Arai Fumio, Hirao Atsushi, Suda Toshio
Department of Cell Differentiation, Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, Tokyo, Japan.
Int J Hematol. 2005 Dec;82(5):371-6. doi: 10.1532/IJH97.05100.
Hematopoietic stem cells (HSCs) are responsible for blood cell production throughout the lifetime of an individual. Interaction of HSCs with their particular microenvironments, known as stem cell niches, is critical for maintaining stem cell properties, including self-renewal capability and ability for differentiation into single and multiple lineages. In the niche, the niche cells produce signaling molecules, extracellular matrix, and cell adhesion molecules and regulate stem cell fates. Long-term bone marrow (BM)-repopulating HSCs recently have been found frequently to exist in the BM trabecular bone surface, and it has been clarified that osteoblasts (OBs) are a critical component for sustaining HSCs. HSCs keep a balance between quiescence and cell division/proliferation in the osteoblastic niche. The specific properties of HSCs are controlled dynamically by signaling of receptor/ligand and cell adhesion molecules produced by OBs.
造血干细胞（HSCs）在个体的整个生命周期中负责血细胞的生成。造血干细胞与其特定的微环境（即干细胞龛）之间的相互作用对于维持干细胞特性至关重要，这些特性包括自我更新能力以及分化为单谱系和多谱系的能力。在龛中，龛细胞产生信号分子、细胞外基质和细胞黏附分子，并调节干细胞的命运。最近发现，长期重建造血的造血干细胞经常存在于骨髓小梁骨表面，并且已经明确成骨细胞（OBs）是维持造血干细胞的关键组成部分。造血干细胞在成骨龛中维持静止与细胞分裂/增殖之间的平衡。造血干细胞的特定特性由成骨细胞产生的受体/配体信号和细胞黏附分子动态控制。
