Abstract
Globin gene regulation occurs in the context of a maturing erythroid cell, which is undergoing significant changes in chromatin structure and gene expression. There are few model systems available that facilitate studies of globin gene regulation in the context of erythroid maturation. Extensively self-renewing erythroblasts (ESREs) are a nontransformed model of erythroid maturation derived from murine fetal liver or yolk sac. Imaging flow cytometry and RNA-seq studies demonstrate that ESREs functionally and molecularly model erythroid maturation. To address the need for a model system that also recapitulates human globin switching, ESREs were derived from mice transgenic for the complete human β-globin locus (β-yac ESREs). β-yac ESREs express β-globin from the transgenic human locus, with minimal γ-globin expression. When treated with hydroxyurea or inhibitors to histone deacetylases, DNA methyltransferases, or the histone demethylase lysine specific demethylase 1 (LSD1), β-Yac ESREs significantly increase their γ-globin expression, demonstrating their utility for studying agents that influence maturational globin switching. β-yac ESREs were further used to characterize the secondary effects of LSD1 inhibition on erythroid maturation, with inhibition of LSD1 resulting in altered cell and nuclear size, prolonged Kit expression, and decreased rates of enucleation consistent with impaired maturation. Taken together, these studies demonstrate that β-yac ESREs have significant utility for identifying modulators of maturational globin switching as well as for studying the broader role of those modulators in erythroid maturation.