Effects of ActivinA/EDF (Erythroid Differentiation Factor) on Differentiation of Human Hematopoietic Stem Cell

ActivinA/EDF (Erythroid Differentiation Factor) purified from the culture fluid of human monocytic cells (THP-1 cells) has shown to be potential to a differentiation murine erythroleukemic cells (Friend cells). In this study, we demonstrated that ActivinA/EDF increases in the number of hemoglobin positive cells in human erythroleukemia cell lines without the reduction of cell proliferation. In addition, it enhances erythroid colony formation from human erythroid progenitors of normal and MDS (myelodysplastic syndrome) in vitro. On the other hand, cyclo-oxygenase (CO) mRNA levels increase in liquid culture of human erythroleukemia cell lines after incubation with ActivinA/EDF by RT-PCR (reverse transcription-polymerase chain reaction). These results suggest that ActivinA/EDF possibly acts as an important cytokine of erythropoiesis and megakaryocytic differentiation of human hematopoietic stem cell