ORCID Profile
0000-0002-8013-4273
Current Organisation
Centro Pfizer - Universidad de Granada - Junta de Andalucía de Genómica e Investigación Oncológica
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Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.SCR.2015.07.002
Abstract: We have generated iPSCs from peripheral blood mononuclear cells (PBMCs) of a healthy man using heat sensitive and non-integrative Sendai virus containing Sox2, Oct3/4, c-Myc and Klf4. Human GRX-MCiPS4F-A2 cell line was established and characterized through this study.
Publisher: Oxford University Press (OUP)
Date: 23-09-2017
DOI: 10.1002/STEM.2700
Abstract: Runt-related transcription factor 1 (Runx1) is a master hematopoietic transcription factor essential for hematopoietic stem cell (HSC) emergence. Runx1-deficient mice die during early embryogenesis due to the inability to establish definitive hematopoiesis. Here, we have used human pluripotent stem cells (hPSCs) as model to study the role of RUNX1 in human embryonic hematopoiesis. Although the three RUNX1 isoforms a, b, and c were induced in CD45+ hematopoietic cells, RUNX1c was the only isoform induced in hematoendothelial progenitors (HEPs)/hemogenic endothelium. Constitutive expression of RUNX1c in human embryonic stem cells enhanced the appearance of HEPs, including hemogenic (CD43+) HEPs and promoted subsequent differentiation into blood cells. Conversely, specific deletion of RUNX1c dramatically reduced the generation of hematopoietic cells from HEPs, indicating that RUNX1c is a master regulator of human hematopoietic development. Gene expression profiling of HEPs revealed a RUNX1c-induced proinflammatory molecular signature, supporting previous studies demonstrating proinflammatory signaling as a regulator of HSC emergence. Collectively, RUNX1c orchestrates hematopoietic specification of hPSCs, possibly in cooperation with proinflammatory signaling.
Publisher: Elsevier BV
Date: 11-0007
DOI: 10.1016/J.SCR.2015.10.009
Abstract: Here we describe the generation and characterization of the human induced pluripotent stem cell (iPSC) line PBMC1-iPS4F1 from peripheral blood mononuclear cells from a healthy female with Spanish background. We used heat sensitive, non-integrative Sendai viruses containing the reprogramming factors Oct3/4, Sox2, Klf4 and c-Myc, whose expression was silenced in the established iPSC line. Characterization of the PBMC1-iPS4F1 cell line included analysis of typical pluripotency-associated factors at mRNA and protein level, alkaline phosphatase enzymatic activity, and in vivo and in vitro differentiation studies.
Publisher: Springer Science and Business Media LLC
Date: 2009
DOI: 10.1038/NBT.1516
Abstract: Cultured human embryonic stem (hES) cells can acquire genetic and epigenetic changes that make them vulnerable to transformation. As hES cells with cancer-cell characteristics share properties with normal hES cells, such as self-renewal, teratoma formation and the expression of pluripotency markers, they may be misconstrued as superior hES cells with enhanced 'stemness'. We characterize two variant hES cell lines (v-hESC-1 and v-hESC-2) that express pluripotency markers at high levels and do not harbor chromosomal abnormalities by standard cytogenetic measures. We show that the two lines possess some features of neoplastic progression, including a high proliferative capacity, growth-factor independence, a 9- to 20-fold increase in frequency of tumor-initiating cells, niche independence and aberrant lineage specification, although they are not malignant. Array comparative genomic hybridization reveals an lification at 20q11.1-11.2 in v-hESC-1 and a deletion at 5q34a-5q34b q3 and a mosaic gain of chromosome 12 in v-hESC-2. These results emphasize the need for functional characterization to distinguish partially transformed and normal hES cells.
Publisher: Wiley
Date: 03-12-2004
DOI: 10.1002/DVDY.20211
Abstract: Oct4 is a transcription factor that has been associated with pluripotency and fate determination in the initial cell lineages of mammals. On the other hand, Pou2, the ortholog of Oct4 in zebrafish, serves additional later functions during brain development acting as a differentiation switch. In mice, Oct4 is expressed throughout the neural plate of embryos until embryonic day (E) 8.0. In this study, we produced transgenic mouse embryos that ubiquitously express Oct4 and analyzed the consequences during development. We show that, at E8.0, a higher dosage of Oct4 in the neuroectoderm is sufficient to transiently alter mid-hindbrain patterning and produced a strong up-regulation of Pax2, indicating that Oct4 can regulate this gene in vivo. After E9.5, ectopic Oct4 in this region produced cell death and affected the development of the forebrain, suggesting that, at these later stages, Oct4 down-regulation is necessary for normal development to proceed. The phenotype of the transgenic embryos was also accompanied with an increase of Fgf8 expression in several of its endogenous domains, suggesting the possibility that Oct4 can participate in the regulation of expression of this ligand. Our observations support the hypothesis that Oct4, like zebrafish Pou2, has a conserved function during early brain patterning in mouse.
Location: Spain
No related grants have been discovered for Veronica Ramos-Mejia.