Synergistic effect of cytokines EPO, IL-3 and SCF on the proliferation, differentiation and apoptosis of erythroid progenitor cells.

Erythroblasts were obtained from murine spleen. After cultured for 12 hr, the cells were divided into four groups with the use of the following cytokines in culture: EPO, EPO+SCF, EPO+IL-3, and EPO+IL-3+SCF. Cell proliferation assay was done. Apoptosis rates were obtained by using a flow cytometer. Mitochondrial membrane potential (MMP) was assessed in flow cytometry (FCM) by labeling with rhodamine 123. Mitochondrial enzyme activity (MEA) was evaluated with MTT colorimetric assay. The cells were labeled with Fluo-3/Am Ester and Ca(2+) concentration was measured. The expression of Bax mRNA and Bcl-2 mRNA was analyzed by RT-PCR. At same time, the expression of Bax and Bcl-2 was analyzed by western blotting. Our results showed that IL-3 and SCF have synergistic effects with EPO on the proliferation, differentiation and apoptosis of erythroid progenitors.