Tgf-Beta 1 Negatively Regulates The Number And Function Of Hematopoietic Stem Cells

Transforming growth factor beta 1 (TGF-beta 1) plays a role in the maintenance of quiescent hematopoietic stem cells (HSCs) in vivo. We asked whether TGF-beta 1 controls the cell cycle status of HSCs in vitro to enhance the reconstitution activity. To examine the effect of TGF-beta 1 on the HSC function, we used an in vitro culture system in which single HSCs divide with the retention of their short- and long-term reconstitution ability. Extensive single-cell analyses showed that, regardless of its concentration, TGF-beta 1 slowed down the cell cycle progression of HSCs but consequently suppressed their self-renewal potential. Cycling HSCs were not able to go back to quiescence with TGF-beta 1. This study revealed a negative role of TGF-beta 1 in the regulation of the HSC number and reconstitution activity.