P190-B RhoGAP and intracellular cytokine signals balance hematopoietic stem and progenitor cell self-renewal and differentiation.

ABSTRACT: The mechanisms regulating hematopoietic stem and progenitor cell (HSPC) fate choices remain ill-defined. Here, we show that a signalling network of p190-B RhoGAP-ROS-TGF-?-p38MAPK balances HSPC self-renewal and differentiation. Upon transplantation, HSPCs express high amounts of bioactive TGF-?1 protein, which is associated with high levels of p38MAPK activity and loss of HSC self-renewal in vivo. Elevated levels of bioactive TGF-?1 are associated with asymmetric fate choice in vitro in single HSPCs via p38MAPK activity and this is correlated with the asymmetric distribution of activated p38MAPK. In contrast, loss of p190-B, a RhoGTPase inhibitor, normalizes TGF-? levels and p38MAPK activity in HSPCs and is correlated with increased HSC self-renewal in vivo. Loss of p190-B also promotes symmetric retention of multi-lineage capacity in single HSPC myeloid cell cultures, further suggesting a link between p190-B-RhoGAP and non-canonical TGF-? signalling in HSPC differentiation. Thus, intracellular cytokine signalling may serve as 'fate determinants' used by HSPCs to modulate their activity.

SUBMITTER: Hinge A 

PROVIDER: S-EPMC5309857 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature