Ikaros And Erythropoiesis

Mostly studied in murine models, Ikaros - a factor that positively or negatively controls gene transcription - was first described as essential to lymphopoiesis until its involvement in numerous hematopoietic lineages was documented. Indeed, Ikaros is also active in murine erythropoiesis and more precisely during fetal to adult globin switching. Recently, these observations were confirmed by our team in a human context. We here review some of the most important characteristics of Ikaros, and detail more precisely how defects of Ikaros activity either by gene inactivation or mutation in mice, or by forced expression of dominant negative isoforms in human precursor cells, modify the erythroid differentiation. An increased cell death, together with decreased cell proliferation, decreased expression of erythroid-specific genes including GATA1, and a delay in fetal to adult globin switching were observed. At the some time, myeloid differentiation was slightly favoured thus suggesting that Ikaros could be involved in the control of the myeloid/erythroid commitment.