Hematopoietic stem cells are difficult to maintain in vitro, hampering their clinical use. Jian Huang et al. show that mouse and human hematopoietic stem cells can be maintained in culture in the absence of exogenous cytokines by combined treatment with agents that activate Wnt and inhibit mTOR signaling, two major signaling pathways implicated in stem cell homeostasis. Moreover, treatment with two such compounds used clinically increases the number of hematopoietic stem cells in mice in vivo.
- Jian Huang
- Michelle Nguyen-McCarty
- Peter S Klein