Isolation of mineralizing Nestin+ Nkx6.1+ vascular muscular cells from the adult human spinal cord

<p>Abstract</p> <p>Background</p> <p>The adult central nervous system (CNS) contains different populations of immature cells that could possibly be used to repair brain and spinal cord lesions. The diversity and the properties of these cells in the human adult CNS remain to be fully explored. We previously isolated Nestin⁺Sox2⁺neural multipotential cells from the adult human spinal cord using the neurosphere method (i.e. non adherent conditions and defined medium).</p> <p>Results</p> <p>Here we report the isolation and long term propagation of another population of Nestin⁺cells from this tissue using adherent culture conditions and serum. QPCR and immunofluorescence indicated that these cells had mesenchymal features as evidenced by the expression of Snai2 and Twist1 and lack of expression of neural markers such as Sox2, Olig2 or GFAP. Indeed, these cells expressed markers typical of smooth muscle vascular cells such as Calponin, Caldesmone and Acta2 (Smooth muscle actin). These cells could not differentiate into chondrocytes, adipocytes, neuronal and glial cells, however they readily mineralized when placed in osteogenic conditions. Further characterization allowed us to identify the Nkx6.1 transcription factor as a marker for these cells. Nkx6.1 was expressed in vivo by CNS vascular muscular cells located in the parenchyma and the meninges.</p> <p>Conclusion</p> <p>Smooth muscle cells expressing Nestin and Nkx6.1 is the main cell population derived from culturing human spinal cord cells in adherent conditions with serum. Mineralization of these cells in vitro could represent a valuable model for studying calcifications of CNS vessels which are observed in pathological situations or as part of the normal aging. In addition, long term propagation of these cells will allow the study of their interaction with other CNS cells and their implication in scar formation during spinal cord injury.</p

Grafted Human Embryonic Progenitors Expressing Neurogenin-2 Stimulate Axonal Sprouting and Improve Motor Recovery after Severe Spinal Cord Injury

7 p.Background: Spinal cord injury (SCI) is a widely spread pathology with currently no effective treatment for any symptom. Regenerative medicine through cell transplantation is a very attractive strategy and may be used in different non-exclusive ways to promote functional recovery. We investigated functional and structural outcomes after grafting human embryonic neural progenitors (hENPs) in spinal cord-lesioned rats.Methods and Principal Findings: With the objective of translation to clinics we have chosen a paradigm of delayed grafting, i.e., one week after lesion, in a severe model of spinal cord compression in adult rats. hENPs were either naive or engineered to express Neurogenin 2 (Ngn2). Moreover, we have compared integrating and non-integrating lentiviral vectors, since the latter present reduced risks of insertional mutagenesis. We show that transplantation of hENPs transduced to express Ngn2 fully restore weight support and improve functional motor recovery after severe spinal cord compression at thoracic level. This was correlated with partial restoration of serotonin innervations at lumbar level, and translocation of 5HT1A receptors to the plasma membrane of motoneurons. Since hENPs were not detectable 4 weeks after grafting, transitory expression of Ngn2 appears sufficient to achieve motor recovery and to permit axonal regeneration. Importantly, we also demonstrate that transplantation of naive hENPs is detrimental to functional recovery.Conclusions and Significance: Transplantation and short-term survival of Ngn2-expressing hENPs restore weight support after SCI and partially restore serotonin fibers density and 5HT1A receptor pattern caudal to the lesion. Moreover, grafting of naive-hENPs was found to worsen the outcome versus injured only animals, thus pointing to the possible detrimental effect of stem cell-based therapy per se in SCI. This is of major importance given the increasing number of clinical trials involving cell grafting developed for SCI patients.This study was supported by the European Union FP6 "RESCUE" STREP; the "Institut pour la Recherche sur la Moelle Epiniere"; the "Academie de Medecine"; the "Societe Francaise de Neurochirurgie"; "Verticale" and the "Association Demain Debout Aquitaine". The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Etude théorique et validation expérimentale de l'analyse électromagnétique d'un radar destiné au sondage du sous-sol martien

Le travail présenté dans ce manuscrit concerne l'analyse électromagnétique d'un radar destiné au sondage du sous-sol martien. Cette étude, réalisée dans le cadre de la mission Netlander, s'appuie sur des mesures effectuées sur la dune du Pyla. Après la présentation de la planète Mars, du radar et de la méthode F.D.T.D. (Différences Finies dans le Domaine Temporel), l'analyse électromagnétique théorique des monopoles du G.P.R. consiste à déterminer les facteurs influençant ses performances. Nous avons ensuite étudié les résultats de mesure obtenus par le C.E.T.P. (Centre d'étude des Environnements Terrestres et Planétaires) dans le but de les retrouver par la simulation. Enfin, quelques études complémentaires concernant les antennes du radar sont présentées : la détermination de la permittivité du sol, l'utilisation en dipôle plutôt qu'en monopole et la perturbation due aux antennes électriques sur la mesure du champ magnétiqueLIMOGES-BU Sciences (870852109) / SudocSudocFranceF

Repair strategies and functional restoration of the injured spinal cord

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Strategies for spinal cord repair after injury: A review of the literature and information.

International audienceINTRODUCTION: Thanks to the Internet, we can now have access to more information about spinal cord repair. Spinal cord injured (SCI) patients request more information and hospitals offer specific spinal cord repair medical consultations. OBJECTIVE: Provide practical and relevant elements to physicians and other healthcare professionals involved in the care of SCI patients in order to provide adequate answers to their questions. METHOD: Our literature review was based on English and French publications indexed in PubMed and the main Internet websites dedicated to spinal cord repair. RESULTS: A wide array of research possibilities including notions of anatomy, physiology, biology, anatomopathology and spinal cord imaging is available for the global care of the SCI patient. Prevention and repair strategies (regeneration, transplant, stem cells, gene therapy, biomaterials, using sublesional uninjured spinal tissue, electrical stimulation, brain/computer interface, etc.) for the injured spinal cord are under development. It is necessary to detail the studies conducted and define the limits of these new strategies and benchmark them to the realistic medical and rehabilitation care available to these patients. CONCLUSION: Research is quickly progressing and clinical trials will be developed in the near future. They will have to answer to strict methodological and ethical guidelines. They will first be designed for a small number of patients. The results will probably be fragmented and progress will be made through different successive steps

Stem cells: therapeutical interest in neurological pathologies.

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Stem cells: therapeutical interest in neurological pathologies.

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Early functional outcomes and histological analysis after spinal cord compression injury in rats

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