Arai Fumio, Suda Toshio
Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, School of Medicine, Keio University, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan.
Ann N Y Acad Sci. 2007 Jun;1106:41-53. doi: 10.1196/annals.1392.005. Epub 2007 Mar 1.
Hematopoietic stem cells (HSCs) are responsible for blood cell production throughout an individual's lifetime. Interaction of HSCs with their specific microenvironments, known as stem cell niches, is critical for maintaining stem cell properties, including self-renewal capacity and the ability to differentiate into multiple lineages. During postnatal life, the bone marrow (BM) supports both self-renewal and differentiation of HSCs in specialized microenvironmental niches. In the adult BM, HSCs are located in the trabecular endosteum (osteoblastic niche) or sinusoidal perivascular (vascular niche) areas. Here we show that osteoblastic cells (OBs) are a critical component for sustaining slow-cycling or quiescent HSCs. Interaction of HSCs with OBs through signaling and cell adhesion molecules maintains the balance in HSCs between cell division/proliferation and quiescence. In particular, the quiescent state is thought to be an essential mechanism to protect HSCs from stress and to sustain long-term hematopoiesis.
造血干细胞（HSCs）在个体的一生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多种细胞谱系的能力。在出生后的生命过程中，骨髓（BM）在特殊的微环境龛中支持造血干细胞的自我更新和分化。在成年骨髓中，造血干细胞位于小梁骨内膜（成骨细胞龛）或窦周血管（血管龛）区域。在这里，我们表明成骨细胞（OBs）是维持慢循环或静止造血干细胞的关键组成部分。造血干细胞通过信号传导和细胞粘附分子与成骨细胞的相互作用维持了造血干细胞在细胞分裂/增殖和静止之间的平衡。特别是，静止状态被认为是保护造血干细胞免受应激并维持长期造血的重要机制。
