Stem Cells, Vol 12, 329-338, Copyright © 1994 by AlphaMed Press
Stimulatory effect of human insulin on erythroid progenitors (CFU-E and BFU-E) in human CD34+ separated bone marrow cells and the relationship between insulin and erythropoietin
I Aoki, M Taniyama, K Toyama, M Homori and K Ishikawa
Second Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan.
Erythropoietin is known to be effective for the treatment of anemia in
chronic renal failure, but the efficacy of erythropoietin for anemia in
other diseases is not so great. Insulin exerts a growth promoting activity
in various kinds of cells. In the present study, the effects of insulin on
erythroid progenitors (colony forming units-erythroid, CFU-E; and burst
forming units-erythroid, BFU-E) in human bone marrow were examined at
various concentrations of recombinant human erythropoietin (rh-Epo) to
clarify the relationship between erythropoietin and insulin. Human insulin
stimulated the formation of CFU-E and BFU-E in the presence of three
concentrations (0.25, 5, and 100 U/ml) of rh-Epo. Stimulatory effects of
human insulin on CFU-E and BFU-E were also observed in the nonphagocytic
and nonadherent bone marrow fraction (NP-NA fraction) and in the NP-NA and
T cell-depleted fraction at each concentration of rh-Epo. Human insulin
further stimulated the CFU-E and BFU-E growth in CD34+ separated bone
marrow cells. These results indicate that the enhancing effect of human
insulin on erythroid progenitors is not mediated through monocytes and
macrophages or T cells, suggesting a direct action on erythroid
progenitors.
