EMP1 upregulates EPO expression in BMMCs. Normal BMMCs were cultured for 2 hours in serum-free medium and then stimulated for 6 hours with EMP1 (0, 0.05, 0.1, and 0.5 μmol/L). Cell lysates (10 μg/lane) were analyzed for EPO on Western blots (A). EMP1 upregulates EPO expression in BMMCs with increasing EMP1 concentration up to 0.1 μmol/L. No carrier protein was added to rhEPO in lane 1 and, thus, the intensity of rhEPO band is not comparable with the intensities of EPO bands detected in cell lysates. (B) Coomassie staining of 10% SDS-PAGE separated cell lysates (10 μg per lane). In the EPO lane, 50 U of rhEPO was used.