Abstract
In the bone marrow, hematopoietic cells proliferate and differentiate in close association with a three-dimensional (3D) hematopoietic microenvironment. Previously, we established a 3D bone marrow culture system. In this study, we analyzed the kinetics of hematopoietic cells, and more than 50% of hematopoietic progenitor cells, including CFU-Mix, CFU-GM and BFU-E in 3D culture were in a resting (non-S) phase. Furthermore, we examined the hematopoietic supportive ability of stromal cells by measuring the expression of various mRNAs relevant to hematopoietic regulation. Over the 4 weeks of culture, the stromal cells in the 3D culture are not needlessly activated and “quietly” regulate hematopoietic cell proliferation and differentiation during the culture, resulting in the presence of resting hematopoietic stem cells in the 3D culture for a long time. Thus, the 3D culture system may be a new tool for investigating hematopoietic stem cell–stromal cell interactions in vitro.
Acknowledgements
We thank Ms. Sonoko Araki and Ms. Miyuki Yuda for their technical assistance.
Declaration of interest
This work was supported in part by a Grant-in-aid for Scientific Research (C) from the Japan Society for the Promotion of Science. The authors have no conflict of interest to declare.