Search results for "BEP"
showing 10 items of 119 documents
Mesenchymal stromal-cell transplants induce oligodendrocyte progenitor migration and remyelination in a chronic demyelination model.
2013
Demyelinating disorders such as leukodystrophies and multiple sclerosis are neurodegenerative diseases characterized by the progressive loss of myelin that may lead toward a chronic demyelination of the brain’s white matter, impairing normal axonal conduction velocity and ultimately causing neurodegeneration. Current treatments modifying the pathological mechanisms are capable of ameliorating the disease; however, frequently, these therapies are not sufficient to repress the progressive demyelination into a chronic condition and permanent loss of function. To this end, we analyzed the effect that bone marrow-derived mesenchymal stromal cell (BM-MSC) grafts exert in a chronically demyelinate…
Regulated segregation of kinase Dyrk1A during asymmetric neural stem cell division is critical for EGFR-mediated biased signaling.
2010
SummaryStem cell division can result in two sibling cells exhibiting differential mitogenic and self-renewing potential. Here, we present evidence that the dual-specificity kinase Dyrk1A is part of a molecular pathway involved in the regulation of biased epidermal growth factor receptor (EGFR) signaling in the progeny of dividing neural stem cells (NSC) of the adult subependymal zone (SEZ). We show that EGFR asymmetry requires regulated sorting and that a normal Dyrk1a dosage is required to sustain EGFR in the two daughters of a symmetrically dividing progenitor. Dyrk1A is symmetrically or asymmetrically distributed during mitosis, and biochemical analyses indicate that it prevents endocyto…
Vascular niche factor PEDF modulates Notch-dependent stemness in the adult subependymal zone.
2009
We sought to address the fundamental question of how stem cell microenvironments can regulate self-renewal. We found that Notch was active in astroglia-like neural stem cells (NSCs), but not in transit-amplifying progenitors of the murine subependymal zone, and that the level of Notch transcriptional activity correlated with self-renewal and multipotency. Moreover, dividing NSCs appeared to balance renewal with commitment via controlled segregation of Notch activity, leading to biased expression of known (Hes1) and previously unknown (Egfr) Notch target genes in daughter cells. Pigment epithelium-derived factor (PEDF) enhanced Notch-dependent transcription in cells with low Notch signaling,…
Oligodendrogliogenic and neurogenic adult subependymal zone neural stem cells constitute distinct lineages and exhibit differential responsiveness to…
2012
The adult mouse subependymal zone (SEZ) harbours adult neural stem cells (aNSCs) that give rise to neuronal and oligodendroglial progeny. However it is not known whether the same aNSC can give rise to neuronal and oligodendroglial progeny or whether these distinct progenies constitute entirely separate lineages. Continuous live imaging and single-cell tracking of aNSCs and their progeny isolated from the mouse SEZ revealed that aNSCs exclusively generate oligodendroglia or neurons, but never both within a single lineage. Moreover, activation of canonical Wnt signalling selectively stimulated proliferation within the oligodendrogliogenic lineage, resulting in a massive increase in oligodendr…
Enhanced Spatial Navigation Skills in Sequence-Space Synesthetes
2018
Contains fulltext : 219554.pdf (Publisher’s version ) (Closed access) Individuals with sequence-space synesthesia (SSS) perceive sequences like months, days and numbers in certain spatial arrangements. Several cognitive benefits have been associated with SSS, such as enhanced mental rotation, more vivid visual imagery and an advantage in spatial processing. The current study aimed to further investigate these cognitive benefits, focusing on spatial navigation skills, to explore if their enhanced sensitivity to spatial relations is reflected in enhanced navigational performance. Synesthetes were distinguished from controls by means of a questionnaire, a consistency test and drawings. A virtu…
How Journalists Think about Media Effects—And Why We Should Care
2019
Research suggests that journalists’ beliefs about media effects are influenced by unsystematically gathered knowledge and subjective-intuitive judgments. However, it has also been shown that these presumptions must be considered important factors for the formation of journalistic coverage. Against this background, this article synthesizes existing research on dimensions, determinants, and consequences of journalists’ presumptions of media effects. The resulting framework offers researchers in the field of journalistic content production a comprehensive overview of the possible role that presumptions of media effects could play for journalistic content creation. In a second step, we summariz…
How to Define Games and Why We Need to
2019
This article provides guidelines on how to make useful game definitions and discusses when that is a worthwhile undertaking. It examines a recent article attempting to define videogames (Bergonse in Comput Games J 6(4):239–255, 2017. https://doi.org/10.1007/s40869-017-0045-4), and uses it as an example to discuss game definitions in general. It concludes with reasons why making a final definition of games is not possible and why we need to continue to define games. peerReviewed
How and when do mobile media demands impact well-being? Explicating the integrative model of mobile media use and need experiences (IM3UNE)
2021
Using mobile media can be both detrimental and beneficial for well-being. Thus, explaining how and when they elicit such effects is of crucial importance. To explicate boundary conditions and processes for digital well-being, this article introduces the Integrative Model of Mobile Media Use and Need Experiences (IM³UNE). Instead of assuming mobile media to be pathogenic, the IM³UNE offers a salutogenic perspective—it focuses on how we can stay healthy when using mobile media ubiquitously in daily life. More specifically, the model assumes that both the satisfaction and the frustration of basic psychological needs are key underlying mechanisms linking demanding mobile media use to well-being…
Transcriptional repression of Bmp2 by p21(Waf1/Cip1) links quiescence to neural stem cell maintenance.
2013
Relative quiescence and self renewal are defining features of adult stem cells, but their potential coordination remains unclear. Subependymal neural stem cells (NSCs) lacking cyclin-dependent kinase (CDK) inhibitor (CKI) 1a (p21) exhibit rapid expansion that is followed by their permanent loss later in life. Here we demonstrate that transcription of the gene encoding bone morphogenetic protein 2 (Bmp2) in NSCs is under the direct negative control of p21 through actions that are independent of CDK. Loss of p21 in NSCs results in increased levels of secreted BMP2, which induce premature terminal differentiation of multipotent NSCs into mature non-neurogenic astrocytes in an autocrine and/or …
Cyclin-dependent kinase inhibitor p21 controls adult neural stem cell expansion by regulating Sox2 gene expression.
2012
Summary In the adult brain, continual neurogenesis of olfactory neurons is sustained by the existence of neural stem cells (NSCs) in the subependymal niche. Elimination of the cyclin-dependent kinase inhibitor 1A (p21) leads to premature exhaustion of the subependymal NSC pool, suggesting a relationship between cell cycle control and long-term self-renewal, but the molecular mechanisms underlying NSC maintenance by p21 remain unexplored. Here we identify a function of p21 in the direct regulation of the expression of pluripotency factor Sox2, a key regulator of the specification and maintenance of neural progenitors. We observe that p21 directly binds a Sox2 enhancer and negatively regulate…