有助于揭示让只在胚胎中发现的一种前体细胞变成造血干细胞的秘密。如果要这种前体细胞变成造血干细胞，那么β-连环蛋白必必须被激活一段时间同时维持一种特定的剂量。”
这种蛋白也在产生和维持一些类型的白血病中发挥着基础性的作用。在正常干细胞和白血病干细胞之间存在的这种类似性表明调节这种细胞群体的分子途径是一样的。因此，这项研究将有助于人们理解这些疾病的起源。(生物谷：Bioon.com)
本文编译自Key function of protein discovered for obtaining blood stem cells as source for transplants
doi: 10.1084/jem.20120225
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Hematopoietic stem cell development requires transient Wnt/β-catenin activity
Cristina Ruiz-Herguido1, Jordi Guiu1, Teresa D'Altri1, Julia Inglés-Esteve1, Elaine Dzierzak2, Lluis Espinosa1, and Anna Bigas
Understanding how hematopoietic stem cells (HSCs) are generated and the signals that control this process is a crucial issue for regenerative medicine applications that require in vitro production of HSC. HSCs emerge during embryonic life from an endothelial-like cell population that resides in the aorta-gonad-mesonephros (AGM) region. We show here that β-catenin is nuclear and active in few endothelial nonhematopoietic cells closely associated with the emerging hematopoietic clusters of the embryonic aorta during mouse development. Importantly, Wnt/β-catenin activity is transiently required in the AGM to generate long-term HSCs and to produce hematopoietic cells in vitro from AGM endothelial precursors. Genetic deletion of β-catenin from the embryonic endothelium stage (using VE-cadherin–Cre recombinase), but not from embryonic hematopoietic cells (using Vav1-Cre), precludes progression of mutant cells toward the hematopoietic lineage; however, these mutant cells still contribute to the adult endothelium. Together, those findings indicate that Wnt/β-catenin activity is needed for the emergence but not the maintenance of HSCs in mouse embryos.
