Functional Integrity and Gene Expression Profiles of Human Cord Blood-Derived Hematopoietic Stem and Progenitor Cells Generated in Vitro

Abstract

To date, different experimental strategies have been developed for the ex vivo expansion of human hematopoietic stem (HSCs) and progenitor (HPCs) cells. This has resulted in significant advances on the use of such expanded cells in transplantation settings. To this day, however, it is still unclear to what extent those stem and progenitor cells generated in vitro retain the functional and genomic integrity of their freshly isolated counterparts. In trying to contribute to the solving of this issue, in the present study we have selected and purified three different hematopoietic cell populations: HSCs (CD34 + CD38 -CD45RA -CD71 -Lincells), myeloid progenitor cells (CD34 + CD38 + CD45RA + CD71 -Lincells), and erythroid progenitor cells (CD34 + CD38 + CD45RA -CD71 + Lincells), obtained directly from fresh human umbilical cord blood (UCB) units or generated in vitro under particular culture conditions. We, then, compared their functional integrity in vitro and their gene expression profiles. Our results indicate that in spite of being immunophenotipically similar, fresh and in vitro generated cells showed significant differences, both in functional and genetic terms. As compared to their fresh counterparts, those HSCs generated in our culture system showed a deficient content of long-term culture-initiating cells, and a marked differentiation bias toward the myeloid lineage. In addition, in vitro generated HSCs and HPCs showed a limited expansion potential. Such functional alterations correlated with differences in their gene expression profiles. These observations are relevant in terms of HSC biology and may have implications in UCB expansion and transplantation. STEM CELLS TRANSLATIONAL MEDICINE 2018;7:602-614 SIGNIFICANCE STATEMENTThis study presents evidence indicating that in vitro-generated hematopoietic stem and progenitor cells differ in functional and genetic terms from their freshly obtained counterparts. These findings have biologic and clinical implications.

MEK1 activation enhances the ex vivo proliferation of haematopoietic stem/progenitor cell

“…Maldonado et al found that in vitro generated HSC had higher activity of NF-κB, JAK-STAT and PI3K-AKT signalling pathways determined through KEGG and GO analyses. 35 Related to these findings, we previously observed NF-κB pathway inhibition promoted maintenance of human phenotypical HSPC ex vivo. 36 On the one Some research found the high expression of MEK1 in excessively expanded cells, 37,38 showing a potential regulatory role in cell proliferation.…”

The effects of cannabidiol via TRPV2 channel in chronic myeloid leukemia cells and its combination with imatinib

“…A CD38 Micro Bead Kit (Miltenyi Biotech Inc.) was used to isolate CD38 + common myeloid progenitors from human cord blood CD34 + progenitor cells (Sigma Aldrich) 15 …”

Expansion or Incubation? Which is Better to Manipulating Stem Cells for Improving the Effects of Umbilical Cord Blood Transplantation

“…Sean J. Morrison et al [66] thought the goals of stem cells ex vivo expansion was to preserve the self-renewal ability while inhibit the differentiation tendency. Roberto et al [67] further indicated that in spite of being immunophenotipically similar, freshly isolated stem cells and ex vivo expanded stem cells showed signi cant differences both in functional and genetic terms. As a result, the long-term hematopoietic capacity of expanded stem cells may be impaired.…”