Department of Immunobiology and Hematology, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, Japan.
Immunity. 2010 Sep 24;33(3):387-99. doi: 10.1016/j.immuni.2010.08.017.
Hematopoietic stem cells (HSCs) and their lympho-hematopoietic progeny are supported by microenvironmental niches within bone marrow; however, the identity, nature, and function of these niches remain unclear. Short-term ablation of CXC chemokine ligand (CXCL)12-abundant reticular (CAR) cells in vivo did not affect the candidate niches, bone-lining osteoblasts, or endothelial cells but severely impaired the adipogenic and osteogenic differentiation potential of marrow cells and production of the cytokines SCF and CXCL12 and led to a marked reduction in cycling lymphoid and erythroid progenitors. HSCs from CAR cell-depleted mice were reduced in number and cell size, were more quiescent, and had increased expression of early myeloid selector genes, similar to the phenotype of wild-type HSCs cultured without a niche. Thus, the niche composed of adipo-osteogenic progenitors is required for proliferation of HSCs and lymphoid and erythroid progenitors, as well as maintenance of HSCs in an undifferentiated state.
造血干细胞 (HSCs) 及其淋巴造血祖细胞由骨髓中的微环境龛支持；然而，这些龛的特性、本质和功能仍不清楚。体内短期消除 CXCL 趋化因子配体 (CXCL)12 丰富的网状 (CAR) 细胞不会影响候选龛、骨衬成骨细胞或内皮细胞，但严重损害骨髓细胞的成脂和成骨分化潜能以及细胞因子 SCF 和 CXCL12 的产生，并导致循环淋巴和红细胞祖细胞明显减少。CAR 细胞耗尽小鼠的 HSCs 数量减少，细胞体积减小，更静止，早期髓系选择基因表达增加，类似于在没有龛的情况下培养的野生型 HSCs 的表型。因此，由脂肪 - 成骨祖细胞组成的龛对于 HSCs 和淋巴造血祖细胞的增殖以及维持 HSCs 的未分化状态是必需的。
