Detection of Functional Hematopoietic Stem Cell Niche Using Real-Time Imaging

摘要: Hematopoietic stem cell (HSC) niches play an essential role in regulating adult self-renewal and differentiation. HSC have only recently been identified based on genetic models that showed a parallel increase the numbers of both HSCs osteoblasts, or by static immunolabeling putative adjacent locations. However, osteoblasts vasculature were viewed as separate with distinctive roles, their interrelationships interactions vivo remain largely undefined. To study dynamic interaction between its niche, we developed method ex imaging cells (EVISC) using two-photon microscopy. This combined technology real-time functional feature Flk2−LSK can be prospectively isolated high purity home to niche upon transplantation into irradiated recipient mice. Using EVISC combination immunoassaying, found transplanted tended endosteal region predominantly trabecular bone area (TBA) compared compact (CBA) under conditions, but randomly distributed unstable non-irradiated conditions. Mechanistically, ratio expression level SDF-1 TBA CBA was significantly increased response irradiation. By monitoring individual behavior ranging from minutes 16-hours, small portion homed underwent active division mice, coinciding initial expansion measured flow assay immunoassay. Our findings suggest formed special zone, which normally maintains promotes zone includes osteoblastic vascular components signals, changes homeostatic stressed