title: Effect of recombinant erythropoietin in interaction with stromal factors on cord blood hematopoiesis.
abstract: To investigate the effect of recombinant erythropoietin (Epo) on primitive human hematopoietic progenitor cells, we cultured cord blood mononuclear cells (CBMNC) and CB CD34+ cells in a Dexter-type long-term culture system (LTC), to which various concentrations of Epo were added at day 0 or 7, with or without direct contact with irradiated allogeneic human marrow stromal layers. In regular stroma-contact cultures, when CBMNC were inoculated, the addition of Epo at 1 to 10 U/mL induced a significant increase in LTC-initiating cells (LTC-IC), particularly in the myeloid component, compared with the control without Epo. Significantly more LTC-IC were generated by the delayed addition of Epo on day 7 than on day 0. On the other hand, when CD34+ cells were inoculated, physiologic concentrations of Epo (0.1 U/mL) induced a more than twofold increase in LTC-IC, which was attributed equally to both the myeloid and erythroid lineages, only when added on day 0. In stroma-noncontact cultures, which were created using a Transwell 0.4-micron microporous membrane filter, dose-dependent suppression of the myeloid component of LTC-IC was observed with a higher concentration of Epo (1 to 100 U/mL) when CBMNC was inoculated. On the other hand, without Epo, fourfold more LTC-IC was generated from CD34+ cells in stroma-noncontact than in stroma-contact cultures, which was then significantly augmented by the addition of Epo (0.1 or 10 U/mL) on day 0. This increase was due to both the myeloid and erythroid lineages. A higher concentration of Epo (100 U/mL) resulted in a decrease in LTC-IC, mainly in myeloid progeny, in all of the culture conditions. Hence, Epo may play an important physiologic role in the maintenance and proliferation of immature stem/progenitor cells, in close interaction with factors from marrow stromal cells.
authors.affiliation: Department of Pediatrics, University Hospital of Tokushima, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Abe
authors.forename: Y
authors.initials: Y
authors.lastname: Takaue
authors.forename: Y
authors.initials: Y
authors.lastname: Kawano
authors.forename: Y
authors.initials: Y
authors.lastname: Kuroda
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis; D001685:Biological Factors / Q000378:metabolism / Q000494:pharmacology*; D001853:Bone Marrow / Q000378:metabolism; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003238:Connective Tissue / Q000378:metabolism*; D017077:Culture Media, Conditioned; D004921:Erythropoietin / Q000494:pharmacology*; D005312:Fetal Blood / Q000166:cytology*; D006410:Hematopoiesis / Q000187:drug effects*; D006412:Hematopoietic Stem Cells / Q000187:drug effects*; D006801:Humans; D011994:Recombinant Proteins / Q000494:pharmacology
chemical_list: D018952:Antigens, CD34; D001685:Biological Factors; D017077:Culture Media, Conditioned; D011994:Recombinant Proteins; D004921:Erythropoietin