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- Lin- cells), myeloid progenitor cells (CD34+ CD38+ CD45RA+ CD71- Lin- cells), and erythroid progenitor cells (CD34+ CD38+ CD45RA- CD71+ Lin- cells), 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.
Subject(s)
Hematopoietic Stem Cells/metabolism , Stem Cells/metabolism , Transcriptome , Antigens, CD/genetics , Antigens, CD/metabolism , Antigens, CD34/genetics , Antigens, CD34/metabolism , Cell Culture Techniques , Cells, Cultured , Fetal Blood/cytology , Hematopoietic Stem Cells/cytology , Humans , Leukocyte Common Antigens/genetics , Leukocyte Common Antigens/metabolism , Oligonucleotide Array Sequence Analysis , Receptors, Transferrin/genetics , Receptors, Transferrin/metabolism , Stem Cells/cytologyABSTRACT
Mesenchymal stem/stromal cells (MSCs) from bone marrow (BM) have been used in coculture systems as a feeder layer for promoting the expansion of hematopoietic progenitor cells (HPCs) for hematopoietic cell transplantation. Because BM has some drawbacks, umbilical cord blood (UCB) and placenta (PL) have been proposed as possible alternative sources of MSCs. However, MSCs from UCB and PL sources have not been compared to determine which of these cell populations has the best capacity of promoting hematopoietic expansion. In this study, MSCs from UCB and PL were cultured under the same conditions to compare their capacities to support the expansion of HPCs in vitro. MSCs were cocultured with CD34+CD38-Lin- HPCs in the presence or absence of early acting cytokines. HPC expansion was analyzed through quantification of colony-forming cells (CFCs), long-term culture-initiating cells (LTC-ICs), and CD34+CD38-Lin- cells. MSCs from UCB and PL have similar capacities to increase HPC expansion, and this capacity is similar to that presented by BM-MSCs. Here, we are the first to determine that MSCs from UCB and PL have similar capacities to promote HPC expansion; however, PL is a better alternative source because MSCs can be obtained from a higher proportion of samples.
ABSTRACT
Se estudiaron 51 niños con diagnóstico de asma bronquial y se les sometió a reto con metacolina a diferentes diluciones para obtener su PD 20. Una vez obtenida ésta, se correlacionó con la edad de inicio de los síntomas y con la intensidad de los mismos. Se encontró que en los que iniciaron sus síntomas a edades más tempranas, en los mayores de cinco años y en los que presentaron mayor intensidad de los cuadros, su PD 20 fue menor, es decir, presentaban una mayor hiperreactividad bronquial. Nuestros resultados son similares a los reportados en la literatura mundial
