Abstract
The purpose of this study was to evaluate the influence of bone marrow-mesenchymal stem cells (BM-MSC) and exogenously added cytokines on the proliferation, primitive cell subpopulation maintenance (including the c-kit+ marker) and clonogenic capacity of hematopoietic stem cells (HSC). BM-MSC were collected from volunteer donors, isolated and characterized. Umbilical cord blood (UCB) samples were collected from healthy full-term deliveries. UCB-CD34+ cells were cultured in the presence or absence of BM-MSC and/or cytokines for 3 and 7 days. CD34+ cell proliferation was evaluated using the CSFE method and cell phenotype was determined by CD34, c-kit, CD33, CD38, HLA-DR, cyCD22 and cyCD3 detection. Cell clonogenic ability was also assessed. Exogenously added SCF, TPO and FLT3L increasedCD34+ cell proliferation in the presence or absence of BM-MSC, but with concomitant cell differentiation. Without any added cytokines, BM-MSC are able to increase the percentage of primitive progenitors as evaluated by c-kit expression and CFU-GEMM increase. Interestingly, this latter effect was dependent on both cell-cell interactions and secreted factors. A 7-day co-culture period will be optimal for obtaining an increased primitive HSC level. Including c-kit as a marker for primitive phenotype evaluation has shown the relevance of BM-MSC and their secreted factors on UCB-HSC stemness function. This effect could be dissociated from that of the addition of exogenous cytokines, which induced cellular differentiation instead.Electronic Supplementary MaterialSupplementary material is available for this article at 10.2478/s11658-012-0036-1 and is accessible for authorized users.
Highlights
Experimental evidence from the last two decades has established that hematopoietic stem cells (HSC) from umbilical cord blood (UCB) can be used as a cell source for treatments for hematopoietic system-associated diseases [1]
UCB-CD34+ cell proliferation in bone marrow (BM)-mesenchymal stem cells (MSC) co-cultures The BM repopulating efficiency of UCB-CD34+ cells in a transplant setting depends in part on the number of transplanted cells [1]
After 3 and 7 days, UCB-CD34+ cells cultured in the presence of recombinant cytokines (SCF, FMS-like tyrosine kinase 3 ligand (Flt-3L), TPO) with or without bone marrow-mesenchymal stem cells (BM-MSC) (HMC and hematopoietic cytokines (HC) conditions) significantly increased the total UCB-CD34+ numbers and the percentage of cells with several cell divisions (Fig. 3B, C, F and G) compared to arrested cells (Fig. 3A) or hematopoietic mesenchymal (HM) setting (Fig. 3D-E)
Summary
Experimental evidence from the last two decades has established that hematopoietic stem cells (HSC) from umbilical cord blood (UCB) can be used as a cell source for treatments for hematopoietic system-associated diseases [1]. Human clinical studies have shown that the primitive hematopoietic progenitor cells, including the burst-forming unit megakaryocyte, the high proliferative potential colony-forming cell and the long-term BM culture-initiating cell, are contained within the CD34+c-kit+HLA-DR subpopulation, indicating that human stem cells are c-kit positive [34]. It has been shown that changes in c-kit and HLA-DR antigen expression on the CD34+ cell population can be indicative of HSC primitive progenitor characteristics or commitment to the monocytic lineage [28, 35]. Short-term (3- and 7-day) UCB-HSC cultures were established to study the effect of BM-MSC on secreted or exogenously added cytokines over HSC proliferation, myeloid or lymphoid primitive-associated progenitor phenotypes and clonogenic capacity. Our results showed that in the absence of exogenously added cytokines, BM-MSC induce slight CD34+ proliferation, promoting primitive progenitor maintenance with higher multi-lineage potential and increased CD34 and c-kit expression
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
