Hamaguchi I, Huang X L, Takakura N, Tada J, Yamaguchi Y, Kodama H, Suda T
Department of Cell Differentiation, Institute of Molecular Embryology and Genetics, Kumamoto University School of Medicine, Kumamoto, Japan.
Blood. 1999 Mar 1;93(5):1549-56.
Recent studies have shown that long-term repopulating hematopoietic stem cells (HSCs) first appear in the aorta-gonad-mesonephros (AGM) region. Our immunohistochemistry study showed that TEK+ cells existed in the AGM region. Approximately 5% of AGM cells were TEK+, and most of these were CD34(+) and c-Kit+. We then established a coculture system of AGM cells using a stromal cell line, OP9, which is deficient in macrophage colony-stimulating factor (M-CSF). With this system, we showed that AGM cells at 10.5 days postcoitum (dpc) differentiated and proliferated into both hematopoietic and endothelial cells. Proliferating hematopoietic cells contained a significant number of colony-forming cells in culture (CFU-C) and in spleen (CFU-S). Among primary AGM cells at 10.5 dpc, sorted TEK+ AGM cells generated hematopoietic cells and platelet endothelial cell adhesion molecule (PECAM)-1(+) endothelial cells on the OP9 stromal layer, while TEK- cells did not. When a ligand for TEK, angiopoietin-1, was added to the single-cell culture of AGM, endothelial cell growth was detected in the wells where hematopoietic colonies grew. Although the incidence was still low (1/135), we showed that single TEK+ cells generated hematopoietic cells and endothelial cells simultaneously, using a single-cell deposition system. This in vitro coculture system shows that the TEK+ fraction of primary AGM cells is a candidate for hemangioblasts, which can differentiate into both hematopoietic cells and endothelial cells.
最近的研究表明，长期重建造血干细胞（HSCs）最初出现在主动脉-性腺-中肾（AGM）区域。我们的免疫组织化学研究表明，TEK+细胞存在于AGM区域。大约5%的AGM细胞为TEK+，其中大多数为CD34(+)和c-Kit+。然后，我们使用缺乏巨噬细胞集落刺激因子（M-CSF）的基质细胞系OP9建立了AGM细胞的共培养系统。利用该系统，我们发现妊娠10.5天（dpc）的AGM细胞可分化并增殖为造血细胞和内皮细胞。增殖的造血细胞在培养物（CFU-C）和脾脏（CFU-S）中含有大量集落形成细胞。在10.5 dpc的原代AGM细胞中，分选的TEK+ AGM细胞在OP9基质层上产生造血细胞和血小板内皮细胞黏附分子（PECAM）-1(+)内皮细胞，而TEK-细胞则不能。当将TEK的配体血管生成素-1添加到AGM的单细胞培养物中时，在造血集落生长的孔中检测到内皮细胞生长。尽管发生率仍然很低（1/135），但我们使用单细胞沉积系统表明，单个TEK+细胞可同时产生造血细胞和内皮细胞。这种体外共培养系统表明，原代AGM细胞的TEK+部分是成血管细胞的候选者，成血管细胞可分化为造血细胞和内皮细胞。
