Search results for "EURA"
showing 10 items of 3336 documents
Ordered networks of rat hippocampal neurons attached to silicon oxide surfaces.
2001
The control of neuronal cell position and outgrowth is of fundamental interest in the development of applications ranging from cellular biosensors to tissue engineering. We have produced rectangular networks of functional rat hippocampal neurons on silicon oxide surfaces. Attachment and network formation of neurons was guided by a geometrical grid pattern of the adhesion peptide PA22-2 which matches in sequence a part of the A-chain of laminin. PA22-2 was applied by contact printing onto the functionalised silicon oxide surface and was immobilised by hetero-bifunctional cross-linking with sulfo-GMBS. Geometric pattern matching was achieved by microcontact printing using a polydimethylsiloxa…
Ion conductance changes associated with spike adaptation in the rapidly adapting stretch receptor of the crayfish.
1975
The time course of the repetitive impulse discharges has been investigated for two high intensities of maintained depolarizing currents, 30 nA and 50 nA, for which the receptor adaptation was complete within 70 msec. The changes in sodium and potassium conductance associated with the decline in spike activity have been analyzed at different instances of time by interrupting in successive experiments the various action potentials in the pulse trains either at the early phase by holding the potential at about -60 mV and recording the inward current (upstroke-gNa) or by evaluating the delayed outward current flowing as the result of a depolarizing voltage pulse which at the end of the action p…
PECAM-1 expression in human mesothelial cells: an in vitro study.
1996
Mesothelial cells are actively involved in inflammatory processes by expressing a set of cell adhesion molecules (CAMs). Transmigration of leukocytes into inflamed tissues requires a chemotactic stimulus and engagement of platelet-endothelial cell adhesion molecule-1 (PECAM-1). To investigate the kinetics involved in peritonitis, pure cultures of mesothelial cells are necessary. In previous studies, we have found that human mesothelial cells (HOMES) show a weak constitutive expression of PECAM-1, which cannot be further stimulated by cytokines. It is known that all serous cavities and body fluids contain numerous macrophages which strongly express this adhesion molecule. To identify the cel…
Central nicotinic receptors, neurotrophic factors and neuroprotection
2000
The multiple combinations of nAChR subunits identified in central nervous structures possess distinct pharmacological and physiological properties. A growing number of data have shown that compounds interacting with neuronal nAChRs have, both in vivo and in vitro, the potential to be neuroprotective and that treatment with nAChR agonists elicit long-lasting improving of cognitive performance in a variety of behavioural tests in rats, monkeys and humans. Epidemiological and clinical studies suggested also a potential neuroprotective/trophic role of (-)-nicotine in neurodegenerative disease, such as Alzheimer's and Parkinson's disease. Taken together experimental and clinical data largely ind…
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,…
Multiple sclerosis patient-derived CSF induces transcriptional changes in proliferating oligodendrocyte progenitors.
2014
Background: Cerebrospinal fluid (CSF) is in contact with brain parenchyma and ventricles, and its composition might influence the cellular physiology of oligodendrocyte progenitor cells (OPCs) thereby contributing to multiple sclerosis (MS) disease pathogenesis. Objective: To identify the transcriptional changes that distinguish the transcriptional response induced in proliferating rat OPCs upon exposure to CSF from primary progressive multiple sclerosis (PPMS) or relapsing remitting multiple sclerosis (RRMS) patients and other neurological controls. Methods: We performed gene microarray analysis of OPCs exposed to CSF from neurological controls, or definitive RRMS or PPMS disease course. R…
A Safe and Effective Magnetic Labeling Protocol for MRI-Based Tracking of Human Adult Neural Stem Cells
2019
Magnetic resonance imaging (MRI) provides a unique tool for in vivo visualization and tracking of stem cells in the brain. This is of particular importance when assessing safety of experimental cell treatments in the preclinical or clinical setup. Yet, specific imaging requires an efficient and non-perturbing cellular magnetic labeling which precludes adverse effects of the tag, e.g., the impact of iron-oxide-nanoparticles on the critical differentiation and integration processes of the respective stem cell population investigated. In this study we investigated the effects of very small superparamagnetic iron oxide particle (VSOP) labeling on viability, stemness, and neuronal differentiatio…
Extracellular Vesicles from Neural Stem Cells Transfer IFN-γ via Ifngr1 to Activate Stat1 Signaling in Target Cells
2014
The idea that stem cell therapies work only via cell replacement is challenged by the observation of consistent intercellular molecule exchange between the graft and the host. Here we defined a mechanism of cellular signaling by which neural stem/precursor cells (NPCs) communicate with the microenvironment via extracellular vesicles (EVs), and we elucidated its molecular signature and function. We observed cytokine-regulated pathways that sort proteins and mRNAs into EVs. We described induction of interferon gamma (IFN-γ) pathway in NPCs exposed to proinflammatory cytokines that is mirrored in EVs. We showed that IFN-γ bound to EVs through Ifngr1 activates Stat1 in target cells. Finally, we…
Extrinsic and Intrinsic Factors Modulating Proliferation and Self-renewal of Multipotential CNS Progenitors and Adult Neural Stem Cells of the Subven…
2006
Although stem cell therapy has been proposed for therapeutic strategies aimed at repairing functions, it is important to realize that as yet, relatively little is known about the behavior of embryonic and adult stem cells in terms of responsiveness to extracellular cues and intracellular signaling molecules.