Characterization of the First HSCs During Mouse Ontogeny

小鼠个体发育过程中第一个 HSC 的表征

• 批准号: 6753650
• 负责人: ELAINE A DZIERZAK
• 金额: $ 15.02万
• 依托单位: ERASMUS UNIVERSITY OF ROTTERDAM
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-06-01 至 2006-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6753650
• 关键词: Mus musculus; aorta; bone marrow; cell differentiation; cell migration; cell population study; cell transplantation; early embryonic stage; embryo /fetus culture; embryogenesis; genetically modified animals; hematopoiesis; hematopoietic growth factor; hematopoietic stem cells; laboratory mouse; leukemia; stromal cells

The continuous and life-long production of all mature blood cells in the circulation and hematopoietic tissues is contingent upon hematopoietic stem cells (HSCs). These rare cells, at the base of the hematopoietic differentiation hierarchy, reside in the bone marrow of adult mammals. In human medicine, HSCs are clinically important cells in transplantation therapies for blood-related diseases and leukemias. The ability to manipulate adult HSCs, particularly to expand the limiting numbers of these cells in vitro, has been difficult. Despite the isolation and characterization of many hematopoietic growth factors, HSC numbers can only (at best) be maintained in culture. Taking a developmental approach, we have been investigating the origins and growth of HSCs in the mouse embryo. We conjectured that at some early stage the embryo must induce the production of HSCs, generate a supportive microenvironment, and expand HSC numbers. With insight into these processes, novel factors to promote HSC induction/expansion may be discovered. We have shown that the aorta-gonads-mesonephros (AGM) region autonomously generates the first fully potent adult HSCs and that HSC activity is localized to the major vascular regions of the embryo body; the dorsal aorta, vitelline and umbilical arteries. Presently, the direct precursor cells to HSCs are unknown but are speculated to be hemangioblasts, hemogenic endothelial cells or mesenchymal cells in these vascular regions. Additionally, the lineage relationships of the first intraembryonic HSCs to those in the adult have not yet been established. Thus, we propose to examine cellular source of HSCs in the mouse embryo and to follow the migration of HSCs and the colonization of fetal and adult hematopoietic tissues by HSCs. Cultured whole mouse embryos will be injected with dye to fate map putative HSC precursors. Also, sorted putative HSC precursors will be injected into cultured whole mouse embryos to follow their migration and functional potential. Finally, cre-lox recombination will be used to specifically mark putative pre-HSCs so as to follow their functional potential and fate in fetal and adult hematopoietic tissues. These results should give insight into the source and complexity of adult HSC production.

循环和造血组织中所有成熟血细胞的连续生产和终身产生均取决于造血干细胞（HSC）。 这些稀有细胞位于造血分化等级的底部，位于成年哺乳动物的骨髓中。 在人类医学中，HSC是血液相关疾病和白血病的移植疗法中临床上重要的细胞。 操纵成年HSC的能力，尤其是在体外扩大这些细胞的限制数量的能力。 尽管许多造血生长因子隔离和表征，但HSC数量只能（充其量）在培养中保持。采用发展方法，我们一直在研究小鼠胚胎中HSC的起源和生长。 我们推测，在某个早期，胚胎必须诱导HSC的产生，产生支持性的微环境并扩大HSC数量。 通过深入了解这些过程，可以发现促进HSC诱导/扩展的新因素。 我们已经表明，主动脉 - 甲虫（AGM）区域自主产生第一个完全有效的成人HSC，HSC活性定位于胚胎体的主要血管区域。背主动脉，卵黄和脐动脉。 目前，在这些血管区域中，直接的HSC前体细胞是未知的，但据推测是血管细胞，血管细胞，血管内皮细胞或间质细胞。 此外，尚未建立第一个胚胎内HSC与成年人的谱系关系。 因此，我们建议检查小鼠胚胎中HSC的细胞来源，并跟随HSC的迁移以及HSC胎儿和成人造血组织的定殖。 培养的整个小鼠胚胎将注入染料，以命运图提出的HSC前体。 同样，分类的推定的HSC前体将被注入培养的整个小鼠胚胎中，以遵循其迁移和功能潜力。 最后，将使用Cre-Lox重组来特异性标记假定的HSC，以遵循其功能潜力和命运在胎儿和成人造血组织中。 这些结果应深入了解成人HSC生产的来源和复杂性。