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.
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.
Kie
Jeong-Hae
JH
Department of Pathology, College of Medicine, Yonsei University, Seoul, Korea.
Yang
Woo-Ick
WI
Lee
Mi-Kyung
MK
Kwon
Tae-Jung
TJ
Min
Yoo-Hong
YH
Kim
Hyun-Ok
HO
Ahn
Hyo-Seop
HS
Im
Seock-Ah
SA
Kim
Hyung-Lae
HL
Park
Hae-Young
HY
Ryu
Kyung-Ha
KH
Chung
Wha-Soon
WS
Shin
Myeong-Heon
MH
Jung
Yu-Jin
YJ
Woo
So-Youn
SY
Park
Hae-Kyung
HK
Seoh
Ju-Young
JY
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
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