• Perreault AA, Benton ML, Koury MJ, Brandt SJ, Venters BJ. Epo reprograms the epigenome of erythroid cells. Experimental hematology. 2017 Apr 11. PMID: 28410882 [PubMed].

Abstract 

The hormone erythropoietin (Epo) is required for erythropoiesis, yet its molecular mechanism of action remains poorly understood, particularly in regards to chromatin dynamics. To investigate how Epo modulates the erythroid epigenome, we performed epigenetic profiling using an ex vivo murine cell system that undergoes synchronous erythroid maturation in response to Epo stimulation. Our findings define the repertoire of Epo-modulated enhancers, illuminating a new facet of Epo signaling. First, a large number of enhancers rapidly responded to Epo stimulation, revealing a cis-regulatory network of Epo-responsive enhancers. In contrast, most of the other identified enhancers remained in an active acetylated state during Epo signaling, suggesting that most erythroid enhancers are established at an earlier precursor stage. Second, we identified several hundred super enhancers that were linked to key erythroid genes, such as TAL1, BCL11A, and MIR144/451. Third, experimental and computational validation demonstrated that many predicted enhancer regions were occupied by Tal1 and enriched with DNA binding motifs for Gata1, Klf1, Tal1/E-box and Stat5. Additionally, many of these cis-regulatory regions were evolutionarily conserved and displayed correlated enhancer:promoter acetylation. Together, these findings define a cis-regulatory enhancer network for Epo signaling during erythropoiesis, and provide the framework for future studies involving the interplay of epigenetics and Epo signaling.