An immortalized cell line representing the primitive erythroid (EryP) lineage was established from in vitro-differentiated progeny (embryoid bodies [EBs]) of embryonic stem (ES) cells using a retrovirai insertional mutation, and has been termed EB-PE for embryoid body-derived primitive erythroid. Even though EB-PE cells are immortalized, they show characteristics of normal EryP cells, such as gene expression and growth factor dependency. In addition, EB- PE cells can differentiate further in culture. Investigation of growth factor requirements of EB-PE cells showed that basic fibroblast growth factor (bFGF) and erythropoietin (Epo) play unique roles in EB-PE proliferation and differentiation. While bFGF was a strong mitogen, Epo was required for both proliferation and differentiation. The unique proliferative response to bFGF coincided with upregulation of its receptor, fibroblast growth factor receptor (fgfr-1), and downregulation of erythropoietin receptor (EpoR) gene expression. Studies of primary EryP cells derived from early EBs, when tested in a colony-formation assay, also provided evidence for the mitogenic role of bFGF in concert with Epo.
|Number of pages||8|
|State||Published - May 1 1998|