FIGURE 5.

Calpeptin increases expression of α- and β_maj-globin genes in primary c-Kit⁺/CD71⁺ erythroid progenitor cells. CD71⁺/c-Kit⁺ cells were isolated from mouse bone marrow, enriched by fluorescence-activated cell sorting, and incubated in the presence of 0.03% DMSO or in the presence of 30 μm calpeptin, 0.03% DMSO for 4 days. RNA was isolated from the cells, reverse transcribed, and subjected to quantitative PCR using primers against β-actin, α-globin, and β_maj-globin genes. A, α- and β_maj-globin mRNA levels in primary erythroid cells in the absence (Control), in the presence of 0.03% DMSO, or in the presence of 30 μm calpeptin, 0.03% DMSO. Expression was normalized to that of β-actin. B, mRNA levels of β-actin in cells incubated in the absence (DMSO control) or presence of calpeptin. Error bars reflect S.D. from two experiments using different cDNA preparations.