Mesenchymal stem cells from bone marrow show a stronger stimulating effect on megakaryocyte progenitor expansion than those from non-hematopoietic tissues

Abstract

In order to evaluate whether mesenchymal stem cells (MSCs) from non-hematopoietic tissues are able to regulate megakaryocytopoiesis, we identified human MSCs from adult bone marrow (ABM), fetal pancreas (FPan) and umbilical cord (UC), and their abilities to support megakaryocyte (MK) differentiation from CD34(+) hematopoietic progenitor cells (HPCs) were comparatively studied. First, MSCs were isolated from ABM, FPan and UC then their growth kinetics, molecular characterization and mesodermal differentiation capacity were determined. ABM-MSCs, FPan-MSCs and UC-MSCs were irradiated and cocultured with human umbilical cord blood (UCB) CD34(+) cells, and the expansion efficiency of MK progenitor cells and MK formation were analysed and compared. Finally, SCF, IL-6 and GM-CSF expression by the three types of MSCs were also examined. Our results showed that FPan-MSCs and UC-MSCs shared most of the characteristic of ABM-MSCs, including morphology, immunophenotype, adipogenic and osteogenic differentiation potentials. Compared with ABM-MSCs, fetal MSCs had higher proliferative capacity. After 7 days' coculture, the maximal production of CD34(+)/CD41a(+) cells was obtained in a group of CD34(+) HPCs + ABM-MSCs. Furthermore, this group produced more MK colonies than other groups (p < 0.05). Surface antigen and ploidy analysis morphological observation demonstrated that a proportion of expanded cells in each group differentiated into mature MKs. ABM-MSCs, FPan-MSCs and UC-MSCs were revealed to express SCF, IL-6 and GM-CSF at mRNA level. We conclude that FPan-MSCs and UC-MSCs have the ability to promote megakaryocytopoiesis, while ABM-MSCs expand more MK progenitor cells from CD34(+) HPCs than MSCs from non-hematopoietic tissues and CD34(+) cells alone.

Developing a co-culture system for effective megakaryo/thrombopoiesis from umbilical cord blood hematopoietic stem/progenitor cells

“…After 7 days of differentiation in direct cell-cell contact with BM-MSC, under serum-free conditions supplemented with cytokines, 25% of cells were polyploid (DNA content > 4N) when cells were previously expanded for 7 days with the use of the Z9 cocktail. Consistent with this result, Liu et al [24] reported that approximately 25% of Mks (from human UCB), co-cultured with BM-MSC, had higher polyploid content (>4N) after 12 days in culture. UCB-derived Mks generated ex vivo in the present study have shown extended Dm and abundant presence of granules in the cytoplasm.…”

“…It was previously shown that accessory cells such as human MSC from BM, UCB and human BM endothelial cells regulate Mk development and differentiation in vitro [15,45,46]. BM stromal cells provide physical support for HSC/HPC and secret several cytokines/ growth factors such as granulocyte-macrophage colony-stimulating factor, IL-6 and SCF, which act together with TPO to regulate megakaryocytic commitment [15,23,24]. The results of the current study demonstrated that the highest EY (202 AE 34 Mks per seeded CD 34 þ cells) and %CD41 þ content (58% AE 4.9%) in the differentiation stage were achieved by combination of Cyt addition with Feeder co-culture, with the use of a serum-free medium.…”

“…It was also shown that signaling molecules secreted by stromal cells, as well as cellcell interactions in the BM niche, are elementary modulators of the megakaryo/thrombopoiesis process [15,22]. For example, besides providing physical support for HSC/HPC, BM-MSC secrete cytokines, such as granulocyte-macrophage colony-stimulating factor, IL-6 and stem cell factor (SCF), which regulate megakaryopoiesis [15,23,24].…”

Advances in umbilical cord blood stem cell expansion and clinical translation

“…This discovery led to the development of a considerable number of coculture systems for the expansion of HSPCs with various sources of feeder cells including BM-derived stromal cells [37,38], immortalized stromal cells [39][40][41] and endothelial cells [42][43][44][45][46] and bone marrow mesenchymal stem cells (MSC) [47][48][49][50][51][52][53]. Examples of such system are presented in Table 1 along with their principal properties and results.…”

IL-6 Production Stimulated by CD14+Monocytes-paracrined IL-1ß does not Contribute to the Immunosuppressive Activity of Human Umbilical Cord Mesenchymal Stem Cells

“…IL-6 also mediates the promotional effect of BM-MSCs and hUC-MSCs in megakaryocytopoiesis [39]. In addition, IL-6 is important in normal wound healing [22] and angiogenesis [21].…”