Effective expansion of umbilical cord blood hematopoietic stem/progenitor cells by regulation of microencapsulated osteoblasts under hypoxic condition

Abstract

The expansion of hematopoietic stem/progenitor cells (HSPCs) from umbilical cord blood (UCB) with the support of microencapsulated osteoblasts under hypoxia environment was investigated. The expansion of HSPCs was evaluated through the total number of UCB mononuclear cells (MNCs) produced, their repopulating potential with the colony-forming unit assay (CFU-Cs) and CD34(+) phenotypic analysis with flow cytometry. At the end of 7 days of culture, the UCB-MNCs, CFU-Cs and CD34(+) cells had achieved 18.7 +/- 1.6, 11.6 +/- 0.9 and 23.4 +/- 2-fold expansions, respectively, in the test groups. These were significantly different from those in control groups. Microencapsulated osteoblasts under hypoxia conditions had therefore a significant effect on the expansion potential of HSPCs in vitro.

Combination of low O2 concentration and mesenchymal stromal cells during culture of cord blood CD34+ cells improves the maintenance and proliferative capacity of hematopoietic stem cells

“…However, unlike SRC CD , where 1.5% O 2 concentration was most effective, both 5% and 1.5% were effective for pre-CFC. This underlines functional difference between two stem cell populations, a schedule completely in line with all the data related to the heterogeneity of stem and progenitor cells sub-populations with respect to their demands for O 2 published so far (Cipolleschi et al, 1993;Simsek et al, 2010, reviewed in Parmar et al, 2007Ivanovic, 2009 Although several studies concerning low O 2 concentration (5%) for co-cultures of hematopoietic and stromal cells were published (Koller et al, 1992b;Song et al, 2009;Zhambalova et al, 2009), our study is first performed in serum-free conditions, comparing 1.5% and 5% O 2 and using in vivo approach (SRC) for stem cell detection. These studies could not be directly compared due to differences in conditions: Zimbalova et al studied the culture of mononuclear cells (MNC) on stromal cells without adding cytokines, Koller et al did not employ SRC assay, Song et al employed the osteoblasts as stromal cells .…”

Human Adipose-Tissue Derived Stromal Cells in Combination with Hypoxia Effectively Support Ex Vivo Expansion of Cord Blood Haematopoietic Progenitors

“…This resulted in the more pronounced formation of haematopoietic colonies and increased production of IL-6, IL-8 as compared to co-culture in standard conditions (20% O 2 ) [ 23 ]. In the case of hypoxia, improved expansion of CD34 + HSPCs in the presence of osteoblasts [ 24 ] and bone marrow [ 1 , 25 , 26 ] MSCs was demonstrated.…”

Investigation of the Effective Action Distance Between Hematopoietic Stem/Progenitor Cells and Human Adipose-Derived Stem Cells During Their In Vitro Co-culture

“…However, as knowledge develops, the idea [23,24] that simulating microenvironment in vivo could be the most suitable method has gradually been realized. In vivo microenvironment, stromal cells and hematopoietic cells coexist, and stromal cells play an important role in supporting the expansion of hematopoietic cells and regulating haematogenesis via secreting growth factors, extracellular matrix, and interacting with hematopoietic cells [25].…”