title: Decrease in apoptosis and increase in polyploidization of megakaryocytes by stem cell factor during ex vivo expansion of human cord blood CD34+ cells using thrombopoietin.
abstract: Thrombopoietin (TPO) is widely used for ex vivo expansion of hematopoietic stem cells. Previously, we have reported that TPO induces a characteristic pattern of apoptosis, and the TPO-induced apoptosis is closely associated with megakaryocyte (MK) differentiation. In the present study, several cytokines, flt3-ligand, stem cell factor (SCF), interleukin-3 (IL-3), IL-6, IL-11, leukemia inhibitory factor, G-CSF, and erythropoietin, which are known to affect megakaryocytopoiesis, have been evaluated to elucidate their effects on the TPO-induced apoptosis. Measurement of apoptosis by flow cytometry revealed that only SCF absolutely reduced the TPO-induced apoptosis in MK fractions, particularly in the late phase of ex vivo expansion. Platelet production was demonstrated by electron microscopy in a later phase when SCF was added. Simultaneous measurement of DNA contents with immunophenotyping demonstrated a significant increase in polyploidization in the CD41+ cell fraction when cultured with SCF. These results suggested that SCF not only inhibited premature senescence but also enhanced maturation of the differentiating cells of MK lineage during ex vivo expansion using TPO.
authors.affiliation: Department of Pathology, College of Medicine, Yonsei University, Seoul, Korea.
authors.forename: Jeong-Hae
authors.initials: JH
authors.lastname: Kie
authors.forename: Woo-Ick
authors.initials: WI
authors.lastname: Yang
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Lee
authors.forename: Tae-Jung
authors.initials: TJ
authors.lastname: Kwon
authors.forename: Yoo-Hong
authors.initials: YH
authors.lastname: Min
authors.forename: Hyun-Ok
authors.initials: HO
authors.lastname: Kim
authors.forename: Hyo-Seop
authors.initials: HS
authors.lastname: Ahn
authors.forename: Seock-Ah
authors.initials: SA
authors.lastname: Im
authors.forename: Hyung-Lae
authors.initials: HL
authors.lastname: Kim
authors.forename: Hae-Young
authors.initials: HY
authors.lastname: Park
authors.forename: Kyung-Ha
authors.initials: KH
authors.lastname: Ryu
authors.forename: Wha-Soon
authors.initials: WS
authors.lastname: Chung
authors.forename: Myeong-Heon
authors.initials: MH
authors.lastname: Shin
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Jung
authors.forename: So-Youn
authors.initials: SY
authors.lastname: Woo
authors.forename: Hae-Kyung
authors.initials: HK
authors.lastname: Park
authors.forename: Ju-Young
authors.initials: JY
authors.lastname: Seoh
mesh_terms: D018952:Antigens, CD34 / Q000096:biosynthesis*; D017209:Apoptosis; D002455:Cell Division; D019070:Cell Lineage; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D004921:Erythropoietin / Q000096:biosynthesis; D005312:Fetal Blood / Q000378:metabolism*; D005434:Flow Cytometry; D016179:Granulocyte Colony-Stimulating Factor / Q000096:biosynthesis; D006131:Growth Inhibitors / Q000096:biosynthesis; D006801:Humans; D017370:Interleukin-11 / Q000096:biosynthesis; D007377:Interleukin-3 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000096:biosynthesis; D008533:Megakaryocytes / Q000166:cytology* / Q000378:metabolism*; D008565:Membrane Proteins / Q000096:biosynthesis; D008854:Microscopy, Electron; D011003:Ploidies; D019089:Stem Cell Factor / Q000096:biosynthesis / Q000378:metabolism*; D013926:Thrombopoietin / Q000096:biosynthesis*; D013997:Time Factors
chemical_list: D018952:Antigens, CD34; D016895:Culture Media, Serum-Free; D006131:Growth Inhibitors; D017370:Interleukin-11; D007377:Interleukin-3; D015850:Interleukin-6; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines; D008565:Membrane Proteins; D019089:Stem Cell Factor; C084881:flt3 ligand protein; D004921:Erythropoietin; D016179:Granulocyte Colony-Stimulating Factor; D013926:Thrombopoietin