Browsing by Subject "Pluripotency"

Now showing 1 - 4 of 4
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    Isolation of pluripotent stem cells from human third molar dental pulp
    (Editores F. Hernandez y Juan F. Madrid. Murcia, Universidad de Murcia, Departamento de Biologia Celular e Histologia, 2011) Atari, M.; Barajas, M.; Hernández-Alfaro, F.; Gil, C.; Fabregat, M.; Ferrés Padró, E.; Giner, L.; Casals, N.
    Potent stem/progenitor cells have been isolated from normal human dental pulps, termed dental pulp stem cells (DPSCs). However, no study has described the presence of stem cell populations in human dental pulp from the third molar with embryonic phenotypes. The dental pulp tissue was cultured in media with the presence of LIF, EGF, and PDGF. In the present study, we describe a new population of pluripotent stem cells that were isolated from dental pulp (DPPSC). These cells are SSEA-4+, Oct4+, Nanog+, FLK-1+, HNF3beta+, Nestin+, Sox2+, Lin28+, c-Myc+, CD13+, CD105+, CD34- , CD45- , CD90low, CD29+, CD73low, STRO-1low and CD146- . We have investigated by SEM analysis and q-RT-PCR the capacity of DPPSCs to 3D differentiate in vitro using the Cell Carrier 3D glass scaffold into tissues that have similar characteristics to embryonic mesoderm and endoderm layers. These data would support the use of these cells, which are derived from an easily accessible source and can be used in future regeneration protocols for many tissue types that differentiate from the three embryonic layers.
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    Stem cells and germ cells, microRNA and gene expression signatures
    (Murcia : F. Hernández, 2010) Dyce, Paul William; Toms, Derek; Li, Julang
    The study of primordial germ cell development in vivo is hampered by their low numbers and inaccessibility. Recent research has shown the ability of embryonic and adult stem cells to differentiate into primordial germ cells and more mature gametes and this generation of germ cells in vitro may be an attractive model for their study. One of the biggest challenges facing in vitro differentiation of stem cells into primordial germ cells is the lack of markers to clearly distinguish the two. As both cell types originate early in embryonic development they share many pluripotent markers such as OCT4, VASA, FRAGILIS, and NANOG. Genome wide microarray profiling has been used to identify transcriptome patterns unique to primordial germ cells. A more thorough analysis of the temporal and quantitative expression of a panel of genes may be more robust in distinguishing these two cell populations. MicroRNAs, short RNA molecules that have been shown to regulate translation through interactions with mRNA transcripts, have also recently come under investigation for the role they may play in pluripotency. Attempts to elucidate key microRNAs responsible for both stem cell and primordial germ cell characteristics have recently been undertaken. Unique microRNAs, either individually or as global profiles, may also help to distinguish differentiated primordial germ cells from stem cells in vitro. This review will examine gene expression and microRNA signatures in stem cells and germ cells as ways to distinguish these closely related cell types.
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    The impact of mechanical stress on stem cell properties: The link between cell shape and pluripotency
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Caifeng Ho, Jolene; Ueda, Jun; Shimizu, Takeshi
    y. Embryonic development and differentiation are controlled largely by external stimuli. Mechanical forces, such as those exerted by the surrounding cells and tissues, gravity and substrate rigidity, have been shown to affect cell morphology and spreading, thus triggering signaling pathways that dictate their development. These mechanosignaling pathways play important roles in cellular differentiation and the determination of cell fate. In this review, we discuss the effects of external environmental stimuli on cell differentiation and how this affects pluripotency, as well as the key molecules and pathways involved in mechanosignaling, particularly in relation to embryonic stem cells. Advances in experimental techniques and devices used to study the different aspects of mechanobiology are also examined. Finally, the effects of mechanical stress on the initiation and maintenance of pathological processes such as cancer, as well as their implications for prognosis and possible therapies, are discussed.
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    Transcriptional regulation of the Oct4 gene, a master gene for pluripotency
    (Murcia : F. Hernández, 2010) Kellner, Steven; Kikyo, Nobuaki
    Oct4 is one of the most importanttranscription factors required to maintain anundifferentiated state (self-renewal) and pluripotency ofhuman and mouse embryonic stem (ES) cells as well asearly embryonic cells. In addition, Oct4 is the onlyknown transcription factor that has to be exogenouslyintroduced into differentiated cells to make inducedpluripotent stem (iPS) cells. Therefore, it is of greatimportance to understand howOct4transcription isregulated in ES cells and embryos and how it becomesactivated during iPS cell formation. In this article, wewill review the regulation of the mouse Oct4gene fromthe viewpoint of DNA methylation, binding of orphannuclear receptors, histone modifications and synergisticeffects with other pluripotency factors. We will also raiseseveral key questions that need to be addressed in futurework to improve our understanding of Oct4generegulation and its essential role in self-renewal andpluripotency.