Materials Science and Engineering, Commonwealth Scientific and Industrial Research Organization (CSIRO), Melbourne, Australia.
Ann N Y Acad Sci. 2014 Mar;1310:119-28. doi: 10.1111/nyas.12329. Epub 2014 Jan 15.
The existence of a bone marrow (BM) niche--the location in which hematopoietic stem cells (HSCs) reside--was proposed more than 30 years ago. Recent data suggest that the interaction of HSCs with cellular and extracellular components within the BM is critical for HSC regulation. The tracking of immunofluorescently labeled, prospectively isolated HSCs to and within the BM cavity allows the assessment of the regulatory processes involved in (1) homing, which involves transendothelial migration into the BM; (2) lodgment, including transmarrow migration through the extravascular space; and (3) BM reconstitution. Together, such analyses provide a better understanding of the cellular and extracellular components involved in the regulation of HSC quiescence and differentiation. Homing and lodgment of transplanted HSCs, the first critical steps in engraftment, involve multiple interactions between HSCs and the BM microenvironment. Herein, we describe a refined method of analyzing homing efficiency and spatial distribution of HSCs harvested from endosteal and/or central BM regions; we also review alternate methods. Using these techniques, microenvironment modifications within the recipient or surface protein-expression modifications on donor HSCs in animal models provide insights into components influencing the homing, lodgment, and engraftment processes.
骨髓（BM）龛的存在——造血干细胞（HSCs）驻留的位置——是在 30 多年前提出的。最近的数据表明，HSCs 与 BM 内细胞和细胞外成分的相互作用对于 HSC 的调节至关重要。通过对免疫荧光标记的、前瞻性分离的 HSCs 进行追踪，可评估参与以下过程的调节机制：（1）归巢，涉及穿过内皮细胞迁移到 BM 中；（2）定位，包括通过血管外空间的骨髓内迁移；以及（3）BM 重建。这些分析共同提供了对调节 HSC 静止和分化所涉及的细胞和细胞外成分的更好理解。移植 HSCs 的归巢和定位，即植入的第一个关键步骤，涉及 HSCs 与 BM 微环境之间的多种相互作用。在此，我们描述了一种从骨内膜和/或中央 BM 区域中收获的 HSCs 归巢效率和空间分布的改良分析方法；我们还回顾了其他方法。使用这些技术，在动物模型中，对受者微环境的修饰或供者 HSCs 表面蛋白表达的修饰，为影响归巢、定位和植入过程的因素提供了见解。
