HIF1alpha synergizes with glucocorticoids to promote BFU-E progenitor self-renewal.

ABSTRACT: With the aim of finding small molecules that stimulate erythropoiesis earlier than erythropoietin and that enhance erythroid colony-forming unit (CFU-E) production, we studied the mechanism by which glucocorticoids increase CFU-E formation. Using erythroid burst-forming unit (BFU-E) and CFU-E progenitors purified by a new technique, we demonstrate that glucocorticoids stimulate the earliest (BFU-E) progenitors to undergo limited self-renewal, which increases formation of CFU-E cells > 20-fold. Interestingly, glucocorticoids induce expression of genes in BFU-E cells that contain promoter regions highly enriched for hypoxia-induced factor 1? (HIF1?) binding sites. This suggests activation of HIF1? may enhance or replace the effect of glucocorticoids on BFU-E self-renewal. Indeed, HIF1? activation by a prolyl hydroxylase inhibitor (PHI) synergizes with glucocorticoids and enhances production of CFU-Es 170-fold. Because PHIs are able to increase erythroblast production at very low concentrations of glucocorticoids, PHI-induced stimulation of BFU-E progenitors thus represents a conceptually new therapeutic window for treating erythropoietin-resistant anemia.

SUBMITTER: Flygare J 

PROVIDER: S-EPMC3069680 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature