265 research outputs found

    Enhancement of Dormant Pathways in the Brain following Rat Contusive Spinal Cord Injury

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    Spinal cord injury (SCI) induces distal effects on neural activity in the brain. To date, precise, high quality anatomical studies have not been performed. The goal of this study was to delineate neuroanatomical enhancement of dormant pathways in the brain following SCI using an appropriate serotype of an adeno-associated-virus (AAV) with a CAG promotor

    DNA diagnosis in the NF2 gene

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    Neurofibromatosis 2 (NF2) is a genetic disorder characterized by the develop-ment of multiple tumors in the central nervous system. Recently, the NF2 gene has been cloned and found to encode a novel member of the protein 4.1 family which is thought to link integral membrane proteins to the cytoskeleton. The identification of the NF2 tumor suppresser gene has allowed us to screen for pathological mutations in the gene. We have studied germline mutations in the NF2 gene by direct sequence analysis of genomic DNA from blood samples of NF2 patients. In the present report, we demonstrate a novel pathological missense mutation in a patient with NF2, which reveals that the variant observed may affect important functional regions or alter the protein on a larger scale by affecting conformation or degradation

    Intravenous preload of mesenchymal stem cells rescues erectile function in a rat model of cavernous nerve injury

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    骨髄間葉系幹細胞(MSC)を海綿体神経損傷前に静脈投与することで,神経損傷後の勃起機能が温存された.投与された MSC は骨盤神経節や海綿体神経に分布しており,神経栄養因子の発現が亢進することが神経保護作用を誘導する理由の一つであると推測された

    Operating organic light-emitting diodes imaged by super-resolution spectroscopy

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    Super-resolution stimulated emission depletion (STED) microscopy is adapted here for materials characterization that would not otherwise be possible. With the example of organic light-emitting diodes (OLEDs), spectral imaging with pixel-by-pixel wavelength discrimination allows us to resolve local-chain environment encoded in the spectral response of the semi-conducting polymer, and correlate chain packing with local electroluminescence by using externally applied current as the excitation source. We observe nanoscopic defects that would be unresolvable by traditional microscopy. They are revealed in electroluminescence maps in operating OLEDs with 50 nm spatial resolution. We find that brightest emission comes from regions with more densely packed chains. Conventional microscopy of an operating OLED would lack the resolution needed to discriminate these features, while traditional methods to resolve nanoscale features generally cannot be performed when the device is operating. This points the way towards real-time analysis of materials design principles in devices as they actually operateope

    Convergence of Cells from the Progenitor Fraction of Adult Olfactory Bulb Tissue to Remyelinating Glia in Demyelinating Spinal Cord Lesions

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    Progenitor cells isolated from adult brain tissue are important tools for experimental studies of remyelination. Cells harvested from neurogenic regions in the adult brain such as the subependymal zone have demonstrated remyelination potential. Multipotent cells from the progenitor fraction have been isolated from the adult olfactory bulb (OB) but their potential to remyelinate has not been studied. cell bodies adjacent to and surrounding peripheral-type myelin rings.We report that neural cells from the progenitor fraction of the adult rat OB grown in monolayers can be expanded for several passages in culture and that upon transplantation into a demyelinated spinal cord lesion provide extensive remyelination without ectopic neuronal differentiation

    Mesenchymal Stem Cell Graft Improves Recovery after Spinal Cord Injury in Adult Rats through Neurotrophic and Pro-Angiogenic Actions

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    Numerous strategies have been managed to improve functional recovery after spinal cord injury (SCI) but an optimal strategy doesn't exist yet. Actually, it is the complexity of the injured spinal cord pathophysiology that begets the multifactorial approaches assessed to favour tissue protection, axonal regrowth and functional recovery. In this context, it appears that mesenchymal stem cells (MSCs) could take an interesting part. The aim of this study is to graft MSCs after a spinal cord compression injury in adult rat to assess their effect on functional recovery and to highlight their mechanisms of action. We found that in intravenously grafted animals, MSCs induce, as early as 1 week after the graft, an improvement of their open field and grid navigation scores compared to control animals. At the histological analysis of their dissected spinal cord, no MSCs were found within the host despite their BrdU labelling performed before the graft, whatever the delay observed: 7, 14 or 21 days. However, a cytokine array performed on spinal cord extracts 3 days after MSC graft reveals a significant increase of NGF expression in the injured tissue. Also, a significant tissue sparing effect of MSC graft was observed. Finally, we also show that MSCs promote vascularisation, as the density of blood vessels within the lesioned area was higher in grafted rats. In conclusion, we bring here some new evidences that MSCs most likely act throughout their secretions and not via their own integration/differentiation within the host tissue

    Ezrin Mediates Tethering of the γ-Aminobutyric Acid Transporter GAT1 to Actin Filaments Via a C-Terminal PDZ-Interacting Domain

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    A high density of neurotransmitter transporters on axons and presynaptic boutons is required for the efficient clearance of neurotransmitters from the synapse. Therefore, regulators of transporter trafficking (insertion, retrieval, and confinement) can play an important role in maintaining the transporter density necessary for effective function. We determined the interactions that confine GAT1 at the membrane by investigating the lateral mobility of GAT1-yellow fluorescent protein-8 (YFP8) expressed in neuroblastoma 2a cells. Through fluorescence recovery after photobleaching, we found that a significant fraction (~50%) of membrane-localized GAT1 is immobile on the time scale investigated (~150 s). The mobility of the transporter can be increased by depolymerizing actin or by interrupting the GAT1 postsynaptic density 95/Discs large/zona occludens 1 (PDZ)-interacting domain. Microtubule depolymerization, in contrast, does not affect GAT1 membrane mobility. We also identified ezrin as a major GAT1 adaptor to actin. Förster resonance energy transfer suggests that GAT1-YFP8 and cyan fluorescent (CFP) tagged ezrin (ezrin-CFP) exist within a complex that has a Förster resonance energy transfer efficiency of 19% ± 2%. This interaction can be diminished by disrupting the actin cytoskeleton. In addition, the disruption of actin results in a >3-fold increase in γ-aminobutyric acid uptake, apparently via a mechanism distinct from the PDZ-interacting protein. Our data reveal that actin confines GAT1 to the plasma membrane via ezrin, and this interaction is mediated through the PDZ-interacting domain of GAT1

    Mesenchymal stem/stromal cells as a delivery platform in cell and gene therapies

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