Identification of characteristic proteins at late-stage erythroid differentiation in vitro.

The production of red blood cells in vitro, which is useful for basic or clinical research, has been improved. Further optimization of culture protocols may facilitate erythroid differentiation from hematopoietic stem cells to red blood cells. However, the details of erythropoiesis, particularly regarding the behaviors of differentiation-related proteins, remain unclear. Here, we performed erythroid differentiation using two independent bone marrow- or cord blood-derived CD34+ cell sources and identified proteins showing reproducible differential expression in all groups. Notably, most of the proteins expressed at the early stage were downregulated during erythroid differentiation. However, seven proteins showed upregulated expression in both bone marrow cells and cord blood cells. These proteins included alpha-synuclein and selenium-binding protein 1, the roles of which have not been clarified in erythropoiesis. There is a possibility that these factors contribute to erythroid differentiation as they maintained a high expression level. These findings provide a foundation for further mechanistic studies on erythropoiesis.