Article

The use of transplanted glial cells to reconstruct glial environments in the CNS.

Department of Clinical Veterinary Medicine and MRC Cambridge Centre for Brain Repair, UK.
Brain Pathology (Impact Factor: 4.35). 11/1995; 5(4):443-50. DOI: 10.1111/j.1750-3639.1995.tb00623.x
Source: PubMed

ABSTRACT Transplantation studies have demonstrated that glia-depleted areas of the CNS can be reconstituted by the introduction of cultured cells. Thus, the influx of Schwann cells into glia-free areas of demyelination in the spinal cord can be prevented by the combined introduction of astrocytes and cells of the O-2A lineage. Although Schwann cell invasion of areas of demyelination is associated with destruction of astrocytes, the transplantation of rat tissue culture astrocytes ("type-1") alone cannot suppress this invasion, indicating a role for cells of the O-2A lineage in reconstruction of glial environments. By transplanting different glial cell preparations and manipulating lesions so as to prevent meningeal cell and Schwann cell proliferation it is possible to demonstrate that the behaviour of tissue culture astrocytes ("type-1") and astrocytes derived from O-2A progenitor cells ("type-2") is different. In the presence of meningeal cells, tissue culture astrocytes clump together to form cords of cells. In contrast, type-2 astrocytes spread throughout glia-free areas in a manner unaffected by the presence of meningeal cells or Schwann cells. Thus, progenitor-derived astrocytes show a greater ability to fill glia-free areas than tissue culture astrocytes. Similarly, when introduced into infarcted white matter in the spinal cord, progenitor-derived astrocytes fill the malacic area more effectively than tissue culture astrocytes, although axons do not regenerate into the reconstituted area.

0 Followers
 · 
68 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Tissue engineering of Schwann cells (SCs) can serve a number of purposes, such as in vitro SC-related disease modeling, treatment of peripheral nerve diseases or peripheral nerve injury, and, potentially, treatment of CNS diseases. SCs can be generated from autologous stem cells in vitro by recapitulating the various stages of in vivo neural crest formation and SC differentiation. In this review, we survey the cellular and molecular mechanisms underlying these in vivo processes. We then focus on the current in vitro strategies for generating SCs from two sources of pluripotent stem cells, namely embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Different methods for SC engineering from ESCs and iPSCs are reviewed and suggestions are proposed for optimizing the existing protocols. Potential safety issues regarding the clinical application of iPSC-derived SCs are discussed as well. Lastly, we will address future aspects of SC engineering.
    Stem Cell Reviews and Reports 11/2014; DOI:10.1007/s12015-014-9577-1 · 3.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Over the last few years the therapeutic approach to demyelinating diseases has radically changed, strategies having been developed aimed at partnering the classic symptomatic treatments with the most advanced regenerative medicine tools. At first, the transplantation of myelinogenic cells, Schwann cells or oligodendrocytes was suggested, but the considerable technical difficulties, (poor availability, difficulties in harvesting and culturing, and the problem of rejection in the event of non-autologous sources), shifted attention towards more versatile cellular types, such as Mesenchymal Stem Cells (MSCs). Recent studies have already demonstrate both in vitro and in vivo that glially-primed MSCs (through exposure to chemical cocktails) have myelogenic abilities. In spite of a large number of papers on glially-differentiated MSCs, little is known about the ability of undifferentiated MSCs to myelinate axons and processes. Here we have demonstrated that also undifferentiated MSCs have the ability to myelinate, since they induce the myelination of rat DRG neuron processes after direct co-culturing. In this process a pivotal role is performed by the p75 receptor.
    Experimental Cell Research 08/2013; DOI:10.1016/j.yexcr.2013.08.016 · 3.37 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Twenty-one volunteers were exposed in a radon chamber during well-controlled aerosol and radon progeny conditions, with predominantly unattached radon daughters (Po-218, Pb-214 and Bi-214). The activity of these radionuclides deposited in the respiratory tract was measured in-vivo after the exposures. The results of these measurements are in agreement with predictions calculated with the ICRP Publication 66 Human Respiratory Tract Model (HRTM). Temporal analysis of the activity deposited in the head of the volunteers leads to the conclusion that a significant amount of the deposited activity associated with particle diameters of about 1 nm is not subject to fast particle transport to the gastrointestinal tract as generally reported for larger aerosol particles. Measurements of radon progeny in blood samples of these volunteers yielded absorption half-times of 20 to 60 min. Former determinations, mainly performed with much larger aerosol particles of diameters between 100 and 1000 nm, derived absorption half-times around 10 h. This indicates that the absorption from ciliated airways into blood is dependent upon particle size and particle composition.

Similar Publications