scholarly journals Cell cycling status of human cord blood CD34+ cells during ex vivo expansion is related to the level of very late antigen expression

2001 ◽  
Vol 16 (1) ◽  
pp. 20 ◽  
Author(s):  
Ju Young Seoh ◽  
Hae Young Park ◽  
Wha Soon Chung ◽  
Seung Cheol Kim ◽  
Myong Joon Hahn ◽  
...  
Keyword(s):  
Cord Blood ◽  
Ex Vivo ◽  
Antigen Expression ◽  
Ex Vivo Expansion ◽  
Human Cord Blood ◽  
Cd34 Cells ◽  
Late Antigen ◽  
Cord Blood Cd34 ◽  
Cell Cycling

scholarly journals Apoptosis and megakaryocytic differentiation during ex vivo expansion of human cord blood CD34+ cells using thrombopoietin

2001 ◽  
Vol 113 (2) ◽  
pp. 470-478 ◽  
Author(s):  
Kyung-Ha Ryu ◽  
Susan Chun ◽  
Steve Carbonierre ◽  
Seock-Ah Im ◽  
Hyung-Lae Kim ◽  
...  
Keyword(s):  
Cord Blood ◽  
Ex Vivo ◽  
Ex Vivo Expansion ◽  
Human Cord Blood ◽  
Megakaryocytic Differentiation ◽  
Cd34 Cells ◽  
Cord Blood Cd34

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

Stem Cells ◽  
2002 ◽  
Vol 20 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Jeong-Hae Kie ◽  
Woo-Ick Yang ◽  
Mi-Kyung Lee ◽  
Tae-Jung Kwon ◽  
Yoo-Hong Min ◽  
...  
Keyword(s):  
Stem Cell ◽  
Cord Blood ◽  
Stem Cell Factor ◽  
Ex Vivo ◽  
Ex Vivo Expansion ◽  
Human Cord Blood ◽  
Cd34 Cells ◽  
Cord Blood Cd34

Study of the Mechanisms by Which Angptl5 and IGFBP2 Support Ex Vivo Expansion of Human Cord Blood Hematopoietic Stem Cells.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2308-2308
Author(s):  
Junke Zheng ◽  
Chengcheng Zhang
Keyword(s):  
Stem Cells ◽  
Transcription Factors ◽  
Cord Blood ◽  
Ex Vivo ◽  
Ex Vivo Expansion ◽  
Human Cord Blood ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Cord Blood Cd34

Abstract We previously showed that angiopoietin-like protein 5 (Angptl5) and IGF Binding Protein 2 (IGFBP2) support dramatic ex vivo expansion of human hematopoietic stem cells (HSCs). To understand the mechanisms of their action, here we studied the effects of Angptl5 and IGFBP2 on the surface phenotype, signaling activation, self-renewal, apoptosis, differentiation, and homing of human cord blood CD34+ cells. Using immunofluorescence staining, we showed that Angptl5 and IGFBP2 activate certain signaling pathways such as MAPK and Stat5 in human cord blood CD34+ cells. IGFBP2 and Angptl5 increased the expression of transcription factors HoxB4, Bmi-1, EZH2, and survivin, measured by intracellular staining flow cytometry analysis and real-time RT-PCR. IGFBP2 and Angptl5 also inhibit expression of certain transcription factors important for differentiation of myeloid, erythroid, and lymphoid lineages. To test whether IGFBP2 and Angptl5 affect the homing of HSCs, we cultured human cord blood CD34+ cells in serum-free medium supplemented with SCF, TPO, Flt3-L, IGFBP2 or Angptl5, and transplanted them into sublethally irradiated NOD/SCID mice intraveneously or intrafemorally. Both IGFBP2 and Angptl5 support ex vivo expansion of SRCs in intrafemorally injected mice, suggesting the expansion-stimulating effects elicited by both factors are not caused by modulation of HSC homing. Interestingly, when we used intrafemoral injection, we found that Angptl5 treated HSCs have enhanced engraftment in non-injected bone marrow. This suggests Angptl5 treated HSCs further facilitate the mobilization of HSCs in vivo. We conclude that IGFBP2 and Angptl5 support self-renewal and inhibit differentiation of human cord blood HSCs. Our data also suggest that a combination of expression of transcription factors important for self-renewal, survival, and differentiation of HSCs can be used as a “stemness index” that predicts the activity of cultured human HSCs.

scholarly journals Megakaryothrombopoiesis During Ex Vivo Expansion of Human Cord Blood CD34+ Cells Using Thrombopoietin

2002 ◽  
Vol 55 (1) ◽  
pp. 88-95 ◽  
Author(s):  
S.-Y. Woo ◽  
J.-H. Kie ◽  
K.-H. Ryu ◽  
H.-S. Moon ◽  
W.-S. Chung ◽  
...  
Keyword(s):  
Cord Blood ◽  
Ex Vivo ◽  
Ex Vivo Expansion ◽  
Human Cord Blood ◽  
Cd34 Cells ◽  
Cord Blood Cd34

Ex-Vivo Expansion of Human Cord Blood CD34+ Cells by Overexpression of Bmi-1.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1329-1329
Author(s):  
Aleksandra Rizo ◽  
Edo Vellenga ◽  
Gerald de Haan ◽  
Jan Jacob Schuringa
Keyword(s):  
Cord Blood ◽  
Cell Expansion ◽  
Cultured Cells ◽  
Ex Vivo ◽  
Human Cord Blood ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Cord Blood Cd34

Abstract Hematopoietic stem cells (HSCs) are able to self-renew and differentiate into cells of all hematopoietic lineages. Because of this unique property, they are used for HSC transplantations and could serve as a potential source of cells for future gene therapy. However, the difficulty to expand or even maintain HSCs ex vivo has been a major limitation for their clinical applications. Here, we report that overexpression of the Polycomb group gene Bmi-1 in human cord blood-derived HSCs can potentially overcome this limitation as stem/progenitor cells could be maintained in liquid culture conditions for over 16 weeks. In mouse studies, it has been reported that increased expression of Bmi-1 promotes HSC self-renewal, while loss-of-function analysis revealed that Bmi-1 is implicated in maintenance of the hematopoietic stem cells (HSC). In a clinically more relevant model, using human cord blood CD34+ cells, we have established a long-term ex-vivo expansion method by stable overexpression of the Bmi-1 gene. Bmi-1-transduced cells proliferated in liquid cultures supplemented with 20% serum, SCF, TPO, Flt3 ligand, IL3 and IL6 for more than 4 months, with a cumulative cell expansion of more then 2×105-fold. The cells remained cytokine-dependent, while about 4% continued to express CD34 for over 20 weeks of culture. The cultured cells retained their progenitor activity throughout the long-term expansion protocol. The colony-forming units (CFUs) were present at a frequency of ~ 30 colonies per 10 000 cells 16 weeks after culture and consisted of CFU-GM, BFU-E and high numbers of CFU-GEMM type progenitors. After plating the transduced cells in co-cultures with the stromal cell line MS5, Bmi-1 cells showed a proliferative advantage as compared to control cells, with a cumulative cell expansion of 44,9 fold. The non-adherent cells from the co-cultures gave rise to higher numbers of colonies of all types (~70 colonies/10.000 cells) after 4 weeks of co-culture. The LTC-IC frequencies were 5-fold higher in the Bmi-1-transduced cells compared to control cells (1/361 v.s. 1/2077, respectively). Further studies will be focused on in-vivo transplantation of the long-term cultured cells in NOD/SCID mice to test their repopulating capacity. In conclusion, our data implicate Bmi-1 as an important modulator of human HSC self-renewal and suggest that it can be a potential target for therapeutic manipulation of human HSCs.

Chromosome analysis after ex vivo expansion of CD34+ cells from human cord blood

2001 ◽  
Vol 125 (2) ◽  
pp. 161-162 ◽  
Author(s):  
Yoshio Katayama ◽  
Kanji Miyamoto ◽  
Katsuto Takenaka ◽  
Kenji Imajyo ◽  
Katsuji Shinagawa ◽  
...  
Keyword(s):  
Cord Blood ◽  
Ex Vivo ◽  
Chromosome Analysis ◽  
Ex Vivo Expansion ◽  
Human Cord Blood ◽  
Cd34 Cells
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