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Sample records for schwann cell p75ntr

  1. p75(NTR) expression and nuclear localization of p75(NTR) intracellular domain in spiral ganglion Schwann cells following deafness correlate with cell proliferation.

    Science.gov (United States)

    Provenzano, Matthew J; Minner, Sarah A; Zander, Kaitlin; Clark, J Jason; Kane, Catherine J; Green, Steven H; Hansen, Marlan R

    2011-08-01

    Spiral ganglion Schwann cells (SGSCs) myelinate spiral ganglion neurons (SGNs) and represent a potential source of neurotrophic support for SGNs. Deafening due to loss of hair cells results in gradual degeneration and death of SGNs. Successful efforts to maintain or regenerate a functional auditory nerve may depend on a healthy population of SGSCs, yet the responses of SGSCs to neural injury remain largely unknown. Here we investigate the role of p75(NTR) in SGSC responses to gradual denervation. Following deafening, SGSCs in the osseous spiral lamina (OSL) and, subsequently, in Rosenthal's canal (RC) expressed elevated p75(NTR) compared to hearing controls. p75(NTR)-positive cells co-labeled with S100 and RIP antibodies (Schwann cell markers), but not with anti-neurofilament. The pattern of p75(NTR) expression mirrored the pattern of neural degeneration, beginning in the OSL of the cochlea base and later extending into the apex. SGSCs expressed sortilin, a p75(NTR) co-receptor for pro-neurotrophins. Both pro-nerve growth factor (pro-NGF) and pro-brain derived neurotrophic factor (proBDNF) induced apoptosis in cultured SGSCs. Deafened animals exhibited significantly higher levels of SGSC proliferation (as measured by BrdU uptake) compared to hearing animals while total Schwann cell density remained stable, suggesting a tight regulation of SGSC proliferation and cell death. SGSCs undergoing cell division lose p75(NTR) expression from the cell surface and demonstrate nuclear localization of the intracellular domain (ICD), raising the possibility that p75(NTR) cleavage and ICD nuclear localization regulate SGSC proliferation. These results suggest that p75(NTR) contributes to SGSC responses to deafening and neural degeneration. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Merlin status regulates p75(NTR) expression and apoptotic signaling in Schwann cells following nerve injury.

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    Ahmad, Iram; Fernando, Augusta; Gurgel, Richard; Jason Clark, J; Xu, Linjing; Hansen, Marlan R

    2015-10-01

    After nerve injury, Schwann cells (SCs) dedifferentiate, proliferate, and support axon regrowth. If axons fail to regenerate, denervated SCs eventually undergo apoptosis due, in part, to increased expression of the low-affinity neurotrophin receptor, p75(NTR). Merlin is the protein product of the NF2 tumor suppressor gene implicated in SC tumorigenesis. Here we explore the contribution of merlin to SC responses to nerve injury. We find that merlin becomes phosphorylated (growth permissive) in SCs following acute axotomy and following gradual neural degeneration in a deafness model, temporally correlated with increased p75(NTR) expression. p75(NTR) levels are elevated in P0SchΔ39-121 transgenic mice that harbor an Nf2 mutation in SCs relative to wild-type mice before axotomy and remain elevated for a longer period of time following injury. Replacement of wild-type, but not phospho-mimetic (S518D), merlin isoforms suppresses p75(NTR) expression in primary human schwannoma cultures which otherwise lack functional merlin. Despite elevated levels of p75(NTR), SC apoptosis following axotomy is blunted in P0SchΔ39-121 mice relative to wild-type mice suggesting that loss of functional merlin contributes to SC resistance to apoptosis. Further, cultured SCs from mice with a tamoxifen-inducible knock-out of Nf2 confirm that SCs lacking functional merlin are less sensitive to p75(NTR)-mediated cell death. Taken together these results point to a model whereby loss of axonal contact following nerve injury results in merlin phosphorylation leading to increased p75(NTR) expression. Further, they demonstrate that merlin facilitates p75(NTR)-mediated apoptosis in SCs helping to explain how neoplastic SCs that lack functional merlin survive long-term in the absence of axonal contact. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Merlin status regulates p75NTR expression and apoptotic signaling in Schwann cells following nerve injury

    Science.gov (United States)

    Ahmad, Iram; Fernando, Augusta; Gurgel, Richard; Clark, J. Jason; Xu, Linjing; Hansen, Marlan R.

    2015-01-01

    After nerve injury, Schwann cells (SCs) dedifferentiate, proliferate, and support axon regrowth. If axons fail to regenerate, denervated SCs eventually undergo apoptosis due, in part, to increased expression of the low-affinity neurotrophin receptor, p75NTR. Merlin is the protein product of the NF2 tumor suppressor gene implicated in SC tumorigenesis. Here we explore the contribution of merlin to SCs responses to nerve injury. We find that merlin becomes phosphorylated (growth permissive) in SCs following acute axotomy and following gradual neural degeneration in a deafness model, temporally correlated with increased p75NTR expression. p75NTR levels are elevated in P0SchΔ39-121 transgenic mice that harbor a Nf2 mutation in SCs relative to wild-type mice before axotomy and remain elevated for a longer period of time following injury. Replacement of wild-type, but not phosphomimetic (S518D), merlin isoforms suppresses p75NTR expression in primary human schwannoma cultures which otherwise lack functional merlin. Despite elevated levels of p75NTR, SC apoptosis following axotomy is blunted in P0SchΔ39-121 mice relative to wild-type mice suggesting that loss of functional merlin contributes to SC resistance to apoptosis. Further, cultured SCs from mice with a tamoxifen-inducible knock-out of Nf2 confirm that SCs lacking functional merlin are less-sensitive to p75NTR-mediated cell death. Taken together these results point to a model whereby loss of axonal contact following nerve injury results in merlin phosphorylation leading to increased p75NTR expression. Further, they demonstrate that merlin facilitates p75NTR-mediated apoptosis in SCs helping to explain how neoplastic SCs that lack functional merlin survive long-term in the absence of axonal contact. PMID:26057084

  4.  p75NTR receptor – role in cell growth and apoptosis

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    Anna Urbaniak

    2012-05-01

    Full Text Available  The neurotrophins play an important role in the development of the nervous system. These trophic factors affect the cells through the neurotrophin receptors Trk and p75NTR. Trk (tyrosine kinase receptor mediated signaling promotes survival and growth, while p75NTR-mediated signaling promotes cell death. The structure of p75NTR and its role in the regulation of survival, growth and induction of apoptosis are discussed. p75NTR can interact with the aggregated form of Aβ peptides and by influencing protein tau hyperphosphorylation plays an important role in etiopathogenesis of Alzheimer’s disease.

  5. Pan-neurotrophin receptor p75NTR expression is strongly induced in lesional atopic mast cells.

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    Fischer, T C; Lauenstein, H-D; Serowka, F; Pilzner, C; Groneberg, D A; Welker, P

    2008-07-01

    Neurotrophins such as nerve growth factor or brain-derived neurotrophic factor influence neuronal proliferation and differentiation via the low-affinity pan-neurotrophin receptor p75NTR that may play a pivotal role in linking the immune with the nervous system. Because the precise regulation of p75NTR gene transcription in mast cells under states of allergic inflammation has not been investigated in detail so far, the present studies assessed the gene regulation and expression of this receptor. Transcriptional expression of p75NTR in human skin was studied in isolated cutaneous cells by means of RT-PCR. In situ lesional mast cell p75NTR expression was analysed by immunohistochemistry. The p75NTR mRNA expression was found in isolated human skin mast cells and keratinocytes. Lower mRNA levels were present in fibroblasts and melanocytes but no transcripts were found in endothelial cells. The p75NTR protein expression was found in situ in lesional and non-lesional mast cells. A significantly increased expression of p75NTR protein was found in atopic dermatitis lesional mast cells when compared with control mast cell expression (Pneurotrophin receptor sensitivity of mast cells under states of allergic inflammation. Topically administered neurotrophin receptor-modulating compounds may act as anti-inflammatory mediators in cutaneous allergic inflammation.

  6. Induction of the p75NTR by Aryl Propionic Acids in Prostate Cancer Cells

    National Research Council Canada - National Science Library

    Quann, Emily

    2007-01-01

    .... I have found that treatment of prostate cancer cells with the aryl propionic acids R-flurbiprofen and ibuprofen induces reexpression of p75NTR, decreases cell survival, and increases apoptosis...

  7. Neurotrophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells

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    Joanna Bandoła

    2017-08-01

    Full Text Available Plasmacytoid dendritic cells (pDCs regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR by the antigen-presenting pDCs, mediated by toll-like receptor (TLR 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders.

  8. Induction of the p75NTR by Aryl Propionic Acids in Prostate Cancer Cells

    Science.gov (United States)

    2008-12-01

    flurbiprofen, which lacks COX inhibitory activity, was able to inhibit progression of prostate cancer in the TRAMP mouse (11). In addition...progression of prostate cancer in the TRAMP mouse. Cancer Res 2000;60:2203-8. 12) Krygier S, Djakiew D. The neurotrophin receptor p75NTR is a tumor...incubated in the presence of 5% CO2 and air at 37jC. Figure 1. Immunoblots of p75NTR levels in PC-3 and DU-145 cells following 48 h treatment with 0, 0.1

  9. Immunohistochemical location of the p75 neurotrophin receptor (p75NTR) in oral leukoplakia and oral squamous cell carcinoma.

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    Kiyosue, Takahiro; Kawano, Shintaro; Matsubara, Ryota; Goto, Yuichi; Hirano, Mitsuhiro; Jinno, Teppei; Toyoshima, Takeshi; Kitamura, Ryoji; Oobu, Kazunari; Nakamura, Seiji

    2013-02-01

    Recent studies have demonstrated that the p75 neurotrophin receptor (p75NTR) is a useful marker of keratinocyte stem cells. Although the stem cell markers of original normal tissue have been used to identify cancer stem cells in a variety of cancers, the expression and function of p75NTR have been poorly understood in oral squamous cell carcinoma (OSCC). The objective of this study is, thus, to examine p75NTR expression immunohistochemically in oral leukoplakia (OL), the most frequent precancerous lesion, and OSCC, and to reveal the usefulness of p75NTR as a marker for undifferentiated cancer cells and a novel prognostic factor for OSCC patients. In this study immunohistochemical expression of p75NTR, Ki-67, cytokeratin (CK) 5, and CK14 was examined in 112 cases of OL and 81 of OSCC. The labeling indices (LIs) of p75NTR and Ki-67 were calculated, and the association of these LIs with histopathologic characteristics was then evaluated. In the normal oral epithelium and OL, p75NTR was expressed only in the basal layer, and its LI was invariant, irrespective of the extent of epithelial dysplasia. In OSCC, however, p75NTR-LI was significantly increased in association with upgrading of histologic grade and mode of tumor invasion. Furthermore, the prognosis of the high p75NTR-LI group (LI ≥ 53.1%) was poorer than that of the low p75NTR-LI group (LI < 53.1%). These results suggest that p75NTR is expressed in undifferentiated cell populations in OL and OSCC. Furthermore, p75NTR is possibly involved in invasion and poor prognosis in OSCC.

  10. Nerve growth factor receptor (p75 NTR) and pattern of invasion predict poor prognosis in oral squamous cell carcinoma.

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    Søland, T M; Brusevold, I J; Koppang, H S; Schenck, K; Bryne, M

    2008-07-01

    To evaluate the expression of p75 neurotrophin receptor (p75(NTR)) in oral squamous cell carcinoma (OSCC). The results were related to tumour node metastasis (TNM) stage, World Health Organization (WHO) grade, invasive front grading (IFG) and prognosis. Immunohistochemically, the expression of p75(NTR) was assessed in 53 T1-T2 OSCCs. Clinical data were recorded prospectively. The end-point was disease-free survival. All tumours expressed p75(NTR), and this expression, both in central/superficial tumour areas and at the invasive front, was associated with poor prognosis (P = 0.03 and P = 0.02) (log rank test). Tumours with marked cellular dissociation (IFG parameter) had more recurrences than tumours with collective tumour cell invasion (P = 0.03). In tumours showing both p75(NTR) at the invasive front and marked tumour cell dissociation, the average risk of recurrence was increased about 17 times (Cox regression analysis) compared with tumours with low p75(NTR) expression and collective invasion. Traditional prognostic systems were of no prognostic significance. p75(NTR) was expressed in all OSCCs. p75(NTR) expression and the pattern of invasion were significantly associated with a poor prognosis in OSCCs, and both were better prognostic factors than traditional prognostic parameters. The combination of p75(NTR) expression and the pattern of invasion strongly increased precision in the identification of tumours with poor disease-free survival.

  11. Cell cycle phase-specific surface expression of nerve growth factor receptors TrkA and p75(NTR).

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    Urdiales, J L; Becker, E; Andrieu, M; Thomas, A; Jullien, J; van Grunsven, L A; Menut, S; Evan, G I; Martín-Zanca, D; Rudkin, B B

    1998-09-01

    Expression of the nerve growth factor (NGF) receptors TrkA and p75(NTR) was found to vary at the surface of PC12 cells in a cell cycle phase-specific manner. This was evidenced by using flow cytometric and microscopic analysis of cell populations labeled with antibodies to the extracellular domains of both receptors. Differential expression of these receptors also was evidenced by biotinylation of surface proteins and Western analysis, using antibodies specific for the extracellular domains of TrkA and p75(NTR). TrkA is expressed most strongly at the cell surface in M and early G1 phases, whereas p75(NTR) is expressed mainly in late G1, S, and G2 phases. This expression reflects the molecular and cellular responses to NGF in specific phases of the cell cycle; in the G1 phase NGF elicits both the anti-mitogenic effect, i.e., inhibition of the G1 to S transition, and the differentiation response whereas a survival effect is provoked elsewhere in the cell cycle. A model is proposed relating these responses to the surface expression of the two receptors. These observations open the way for novel approaches to the investigation of the mechanism of NGF signal transduction.

  12. Neurotrophin p75 receptor (p75NTR) promotes endothelial cell apoptosis and inhibits angiogenesis: implications for diabetes-induced impaired neovascularization in ischemic limb muscles

    NARCIS (Netherlands)

    Caporali, Andrea; Pani, Elisabetta; Horrevoets, Anton J. G.; Kraenkel, Nicolle; Oikawa, Atsuhiko; Sala-Newby, Graciela B.; Meloni, Marco; Cristofaro, Brunella; Graiani, Gallia; Leroyer, Aurelie S.; Boulanger, Chantal M.; Spinetti, Gaia; Yoon, Sung Ok; Madeddu, Paolo; Emanueli, Costanza

    2008-01-01

    Diabetes impairs endothelial function and reparative neovascularization. The p75 receptor of neurotrophins (p75(NTR)), which is scarcely present in healthy endothelial cells (ECs), becomes strongly expressed by capillary ECs after induction of peripheral ischemia in type-1 diabetic mice. Here, we

  13. Differential expression of the neurotrophin receptors p75NTR, TrkA, TrkB and TrkC in human peripheral blood mononuclear cells.

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    Nassenstein, Christina; Möhring, Ute Hanna; Luttmann, Werner; Virchow, Johann Christian; Braun, Armin

    2006-06-01

    Neurotrophins are involved in the pathogenesis of allergic asthma. In addition to their influence on afferent sensory nerves within the lung, it has been shown in the last years that these factors modulate allergic airway inflammation. The knowledge about their immunomodulatory roles on diverse subsets of immune cells is still fragmentary and incomplete. Since neurotrophin receptor surface expression is essential for neurotrophin action, the aim of our study was to systematically investigate the expression pattern of the low affinity pan neurotrophin receptor p75NTR as well as the high-affinity receptors TrkA, TrkB and TrkC in human peripheral blood mononuclear cells. Our results show that each of the receptors has an individual expression pattern in diverse immune cell subtypes. However, there were no differences in neurotrophin receptor expression in healthy controls and patients with allergies.

  14. Biological and clinical significance of p75NTR expression in laryngeal squamous epithelia and laryngocarcinoma.

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    Li, Xiaoming; Shen, Yupeng; Di, Bin; Li, Jun; Geng, Jiangqiao; Lu, Xiuying; He, Zhanguo

    2012-03-01

    The apparent features of p75 neurotrophin receptor (p75(NTR)) expression indicated that p75(NTR) would serve as a potential stem cell marker for normal human laryngeal squamous epithelia. In human laryngeal squamous cell carcinoma (LSCC) p75(NTR) is differentially expressed. The abnormal expression and distribution of p75(NTR) may indicate malignant transformation. To investigate the expression of p75(NTR) and its possible roles in normal laryngeal squamous epithelia and LSCC. We used immunohistochemistry methods to examine normal laryngeal epithelia, para-cancer mucosa with dysplasia, laryngeal papilloma, and LSCC specimens for the expression of p75(NTR), nerve growth factor (NGF), -tyrosine kinase receptor (TrkA), p63, and Ki67. Immunocytochemistry and flow cytometry were used to examine the expression of p75(NTR) in Hep-2 cells. The expression of p75(NTR) was only located in basal cells of normal laryngeal epithelia, consistent with the staining features of epithelial stem cells as evidenced by parallel staining of p63, a putative keratinocyte stem cell marker. p75(NTR) is differentially expressed in LSCC, although no significant relationship was found with many clinicopathologic factors, this expression and distribution may correlate to malignant transformation and tumor proliferation. Co-expression of p75(NTR) and CD133 was confirmed, showing the association of p75(NTR)-positive cells with cancer stem cells in Hep-2 cells.

  15. Nerve growth factor stimulation of ERK1/2 phosphorylation requires both p75NTR and α9β1 integrin and confers myoprotection towards ischemia in C2C12 skeletal muscle cell model.

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    Ettinger, Keren; Lecht, Shimon; Arien-Zakay, Hadar; Cohen, Gadi; Aga-Mizrachi, Shlomit; Yanay, Nurit; Saragovi, H Uri; Nedev, Hinyu; Marcinkiewicz, Cezary; Nevo, Yoram; Lazarovici, Philip

    2012-12-01

    The functions of nerve growth factor (NGF) in skeletal muscles physiology and pathology are not clear and call for an updated investigation. To achieve this goal we sought to investigate NGF-induced ERK1/2 phosphorylation and its role in the C2C12 skeletal muscle myoblasts and myotubes. RT-PCR and western blotting experiments demonstrated expression of p75(NTR), α9β1 integrin, and its regulator ADAM12, but not trkA in the cells, as also found in gastrocnemius and quadriceps mice muscles. Both proNGF and βNGF induced ERK1/2 phosphorylation, a process blocked by (a) the specific MEK inhibitor, PD98059; (b) VLO5, a MLD-disintegrin with relative selectivity towards α9β1 integrin; and (c) p75(NTR) antagonists Thx-B and LM-24, but not the inactive control molecule backbone Thx. Upon treatment for 4 days with either anti-NGF antibody or VLO5 or Thx-B, the proliferation of myoblasts was decreased by 60-70%, 85-90% and 60-80% respectively, indicative of trophic effect of NGF which was autocrinically released by the cells. Exposure of myotubes to ischemic insult in the presence of βNGF, added either 1h before oxygen-glucose-deprivation or concomitant with reoxygenation insults, resulted with about 20% and 33% myoprotection, an effect antagonized by VLO5 and Thx-B, further supporting the trophic role of NGF in C2C12 cells. Cumulatively, the present findings propose that proNGF and βNGF-induced ERK1/2 phosphorylation in C2C12 cells by functional cooperation between p75(NTR) and α9β1 integrin, which are involved in myoprotective effects of autocrine released NGF. Furthermore, the present study establishes an important trophic role of α9β1 in NGF-induced signaling in skeletal muscle model, resembling the role of trkA in neurons. Future molecular characterization of the interactions between NGF receptors in the skeletal muscle will contribute to the understanding of NGF mechanism of action and may provide novel therapeutic targets. Copyright © 2012 Elsevier Inc. All

  16. Neuroimmune crosstalk in asthma: dual role of the neurotrophin receptor p75NTR.

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    Nassenstein, Christina; Kammertoens, Thomas; Veres, Tibor Zoltan; Uckert, Wolfgang; Spies, Emma; Fuchs, Barbara; Krug, Norbert; Braun, Armin

    2007-11-01

    Neurotrophins have been implicated in the pathogenesis of asthma because of their ability to induce airway inflammation and to promote hyperreactivity of sensory neurons, which reflects an important mechanism in the pathogenesis of airway hyperreactivity. Neurotrophins use a dual-receptor system consisting of Trk-receptor tyrosine kinases and the structurally unrelated p75NTR. Previous studies revealed an important role of p75NTR in the pathogenesis of allergic asthma. The aim of the study was to investigate the precise mechanisms of neurotrophins in neuroimmune interaction, which can lead to both airway inflammation and sensory nerve hyperreactivity in vivo. Mice selectively expressing p75NTR in immune cells or nerves, respectively, were generated. After sensitization and allergen provocation, hyperreactivity of sensory nerves was tested in response to capsaicin. Airway inflammation was analyzed on the basis of differential cell counts and cytokine levels in bronchoalveolar lavage fluids. Allergic mice selectively expressing p75NTR in immune cells showed normal inflammation but no sensory nerve hyperreactivity, whereas mice selectively expressing p75NTR in nerve cells had a diminished inflammation and a distinct sensory nerve hyperreactivity. Our data indicate that p75NTR plays a dual role by promoting hyperreactivity of sensory nerves and airway inflammation. Additionally, our study provides experimental evidence that development of sensory nerve hyperreactivity depends on an established airway inflammation in asthma. In contrast, development of airway inflammation seems to be independent from sensory nerve hyperreactivity. Because of its dual function, antagonization of p75NTR-mediated signals might be a novel approach in asthma therapy.

  17. Characterization of NGF, trkANGFR, and p75NTR in Retina of Mice Lacking Reelin Glycoprotein

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    Bijorn Omar Balzamino

    2014-01-01

    Full Text Available Both Reelin and Nerve Growth Factor (NGF exert crucial roles in retinal development. Retinogenesis is severely impaired in E-reeler mice, a model of Reelin deficiency showing specific Green Fluorescent Protein expression in Rod Bipolar Cells (RBCs. Since no data are available on Reelin and NGF cross-talk, NGF and trkANGFR/ p75NTR expression was investigated in retinas from E-reeler versus control mice, by confocal microscopy, Western blotting, and real time PCR analysis. A scattered increase of NGF protein was observed in the Ganglion Cell Layer and more pronounced in the Inner Nuclear Layer (INL. A selective increase of p75NTR was detected in most of RBCs and in other cell subtypes of INL. On the contrary, a slight trend towards a decrease was detected for trkANGFR, albeit not significant. Confocal data were validated by Western blot and real time PCR. Finally, the decreased trkANGFR/ p75NTR ratio, representative of p75NTR increase, significantly correlated with E-reeler versus E-control. These data indicate that NGF-trkANGFR/ p75NTR is affected in E-reeler retina and that p75NTR might represent the main NGF receptor involved in the process. This first NGF-trkANGFR/ p75NTR characterization suggests that E-reeler might be suitable for exploring Reelin-NGF cross-talk, representing an additional information source in those pathologies characterized by retinal degeneration.

  18. Biophysical Studies on BEX3, the p75NTR-Associated Cell Death Executor, Reveal a High-Order Oligomer with Partially Folded Regions.

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    Katia M S Cabral

    Full Text Available BEX3 (Brain Expressed X-linked protein 3 is a member of a mammal-specific placental protein family. Several studies have found the BEX proteins to be associated with neurodegeneration, the cell cycle and cancer. BEX3 has been predicted to be intrinsically disordered and also to represent an intracellular hub for cell signaling. The pro-apoptotic activity of BEX3 in association with a number of additional proteins has been widely supported; however, to the best of our knowledge, very limited data are available on the conformation of any of the members of the BEX family. In this study, we structurally characterized BEX3 using biophysical experimental data. Small angle X-ray scattering and atomic force microscopy revealed that BEX3 forms a specific higher-order oligomer that is consistent with a globular molecule. Solution nuclear magnetic resonance, partial proteinase K digestion, circular dichroism spectroscopy, and fluorescence techniques that were performed on the recombinant protein indicated that the structure of BEX3 is composed of approximately 31% α-helix and 20% β-strand, contains partially folded regions near the N- and C-termini, and a core which is proteolysis-resistant around residues 55-120. The self-oligomerization of BEX3 has been previously reported in cell culture and is consistent with our in vitro data.

  19. Nerve Growth Factor Expression and Its Receptors TrkA and p75NTR in Peri-Implantitis Lesions.

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    Douillard, T; Martinelli-Kläy, C P; Lombardi, Tommaso

    2016-06-01

    Nerve growth factor (NGF) can, through its receptors TrkA and p75NTR, convey signals for cell survival or cell differentiation. These proteins are also involved in inflammation and in bone resorption. The aim of this study is to evaluate, for the first time, the expression of NGF and its receptors TrkA and p75NTR in peri-implantitis lesions. Fifteen biopsy specimens from patients with chronic peri-implantitis and 4 of healthy oral mucosa were immunostained with antibodies against NGF, TrkA, and p75NTR. The staining intensity and percentage of stained cells were semi-quantitatively evaluated and results were compared between the 2 groups. In the peri-implant pocket epithelium and gingival epithelium, NGF and TrkA expressions were similar to the healthy oral mucosa, however, a decreased expression of p75NTR was observed. In all cases, more than 75% of the inflammatory cells stained positively for NGF and TrkA, and p75NTR was negatively expressed. The intense expression of NGF and TrkA in the inflammatory cell infiltrate associated with decreased expression of p75NTR in both gingival and pocket epithelium suggests that these proteins may have a role in peri-implantitis lesions.

  20. Expression of nerve growth factor (NGF, TrkA and p75NTR in developing human foetal teeth

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    Thimios A. Mitsiadis

    2016-08-01

    Full Text Available Nerve growth factor (NGF is important for the development and the differentiation of neuronal and non-neuronal cells. NGF binds to specific low- and high-affinity cell surface receptors, respectively p75NTR and TrkA. In the present study, we examined by immunohistochemistry the expression patterns of the NGF, p75NTR and TrkA proteins during human foetal tooth development, in order to better understand the mode of NGF signalling action in dental tissues. The results obtained show that these molecules are expressed in a wide range of dental cells of both epithelial and mesenchymal origin during early stages of odontogenesis, as well as in nerve fibres that surround the developing tooth germs. At more advanced developmental stages, NGF and TrkA are localised in differentiated cells with secretory capacities such as preameloblasts/ameloblasts secreting enamel matrix and odontoblasts secreting dentine matrix. In contrast, p75NTR expression is absent from these secretory cells and restricted in proliferating cells of the dental epithelium. The temporospatial distribution of NGF and p75NTR in foetal human teeth is similar, but not identical, with that observed previously in the developing rodent teeth, thus indicating that the genetic information is well conserved during evolution. The expression patterns of NGF, p75NTR and TrkA during odontogenesis suggest regulatory roles for NGF signalling in proliferation and differentiation of epithelial and mesenchymal cells, as well as in attraction and sprouting of nerve fibres within dental tissues.

  1. Neural-Competent Cells of Adult Human Dermis Belong to the Schwann Lineage

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    Usue Etxaniz

    2014-11-01

    Full Text Available Resident neural precursor cells (NPCs have been reported for a number of adult tissues. Understanding their physiological function or, alternatively, their activation after tissue damage or in vitro manipulation remains an unsolved issue. Here, we investigated the source of human dermal NPCs in adult tissue. By following an unbiased, comprehensive approach employing cell-surface marker screening, cell separation, transcriptomic characterization, and in vivo fate analyses, we found that p75NTR+ precursors of human foreskin can be ascribed to the Schwann (CD56+ and perivascular (CD56− cell lineages. Moreover, neural differentiation potential was restricted to the p75NTR+CD56+ Schwann cells and mediated by SOX2 expression levels. Double-positive NPCs were similarly obtained from human cardiospheres, indicating that this phenomenon might be widespread.

  2. Schwann Cell Phenotype Changes in Aging Human Dental Pulp.

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    Couve, E; Lovera, M; Suzuki, K; Schmachtenberg, O

    2017-10-01

    Schwann cells are glial cells that support axonal development, maintenance, defense, and regeneration in the peripheral nervous system. There is limited knowledge regarding the organization, plasticity, and aging of Schwann cells within the dental pulp in adult permanent teeth. The present study sought to relate changes in the pattern of Schwann cell phenotypes between young and old adult teeth with neuronal, immune, and vascular components of the dental pulp. Schwann cells are shown to form a prominent glial network at the dentin-pulp interface, consisting of nonmyelinating and myelinating phenotypes, forming a multicellular neuroimmune interface in association with nerve fibers and dendritic cells. Schwann cell phenotypes are recognized by the expression of S100, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), Sox10, GAP43, and p75NTR markers. In young adult teeth, a dense population of nonmyelinating Schwann cells projects processes in close association with sensory nerve terminals through the odontoblast layer, reaching the adjacent predentin/dentin domain. While GAP43 and p75NTR are highly expressed in nonmyelinating Schwann cells from young adult teeth, the presence of these markers declines significantly in old adult teeth. Myelinated axons, identified by MBP expression, are mainly present at the Raschkow plexus and within nerve bundles in the dental pulp, but their density is significantly reduced in old adult versus young adult teeth. These data reveal age-related changes within the glial network of the dental pulp, in association with a reduction of coronal dental pulp innervation in old adult versus young adult teeth. The prominence of Schwann cells as a cellular component at the dentin-pulp interface supports the notion that their association with sensory nerve terminals and immune system components forms part of an integrated multicellular barrier for defense against pathogens and dentin repair.

  3. Neurotrophin receptor p75NTR mediates Huntington’s disease–associated synaptic and memory dysfunction

    Science.gov (United States)

    Brito, Verónica; Giralt, Albert; Enriquez-Barreto, Lilian; Puigdellívol, Mar; Suelves, Nuria; Zamora-Moratalla, Alfonsa; Ballesteros, Jesús J.; Martín, Eduardo D.; Dominguez-Iturza, Nuria; Morales, Miguel; Alberch, Jordi; Ginés, Sílvia

    2014-01-01

    Learning and memory deficits are early clinical manifestations of Huntington’s disease (HD). These cognitive impairments have been mainly associated with frontostriatal HD pathology; however, compelling evidence provided by several HD murine models suggests that the hippocampus may contribute to synaptic deficits and memory dysfunction in HD. The neurotrophin receptor p75NTR negatively regulates spine density, which is associated with learning and memory; therefore, we explored whether disturbed p75NTR function in the hippocampus could contribute to synaptic dysfunction and memory deficits in HD. Here, we determined that levels of p75NTR are markedly increased in the hippocampus of 2 distinct mouse models of HD and in HD patients. Normalization of p75NTR levels in HD mutant mice heterozygous for p75NTR prevented memory and synaptic plasticity deficits and ameliorated dendritic spine abnormalities, likely through normalization of the activity of the GTPase RhoA. Moreover, viral-mediated overexpression of p75NTR in the hippocampus of WT mice reproduced HD learning and memory deficits, while knockdown of p75NTR in the hippocampus of HD mice prevented cognitive decline. Together, these findings provide evidence of hippocampus-associated memory deficits in HD and demonstrate that p75NTR mediates synaptic, learning, and memory dysfunction in HD. PMID:25180603

  4. Effects of p75NTR deficiency on cholinergic innervation of the amygdala and anxiety-like behavior.

    Science.gov (United States)

    Busch, Ruben; Baldus, Marian; Vogt, Miriam A; Berger, Stefan M; Bartsch, Dusan; Gass, Peter; von Bohlen Und Halbach, Oliver

    2017-05-01

    The p75 neurotrophin receptor (p75NTR) is a low-affinity receptor that is capable of binding neurotrophins. Two different p75NTR knockout mouse lines are available either with a deletion in Exon III (p75NTR E x III -/- ) or in Exon IV (p75NTR E x IV -/- ). In p75NTR E x III knockout mice, only the full-length p75NTR is deleted, whereas in p75NTR E x IV knockout mice, the full-length as well as the truncated isoform of the receptor is deleted. Deletion of p75NTR has been shown to affect, among others, the septohippocampal cholinergic innervation pattern and neuronal plasticity within the hippocampus. We hypothesize that deletion of p75NTR also alters the morphology and physiology of a further key structure of the limbic system, the amygdala. Our results indicate that deletion of p75NTR also increases cholinergic innervation in the basolateral amygdala in adult as well as aged p75NTR E x III -/- and p75NTR E x IV -/- mice. The p75NTR E x IV -/- mice did not display altered long-term potentiation (LTP) in the basolateral amygdala as compared to age-matched control littermates. However, p75NTR E x III -/- mice display stronger LTP in the basolateral amygdala compared to age-matched controls. Bath-application of K252a (a trk antagonist) did not inhibit the induction of LTP in the basolateral amygdala, but reduced the level of LTP in p75NTR E x III -/- mice to levels seen in respective controls. Moreover, p75NTR E x III -/- mice display altered behavior in the dark/light box. Thus, deletion of p75NTR in mice leads to physiological and morphological changes in the amygdala and altered behavior that is linked to the limbic system. © 2017 International Society for Neurochemistry.

  5. Establishing a cellular FRET-based fluorescence plate reader assay to monitor proNGF-induced cross-linking of sortilin and the neurotrophin receptor p75(NTR)

    DEFF Research Database (Denmark)

    Skeldal, Sune; Kjaergaard, Maj M; Alwasel, Saleh

    2015-01-01

    the vps10p domain receptor sortilin and the neurotrophin receptor p75(NTR). However, proNGF-induced receptor complex formation has been difficult to directly assess other than by western blotting. We here describe a fluorescence resonance energy transfer (FRET) based fluorescence plate reader assay...... to monitor the interaction between fluorescently tagged sortilin and p75(NTR) in live cells. The method is based on a standard fluorescent plate reader found in many biochemical laboratories and the results are evaluated using a microscopy-based quantified sensitized acceptor emission FRET approach making...... use of a pair of FRET standard constructs. As a result, the effect of proNGF on the interaction between sortilin and p75(NTR) can be evaluated in live cells allowing for screening and selection of therapeutic compounds interfering with proNGF-induced cell death....

  6. Changes in expression of BDNF and its receptors TrkB and p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence

    Energy Technology Data Exchange (ETDEWEB)

    Xu, R.; Duan, S.R.; Zhao, J.W.; Wang, C.Y. [Neurology Ward of Internal Medicine, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province (China)

    2015-06-23

    Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF) and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females) were obtained from Harbin Medical University. A stable alcoholism model was established through ad libitum feeding, and anti-alcohol drug treatment (Zhong Yao Jie Jiu Ling, the main ingredient was the stems of watermelon; developed in our laboratory), at low- and high-doses, was carried out. The Zhong Yao Jie Jiu Ling was effective for the alcoholism in dogs. The morphology of hippocampal neurons was evaluated using hematoxylin-eosin staining. The number and morphological features of BDNF, TrkB and p75NTR-positive neurons in the dentate gyrus (DG), and the CA1, CA3 and CA4 regions of the hippocampus were observed using immunohistochemistry. One-way ANOVA was used to determine differences in BDNF, TrkB and p75NTR expression. BDNF, TrkB and p75NTR-positive cells were mainly localized in the granular cell layer of the DG and in the pyramidal cell layer of the CA1, CA3 and CA4 regions (DG>CA1>CA3>CA4). Expression levels of both BDNF and TrkB were decreased in chronic alcoholism, and increased after abstinence. The CA4 region appeared to show the greatest differences. Changes in p75NTR expression were the opposite of those of BDNF and TrkB, with the greatest differences observed in the DG and CA4 regions.

  7. Changes in expression of BDNF and its receptors TrkB and p75NTR in the hippocampus of a dog model of chronic alcoholism and abstinence.

    Science.gov (United States)

    Xu, R; Duan, S R; Zhao, J W; Wang, C Y

    2015-08-01

    Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF) and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females) were obtained from Harbin Medical University. A stable alcoholism model was established through ad libitum feeding, and anti-alcohol drug treatment (Zhong Yao Jie Jiu Ling, the main ingredient was the stems of watermelon; developed in our laboratory), at low- and high-doses, was carried out. The Zhong Yao Jie Jiu Ling was effective for the alcoholism in dogs. The morphology of hippocampal neurons was evaluated using hematoxylin-eosin staining. The number and morphological features of BDNF, TrkB and p75NTR-positive neurons in the dentate gyrus (DG), and the CA1, CA3 and CA4 regions of the hippocampus were observed using immunohistochemistry. One-way ANOVA was used to determine differences in BDNF, TrkB and p75NTR expression. BDNF, TrkB and p75NTR-positive cells were mainly localized in the granular cell layer of the DG and in the pyramidal cell layer of the CA1, CA3 and CA4 regions (DG>CA1>CA3>CA4). Expression levels of both BDNF and TrkB were decreased in chronic alcoholism, and increased after abstinence. The CA4 region appeared to show the greatest differences. Changes in p75NTR expression were the opposite of those of BDNF and TrkB, with the greatest differences observed in the DG and CA4 regions.

  8. A novel antagonist of p75NTR reduces peripheral expansion and CNS trafficking of pro-inflammatory monocytes and spares function after traumatic brain injury.

    Science.gov (United States)

    Lee, Sangmi; Mattingly, Aaron; Lin, Amity; Sacramento, Jeffrey; Mannent, Leda; Castel, Marie-Noelle; Canolle, Benoit; Delbary-Gossart, Sandrine; Ferzaz, Badia; Morganti, Josh M; Rosi, Susanna; Ferguson, Adam R; Manley, Geoffrey T; Bresnahan, Jacqueline C; Beattie, Michael S

    2016-04-22

    Traumatic brain injury (TBI) results in long-term neurological deficits, which may be mediated in part by pro-inflammatory responses in both the injured brain and the circulation. Inflammation may be involved in the subsequent development of neurodegenerative diseases and post-injury seizures. The p75 neurotrophin receptor (p75NTR) has multiple biological functions, affecting cell survival, apoptotic cell death, axonal growth, and degeneration in pathological conditions. We recently found that EVT901, a novel piperazine derivative that inhibits p75NTR oligomerization, is neuroprotective, reduces microglial activation, and improves outcomes in two models of TBI in rats. Since TBI elicits both CNS and peripheral inflammation, we used a mouse model of TBI to examine whether EVT901 would affect peripheral immune responses and trafficking to the injured brain. Cortical contusion injury (CCI)-TBI of the sensory/motor cortex was induced in C57Bl/6 wild-type mice and CCR2(+/RFP) heterozygote transgenic mice, followed by treatment with EVT901, a selective antagonist of p75NTR, or vehicle by i.p. injection at 4 h after injury and then daily for 7 days. Brain and blood were collected at 1 and 6 weeks after injury. Flow cytometry and histological analysis were used to determine peripheral immune responses and trafficking of peripheral immune cells into the lesion site at 1 and 6 weeks after TBI. A battery of behavioral tests administered over 6 weeks was used to evaluate neurological outcome, and stereological estimation of brain tissue volume at 6 weeks was used to assess tissue damage. Finally, multivariate principal components analysis (PCA) was used to evaluate the relationships between inflammatory events, EVT901 treatment, and neurological outcomes. EVT901 is neuroprotective in mouse CCI-TBI and dramatically reduced the early trafficking of CCR2+ and pro-inflammatory monocytes into the lesion site. EVT901 reduced the number of CD45(high)CD11b+ and CD45(high)F4/80+ cells

  9. MAL Overexpression Leads to Disturbed Expression of Genes That Influence Cytoskeletal Organization and Differentiation of Schwann Cells

    Directory of Open Access Journals (Sweden)

    Daniela Schmid

    2014-09-01

    Full Text Available In the developing peripheral nervous system, a coordinated reciprocal signaling between Schwann cells and axons is crucial for accurate myelination. The myelin and lymphocyte protein MAL is a component of lipid rafts that is important for targeting proteins and lipids to distinct domains. MAL overexpression impedes peripheral myelinogenesis, which is evident by a delayed onset of myelination and reduced expression of the myelin protein zero (Mpz/P0 and the low-affinity neurotrophin receptor p75NTR . This study shows that MAL overexpression leads to a significant reduction of Mpz and p75NTR expression in primary mouse Schwann cell cultures, which was already evident before differentiation, implicating an effect of MAL in early Schwann cell development. Their transcription was robustly reduced, despite normal expression of essential transcription factors and receptors. Further, the cAMP response element-binding protein (CREB and phosphoinositide 3-kinase signaling pathways important for Schwann cell differentiation were correctly induced, highlighting that other so far unknown rate limiting factors do exist. We identified novel genes expressed by Schwann cells in a MAL-dependent manner in vivo and in vitro. A number of those, including S100a4, RhoU and Krt23, are implicated in cytoskeletal organization and plasma membrane dynamics. We showed that S100a4 is predominantly expressed by nonmyelinating Schwann cells, whereas RhoU was localized within myelin membranes, and Krt23 was detected in nonmyelinating as well as in myelinating Schwann cells. Their differential expression during early peripheral nerve development further underlines their possible role in influencing Schwann cell differentiation and myelination.

  10. Biology of Schwann cells.

    Science.gov (United States)

    Kidd, Grahame J; Ohno, Nobuhiko; Trapp, Bruce D

    2013-01-01

    The fundamental roles of Schwann cells during peripheral nerve formation and regeneration have been recognized for more than 100 years, but the cellular and molecular mechanisms that integrate Schwann cell and axonal functions continue to be elucidated. Derived from the embryonic neural crest, Schwann cells differentiate into myelinating cells or bundle multiple unmyelinated axons into Remak fibers. Axons dictate which differentiation path Schwann cells follow, and recent studies have established that axonal neuregulin1 signaling via ErbB2/B3 receptors on Schwann cells is essential for Schwann cell myelination. Extracellular matrix production and interactions mediated by specific integrin and dystroglycan complexes are also critical requisites for Schwann cell-axon interactions. Myelination entails expansion and specialization of the Schwann cell plasma membrane over millimeter distances. Many of the myelin-specific proteins have been identified, and transgenic manipulation of myelin genes have provided novel insights into myelin protein function, including maintenance of axonal integrity and survival. Cellular events that facilitate myelination, including microtubule-based protein and mRNA targeting, and actin based locomotion, have also begun to be understood. Arguably, the most remarkable facet of Schwann cell biology, however, is their vigorous response to axonal damage. Degradation of myelin, dedifferentiation, division, production of axonotrophic factors, and remyelination all underpin the substantial regenerative capacity of the Schwann cells and peripheral nerves. Many of these properties are not shared by CNS fibers, which are myelinated by oligodendrocytes. Dissecting the molecular mechanisms responsible for the complex biology of Schwann cells continues to have practical benefits in identifying novel therapeutic targets not only for Schwann cell-specific diseases but other disorders in which axons degenerate. Copyright © 2013 Elsevier B.V. All rights

  11. LINGO-1-mediated inhibition of oligodendrocyte differentiation does not require the leucine-rich repeats and is reversed by p75(NTR) antagonists.

    Science.gov (United States)

    Bourikas, Dimitris; Mir, Anis; Walmsley, Adrian Robert

    2010-12-01

    LINGO-1 is a potent negative regulator of oligodendrocyte differentiation and hence may play a pivotal restrictive role during remyelination in demyelinating diseases such as multiple sclerosis. However, little is known as to which stages of oligodendrocyte differentiation are inhibited by LINGO-1, which domains of the protein are involved and whether accessory proteins are required. Here, we show that LINGO-1 expression in the human oligodendroglial cell line MO3.13 inhibited process extension and this was reversed by an anti-LINGO-1 antibody or the antagonist LINGO-1-Fc. LINGO-1 expression was also found to inhibit myelin basic protein transcription in the rat oligodendroglial cell line CG4. Both of these inhibitory actions of LINGO-1 were abrogated by deletion of the entire ectodomain or cytoplasmic domains but, surprisingly, were unaffected by deletion of the leucine-rich repeats (LRRs). As in neurons, LINGO-1 physically associated with endogenous p75(NTR) in MO3.13 cells and, correspondingly, its inhibition of process extension was reversed by antagonists of p75(NTR). Thus, LINGO-1 inhibits multiple aspects of oligodendrocyte differentiation independently of the LRRs via a process that requires p75(NTR) signalling. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Establishing a cellular FRET-based fluorescence plate reader assay to monitor proNGF-induced cross-linking of sortilin and the neurotrophin receptor p75(NTR)

    DEFF Research Database (Denmark)

    Skeldal, Sune; Kjaergaard, Maj M; Alwasel, Saleh

    2015-01-01

    Whereas the proform of the nerve growth factor (proNGF) is crucial for eliminating superfluous cells during neuronal development it also promotes apoptosis following brain trauma and neuronal injury. The apoptotic signal is elicited upon formation of a trimeric receptor complex also containing th...... use of a pair of FRET standard constructs. As a result, the effect of proNGF on the interaction between sortilin and p75(NTR) can be evaluated in live cells allowing for screening and selection of therapeutic compounds interfering with proNGF-induced cell death....

  13. Subconjunctival Delivery of p75NTR Antagonists Reduces the Inflammatory, Vascular, and Neurodegenerative Pathologies of Diabetic Retinopathy.

    Science.gov (United States)

    Galan, Alba; Barcelona, Pablo F; Nedev, Hinyu; Sarunic, Marinko V; Jian, Yifan; Saragovi, H Uri

    2017-06-01

    The p75NTR is a novel therapeutic target validated in a streptozotocin mouse model of diabetic retinopathy. Intravitreal (IVT) injection of small molecule p75NTR antagonist THX-B was therapeutic and resolved the inflammatory, vascular, and neurodegenerative phases of the retinal pathology. To simplify clinical translation, we sought a superior drug delivery method that circumvents risks associated with IVT injections. We compared the pharmacokinetics of a single 40 μg subconjunctival (SCJ) depot to the reported effective 5 μg IVT injections of THX-B. We quantified therapeutic efficacy, with endpoints of inflammation, edema, and neuronal death. The subconjunctival depot affords retinal exposure equal to IVT injection, without resulting in detectable drug in circulation. At week 2 of diabetic retinopathy, the SCJ depot provided therapeutic efficacy similar to IVT injections, with reduced inflammation, reduced edema, reduced neuronal death, and a long-lasting protection of the retinal structure. Subconjunctival injections are a safe and effective route for retinal delivery of p75NTR antagonists. The subconjunctival route offers an advantageous, less-invasive, more compliant, and nonsystemic method to deliver p75NTR antagonists for the treatment of retinal diseases.

  14. SN56 basal forebrain cholinergic neuronal loss after acute and long-term chlorpyrifos exposure through oxidative stress generation; P75(NTR) and α7-nAChRs alterations mediated partially by AChE variants disruption.

    Science.gov (United States)

    Del Pino, Javier; Moyano, Paula; Anadon, María José; García, José Manuel; Díaz, María Jesús; Gómez, Gloria; García, Jimena; Frejo, María Teresa

    2016-04-15

    Chlorpyrifos (CPF) is an organophosphates insecticide reported to induce, both after acute and repeated exposure, cognitive disorders and basal forebrain cholinergic neuronal loss, involved on learning and memory regulation, which could be the cause of such cognitive disorders. This neuronal loss was mediated partially by AChE variants alteration, suggesting other mechanisms are involved. In this regard, CPF induces oxidative stress that is implicated in the induction of cognitive deficits, changes in AChE variants expression and neuronal loss. Otherwise, it has been shown that P75(NTR) and the α7-nAChRs expression is altered in basal forebrain of rats after CPF long-term exposure; this alteration has been related with oxidative stress induction, cholinergic cell loss, and disruption of learning and memory processes. According to these data, we hypothesized that CPF induces basal forebrain cholinergic neuronal loss through induction of oxidative stress produced by P75(NTR) and α7-nAChRs altered expression, which could mediate this action in part through AChE variants disruption. We evaluated this hypothesis in septal SN56 basal forebrain cholinergic neurons, after 24h and 14days CPF exposure in vitro. This study shows that CPF upregulated P75(NTR) and downregulated α7-nAChRs expression, which increased H2O2 and malondialdehyde content and reduced cell viability partially through AChE variants induction. Alpha7-nAChRs repression induced oxidative stress and cell death partially through this mechanism, but P75(NTR) overexpression did not produce these effects, although it increased oxidative stress and cell death after CPF treatment, showing that its overexpression increases cell vulnerability. Our present results provide new understanding of the mechanisms contributing to the harmful effects of CPF. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. A small molecule p75NTR ligand normalizes signalling and reduces Huntington's disease phenotypes in R6/2 and BACHD mice.

    Science.gov (United States)

    Simmons, Danielle A; Belichenko, Nadia P; Ford, Ellen C; Semaan, Sarah; Monbureau, Marie; Aiyaswamy, Sruti; Holman, Cameron M; Condon, Christina; Shamloo, Mehrdad; Massa, Stephen M; Longo, Frank M

    2016-11-15

    Decreases in the ratio of neurotrophic versus neurodegenerative signalling play a critical role in Huntington’s disease (HD) pathogenesis and recent evidence suggests that the p75 neurotrophin receptor (NTR) contributes significantly to disease progression. p75NTR signalling intermediates substantially overlap with those promoting neuronal survival and synapse integrity and with those affected by the mutant huntingtin (muHtt) protein. MuHtt increases p75NTR-associated deleterious signalling and decreases survival signalling suggesting that p75NTR could be a valuable therapeutic target. This hypothesis was investigated by examining the effects of an orally bioavailable, small molecule p75NTR ligand, LM11A-31, on HD-related neuropathology in HD mouse models (R6/2, BACHD). LM11A-31 restored striatal AKT and other pro-survival signalling while inhibiting c-Jun kinase (JNK) and other degenerative signalling. Normalizing p75NTR signalling with LM11A-31 was accompanied by reduced Htt aggregates and striatal cholinergic interneuron degeneration as well as extended survival in R6/2 mice. The p75NTR ligand also decreased inflammation, increased striatal and hippocampal dendritic spine density, and improved motor performance and cognition in R6/2 and BACHD mice. These results support small molecule modulation of p75NTR as an effective HD therapeutic strategy. LM11A-31 has successfully completed Phase I safety and pharmacokinetic clinical trials and is therefore a viable candidate for clinical studies in HD.

  16. Schwann cell hamartoma: case report

    Directory of Open Access Journals (Sweden)

    Bulfamante Gaetano

    2011-06-01

    Full Text Available Abstract Background Colorectal polyps of mesenchymal origin represent a small percentage of gastrointestinal (GI lesions. Nevertheless, they are encountered with increasing frequency since the widespread adoption of colonoscopy screening. Case presentation We report a case of a small colonic polyp that presented as intramucosal diffuse spindle cell proliferation with a benign cytological appearance, strong and diffuse immunoreactivity for S-100 protein, and pure Schwann cell phenotype. Careful morphological, immunohistochemical and clinical evaluation emphasize the differences from other stromal colonic lesions and distinguish it from schwannoma, a circumscribed benign nerve sheath tumor that rarely arises in the GI tract. Conclusion As recently proposed, this lesion was finally described as mucosal Schwann cell hamartoma.

  17. Contribution of p75NTR to Schwannoma Growth and Therapeutic Responses

    Science.gov (United States)

    2015-05-01

    protects hippocampal neurons against oxidative stress-induced apo- ptosis: Evidence for induction of manganese superoxide dismutase and sup- pression of...biological chemistry 278:42161-42169. Kanning KC, Hudson M, Amieux PS, Wiley JC, Bothwell M, Schecterson LC (2003) Proteolytic processing of the p75... superoxides . Neuro-oncology 13:961-973. Zhou L, Hanemann CO (2012) Merlin, a multi-suppressor from cell membrane to the nucleus. FEBS Lett 586:1403-1408

  18. Ameliorative Effects of p75NTR-ED-Fc on Axonal Regeneration and Functional Recovery in Spinal Cord-Injured Rats.

    Science.gov (United States)

    Wang, Yong-Tang; Lu, Xiu-Min; Zhu, Feng; Huang, Peng; Yu, Ying; Long, Zai-Yun; Wu, Ya-Min

    2015-12-01

    As a co-receptor of Nogo-66 receptor (NgR) and a critical receptor for paired immunoglobulin-like receptor (PirB), p75 neurotrophin receptor (p75NTR) mediates the inhibitory effects of myelin-associated inhibitors on axonal regeneration after spinal cord injury. Therefore, the p75NTR antagonist, such as recombinant p75NTR protein or its homogenates may block the inhibitory effects of myelin and promote the axonal regeneration and functional recovery. The purposes of this study are to subclone and express the extracellular domain gene of human p75NTR with IgG-Fc (hp75NTR-ED-Fc) in prokaryotic expression system and investigate the effects of the recombinant protein on axonal regeneration and functional recovery in spinal cord-injured rats. The hp75NTR-ED-Fc coding sequence was amplified from pcDNA-hp75NTR-ED-Fc by polymerase chain reaction (PCR) and subcloned into vector pET32a (+), then the effects of the purified recombinant protein on neurite outgrowth of dorsal root ganglion (DRG) neurons cultured with myelin-associated glycoprotein (MAG) were determined, and the effects of the fusion protein on axonal regeneration, functional recovery, and its possible mechanisms in spinal cord-injured rats were further investigated. The results indicated that the purified infusion protein could promote neurite outgrowth of DRG neurons, promote axonal regeneration and functional recovery, and decrease RhoA activation in spinal cord-injured rats. Taken together, the findings revealed that p75NTR still may be a potential and novel target for therapeutic intervention for spinal cord injury and that the hp75NTR-ED-Fc fusion protein treatment enhances functional recovery by limiting tissue loss and stimulating axonal growth in spinal cord-injured rats, which may result from decreasing the activation of RhoA.

  19. Pluripotent Stem Cells for Schwann Cell Engineering

    NARCIS (Netherlands)

    Ma, Ming-San; Boddeke, Erik; Copray, Sjef

    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

  20. La célula de Schwann The Schwann Cell

    Directory of Open Access Journals (Sweden)

    Spinel Clara

    2004-12-01

    Full Text Available Las neuronas son las células del sistema nervioso y están recubiertas y protegidas por células gliales. En el sistema nerviosos periférico las células de Schwann (CS son la glía de los nervios. Las prolongaciones o neuritas (axón y dendrita de los cuerpos de las neuronas son recubiertas por las CS y constituyen las fibras nerviosas. La relación íntima entre la CS y la neurita se determina durante el desarrollo embrionario. La CS es esencial en la migración correcta de las neuritas hacia su destino final, pero a su vez las neuritas inducen la maduración de las CS. Esta interacción entre CS y neurita está determinada por factores paracrinos y receptores de membrana de las dos células que interactúan, induciendo la diferenciación de las CS en mielinizadas o no, determinando el número de CS necesarias para cubrir las neuritas, formación adecuada de la vaina de mielina y relación correcta de la CS con la matriz extracelular. De esta manera se forma la fibra nerviosa que culmina inervando o recibiendo estímulos en la periferia del cuerpo. Las CS también son la clave de la regeneración de las neuritas en caso de daño de un nervio periférico.The neurones are the cells of the nervous system and are surrounded and protected by glials cells. In the peripheral nervous system the Schwann cells (SC are the glia of the nerves. The prolongations or neurites (axon and dendrite of the neurones bodies are surrounded by the SC to form nervous fibers. The intimate relationship between the SC and the neurite is determined during embryonic development. The SC is essential for the correct migration of the neurites towards their final destination, but the neurites induce SC maturation as well. This interaction between SC and neurite is determined by paracrine factors and membrane receptors of the two interacting cells, inducing the differentiation of SC in myelinic and non-myelinic, determining the correct number of SC necessary to surround the

  1. Peptides derived from the solvent-exposed loops 3 and 4 of BDNF bind TrkB and p75(NTR) receptors and stimulate neurite outgrowth and survival

    DEFF Research Database (Denmark)

    Fobian, Kristina; Owczarek, Sylwia; Budtz, Christian

    2010-01-01

    to produce more specific compounds without side effects, small peptides mimicking protein function have been developed. The present study characterized two mimetic peptides, Betrofin 3 and Betrofin 4, derived from the BDNF sequence. Both Betrofins bound the cognate BDNF receptors, TrkB and p75(NTR......), and induced neurite outgrowth and enhanced neuronal survival, probably by inducing signaling through tha Akt and MAPK pathways. Distinct, charged residues within the Betrofin sequences were identified as important for generating the neuritogenic response, which was also inhibited when BDNF was added together...... with either Betrofin, indicating partial agonistic effects of the peptides. Thus, two peptides derived from BDNF induced neurite outgrowth and enhanced neuronal survival, probably through binding to BDNF receptors....

  2. Schwann cell myelination requires Dynein function

    Directory of Open Access Journals (Sweden)

    Langworthy Melissa M

    2012-11-01

    Full Text Available Abstract Background Interaction of Schwann cells with axons triggers signal transduction that drives expression of Pou3f1 and Egr2 transcription factors, which in turn promote myelination. Signal transduction appears to be mediated, at least in part, by cyclic adenosine monophosphate (cAMP because elevation of cAMP levels can stimulate myelination in the absence of axon contact. The mechanisms by which the myelinating signal is conveyed remain unclear. Results By analyzing mutations that disrupt myelination in zebrafish, we learned that Dynein cytoplasmic 1 heavy chain 1 (Dync1h1, which functions as a motor for intracellular molecular trafficking, is required for peripheral myelination. In dync1h1 mutants, Schwann cell progenitors migrated to peripheral nerves but then failed to express Pou3f1 and Egr2 or make myelin membrane. Genetic mosaic experiments revealed that robust Myelin Basic Protein expression required Dync1h1 function within both Schwann cells and axons. Finally, treatment of dync1h1 mutants with a drug to elevate cAMP levels stimulated myelin gene expression. Conclusion Dync1h1 is required for retrograde transport in axons and mutations of Dync1h1 have been implicated in axon disease. Our data now provide evidence that Dync1h1 is also required for efficient myelination of peripheral axons by Schwann cells, perhaps by facilitating signal transduction necessary for myelination.

  3. How Schwann Cells Sort Axons: New Concepts.

    Science.gov (United States)

    Feltri, M Laura; Poitelon, Yannick; Previtali, Stefano Carlo

    2016-06-01

    Peripheral nerves contain large myelinated and small unmyelinated (Remak) fibers that perform different functions. The choice to myelinate or not is dictated to Schwann cells by the axon itself, based on the amount of neuregulin I-type III exposed on its membrane. Peripheral axons are more important in determining the final myelination fate than central axons, and the implications for this difference in Schwann cells and oligodendrocytes are discussed. Interestingly, this choice is reversible during pathology, accounting for the remarkable plasticity of Schwann cells, and contributing to the regenerative potential of the peripheral nervous system. Radial sorting is the process by which Schwann cells choose larger axons to myelinate during development. This crucial morphogenetic step is a prerequisite for myelination and for differentiation of Remak fibers, and is arrested in human diseases due to mutations in genes coding for extracellular matrix and linkage molecules. In this review we will summarize progresses made in the last years by a flurry of reverse genetic experiments in mice and fish. This work revealed novel molecules that control radial sorting, and contributed unexpected ideas to our understanding of the cellular and molecular mechanisms that control radial sorting of axons. © The Author(s) 2015.

  4. The genome sequence of the protostome Daphnia pulex encodes respective orthologues of a neurotrophin, a Trk and a p75NTR: Evolution of neurotrophin signaling components and related proteins in the bilateria

    Directory of Open Access Journals (Sweden)

    Wilson Karen HS

    2009-10-01

    Full Text Available Abstract Background Neurotrophins and their Trk and p75NTR receptors play an important role in the nervous system. To date, neurotrophins, Trk and p75NTR have only been found concomitantly in deuterostomes. In protostomes, homologues to either neurotrophin, Trk or p75NTR are reported but their phylogenetic relationship to deuterostome neurotrophin signaling components is unclear. Drosophila has neurotrophin homologues called Spätzles (Spz, some of which were recently renamed neurotrophins, but direct proof that these are deuterostome neurotrophin orthologues is lacking. Trks belong to the receptor tyrosine kinase (RTK family and among RTKs, Trks and RORs are closest related. Flies lack Trks but have ROR and ROR-related proteins called NRKs playing a neurotrophic role. Mollusks have so far the most similar proteins to Trks (Lymnaea Trk and Aplysia Trkl but the exact phylogenetic relationship of mollusk Trks to each other and to vertebrate Trks is unknown. p75NTR belongs to the tumor necrosis factor receptor (TNFR superfamily. The divergence of the TNFR families in vertebrates has been suggested to parallel the emergence of the adaptive immune system. Only one TNFR representative, the Drosophila Wengen, has been found in protostomes. To clarify the evolution of neurotrophin signaling components in bilateria, this work analyzes the genome of the crustacean Daphnia pulex as well as new genetic data from protostomes. Results The Daphnia genome encodes a neurotrophin, p75NTR and Trk orthologue together with Trkl, ROR, and NRK-RTKs. Drosophila Spz1, 2, 3, 5, 6 orthologues as well as two new groups of Spz proteins (Spz7 and 8 are also found in the Daphnia genome. Searching genbank and the genomes of Capitella, Helobdella and Lottia reveals neurotrophin signaling components in other protostomes. Conclusion It appears that a neurotrophin, Trk and p75NTR existed at the protostome/deuterostome split. In protostomes, a "neurotrophin superfamily" includes

  5. Chemical Conversion of Human Fibroblasts into Functional Schwann Cells

    Directory of Open Access Journals (Sweden)

    Eva C. Thoma

    2014-10-01

    Full Text Available Direct transdifferentiation of somatic cells is a promising approach to obtain patient-specific cells for numerous applications. However, conversion across germ-layer borders often requires ectopic gene expression with unpredictable side effects. Here, we present a gene-free approach that allows efficient conversion of human fibroblasts via a transient progenitor stage into Schwann cells, the major glial cell type of peripheral nerves. Using a multikinase inhibitor, we transdifferentiated fibroblasts into transient neural precursors that were subsequently further differentiated into Schwann cells. The resulting induced Schwann cells (iSCs expressed numerous Schwann cell-specific proteins and displayed neurosupportive and myelination capacity in vitro. Thus, we established a strategy to obtain mature Schwann cells from human postnatal fibroblasts under chemically defined conditions without the introduction of ectopic genes.

  6. Glycolaldehyde induces endoplasmic reticulum stress and apoptosis in Schwann cells

    Directory of Open Access Journals (Sweden)

    Keisuke Sato

    2015-01-01

    Full Text Available Schwann cell injury is caused by diabetic neuropathy. The apoptosis of Schwann cells plays a pivotal role in diabetic nerve dysfunction. Glycolaldehyde is a precursor of advanced glycation end products that contribute to the pathogenesis of diabetic neuropathy. In this study, we examined whether glycolaldehyde induces endoplasmic reticulum (ER stress and apoptosis in rat Schwann cells. Schwann cells treated with 500 μM glycolaldehyde showed morphological changes characteristic of apoptosis. Glycolaldehyde activated apoptotic signals, such as caspase-3 and caspase-8. Furthermore, it induced ER stress response involving RNA-dependent protein kinase-like ER kinase (PERK, inositol-requiring ER-to-nucleus signal kinase 1α (IRE1α, and eukaryotic initiation factor 2α (eIF2α. In addition, glycolaldehyde activated CCAAT/enhancer-binding homologous protein (CHOP, an ER stress response factor crucial to executing apoptosis. Knockdown of nuclear factor E2-related factor 2 (Nrf2, which is involved in the promotion of cell survival following ER stress, enhanced glycolaldehyde-induced cytotoxicity, indicating that Nrf2 plays a protective role in the cytotoxicity caused by glycolaldehyde. Taken together, these findings indicate that glycolaldehyde is capable of inducing apoptosis and ER stress in Schwann cells. The ER stress induced by glycolaldehyde may trigger the glycolaldehyde-induced apoptosis in Schwann cells. This study demonstrated for the first time that glycolaldehyde induced ER stress.

  7. Mesenchymal Stem Cells as an Alternative for Schwann Cells in Rat Spinal Cord Injury

    Science.gov (United States)

    Zaminy, Arash; Shokrgozar, Mohammad Ali; Sadeghi, Yousef; Noroozian, Mohsen; Heidari, Mohammad Hassan; Piryaei, Abbas

    2013-01-01

    Background: Spinal cord has a limited capacity to repair; therefore, medical interventions are necessary for treatment of injuries. Transplantation of Schwann cells has shown a great promising result for spinal cord injury (SCI). However, harvesting Schwann cell has been limited due to donor morbidity and limited expansion capacity. Furthermore, accessible sources such as bone marrow stem cells have drawn attentions to themselves. Therefore, this study was designed to evaluate the effect of bone marrow-derived Schwann cell on functional recovery in adult rats after injury. Methods: Mesenchymal stem cells were cultured from adult rats’ bone marrow and induced into Schwann cells in vitro. Differentiation was confirmed by immunocytochemistry and RT-PCR. Next, Schwann cells were seeded into collagen scaffolds and engrafted in 3 mm lateral hemisection defects. For 8 weeks, motor and sensory improvements were assessed by open field locomotor scale, narrow beam, and tail flick tests. Afterwards, lesioned spinal cord was evaluated by conventional histology and immunohistochemistry. Results: In vitro observations showed that differentiated cells had Schwann cell morphology and markers. In this study, we had four groups (n = 10 each): laminectomy, control, scaffold and scaffold + Schwann cells. Locomotor and sensory scores of cell grafted group were significantly better than control and scaffold groups. In histology, axonal regeneration and remyelination were better than control and scaffold groups. Conclusion: This study demonstrates that bone marrow-derived Schwann cells can be considered as a cell source for Schwann cells in SCI treatment. PMID:23748888

  8. Influenza A virus infection of human Schwann cells in vitro.

    Science.gov (United States)

    Levine, Joshua; Buchman, Craig A; Fregien, Nevis

    2003-01-01

    Sudden sensorineural hearing loss, vestibular neuronitis, vocal fold paralysis and Bell's palsy have been associated with a viral etiology, due to the infection of nerve cells. The goal of this research was to ascertain whether Schwann cells can support infection with human influenza A virus and thereby represent a plausible alternative site for virus-host interaction. Viral infection of Schwann cells may lead to secretion of inflammatory mediators, leukocyte recruitment, demyelination and nerve damage. Cultured human Schwann cells were exposed to human influenza A virus. Infection was assayed at various times post-inoculation (0, 24, 48 and 72 h) using light microscopy, immunocytochemistry and influenza A virus-specific reverse transcriptase polymerase chain reaction (RT-PCR). A group of unexposed cells served as controls. Following exposure to the virus, vacuolization, cellular expansion and detachment from the dish were seen as early as 24 h post-inoculation. The exposed cells demonstrated positive immunocytochemical staining for influenza A virus antigen at 24, 48 and 72 h. Using RT-PCR, a sharp rise in influenza A virus-specific mRNA was detected. Human Schwann cells can be infected with human influenza A virus. Further studies will assess the inflammatory response in this model.

  9. Functional Gap Junctions in the Schwann Cell Myelin Sheath

    Science.gov (United States)

    Balice-Gordon, Rita J.; Bone, Linda J.; Scherer, Steven S.

    1998-01-01

    The Schwann cell myelin sheath is a multilamellar structure with distinct structural domains in which different proteins are localized. Intracellular dye injection and video microscopy were used to show that functional gap junctions are present within the myelin sheath that allow small molecules to diffuse between the adaxonal and perinuclear Schwann cell cytoplasm. Gap junctions are localized to periodic interruptions in the compact myelin called Schmidt–Lanterman incisures and to paranodes; these regions contain at least one gap junction protein, connexin32 (Cx32). The radial diffusion of low molecular weight dyes across the myelin sheath was not interrupted in myelinating Schwann cells from cx32-null mice, indicating that other connexins participate in forming gap junctions in these cells. Owing to the unique geometry of myelinating Schwann cells, a gap junction-mediated radial pathway may be essential for rapid diffusion between the adaxonal and perinuclear cytoplasm, since this radial pathway is approximately one million times faster than the circumferential pathway. PMID:9722620

  10. Dual specificity phosphatase 15 regulates Erk activation in Schwann cells.

    Science.gov (United States)

    Rodríguez-Molina, José F; Lopez-Anido, Camila; Ma, Ki H; Zhang, Chongyu; Olson, Tyler; Muth, Katharina N; Weider, Matthias; Svaren, John

    2017-02-01

    Schwann cells and oligodendrocytes are the myelinating cells of the peripheral and central nervous system, respectively. Despite having different myelin components and different transcription factors driving their terminal differentiation there are shared molecular mechanisms between the two. Sox10 is one common transcription factor required for several steps in development of myelinating glia. However, other factors are divergent as Schwann cells need the transcription factor early growth response 2/Krox20 and oligodendrocytes require Myrf. Likewise, some signaling pathways, like the Erk1/2 kinases, are necessary in both cell types for proper myelination. Nonetheless, the molecular mechanisms that control this shared signaling pathway in myelinating cells remain only partially characterized. The hypothesis of this study is that signaling pathways that are similarly regulated in both Schwann cells and oligodendrocytes play central roles in coordinating the differentiation of myelinating glia. To address this hypothesis, we have used genome-wide binding data to identify a relatively small set of genes that are similarly regulated by Sox10 in myelinating glia. We chose one such gene encoding Dual specificity phosphatase 15 (Dusp15) for further analysis in Schwann cell signaling. RNA interference and gene deletion by genome editing in cultured RT4 and primary Schwann cells showed Dusp15 is necessary for full activation of Erk1/2 phosphorylation. In addition, we show that Dusp15 represses expression of several myelin genes, including myelin basic protein. The data shown here support a mechanism by which early growth response 2 activates myelin genes, but also induces a negative feedback loop through Dusp15 to limit over-expression of myelin genes. © 2016 International Society for Neurochemistry.

  11. Transcriptional Regulation Induced by cAMP Elevation in Mouse Schwann Cells

    Directory of Open Access Journals (Sweden)

    Daniela Schmid

    2014-03-01

    Full Text Available In peripheral nerves, Schwann cell development is regulated by a variety of signals. Some of the aspects of Schwann cell differentiation can be reproduced in vitro in response to forskolin, an adenylyl cyclase activator elevating intracellular cAMP levels. Herein, the effect of forskolin treatment was investigated by a comprehensive genome-wide expression study on primary mouse Schwann cell cultures. Additional to myelin-related genes, many so far unconsidered genes were ascertained to be modulated by forskolin. One of the strongest differentially regulated gene transcripts was the transcription factor Olig1 (oligodendrocyte transcription factor 1, whose mRNA expression levels were reduced in treated Schwann cells. Olig1 protein was localized in myelinating and nonmyelinating Schwann cells within the sciatic nerve as well as in primary Schwann cells, proposing it as a novel transcription factor of the Schwann cell lineage. Data analysis further revealed that a number of differentially expressed genes in forskolin-treated Schwann cells were associated with the ECM (extracellular matrix, underlining its importance during Schwann cell differentiation in vitro. Comparison of samples derived from postnatal sciatic nerves and from both treated and untreated Schwann cell cultures showed considerable differences in gene expression between in vivo and in vitro, allowing us to separate Schwann cell autonomous from tissue-related changes. The whole data set of the cell culture microarray study is provided to offer an interactive search tool for genes of interest.

  12. Schwann cells promote neuronal differentiation of bone marrow ...

    African Journals Online (AJOL)

    Administrator

    2011-04-25

    Apr 25, 2011 ... To culture of Schwann cells, sciatic nerves of adult rats were obtained from adult SD rats under aseptic conditions and placed into Hank's balanced salt solution supplemented. The epineurium and connective tissue were removed under microscope, and the sciatic nerves were cut into 2 to 3 mm fragments, ...

  13. Autoimmunoreactivity to Schwann cells in patients with inflammatory neuropathies

    NARCIS (Netherlands)

    Kwa, Marcel S. G.; van Schaik, Ivo N.; de Jonge, Rosalein R.; Brand, Anneke; Kalaydjieva, Luba; van Belzen, Nico; Vermeulen, Marinus; Baas, Frank

    2003-01-01

    Inflammatory demyelinating neuropathies are characterized by a loss of peripheral nerve myelin. Myelin breakdown is thought to result from an autoimmune reaction towards nerve components. Schwann cells play a crucial role in the synthesis and maintenance of peripheral nerve myelin. An immune attack

  14. Edaravone combined with Schwann cell transplantation may repair spinal cord injury in rats

    Directory of Open Access Journals (Sweden)

    Shu-quan Zhang

    2015-01-01

    Full Text Available Edaravone has been shown to delay neuronal apoptosis, thereby improving nerve function and the microenvironment after spinal cord injury. Edaravone can provide a favorable environment for the treatment of spinal cord injury using Schwann cell transplantation. This study used rat models of complete spinal cord transection at T 9. Six hours later, Schwann cells were transplanted in the head and tail ends of the injury site. Simultaneously, edaravone was injected through the caudal vein. Eight weeks later, the PKH-26-labeled Schwann cells had survived and migrated to the center of the spinal cord injury region in rats after combined treatment with edaravone and Schwann cells. Moreover, the number of PKH-26-labeled Schwann cells in the rat spinal cord was more than that in rats undergoing Schwann cell transplantation alone or rats without any treatment. Horseradish peroxidase retrograde tracing revealed that the number of horseradish peroxidase-positive nerve fibers was greater in rats treated with edaravone combined withSchwann cells than in rats with Schwann cell transplantation alone. The results demonstrated that lower extremity motor function and neurophysiological function were better in rats treated with edaravone and Schwann cells than in rats with Schwann cell transplantation only. These data confirmed that Schwann cell transplantation combined with edaravone injection promoted the regeneration of nerve fibers of rats with spinal cord injury and improved neurological function.

  15. Chronic nerve compression induces concurrent apoptosis and proliferation of Schwann cells.

    Science.gov (United States)

    Gupta, Ranjan; Steward, Oswald

    2003-06-23

    Chronic nerve compression (CNC), as in carpal tunnel syndrome, is a common cause of peripheral nerve dysfunction in humans. Previous studies using animal models have demonstrated progressive demyelination and a slowing of nerve conduction velocity. To characterize the Schwann cell response to CNC, we evaluated total Schwann cell number, apoptosis, and proliferation in an animal model of CNC. Design-based stereologic techniques revealed a striking transient increase in Schwann cell number following CNC. Schwann cell number increased sixfold relative to the normal nerve at the site of compression at 1 month and then slowly declined toward control levels. Nevertheless, assays of apoptosis (TUNEL and an antipoly-ADP-ribose polymerase labeling assays) revealed extensive Schwann cell apoptosis at 2 weeks postcompression, which is during the time when Schwann cell number was increasing. Electron microscopic analysis confirmed that these dramatic changes in Schwann cells occurred in the absence of axon degeneration and axonal swelling and before there were any detectable alterations in nerve conduction velocity. Counts of bromodeoxyuridine-labeled Schwann cells revealed that proliferation occurred concurrently with ongoing apoptosis. To define further the possible mitogenic properties of mechanical stimuli on Schwann cells, we used an in-vitro model to deliver shear stress in the form of laminar fluid flow to pure populations of Schwann cells and confirmed that mechanical stimuli induce Schwann cell proliferation. Our findings indicate that chronic nerve compression induces Schwann cell turnover with minimal axonal injury and support the idea that mechanical stimuli have a direct mitogenic effect on Schwann cells. Copyright 2003 Wiley-Liss, Inc.

  16. Differential regulation of NAB corepressor genes in Schwann cells

    Directory of Open Access Journals (Sweden)

    Sachdev Shrikesh

    2007-12-01

    Full Text Available Abstract Background Myelination of peripheral nerves by Schwann cells requires not only the Egr2/Krox-20 transactivator, but also the NGFI-A/Egr-binding (NAB corepressors, which modulate activity of Egr2. Previous work has shown that axon-dependent expression of Egr2 is mediated by neuregulin stimulation, and NAB corepressors are co-regulated with Egr2 expression in peripheral nerve development. NAB corepressors have also been implicated in macrophage development, cardiac hypertrophy, prostate carcinogenesis, and feedback regulation involved in hindbrain development. Results To test the mechanism of NAB regulation in Schwann cells, transfection assays revealed that both Nab1 and Nab2 promoters are activated by Egr2 expression. Furthermore, direct binding of Egr2 at these promoters was demonstrated in vivo by chromatin immunoprecipitation analysis of myelinating sciatic nerve, and binding of Egr2 to the Nab2 promoter was stimulated by neuregulin in primary Schwann cells. Although Egr2 expression activates the Nab2 promoter more highly than Nab1, we surprisingly found that only Nab1 – but not Nab2 – expression levels were reduced in sciatic nerve from Egr2 null mice. Analysis of the Nab2 promoter showed that it is also activated by ETS proteins (Ets2 and Etv1/ER81 and is bound by Ets2 in vivo. Conclusion Overall, these results indicate that induction of Nab2 expression in Schwann cells involves not only Egr2, but also ETS proteins that are activated by neuregulin stimulation. Although Nab1 and Nab2 play partially redundant roles, regulation of Nab2 expression by ETS factors explains several observations regarding regulation of NAB genes. Finally, these data suggest that NAB proteins are not only feedback inhibitors of Egr2, but rather that co-induction of Egr2 and NAB genes is involved in forming an Egr2/NAB complex that is crucial for regulation of gene expression.

  17. Dynamic regulation of Schwann cell enhancers after peripheral nerve injury.

    Science.gov (United States)

    Hung, Holly A; Sun, Guannan; Keles, Sunduz; Svaren, John

    2015-03-13

    Myelination of the peripheral nervous system is required for axonal function and long term stability. After peripheral nerve injury, Schwann cells transition from axon myelination to a demyelinated state that supports neuronal survival and ultimately remyelination of axons. Reprogramming of gene expression patterns during development and injury responses is shaped by the actions of distal regulatory elements that integrate the actions of multiple transcription factors. We used ChIP-seq to measure changes in histone H3K27 acetylation, a mark of active enhancers, to identify enhancers in myelinating rat peripheral nerve and their dynamics after demyelinating nerve injury. Analysis of injury-induced enhancers identified enriched motifs for c-Jun, a transcription factor required for Schwann cells to support nerve regeneration. We identify a c-Jun-bound enhancer in the gene for Runx2, a transcription factor induced after nerve injury, and we show that Runx2 is required for activation of other induced genes. In contrast, enhancers that lose H3K27ac after nerve injury are enriched for binding sites of the Sox10 and early growth response 2 (Egr2/Krox20) transcription factors, which are critical determinants of Schwann cell differentiation. Egr2 expression is lost after nerve injury, and many Egr2-binding sites lose H3K27ac after nerve injury. However, the majority of Egr2-bound enhancers retain H3K27ac, indicating that other transcription factors maintain active enhancer status after nerve injury. The global epigenomic changes in H3K27ac deposition pinpoint dynamic changes in enhancers that mediate the effects of transcription factors that control Schwann cell myelination and peripheral nervous system responses to nerve injury. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Schwann Cell Precursors from Human Pluripotent Stem Cells as a Potential Therapeutic Target for Myelin Repair

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    Han-Seop Kim

    2017-06-01

    Full Text Available Schwann cells play a crucial role in successful nerve repair and regeneration by supporting both axonal growth and myelination. However, the sources of human Schwann cells are limited both for studies of Schwann cell development and biology and for the development of treatments for Schwann cell-associated diseases. Here, we provide a rapid and scalable method to produce self-renewing Schwann cell precursors (SCPs from human pluripotent stem cells (hPSCs, using combined sequential treatment with inhibitors of the TGF-β and GSK-3 signaling pathways, and with neuregulin-1 for 18 days under chemically defined conditions. Within 1 week, hPSC-derived SCPs could be differentiated into immature Schwann cells that were functionally confirmed by their secretion of neurotrophic factors and their myelination capacity in vitro and in vivo. We propose that hPSC-derived SCPs are a promising, unlimited source of functional Schwann cells for treating demyelination disorders and injuries to the peripheral nervous system.

  19. Schwann Cell Precursors from Human Pluripotent Stem Cells as a Potential Therapeutic Target for Myelin Repair.

    Science.gov (United States)

    Kim, Han-Seop; Lee, Jungwoon; Lee, Da Yong; Kim, Young-Dae; Kim, Jae Yun; Lim, Hyung Jin; Lim, Sungmin; Cho, Yee Sook

    2017-06-06

    Schwann cells play a crucial role in successful nerve repair and regeneration by supporting both axonal growth and myelination. However, the sources of human Schwann cells are limited both for studies of Schwann cell development and biology and for the development of treatments for Schwann cell-associated diseases. Here, we provide a rapid and scalable method to produce self-renewing Schwann cell precursors (SCPs) from human pluripotent stem cells (hPSCs), using combined sequential treatment with inhibitors of the TGF-β and GSK-3 signaling pathways, and with neuregulin-1 for 18 days under chemically defined conditions. Within 1 week, hPSC-derived SCPs could be differentiated into immature Schwann cells that were functionally confirmed by their secretion of neurotrophic factors and their myelination capacity in vitro and in vivo. We propose that hPSC-derived SCPs are a promising, unlimited source of functional Schwann cells for treating demyelination disorders and injuries to the peripheral nervous system. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Extracellular ATP inhibits Schwann cell dedifferentiation and proliferation in an ex vivo model of Wallerian degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Youn Ho; Lee, Seo Jin [Department of Anatomy, College of Medicine, Kyung Hee University, Heogi-Dong 1, Dongdaemun-Gu, Seoul 130-701 (Korea, Republic of); Jung, Junyang, E-mail: jjung@khu.ac.kr [Department of Anatomy, College of Medicine, Kyung Hee University, Heogi-Dong 1, Dongdaemun-Gu, Seoul 130-701 (Korea, Republic of)

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer ATP-treated sciatic explants shows the decreased expression of p75NGFR. Black-Right-Pointing-Pointer Extracellular ATP inhibits the expression of phospho-ERK1/2. Black-Right-Pointing-Pointer Lysosomal exocytosis is involved in Schwann cell dedifferentiation. Black-Right-Pointing-Pointer Extracellular ATP blocks Schwann cell proliferation in sciatic explants. -- Abstract: After nerve injury, Schwann cells proliferate and revert to a phenotype that supports nerve regeneration. This phenotype-changing process can be viewed as Schwann cell dedifferentiation. Here, we investigated the role of extracellular ATP in Schwann cell dedifferentiation and proliferation during Wallerian degeneration. Using several markers of Schwann cell dedifferentiation and proliferation in sciatic explants, we found that extracellular ATP inhibits Schwann cell dedifferentiation and proliferation during Wallerian degeneration. Furthermore, the blockage of lysosomal exocytosis in ATP-treated sciatic explants is sufficient to induce Schwann cell dedifferentiation. Together, these findings suggest that ATP-induced lysosomal exocytosis may be involved in Schwann cell dedifferentiation.

  1. SOX10 transactivates S100B to suppress Schwann cell proliferation and to promote myelination.

    Directory of Open Access Journals (Sweden)

    Sayaka Fujiwara

    Full Text Available Schwann cells are an important cell source for regenerative therapy for neural disorders. We investigated the role of the transcription factor sex determining region Y (SRY-box 10 (SOX10 in the proliferation and myelination of Schwann cells. SOX10 is predominantly expressed in rat sciatic nerve-derived Schwann cells and is induced shortly after birth. Among transcription factors known to be important for the differentiation of Schwann cells, SOX10 potently transactivates the S100B promoter. In cultures of Schwann cells, overexpressing SOX10 dramatically induces S100B expression, while knocking down SOX10 with shRNA suppresses S100B expression. Here, we identify three core response elements of SOX10 in the S100B promoter and intron 1 with a putative SOX motif. Knockdown of either SOX10 or S100B enhances the proliferation of Schwann cells. In addition, using dissociated cultures of dorsal root ganglia, we demonstrate that suppressing S100B with shRNA impairs myelination of Schwann cells. These results suggest that the SOX10-S100B signaling axis critically regulates Schwann cell proliferation and myelination, and therefore is a putative therapeutic target for neuronal disorders.

  2. Glial Cells: The Other Cells of the Nervous System-Schwann Cells ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 8. Glial Cells: The Other Cells of the Nervous System - Schwann Cells – Regulators of the Periphery. Yasmin Khan Medha S Rajadhyaksha. Series Article Volume 7 Issue 8 August 2002 pp 8-15 ...

  3. Oriented growth of rat Schwann cells on aligned electrospun poly(methyl methacrylate) nanofibers.

    Science.gov (United States)

    Xia, Haijian; Sun, Xiaochuan; Liu, Dan; Zhou, Yudong; Zhong, Dong

    2016-10-15

    Transplanted Schwann cells have the potential to serve as a support for regenerating neurites after spinal cord injury. However, implanted Schwann cells die off rapidly once transplanted partly owing to the absence of a proper matrix support, with a glia scar and a cavity being present instead at the injury site. For this report, we evaluated aligned electrospun poly(methyl methacrylate) nanofibers as a Schwann cell-loading scaffold in vitro. By monitoring the fluorescence of green fluorescence protein-containing Schwann cells cultured on nanofibers, we found that aligned nanofibers provided better support for the cells than did non-aligned nanofibers. The cells elongated along the long axes of the aligned nanofibers and formed longer cell processes than when the substrate was non-aligned nanofibers. By coculturing Schwann cells with dorsal root ganglion neurons, it was also found that Schwann cells and neurites of dorsal root ganglion neurons could share and both elongate along the orientation of aligned nanofibers and thus they had a higher chance of colocalization than cocultured on film and non-aligned fibers, which might be beneficial to the ensuring process of myelination. The results of the study indicate that aligned electrospun nanofibers may serve as a Schwann cell-loading scaffold for future implantation research. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Myelinating cocultures of rodent stem cell line-derived neurons and immortalized Schwann cells.

    Science.gov (United States)

    Ishii, Tomohiro; Kawakami, Emiko; Endo, Kentaro; Misawa, Hidemi; Watabe, Kazuhiko

    2017-10-01

    Myelination is one of the most remarkable biological events in the neuron-glia interactions for the development of the mammalian nervous system. To elucidate molecular mechanisms of cell-to-cell interactions in myelin synthesis in vitro, establishment of the myelinating system in cocultures of continuous neuronal and glial cell lines are desirable. In the present study, we performed co-culture experiments using rat neural stem cell-derived neurons or mouse embryonic stem (ES) cell-derived motoneurons with immortalized rat IFRS1 Schwann cells to establish myelinating cultures between these cell lines. Differentiated neurons derived from an adult rat neural stem cell line 1464R or motoneurons derived from a mouse ES cell line NCH4.3, were mixed with IFRS1 Schwann cells, plated, and maintained in serum-free F12 medium with B27 supplement, ascorbic acid, and glial cell line-derived neurotrophic factor. Myelin formation was demonstrated by electron microscopy at 4 weeks in cocultures of 1464R-derived neurons or NCH4.3-derived motoneurons with IFRS1 Schwann cells. These in vitro coculture systems utilizing the rodent stable stem and Schwann cell lines can be useful in studies of peripheral nerve development and regeneration. © 2017 Japanese Society of Neuropathology.

  5. cAMP-dependent reorganization of the Cajal bodies and splicing machinery in cultured Schwann cells.

    Science.gov (United States)

    Fernandez, Rosario; Pena, Emma; Navascues, Joaquin; Casafont, Iñigo; Lafarga, Miguel; Berciano, Maria T

    2002-12-01

    It is well established that forskolin-induced elevation of cAMP results in activation of DNA synthesis in Schwann cell cultures. This promitotic response is partially mediated by the Cdk2, which is required for the transition from the G1 to the S phase of the cell cycle. In the present study, we analyze the effects of cAMP elevation in cultured Schwann cells on the transcriptional activity and on the organization of two nuclear compartments involved in pre-mRNA processing: Cajal bodies (CBs) and splicing factor compartments. Our immunofluorescence and quantitative studies show that forskolin treatment induces a 5.6-fold increase in the proportion of S phase Schwann cells, detected by a short pulse (20 min) of BrdU incorporation. This increase in DNA synthesis correlates with an activation of global transcription, as is indicated by the higher nuclear incorporation of BrU in nascent RNA. Forskolin treatment significantly increases the percentage of Schwann cells containing typical CBs, which concentrate spliceosomal snRNPs and the survival motor neuron (SMN) protein. This increase in the number of CBs closely correlates with the activation of transcription. Moreover, the occurrence of CBs is significantly higher in BrdU (+) cells than in BrdU (-) cells, indicating that entry in the S phase promotes the formation of CBs. During the S phase, Schwann cell nuclei display higher Cdk2 nuclear staining and concentrate this kinase in CBs. Forskolin also induces a redistribution of the pre-mRNA splicing factors in Schwann cells. Primary cultures of Schwann cells provide an excellent physiological model to demonstrate that the assembly of CBs is a transcription- and replication-dependent cellular event. Moreover, the S phase accumulation of Cdk2 observed in Schwann cells supports a functional link between CBs and DNA replication, which is mediated by the possible participation of CBs in the regulatory control of histone gene expression. Copyright 2002 Wiley-Liss, Inc.

  6. Behaviour of oligodendrocytes and Schwann cells in an experimental model of toxic demyelination of the central nervous system

    OpenAIRE

    Dominguita Lühers Graça; Eduardo Fernandes Bondan; Luis Antonio Violin Dias Pereira; Cristina Gevehr Fernandes; Paulo César Maiorka

    2001-01-01

    Oligodendrocytes and Schwann cells are engaged in myelin production, maintenance and repairing respectively in the central nervous system (CNS) and the peripheral nervous system (PNS). Whereas oligodendrocytes act only within the CNS, Schwann cells are able to invade the CNS in order to make new myelin sheaths around demyelinated axons. Both cells have some limitations in their activities, i.e. oligodendrocytes are post-mitotic cells and Schwann cells only get into the CNS in the absence of a...

  7. ATP released by injured neurons activates Schwann cells

    Directory of Open Access Journals (Sweden)

    Samuele eNegro

    2016-05-01

    Full Text Available Injured nerve terminals of neuromuscular junctions (NMJs can regenerate. This remarkable and complex response is governed by molecular signals that are exchanged among the cellular components of this synapse: motor axon nerve terminal (MAT, perisynaptic Schwann cells (PSCs, and muscle fibre. The nature of signals that govern MAT regeneration is ill-known. In the present study the spider toxin α-Latrotoxin has been used as tool to investigate the mechanisms underlying peripheral neuroregeneration. Indeed this neurotoxin induces an acute, specific, localized and fully reversible damage of the presynaptic nerve terminal, and its action mimics the cascade of events that leads to nerve terminal degeneration in injured patients and in many neurodegenerative conditions. Here we provide evidence of an early release by degenerating neurons of ATP as alarm messenger, that contributes to the activation of a series of intracellular pathways within SCs that are crucial for nerve regeneration: Ca2+, cAMP, ERK1/2, and CREB. These results contribute to define the cross-talk taking place among degenerating nerve terminals and PSCs, involved in the functional recovery of the NMJ.

  8. Neuronal merlin influences ERBB2 receptor expression on Schwann cells through neuregulin 1 type III signalling.

    Science.gov (United States)

    Schulz, Alexander; Kyselyova, Anna; Baader, Stephan L; Jung, Marie Juliane; Zoch, Ansgar; Mautner, Victor-Felix; Hagel, Christian; Morrison, Helen

    2014-02-01

    Axonal surface proteins encompass a group of heterogeneous molecules, which exert a variety of different functions in the highly interdependent relationship between axons and Schwann cells. We recently revealed that the tumour suppressor protein merlin, mutated in the hereditary tumour syndrome neurofibromatosis type 2, impacts significantly on axon structure maintenance in the peripheral nervous system. We now report on a role of neuronal merlin in the regulation of the axonal surface protein neuregulin 1 important for modulating Schwann cell differentiation and myelination. Specifically, neuregulin 1 type III expression is reduced in sciatic nerve tissue of neuron-specific knockout animals as well as in biopsies from seven patients with neurofibromatosis type 2. In vitro experiments performed on both the P19 neuronal cell line and primary dorsal root ganglion cells demonstrate the influence of merlin on neuregulin 1 type III expression. Moreover, expression of ERBB2, a Schwann cell receptor for neuregulin 1 ligands is increased in nerve tissue of both neuron-specific merlin knockout animals and patients with neurofibromatosis type 2, demonstrating for the first time that axonal merlin indirectly regulates Schwann cell behaviour. Collectively, we have identified that neuronally expressed merlin can influence Schwann cell activity in a cell-extrinsic manner.

  9. Direct Genesis of Functional Rodent and Human Schwann Cells from Skin Mesenchymal Precursors

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    Matthew P. Krause

    2014-07-01

    Full Text Available Recent reports of directed reprogramming have raised questions about the stability of cell lineages. Here, we have addressed this issue, focusing upon skin-derived precursors (SKPs, a dermally derived precursor cell. We show by lineage tracing that murine SKPs from dorsal skin originate from mesenchymal and not neural crest-derived cells. These mesenchymally derived SKPs can, without genetic manipulation, generate functional Schwann cells, a neural crest cell type, and are highly similar at the transcriptional level to Schwann cells isolated from the peripheral nerve. This is not a mouse-specific phenomenon, since human SKPs that are highly similar at the transcriptome level can be made from neural crest-derived facial and mesodermally derived foreskin dermis and the foreskin SKPs can make myelinating Schwann cells. Thus, nonneural crest-derived mesenchymal precursors can differentiate into bona fide peripheral glia in the absence of genetic manipulation, suggesting that developmentally defined lineage boundaries are more flexible than widely thought.

  10. Regulation of retinoid receptors by retinoic acid and axonal contact in Schwann cells.

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    Maria-Jesus Latasa

    Full Text Available BACKGROUND: Schwann cells (SCs are the cell type responsible for the formation of the myelin sheath in the peripheral nervous system (PNS. As retinoic acid (RA and other retinoids have a profound effect as regulators of the myelination program, we sought to investigate how their nuclear receptors levels were regulated in this cell type. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, by using Schwann cells primary cultures from neonatal Wistar rat pups, as well as myelinating cocultures of Schwann cells with embryonic rat dorsal root ganglion sensory neurons, we have found that sustained expression of RXR-γ depends on the continuous presence of a labile activator, while axonal contact mimickers produced an increase in RXR-γ mRNA and protein levels, increment that could be prevented by RA. The upregulation by axonal contact mimickers and the transcriptional downregulation by RA were dependent on de novo protein synthesis and did not involve changes in mRNA stability. On the other hand, RAR-β mRNA levels were only slightly modulated by axonal contact mimickers, while RA produced a strong transcriptional upregulation that was independent of de novo protein synthesis without changes in mRNA stability. CONCLUSIONS/SIGNIFICANCE: All together, our results show that retinoid receptors are regulated in a complex manner in Schwann cells, suggesting that they could have a prominent role as regulators of Schwann cell physiology.

  11. Interleukin-17 impedes Schwann cell-mediated myelination

    Science.gov (United States)

    2014-01-01

    Background Pro-inflammatory cytokines are known to have deleterious effects on Schwann cells (SCs). Interleukin 17 (IL-17) is a potent pro-inflammatory cytokine that exhibits relevant effects during inflammation in the peripheral nervous system (PNS), and IL-17-secreting cells have been reported within the endoneurium in proximity to the SCs. Methods Here, we analyzed the effects of IL-17 on myelination and the immunological properties of SCs. Dorsal root ganglia (DRG) co-cultures containing neurons and SCs from BL6 mice were used to define the impact of IL-17 on myelination and on SC differentiation; primary SCs were analyzed for RNA and protein expression to define the putative immunological alignment of the SCs. Results SCs were found to functionally express the IL-17 receptors A and B. In DRG cultures, stimulation with IL-17 resulted in reduced myelin synthesis, while pro-myelin gene expression was suppressed at the mRNA level. Neuronal outgrowth and SC viability, as well as structural myelin formation, remained unaffected. Co-cultures exhibited SC-relevant pro-inflammatory markers, such as matrix metalloproteinase 9 and SCs significantly increased the expression of the major histocompatibility complex (MHC) I and exhibited a slight, nonsignificant increase in expression of MHCII, and a transporter associated with antigen presentation (TAP) II molecules relevant for antigen processing and presentation. Conclusions IL-17 may act as a myelin-suppressive mediator in the peripheral nerve, directly propagating SC-mediated demyelination, paralleled by an inflammatory alignment of the SCs. Further analyses are warranted to elucidate the role of IL-17 during inflammation in the PNS in vivo, which could be useful in the development of target therapies. PMID:24678820

  12. SncRNA715 Inhibits Schwann Cell Myelin Basic Protein Synthesis.

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    Christina Müller

    Full Text Available Myelin basic proteins (MBP are major constituents of the myelin sheath in the central nervous system (CNS and the peripheral nervous system (PNS. In the CNS Mbp translation occurs locally at the axon-glial contact site in a neuronal activity-dependent manner. Recently we identified the small non-coding RNA 715 (sncRNA715 as a key inhibitor of Mbp translation during transport in oligodendrocytes. Mbp mRNA localization in Schwann cells has been observed, but has not been investigated in much detail. Here we could confirm translational repression of Mbp mRNA in Schwann cells. We show that sncRNA715 is expressed and its levels correlate inversely with MBP in cultured Schwann cells and in the sciatic nerve in vivo. Furthermore we could reduce MBP protein levels in cultured Schwann cells by increasing the levels of the inhibitory sncRNA715. Our findings suggest similarities in sncRNA715-mediated translational repression of Mbp mRNA in oligodendrocytes and Schwann cells.

  13. Hyperbaric oxygen therapy combined with Schwann cell transplantation promotes spinal cord injury recovery

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    Chuan-gang Peng

    2015-01-01

    Full Text Available Schwann cell transplantation and hyperbaric oxygen therapy each promote recovery from spinal cord injury, but it remains unclear whether their combination improves therapeutic results more than monotherapy. To investigate this, we used Schwann cell transplantation via the tail vein, hyperbaric oxygen therapy, or their combination, in rat models of spinal cord contusion injury. The combined treatment was more effective in improving hindlimb motor function than either treatment alone; injured spinal tissue showed a greater number of neurite-like structures in the injured spinal tissue, somatosensory and motor evoked potential latencies were notably shorter, and their amplitudes greater, after combination therapy than after monotherapy. These findings indicate that Schwann cell transplantation combined with hyperbaric oxygen therapy is more effective than either treatment alone in promoting the recovery of spinal cord in rats after injury.

  14. The Comparison of Schwann Cells Transplantation Effect with Autograft Model in Peripheral Nerve Regeneration in Animal Model

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    Sam Zarbakhsh

    2016-11-01

    Full Text Available Background: Transplantation of Schwann cells can facilitate the regeneration of peripheral nerves. The aim of this study was to comparison of Schwann cells transplantation effect with autograft model in peripheral nerve regeneration in animal model. Materials and Methods: 20 male Wistar rats were randomly were divided into 3 groups: control, Schwann cells transplantation and autograft model. In the control group, a 10 mm segment of the left sciatic nerve was removed and a silicone tube replaced into this nerve gap. In the Schwann cells transplantation group, after placing the silicone tube were transplanted into the tubeabout 500,000 Schwann cells. In the autograft model group, 10 mm segment of the left sciatic nerve is removed and it was implanted to the two nerve endings after reversing. 12 weeks after surgery we evaluated the number of axons, the number of blood vessels and the restored myelin sheath thickness. Results: Histological analysis by using one way ANOVA showed that the number of axons and the thickness of myelin sheath in autograft model group was significantly greater than the other groups, and in the Schwann cells transplantation group was significantly greater than the control group. Moreover, the number of restored blood vessels in the Schwann cells transplantation group was significantly greater than the other groups (P<0.05. Conclusion: The results show that Schwann cells transplantation is effective in peripheral nerve regeneration and it may be a good alternative to autograft method.

  15. mTORC1 promotes proliferation of immature Schwann cells and myelin growth of differentiated Schwann cells

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    Milbrandt, Jeffrey

    2017-01-01

    The myelination of axons in peripheral nerves requires precisely coordinated proliferation and differentiation of Schwann cells (SCs). We found that the activity of the mechanistic target of rapamycin complex 1 (mTORC1), a key signaling hub for the regulation of cellular growth and proliferation, is progressively extinguished as SCs differentiate during nerve development. To study the effects of different levels of sustained mTORC1 hyperactivity in the SC lineage, we disrupted negative regulators of mTORC1, including TSC2 or TSC1, in developing SCs of mutant mice. Surprisingly, the phenotypes ranged from arrested myelination in nerve development to focal hypermyelination in adulthood, depending on the level and timing of mTORC1 hyperactivity. For example, mice lacking TSC2 in developing SCs displayed hyperproliferation of undifferentiated SCs incompatible with normal myelination. However, these defects and myelination could be rescued by pharmacological mTORC1 inhibition. The subsequent reconstitution of SC mTORC1 hyperactivity in adult animals resulted in focal hypermyelination. Together our data suggest a model in which high mTORC1 activity promotes proliferation of immature SCs and antagonizes SC differentiation during nerve development. Down-regulation of mTORC1 activity is required for terminal SC differentiation and subsequent initiation of myelination. In distinction to this developmental role, excessive SC mTORC1 activity stimulates myelin growth, even overgrowth, in adulthood. Thus, our work delineates two distinct functions of mTORC1 in the SC lineage essential for proper nerve development and myelination. Moreover, our studies show that SCs retain their plasticity to myelinate and remodel myelin via mTORC1 throughout life. PMID:28484008

  16. Platelet-rich plasma gel in combination with Schwann cells for repair of sciatic nerve injury☆

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    Ye, Fagang; Li, Haiyan; Qiao, Guangxi; Chen, Feng; Tao, Hao; Ji, Aiyu; Hu, Yanling

    2012-01-01

    Bone marrow mesenchymal stem cells were isolated from New Zealand white rabbits, culture-expanded and differentiated into Schwann cell-like cells. Autologous platelet-rich plasma and Schwann cell-like cells were mixed in suspension at a density of 1 × 106 cells/mL, prior to introduction into a poly (lactic-co-glycolic acid) conduit. Fabricated tissue-engineered nerves were implanted into rabbits to bridge 10 mm sciatic nerve defects (platelet-rich plasma group). Controls were established using fibrin as the seeding matrix for Schwann cell-like cells at identical density to construct tissue-engineered nerves (fibrin group). Twelve weeks after implantation, toluidine blue staining and scanning electron microscopy were used to demonstrate an increase in the number of regenerating nerve fibers and thickness of the myelin sheath in the platelet-rich plasma group compared with the fibrin group. Fluoro-gold retrograde labeling revealed that the number of Fluoro-gold-positive neurons in the dorsal root ganglion and the spinal cord anterior horn was greater in the platelet-rich plasma group than in the fibrin group. Electrophysiological examination confirmed that compound muscle action potential and nerve conduction velocity were superior in the platelet-rich plasma group compared with the fibrin group. These results indicate that autologous platelet-rich plasma gel can effectively serve as a seeding matrix for Schwann cell-like cells to construct tissue-engineered nerves to promote peripheral nerve regeneration. PMID:25538751

  17. Neural stem cells promote nerve regeneration through IL12-induced Schwann cell differentiation.

    Science.gov (United States)

    Lee, Don-Ching; Chen, Jong-Hang; Hsu, Tai-Yu; Chang, Li-Hsun; Chang, Hsu; Chi, Ya-Hui; Chiu, Ing-Ming

    2017-03-01

    Regeneration of injured peripheral nerves is a slow, complicated process that could be improved by implantation of neural stem cells (NSCs) or nerve conduit. Implantation of NSCs along with conduits promotes the regeneration of damaged nerve, likely because (i) conduit supports and guides axonal growth from one nerve stump to the other, while preventing fibrous tissue ingrowth and retaining neurotrophic factors; and (ii) implanted NSCs differentiate into Schwann cells and maintain a growth factor enriched microenvironment, which promotes nerve regeneration. In this study, we identified IL12p80 (homodimer of IL12p40) in the cell extracts of implanted nerve conduit combined with NSCs by using protein antibody array and Western blotting. Levels of IL12p80 in these conduits are 1.6-fold higher than those in conduits without NSCs. In the sciatic nerve injury mouse model, implantation of NSCs combined with nerve conduit and IL12p80 improves motor recovery and increases the diameter up to 4.5-fold, at the medial site of the regenerated nerve. In vitro study further revealed that IL12p80 stimulates the Schwann cell differentiation of mouse NSCs through the phosphorylation of signal transducer and activator of transcription 3 (Stat3). These results suggest that IL12p80 can trigger Schwann cell differentiation of mouse NSCs through Stat3 phosphorylation and enhance the functional recovery and the diameter of regenerated nerves in a mouse sciatic nerve injury model. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Spatiotemporal distribution and function of N-cadherin in postnatal Schwann cells: A matter of adhesion?

    DEFF Research Database (Denmark)

    Corell, Mikael; Wicher, Grzegorz; Limbach, Christoph

    2010-01-01

    During embryonic development of the peripheral nervous system (PNS), the adhesion molecule neuronal cadherin (N-cadherin) is expressed by Schwann cell precursors and associated with axonal growth cones. N-cadherin expression levels decrease as precursors differentiate into Schwann cells....... In this study, we investigated the distribution of N-cadherin in the developing postnatal and adult rat peripheral nervous system. N-cadherin was found primarily in ensheathing glia throughout development, concentrated at neuron-glial or glial-glial contacts of the sciatic nerve, dorsal root ganglia (DRG...

  19. Myosin-Va-dependent cell-to-cell transfer of RNA from Schwann cells to axons.

    Science.gov (United States)

    Sotelo, José R; Canclini, Lucía; Kun, Alejandra; Sotelo-Silveira, José R; Xu, Lei; Wallrabe, Horst; Calliari, Aldo; Rosso, Gonzalo; Cal, Karina; Mercer, John A

    2013-01-01

    To better understand the role of protein synthesis in axons, we have identified the source of a portion of axonal RNA. We show that proximal segments of transected sciatic nerves accumulate newly-synthesized RNA in axons. This RNA is synthesized in Schwann cells because the RNA was labeled in the complete absence of neuronal cell bodies both in vitro and in vivo. We also demonstrate that the transfer is prevented by disruption of actin and that it fails to occur in the absence of myosin-Va. Our results demonstrate cell-to-cell transfer of RNA and identify part of the mechanism required for transfer. The induction of cell-to-cell RNA transfer by injury suggests that interventions following injury or degeneration, particularly gene therapy, may be accomplished by applying them to nearby glial cells (or implanted stem cells) at the site of injury to promote regeneration.

  20. Early regenerative effects of NGF-transduced Schwann cells in peripheral nerve repair

    NARCIS (Netherlands)

    Shakhbazau, A.; Kawasoe, J.; Hoyng, S.A.; Kumar, R.; van Minnen, J.; Verhaagen, J.; Midha, R.

    2012-01-01

    Peripheral nerve injury leads to a rapid and robust increase in the synthesis of neurotrophins which guide and support regenerating axons. To further optimize neurotrophin supply at the earliest stages of regeneration, we over-expressed NGF in Schwann cells (SCs) by transducing these cells with a

  1. A suspended carbon fiber culture to model myelination by human Schwann cells.

    Science.gov (United States)

    Merolli, Antonio; Mao, Yong; Kohn, Joachim

    2017-04-01

    Understanding of myelination/remyelination process is essential to guide tissue engineering for nerve regeneration. In vitro models currently used are limited to cell population studies and cannot easily identify individual cell contribution to the process. We established a novel model to study the contribution of human Schwann cells to the myelination process. The model avoids the presence of neurons in culture; Schwann cells respond solely to the biophysical properties of an artificial axon. The model uses a single carbon fiber suspended in culture media far from the floor of the well. The fiber provides an elongated structure of defined diameter with 360-degree of surface available for human Schwann cells to wrap around. This model enabled us to spatially and temporally track the myelination by individual Schwann cells along the fiber. We observed cell attachment, elongation and wrapping over a period of 9 days. Cells remained alive and expressed Myelin Basic Protein and Myelin Associated Glycoprotein as expected. Natural and artificial molecules, and external physical factors (e.g., p atterned electrical impulses), may be tested with this model as possible regulators of myelination.

  2. Sulfatase-mediated manipulation of the astrocyte-Schwann cell interface

    NARCIS (Netherlands)

    O'Neill, Paul; Lindsay, Susan L; Pantiru, Andreea; Guimond, Scott E; Fagoe, N.D.; Verhaagen, J.; Turnbull, Jeremy E; Riddell, John S; Barnett, Susan C

    2017-01-01

    Schwann cell (SC) transplantation following spinal cord injury (SCI) may have therapeutic potential. Functional recovery is limited however, due to poor SC interactions with host astrocytes and the induction of astrogliosis. Olfactory ensheathing cells (OECs) are closely related to SCs, but intermix

  3. Fabrication of Aligned Carbon Nanotube/Polycaprolactone/Gelatin Nanofibrous Matrices for Schwann Cell Immobilization

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    Shiao-Wen Tsai

    2014-01-01

    Full Text Available In this study, we utilized a mandrel rotating collector consisting of two parallel, electrically conductive pieces of tape to fabricate aligned electrospun polycaprolactone/gelatin (PG and carbon nanotube/polycaprolactone/gelatin (PGC nanofibrous matrices. Furthermore, we examined the biological performance of the PGC nanofibrous and film matrices using an in vitro culture of RT4-D6P2T rat Schwann cells. Using cell adhesion tests, we found that carbon nanotube inhibited Schwann cell attachment on PGC nanofibrous and film matrices. However, the proliferation rates of Schwann cells were higher when they were immobilized on PGC nanofibrous matrices compared to PGC film matrices. Using western blot analysis, we found that NRG1 and P0 protein expression levels were higher for cells immobilized on PGC nanofibrous matrices compared to PG nanofibrous matrices. However, the carbon nanotube inhibited NRG1 and P0 protein expression in cells immobilized on PGC film matrices. Moreover, the NRG1 and P0 protein expression levels were higher for cells immobilized on PGC nanofibrous matrices compared to PGC film matrices. We found that the matrix topography and composition influenced Schwann cell behavior.

  4. Ectopic expression of polysialylated neural cell adhesion molecule in adult macaque Schwann cells promotes their migration and remyelination potential in the central nervous system.

    Science.gov (United States)

    Bachelin, C; Zujovic, V; Buchet, D; Mallet, J; Baron-Van Evercooren, A

    2010-02-01

    Recent findings suggested that inducing neural cell adhesion molecule polysialylation in rodents is a promising strategy for promoting tissue repair in the injured central nervous system. Since autologous grafting of Schwann cells is one potential strategy to promote central nervous system remyelination, it is essential to show that such a strategy can be translated to adult primate Schwann cells and is of interest for myelin diseases. Adult macaque Schwann cells were transduced with a lentiviral vector encoding sialyltransferase, an enzyme responsible for neural cell adhesion molecule polysialylation. In vitro, we found that ectopic expression of polysialylate promoted adult macaque Schwann cell migration and improved their integration among astrocytes in vitro without modifying their antigenic properties as either non-myelinating or pro-myelinating. In addition, forced expression of polysialylate in adult macaque Schwann cells decreased their adhesion with sister cells. To investigate the ability of adult macaque Schwann cells to integrate and migrate in vivo, focally induced demyelination was targeted to the spinal cord dorsal funiculus of nude mice, and both control and sialyltransferase expressing Schwann cells overexpressing green fluorescein protein were grafted remotely from the lesion site. Analysis of the spatio-temporal distribution of the grafted Schwann cells performed in toto and in situ, showed that in both groups, Schwann cells migrated towards the lesion site. However, migration of sialyltransferase expressing Schwann cells was more efficient than that of control Schwann cells, leading to their accelerated recruitment by the lesion. Moreover, ectopic expression of polysialylated neural cell adhesion molecule promoted adult macaque Schwann cell interaction with reactive astrocytes when exiting the graft, and their 'chain-like' migration along the dorsal midline. The accelerated migration of sialyltransferase expressing Schwann cells to the lesion

  5. The POU proteins Brn-2 and Oct-6 share important functions in Schwann cell development.

    NARCIS (Netherlands)

    M.M. Jaegle (Martine); M. Ghazvini (Mehrnaz); W.J. Mandemakers (Wim); M. Piirsoo (Marko); S. Driegen (Siska); F. Levavasseur (Francoise); S. Raghoenath; F.G. Grosveld (Frank); D. Meijer (Daniëlle)

    2003-01-01

    textabstractThe genetic hierarchy that controls myelination of peripheral nerves by Schwann cells includes the POU domain Oct-6/Scip/Tst-1and the zinc-finger Krox-20/Egr2 transcription factors. These pivotal transcription factors act to control the onset of myelination during

  6. Regulation of Schwann cell proliferation in cultured segments of the adult rat sciatic nerve

    DEFF Research Database (Denmark)

    Svenningsen, Åsa Fex; Kanje, M

    1998-01-01

    of Schwann cells. Removal of extracellular Ca2+ by addition of EGTA to the culture medium suppressed [3H] thymidine incorporation as did the calmodulin inhibitor 48/80. The Ca2+ ionophore A23187 increased incorporation. Staurosporin, an inhibitor of protein kinase C (PKC), suppressed [3H] thymidine...

  7. Lentivirus-Mediated RNA Interference Targeting RhoA Slacks the Migration, Proliferation, and Myelin Formation of Schwann Cells.

    Science.gov (United States)

    Wen, Jinkun; Qian, Changhui; Pan, Mengjie; Wang, Xianghai; Li, Yuanyuan; Lu, Yanmeng; Zhou, Zhitao; Yan, Qing; Li, Lixia; Liu, Zhongying; Wu, Wutian; Guo, Jiasong

    2017-03-01

    RhoA, a member of Rho GTPases family, is known to play an important role in remodeling actin cytoskeleton. During the development of the peripheral nervous system (PNS), Schwann cells undergo proliferation, migration, and radial sorting and finally wrap the related axons compactly to form myelin sheath. All these processes involve actin cytoskeletal remodeling. However, the role of RhoA on Schwann cell during development is still unclear. To address this question, we first used a lentiviral vector-mediated short hairpin (sh) RNA targeting RhoA to knock down the expression of RhoA in the cultured Schwann cells in vitro. Effects of RhoA on Schwann cell proliferation and migration were examined by BrdU assay and transwell assay, respectively. Results of the present study indicated that downregulated RhoA expression in cultured Schwann cells significantly slacked the cells' capabilities of migration and proliferation. Then, we investigated the role of RhoA in the developing rat sciatic nerves. Immunohistology and Western blotting showed that RhoA was mainly expressed in Schwann cells in the sciatic nerves and was peaked at 2 weeks postnatal then kept in low level up to 8 weeks. In the subjected rats whose sciatic nerves were microinjected with lentiviral vectors at postnatal 3 days, we found that the lentiviruses mainly transfected Schwann cells, and the RhoA expression in the transfected Schwann cells was significantly knocked down. Four weeks after lentivirus microinjection, immunohistology and transmission electron microscopy illustrated that RhoA knockdown resulted in hypomyelination and significant decrease of the thickness of myelin in the transfected area. Overall data of current study suggested that RhoA plays a critical role in Schwann cell biology and is essential for myelination in developing peripheral nerve.

  8. Suspension Matrices for Improved Schwann-Cell Survival after Implantation into the Injured Rat Spinal Cord

    Science.gov (United States)

    Patel, Vivek; Joseph, Gravil; Patel, Amit; Patel, Samik; Bustin, Devin; Mawson, David; Tuesta, Luis M.; Puentes, Rocio; Ghosh, Mousumi

    2010-01-01

    Abstract Trauma to the spinal cord produces endogenously irreversible tissue and functional loss, requiring the application of therapeutic approaches to achieve meaningful restoration. Cellular strategies, in particular Schwann-cell implantation, have shown promise in overcoming many of the obstacles facing successful repair of the injured spinal cord. Here, we show that the implantation of Schwann cells as cell suspensions with in-situ gelling laminin:collagen matrices after spinal-cord contusion significantly enhances long-term cell survival but not proliferation, as well as improves graft vascularization and the degree of axonal in-growth over the standard implantation vehicle, minimal media. The use of a matrix to suspend cells prior to implantation should be an important consideration for achieving improved survival and effectiveness of cellular therapies for future clinical application. PMID:20144012

  9. The influence of electrospun fibre size on Schwann cell behaviour and axonal outgrowth

    Energy Technology Data Exchange (ETDEWEB)

    Gnavi, S., E-mail: sara.gnavi@unito.it [Department of Clinical and Biological Sciences, University of Torino, Orbassano 10043 (Italy); Neuroscience Institute of the Cavalieri-Ottolenghi Foundation, University of Torino, Orbassano 10043 (Italy); Fornasari, B.E., E-mail: benedettaelena.fornasari@unito.it [Department of Clinical and Biological Sciences, University of Torino, Orbassano 10043 (Italy); Neuroscience Institute of the Cavalieri-Ottolenghi Foundation, University of Torino, Orbassano 10043 (Italy); Tonda-Turo, C., E-mail: chiara.tondaturo@polito.it [Politecnico di Torino, Department of Mechanical and Aerospace Engineering, Politecnico of Torino, Torino 10100 (Italy); Ciardelli, G., E-mail: gianluca.ciardelli@polito.it [Politecnico di Torino, Department of Mechanical and Aerospace Engineering, Politecnico of Torino, Torino 10100 (Italy); CNR-IPCF UOS, Pisa 56124 (Italy); Zanetti, M., E-mail: marco.zanetti@unito.it [Nanostructured Interfaces and Surfaces, Department of Chemistry, University of Torino, Torino 10100 (Italy); Geuna, S., E-mail: stefano.geuna@unito.it [Department of Clinical and Biological Sciences, University of Torino, Orbassano 10043 (Italy); Neuroscience Institute of the Cavalieri-Ottolenghi Foundation, University of Torino, Orbassano 10043 (Italy); Perroteau, I., E-mail: isabelle.perroteau@unito.it [Department of Clinical and Biological Sciences, University of Torino, Orbassano 10043 (Italy)

    2015-03-01

    Fibrous substrates functioning as temporary extracellular matrices can be prepared easily by electrospinning, yielding fibrous matrices suitable as internal fillers for nerve guidance channels. In this study, gelatin micro- or nano-fibres were prepared by electrospinning by tuning the gelatin concentration and solution flow rate. The effect of gelatin fibre diameter on cell adhesion and proliferation was tested in vitro using explant cultures of Schwann cells (SC) and dorsal root ganglia (DRG). Cell adhesion was assessed by quantifying the cell spreading area, actin cytoskeleton organization and focal adhesion complex formation. Nano-fibres promoted cell spreading and actin cytoskeleton organization, increasing cellular adhesion and the proliferation rate. However, both migration rate and motility, quantified by transwell and time lapse assays respectively, were greater in cells cultured on micro-fibres. Finally, there was more DRG axon outgrowth on micro-fibres. These data suggest that the topography of electrospun gelatin fibres can be adjusted to modulate SC and axon organization and that both nano- and micro-fibres are promising fillers for the design of devices for peripheral nerve repair. - Highlights: • Electrospinning used to produce gelatin nano- and micro-fibre matrices. • Nano-fibre matrices promote Schwann cell organization and increase proliferation rate. • Micro-fibre matrices promote Schwann cell migration. • Micro-fibre matrices promote axonal outgrowth.

  10. Two factor-based reprogramming of rodent and human fibroblasts into Schwann cells

    Science.gov (United States)

    Mazzara, Pietro Giuseppe; Massimino, Luca; Pellegatta, Marta; Ronchi, Giulia; Ricca, Alessandra; Iannielli, Angelo; Giannelli, Serena Gea; Cursi, Marco; Cancellieri, Cinzia; Sessa, Alessandro; Del Carro, Ubaldo; Quattrini, Angelo; Geuna, Stefano; Gritti, Angela; Taveggia, Carla; Broccoli, Vania

    2017-01-01

    Schwann cells (SCs) generate the myelin wrapping of peripheral nerve axons and are promising candidates for cell therapy. However, to date a renewable source of SCs is lacking. In this study, we show the conversion of skin fibroblasts into induced Schwann cells (iSCs) by driving the expression of two transcription factors, Sox10 and Egr2. iSCs resembled primary SCs in global gene expression profiling and PNS identity. In vitro, iSCs wrapped axons generating compact myelin sheaths with regular nodal structures. Conversely, iSCs from Twitcher mice showed a severe loss in their myelinogenic potential, demonstrating that iSCs can be an attractive system for in vitro modelling of PNS diseases. The same two factors were sufficient to convert human fibroblasts into iSCs as defined by distinctive molecular and functional traits. Generating iSCs through direct conversion of somatic cells offers opportunities for in vitro disease modelling and regenerative therapies. PMID:28169300

  11. Development of a Functional Schwann Cell Phenotype from Autologous Porcine Bone Marrow Mononuclear Cells for Nerve Repair

    Directory of Open Access Journals (Sweden)

    Michael J. Rutten

    2012-01-01

    Full Text Available Adult bone marrow mononuclear cells (BM-MNCs are a potential resource for making Schwann cells to repair damaged peripheral nerves. However, many methods of producing Schwann-like cells can be laborious with the cells lacking a functional phenotype. The objective of this study was to develop a simple and rapid method using autologous BM-MNCs to produce a phenotypic and functional Schwann-like cell. Adult porcine bone marrow was collected and enriched for BM-MNCs using a SEPAX device, then cells cultured in Neurobasal media, 4 mM L-glutamine and 20% serum. After 6–8 days, the cultures expressed Schwann cell markers, S-100, O4, GFAP, were FluoroMyelin positive, but had low p75(NGF expression. Addition of neuregulin (1–25 nM increased p75(NGF levels at 24–48 hrs. We found ATP dose-dependently increased intracellular calcium [Ca2+]i, with nucleotide potency being UTP=ATP>ADP>AMP>adenosine. Suramin blocked the ATP-induced [Ca2+]i but α, β,-methylene-ATP had little effect suggesting an ATP purinergic P2Y2 G-protein-coupled receptor is present. Both the Schwann cell markers and ATP-induced [Ca2+]i sensitivity decreased in cells passaged >20 times. Our studies indicate that autologous BM-MNCs can be induced to form a phenotypic and functional Schwann-like cell which could be used for peripheral nerve repair.

  12. [Phenotypic plasticity of neural crest-derived melanocytes and Schwann cells].

    Science.gov (United States)

    Dupin, Elisabeth

    2011-01-01

    Melanocytes, the pigmented cells of the skin, and the glial Schwann cells lining peripheral nerves are developmentally derived from an early and transient ectodermal structure of the vertebrate embryo, the neural crest, which is also at the origin of multiple neural and non-neural cell types. Besides melanocytes and neural cells of the peripheral nervous system, the neural crest cells give rise to mesenchymal cell types in the head, which form most of the craniofacial skeleton, dermis, fat tissue and vascular musculo-connective components. How such a wide diversity of differentiation fates is established during embryogenesis and is later maintained in adult tissues are among key questions in developmental and stem cell biology. The analysis of the developmental potentials of single neural crest cells cultured in vitro led to characterizing multipotent stem/progenitor cells as well as more restricted precursors in the early neural crest of avian and mammalian embryos. Data support a hierarchical model of the diversification of neural crest lineages through progressive restrictions of multipotent stem cell potentials driven by local environmental factors. In particular, melanocytes and glial Schwann cells were shown to arise from a common bipotent progenitor, which depends upon the peptide endothelin-3 for proliferation and self-renewal ability. In vivo, signaling by endothelin-3 and its receptor is also required for the early development of melanocytes and proper pigmentation of the vertebrate body. It is generally assumed that, after lineage specification and terminal differentiation, specialized cell types, like the melanocytes and Schwann cells, do not change their identity. However, this classic notion that somatic cell differentiation is a stable and irreversible process has been challenged by emerging evidence that dedifferentiation can occur in different biological systems through nuclear transfer, cell fusion, epigenetic modifications and ectopic gene

  13. Merlin knockdown in human Schwann cells: clues to vestibular schwannoma tumorigenesis.

    Science.gov (United States)

    Ahmad, Zana; Brown, Carrie Maiorana; Patel, Andrew K; Ryan, Allen F; Ongkeko, Rutherford; Doherty, Joni K

    2010-04-01

    To investigate the early events in molecular progression toward schwannoma tumorigenesis, we developed an in vitro model of human Schwann cell tumorigenesis by merlin knockdown. Neurofibromatosis 2 (NF2)-related and sporadic vestibular schwannoma (VS) exhibit loss of functional merlin (schwannomin). After loss of merlin expression in the Schwann cell, the initial steps toward VS tumorigenesis are unknown. Merlin, a putative tumor suppressor protein, interacts with many cellular proteins, regulating their function. Among these are receptor tyrosine kinases, including the epidermal growth factor receptor family B (ErbB) family receptors epidermal growth factor receptor and ErbB2. Functional merlin interacts with and internalizes these growth factor receptors, silencing their proliferation and survival signaling. Deregulation of CD44, the cell adhesion/signaling molecule and cancer stem cell marker, has also been implicated in VS tumorigenesis. Merlin knockdown was performed using small interfering RNA transfection into human Schwann cell primary cultures. Knockdown was confirmed by real-time quantitative PCR, immunofluorescence, and Western analysis. Expression profiles of ErbB, merlin, and the stem cell markers nestin and CD44 were examined in knockdowns. Proliferation rate was assessed with bromodeoxyuridine incorporation, and radiation sensitivity was assessed using the Annexin assay in knockdowns versus controls. Merlin knockdowns demonstrated increased proliferation rate, upregulation of epidermal growth factor receptor, ErbB2, and ErbB3, CD44, and nestin. Short-term merlin depletion had no effect on gamma irradiation sensitivity compared with controls. Merlin depletion results in deregulation of ErbB receptor signaling, promotes a dedifferentiated state, and increases Schwann cell proliferation, suggesting critical steps toward schwannoma tumorigenesis.

  14. Schwann cell expression of an oligodendrocyte-like remyelinating pattern after ethidium bromide injection in the rat spinal cord

    OpenAIRE

    Eduardo Fernandes Bondan; Maria Anete Lallo; Maria de Fátima Monteiro Martins; Dominguita Luhers Graça

    2010-01-01

    Schwann cells are recognized by their capacity of producing single internodes of myelin around axons of the peripheral nervous system. In the ethidium bromide (EB) model of primary demyelination in the brainstem, it is observed the entry of Schwann cells into the central nervous system in order to contribute to the myelin repair performed by the oligodendrocytes that survived to the EB gliotoxic action, being able to even remyelinate more than one axon at the same time, in a pattern of repair...

  15. miR-30c promotes Schwann cell remyelination following peripheral nerve injury

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    Sheng Yi

    2017-01-01

    Full Text Available Differential expression of miRNAs occurs in injured proximal nerve stumps and includes miRNAs that are firstly down-regulated and then gradually up-regulated following nerve injury. These miRNAs might be related to a Schwann cell phenotypic switch. miR-30c, as a member of this group, was further investigated in the current study. Sprague-Dawley rats underwent sciatic nerve transection and proximal nerve stumps were collected at 1, 4, 7, 14, 21, and 28 days post injury for analysis. Following sciatic nerve injury, miR-30c was down-regulated, reaching a minimum on day 4, and was then upregulated to normal levels. Schwann cells were isolated from neonatal rat sciatic nerve stumps, then transfected with miR-30c agomir and co-cultured in vitro with dorsal root ganglia. The enhanced expression of miR-30c robustly increased the amount of myelin-associated protein in the co-cultured dorsal root ganglia and Schwann cells. We then modeled sciatic nerve crush injury in vivo in Sprague-Dawley rats and tested the effect of perineural injection of miR-30c agomir on myelin sheath regeneration. Fourteen days after surgery, sciatic nerve stumps were harvested and subjected to immunohistochemistry, western blot analysis, and transmission electron microscopy. The direct injection of miR-30c stimulated the formation of myelin sheath, thus contributing to peripheral nerve regeneration. Overall, our findings indicate that miR-30c can promote Schwann cell myelination following peripheral nerve injury. The functional study of miR-30c will benefit the discovery of new therapeutic targets and the development of new treatment strategies for peripheral nerve regeneration.

  16. Lipoamide Inhibits NF1 Deficiency-induced Epithelial-Mesenchymal Transition in Murine Schwann Cells.

    Science.gov (United States)

    Zhang, Yuchen; Zhou, Rongsheng; Qu, Yiping; Shu, Maoguo; Guo, Shuzhong; Bai, Zhuanli

    2017-11-29

    Neurofibromatosis type I (NF1) is one of the most common neurocutaneous syndromes characterized by development of adult neurofibromas which is mainly made up of Schwann cells. The disease is generally accepted to be caused by inactivation mutation of Nf1 gene. And Nf1 deficiency had been reported to lead to ROS overproduction and epithelial-mesenchymal transition (EMT) phenotype. This study was designed to investigate whether excessive ROS conferred to Nf1 deficiency-induced EMT in Schwann cells. Colony formation, wound healing assay and transwell assay was used to evaluate the effects of stable Nf1 knockdown in SW10 Schwann cells. Western blot and ROS assay was conducted to explore the molecular mechanisms of Nf1 inactivation in tumorigenesis. Animal experiments were performed to assess the inhibitory effects of lipoamide, which is the neutral amide of α-lipoic acid and functions as a potent antioxidant to scavenge ROS, on Nf1-deficiency tumor growth in vivo. Nf1 knockdown enhanced the cellular capacities of proliferation, migration and invasion, promoted ROS generation, decreased the expression of epithelial surface marker E-cadherin, and up-regulated several EMT-associated molecules in Schwann cells. Moreover, lipoamide dose-dependently inhibited not only Nf1 deficiency-induced EMT but also spontaneous EMT. Furthermore, lipoamide markedly suppresses tumor growth in a mouse model of NF1-associated neurofibroma. Our results clearly reveal that ROS overproduction is responsible for Nf1 deficiency-induced EMT and plays a crucial role in NF1 tumor growth. The findings presented herein shed light on the potential of antioxidant therapy to prevent the progression of NF1-associated neurofibroma. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  17. Age-Dependent Schwann Cell Phenotype Regulation Following Peripheral Nerve Injury.

    Science.gov (United States)

    Chen, Wayne A; Luo, T David; Barnwell, Jonathan C; Smith, Thomas L; Li, Zhongyu

    2017-12-01

    Schwann cells are integral to the regenerative capacity of the peripheral nervous system, which declines after adolescence. The mechanisms underlying this decline are poorly understood. This study sought to compare the protein expression of Notch, c-Jun, and Krox-20 after nerve crush injury in adolescent and young adult rats. We hypothesized that these Schwann cell myelinating regulatory factors are down-regulated after nerve injury in an age-dependent fashion. Adolescent (2 months old) and young adult (12 months old) rats (n = 48) underwent sciatic nerve crush injury. Protein expression of Notch, c-Jun, and Krox-20 was quantified by Western blot analysis at 1, 3, and 7 days post-injury. Functional recovery was assessed in a separate group of animals (n = 8) by gait analysis (sciatic functional index) and electromyography (compound motor action potential) over an 8-week post-injury period. Young adult rats demonstrated a trend of delayed onset of the dedifferentiating regulatory factors, Notch and c-Jun, corresponding to the delayed functional recovery observed in young adult rats compared to adolescent rats. Compound motor action potential area was significantly greater in adolescent rats relative to young adult rats, while amplitude and velocity trended toward statistical significance. The process of Schwann cell dedifferentiation following peripheral nerve injury shows different trends with age. These trends of delayed onset of key regulatory factors responsible for Schwann cell myelination may be one of many possible factors mediating the significant differences in functional recovery between adolescent and young adult rats following peripheral nerve injury.

  18. Comparative Analysis of the Cell Fates of Induced Schwann Cells from Subcutaneous Fat Tissue and Naïve Schwann Cells in the Sciatic Nerve Injury Model

    Directory of Open Access Journals (Sweden)

    Mingzi Zhang

    2017-01-01

    Full Text Available Purpose. The fate and function of the induced Schwann cells (iSCs like cells from adipose tissue have not been critically evaluated in vivo after transplantation. The objective of this study is to compare the fate of iSCs with naïve SCs (nSCs after transplantation into the lesion sites of sciatic nerve, respectively. Methods. Adipose-derived stem cells from eGFP-expressing transgenic rat’s subcutaneous fat were induced to iSCs in vitro. iSCs were injected to the sciatic nerve lesion area after crush injury and the cells fate was comparatively analyzed with that of nSCs from the same rat. Results. At 12 weeks after transplantation, nSCs were detected only in the restricted area of cell transplantation site but iSCs were widely distributed all over the sciatic nerve. Based on double fluorescence observations, both iSCs and naïve ones were colocalized with P0-expressing myelin sheath, outbound by laminin-expressing basal membrane, and terminated at contactin-associated protein-expressing doublets. However, some of iSCs were also differentiated to the fibrocyte/fibroblast-like cells. In the histological analysis of repaired sciatic nerves, axon density was higher in iSC-received group than in the nSCs group and normal sciatic nerve. Conclusion. iSCs induced from subcutaneous fat tissues have higher engraftment and migration capacity than nSCs.

  19. Brain-derived neurotrophic factor promotes nerve regeneration by activating the JAK/STAT pathway in Schwann cells.

    Science.gov (United States)

    Lin, Guiting; Zhang, Haiyang; Sun, Fionna; Lu, Zhihua; Reed-Maldonado, Amanda; Lee, Yung-Chin; Wang, Guifang; Banie, Lia; Lue, Tom F

    2016-04-01

    Radical prostatectomy (RP) carries the risk of erectile dysfunction (ED) due to cavernous nerve (CN) injury. Schwann cells are essential for the maintenance of integrity and function of peripheral nerves such as the CNs. We hypothesize that brain-derived neurotrophic factor (BDNF) activates the Janus kinase (JAK)/(signal transducer and activator of transcription) STAT pathway in Schwann cells, not in neuronal axonal fibers, with the resultant secretion of cytokines from Schwann cells to facilitate nerve recovery. Using four different cell lines-human neuroblastoma BE(2)-C and SH-SY5Y, human Schwann cell (HSC), and rat Schwann cell (RSC) RT4-D6P2T-we assessed the effect of BDNF application on the activation of the JAK/STAT pathway. We also assessed the time response of JAK/STAT pathway activation in RSCs and HSCs after BDNF treatment. We then assayed cytokine release from HSCs as a response to BDNF treatment using oncostatin M and IL6 as markers. We showed extensive phosphorylation of STAT3/STAT1 by BDNF at high dose (100 pM) in RSCs, with no JAK/STAT pathway activation in human neuroblastoma cell lines. The time response of JAK/STAT pathway activation in RSCs and HSCs after BDNF treatment showed an initial peak at shortly after treatment and then a second higher peak at 24-48 hours. Cytokine release from HSCs increased progressively after BDNF application, reaching statistical significance for IL6. We demonstrated for the first time the indirect mechanism of BDNF enhancement of nerve regeneration through the activation of JAK/STAT pathway in Schwann cells, rather than directly on neurons. As a result of BDNF application, Schwann cells produce cytokines that promote nerve regeneration.

  20. Schwann Cells Metabolize Extracellular 2′,3′-cAMP to 2′-AMP

    Science.gov (United States)

    Verrier, Jonathan D.; Kochanek, Patrick M.

    2015-01-01

    The 3′,5′-cAMP–adenosine pathway (3′,5′-cAMP→5′-AMP→adenosine) and the 2′,3′-cAMP–adenosine pathway (2′,3′-cAMP→2′-AMP/3′-AMP→adenosine) are active in the brain. Oligodendrocytes participate in the brain 2′,3′-cAMP–adenosine pathway via their robust expression of 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase; converts 2′,3′-cAMP to 2′-AMP). Because Schwann cells also express CNPase, it is conceivable that the 2′,3′-cAMP–adenosine pathway exists in the peripheral nervous system. To test this and to compare the 2′,3′-cAMP–adenosine pathway to the 3′,5′-cAMP–adenosine pathway in Schwann cells, we examined the metabolism of 2′,3′-cAMP, 2′-AMP, 3′-AMP, 3′,5′-cAMP, and 5′-AMP in primary rat Schwann cells in culture. Addition of 2′,3′-cAMP (3, 10, and 30 µM) to Schwann cells increased levels of 2′-AMP in the medium from 0.006 ± 0.002 to 21 ± 2, 70 ± 3, and 187 ± 10 nM/µg protein, respectively; in contrast, Schwann cells had little ability to convert 2′,3′-cAMP to 3′-AMP or 3′,5′-cAMP to either 3′-AMP or 5′-AMP. Although Schwann cells slightly converted 2′,3′-cAMP and 2′-AMP to adenosine, they did so at very modest rates (e.g., 5- and 3-fold, respectively, more slowly compared with our previously reported studies in oligodendrocytes). Using transected myelinated rat sciatic nerves in culture medium, we observed a time-related increase in endogenous intracellular 2′,3′-cAMP and extracellular 2′-AMP. These findings indicate that Schwann cells do not have a robust 3′,5′-cAMP–adenosine pathway but do have a 2′,3′-cAMP–adenosine pathway; however, because the pathway mostly involves 2′-AMP formation rather than 3′-AMP, and because the conversion of 2′-AMP to adenosine is slow, metabolism of 2′,3′-cAMP mostly results in the accumulation of 2′-AMP. Accumulation of 2′-AMP in peripheral nerves postinjury could have

  1. Characterization of p75 neurotrophin receptor expression in human dental pulp stem cells.

    Science.gov (United States)

    Pan, Wenru; Kremer, Karlea L; Kaidonis, Xenia; Ludlow, Victoria E; Rogers, Mary-Louise; Xie, Jianling; Proud, Christopher G; Koblar, Simon A

    2016-10-01

    Human adult dental pulp stem cells (DPSC) are a heterogeneous stem cell population, which are able to differentiate down neural, chondrocyte, osteocyte and adipocyte lineages. We studied the expression pattern of p75 neurotrophin receptors (p75NTR), a marker of neural stem cells, within human DPSC populations from eight donors. p75NTR are expressed at low levels (cell marker), SOX2 (cell pluripotency marker) and nestin (neural stem cell marker) in comparison to p75(-) DPSC. Our results suggest that p75(+) hDPSC may denote a subpopulation with greater neurogenic potential. Copyright © 2016 ISDN. Published by Elsevier Ltd. All rights reserved.

  2. Myelinating Schwann Cell Polarity and Mechanically-Driven Myelin Sheath Elongation.

    Science.gov (United States)

    Tricaud, Nicolas

    2017-01-01

    Myelin sheath geometry, encompassing myelin sheath thickness relative to internodal length, is critical to optimize nerve conduction velocity and these parameters are carefully adjusted by the myelinating cells in mammals. In the central nervous system these adjustments could regulate neuronal activities while in the peripheral nervous system they lead to the optimization and the reliability of the nerve conduction velocity. However, the physiological and cellular mechanisms that underlie myelin sheath geometry regulation are not yet fully elucidated. In peripheral nerves the myelinating Schwann cell uses several molecular mechanisms to reach and maintain the correct myelin sheath geometry, such that myelin sheath thickness and internodal length are regulated independently. One of these mechanisms is the epithelial-like cell polarization process that occurs during the early phases of the myelin biogenesis. Epithelial cell polarization factors are known to control cell size and morphology in invertebrates and mammals making these processes critical in the organogenesis. Correlative data indicate that internodal length is regulated by postnatal body growth that elongates peripheral nerves in mammals. In addition, the mechanical stretching of peripheral nerves in adult animals shows that myelin sheath length can be increased by mechanical cues. Recent results describe the important role of YAP/TAZ co-transcription factors during Schwann cell myelination and their functions have linked to the mechanotransduction through the HIPPO pathway and the epithelial polarity factor Crb3. In this review the molecular mechanisms that govern mechanically-driven myelin sheath elongation and how a Schwann cell can modulate internodal myelin sheath length, independent of internodal thickness, will be discussed regarding these recent data. In addition, the potential relevance of these mechanosensitive mechanisms in peripheral pathologies will be highlighted.

  3. In vitro cytocompatibility assessment of amorphous carbon structures using neuroblastoma and Schwann cells.

    Science.gov (United States)

    Jain, Shilpee; Sharma, Ashutosh; Basu, Bikramjit

    2013-05-01

    The development of scaffolds for neural tissue engineering application requires an understanding of cell adhesion, proliferation, and migration of neuronal cells. Considering the potential application of carbon as scaffold materials and the lack of understanding of compatibility of amorphous carbon with neuronal cells, the carbon-based materials in the forms of carbon films and continuous electrospun carbon nanofibers having average diameter of ~200 nm are being investigated with or without ultraviolet (UV) and oxy-plasma (OP) treatments for cytocompatibility property using mouse Neuroblastoma (N2a) and rat Schwann cells (RT4-D6P2T). The use of Raman spectroscopy in combination with Fourier transform infrared (FTIR) and X-ray diffraction establishes the amorphous nature and surface-bonding characteristics of the studied carbon materials. Although both UV and OP treatments make carbon surfaces more hydrophilic, the cell viability of N2a cells is statistically more significant on OP treated fibers/films compared to UV fiber/film substrates after 4 days in culture. The electrospun carbon fibrous substrate provides the physical guidance to the cultured Schwann cells. Overall, the experimental results of this study demonstrate that the electrospun amorphous carbon nanofibrous scaffolds can be used as a suitable biomaterial substrate for supporting cell adhesion and proliferation of neuronal cells in the context of their applications as artificial nerve implants. Copyright © 2013 Wiley Periodicals, Inc.

  4. Alginate-matrigel microencapsulated schwann cells for inducible secretion of glial cell line derived neurotrophic factor.

    Science.gov (United States)

    de Guzman, Roche C; Ereifej, Evon S; Broadrick, Kristy M; Rogers, Richard A; VandeVord, Pamela J

    2008-10-01

    Controlled expression of glial cell line derived neurotrophic factor (Gdnf) can be integrated in the development of a system for repair of injured peripheral nerves. This delivery strategy was demonstrated via inducible Gdnf from microencapsulated cells in barium alginate. The Schwann cell line RT4-D6P2T was initially modified utilizing an ecdysone-based stable transfection system to produce RT4-Gdnf cells. During construct preparation, it was found that C6 cells (where Gdnf cDNA was isolated) make three Gdnf transcript variants. Additionally, the importance of 5' untranslated region to drive biologically-functional Gdnf synthesis was shown. Encapsulation of RT4-Gdnf in 1% alginate was then performed. It was determined that cells were able to survive at least 1 month in vitro using starting densities of 20, 200 and 2000 cells/capsule and barium ion concentrations of 10, 50, 100 and 200 mM. Most importantly, encapsulated cells secreted exogenous Gdnf upon ponasterone A induction. Mixture of basement membrane extract Matrigel to alginate promoted increased proliferation, cell spreading and Gdnf release. Finally, compression tests showed that cell-loaded microcapsules fractured at 75% diameter compression with 38 kPa of stress. Regulated Gdnf release from these microcapsules in vivo may potentially aid in the regeneration of damaged nerves.

  5. Cooperative interaction of hepatocyte growth factor and neuregulin regulates Schwann cell migration and proliferation through Grb2-associated binder-2 in peripheral nerve repair.

    Science.gov (United States)

    Shin, Yoon Kyoung; Jang, So Young; Yun, Seoug Hoon; Choi, Yun Young; Yoon, Byeol-A; Jo, Young Rae; Park, So Young; Pak, Min Gyoung; Park, Joo In; Park, Hwan Tae

    2017-11-01

    The sequential reactive changes in Schwann cell phenotypes in transected peripheral nerves, including dedifferentiation, proliferation and migration, are essential for nerve repair. Even though the injury-induced migratory and proliferative behaviors of Schwann cells resemble epithelial and mesenchymal transition (EMT) in tumors, the molecular mechanisms underlying this phenotypic change of Schwann cells are still unclear. Here we show that the reactive Schwann cells exhibit migratory features dependent on the expression of a scaffolding oncoprotein Grb2-associated binder-2 (Gab2), which was transcriptionally induced by neuregulin 1-ErbB2 signaling following nerve injury. Injury-induced Gab2 expression was dependent on c-Jun, a transcription factor critical to a Schwann cell reprograming into a repair-type cell. Interestingly, the injury-induced activation (tyrosine phosphorylation) of Gab2 in Schwann cells was regulated by an EMT signal, the hepatocyte growth factor-c-Met signaling, but not by neuregulin 1. Gab2 knockout mice exhibited a deficit in nerve repair after nerve transection due to limited Schwann cell migration. Furthermore, Gab2 was required for the proliferation of Schwann cells following nerve injury and in vitro, and was over-expressed in human Schwann cell-derived tumors. In contrast, the tyrosine phosphorylation of Gab1 after nerve injury was principally regulated by the neuregulin 1-ErbB2 signaling and was indispensable for remyelination after crush injury, but not for the proliferation and migration of Schwann cells. Our findings indicate that Gab1 and Gab2 in Schwann cells are nonredundant and play a crucial role in peripheral nerve repair. © 2017 Wiley Periodicals, Inc.

  6. Myelin repair by Schwann cells in the regenerating goldfish visual pathway: regional patterns revealed by X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nona, S.N.; Stafford, C.A.; Cronly-Dillon, J.R. (Manchester Univ. (United Kingdom). Inst. of Science and Technology); Duncan, A. (Guy' s Hospital, London (United Kingdom). Dept. of Anatomy); Scholes, J. (University Coll., London (United Kingdom))

    1994-07-01

    In the regenerating goldfish optic nerves, Schwann cells of unknown origin reliably infiltrate the lesion site forming a band of peripheral-type myelinating tissue by 1-2 months, sharply demarcated form the adjacent new CNS myelin. To investigate this effect, we have interfered with cell proliferation by locally X-irradiating the fish visual pathway 24 h after the lesion. As assayed by immunohistochemistry and EM, irradiation retards until 6 months formation of new myelin by Schwann cells at the lesion site, and virtually abolishes oligodendrocyte myelination distally, but has little or no effect on nerve fibre regrowth. Optic nerve astrocyte processes normally fail to re-infiltrate the lesion, but re-occupy it after irradiation, suggesting that they are normally excluded by early cell proliferation at this site. Moreover, scattered myelinating Schwann cells also appear in the oligodendrocyte-depleted distal optic nerve after irradiation, although only as far as the optic tract. (Author).

  7. The Scaffolding Protein, Grb2-associated Binder-1, in Skeletal Muscles and Terminal Schwann Cells Regulates Postnatal Neuromuscular Synapse Maturation.

    Science.gov (United States)

    Park, So Young; Jang, So Young; Shin, Yoon Kyoung; Jung, Dong Keun; Yoon, Byeol A; Kim, Jong Kook; Jo, Young Rae; Lee, Hye Jeong; Park, Hwan Tae

    2017-06-01

    The vertebrate neuromuscular junction (NMJ) is considered as a "tripartite synapse" consisting of a motor axon terminal, a muscle endplate, and terminal Schwann cells that envelope the motor axon terminal. The neuregulin 1 (NRG1)-ErbB2 signaling pathway plays an important role in the development of the NMJ. We previously showed that Grb2-associated binder 1 (Gab1), a scaffolding mediator of receptor tyrosine kinase signaling, is required for NRG1-induced peripheral nerve myelination. Here, we determined the role of Gab1 in the development of the NMJ using muscle-specific conditional Gab1 knockout mice. The mutant mice showed delayed postnatal maturation of the NMJ. Furthermore, the selective loss of the gab1 gene in terminal Schwann cells produced delayed synaptic elimination with abnormal morphology of the motor endplate, suggesting that Gab1 in both muscles and terminal Schwann cells is required for proper NMJ development. Gab1 in terminal Schwann cells appeared to regulate the number and process elongation of terminal Schwann cells during synaptic elimination. However, Gab2 knockout mice did not show any defects in the development of the NMJ. Considering the role of Gab1 in postnatal peripheral nerve myelination, our findings suggest that Gab1 is a pleiotropic and important component of NRG1 signals during postnatal development of the peripheral neuromuscular system.

  8. Neuronal Differentiation in Schwann Cell Lineage Underlies Postnatal Neurogenesis in the Enteric Nervous System.

    Science.gov (United States)

    Uesaka, Toshihiro; Nagashimada, Mayumi; Enomoto, Hideki

    2015-07-08

    Elucidation of the cellular identity of neuronal precursors provides mechanistic insights into the development and pathophysiology of the nervous system. In the enteric nervous system (ENS), neurogenesis persists from midgestation to the postnatal period. Cellular mechanism underlying the long-term neurogenesis in the ENS has remained unclear. Using genetic fate mapping in mice, we show here that a subset of Schwann cell precursors (SCPs), which invades the gut alongside the extrinsic nerves, adopts a neuronal fate in the postnatal period and contributes to the ENS. We found SCP-derived neurogenesis in the submucosal region of the small intestine in the absence of vagal neural crest-derived ENS precursors. Under physiological conditions, SCPs comprised up to 20% of enteric neurons in the large intestine and gave rise mainly to restricted neuronal subtypes, calretinin-expressing neurons. Genetic ablation of Ret, the signaling receptor for glial cell line-derived neurotrophic factor, in SCPs caused colonic oligoganglionosis, indicating that SCP-derived neurogenesis is essential to ENS integrity. Identification of Schwann cells as a physiological neurogenic source provides novel insight into the development and disorders of neural crest-derived tissues. Elucidating the cellular identity of neuronal precursors provides novel insights into development and function of the nervous system. The enteric nervous system (ENS) is innervated richly by extrinsic nerve fibers, but little is known about the significance of extrinsic innervation to the structural integrity of the ENS. This report reveals that a subset of Schwann cell precursors (SCPs), which invades the gut alongside the extrinsic nerves, adopts a neuronal fate and differentiates into specific neuronal subtypes. SCP-specific ablation of the Ret gene leads to colonic oligoganglionosis, demonstrating a crucial role of SCP-derived neurogenesis in ENS development. Cross-lineage differentiation capacity in SCPs suggests

  9. Enrichment and Schwann Cell Differentiation of Neural Crest-derived Dental Pulp Stem Cells.

    Science.gov (United States)

    Al-Zer, Heba; Apel, Christian; Heiland, Max; Friedrich, Reinhard E; Jung, Ole; Kroeger, Nadja; Eichhorn, Wolfgang; Smeets, Ralf

    2015-01-01

    As already described in previous studies, neural crest stem cells (NCSCs) can be found in adult human dental pulp. The present study investigated the methodology for enrichment and differentiation-induction of the above mentioned cells. Dental pulp was extracted from human wisdom teeth of four patients and subsequently cultured as explants on fibronectin-coated plates in neurobasal medium supplemented with B27, basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), insulin, l-glutamine and neuregulin-β1. The cells were then characterized by immunofluorescence, while their differentiation-potential was tested by the attempt to induce cells into different lineages, i.e. osteogenic, melanocytic and glial. The enriched cell population expressed nestin, CD271 and SOX10, which are well-known markers for NCSCs. Consequently, the cells were successfully induced to differentiate into osteoblasts, melanocytes and Schwann cells, expressing the corresponding differentiation markers. Human adult dental pulp contains a population of stem cells with neural crest ontogeny, which can thus be recruited for multiple regenerative therapies. Copyright © 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  10. Schwann cells promote neuronal differentiation of bone marrow ...

    African Journals Online (AJOL)

    Bone marrow stromal cells (BMSCs), a type of multipotent stem cell, can differentiate into various types of cells. It has been suggested that the BMSCs have the capacity to differentiate into neurons under specific experimental conditions, using chemical factors. In this study, we showed that BMSCs can be induced to ...

  11. Peripheral Nerve Repair with Cultured Schwann Cells: Getting Closer to the Clinics

    Directory of Open Access Journals (Sweden)

    Maria Carolina O. Rodrigues

    2012-01-01

    Full Text Available Peripheral nerve injuries are a frequent and disabling condition, which affects 13 to 23 per 100.000 persons each year. Severe cases, with structural disruption of the nerve, are associated with poor functional recovery. The experimental treatment using nerve grafts to replace damaged or shortened axons is limited by technical difficulties, invasiveness, and mediocre results. Other therapeutic choices include the adjunctive application of cultured Schwann cells and nerve conduits to guide axonal growth. The bone marrow is a rich source of mesenchymal cells, which can be differentiated in vitro into Schwann cells and subsequently engrafted into the damaged nerve. Alternatively, undifferentiated bone marrow mesenchymal cells can be associated with nerve conduits and afterward transplanted. Experimental studies provide evidence of functional, histological, and electromyographical improvement following transplantation of bone-marrow-derived cells in animal models of peripheral nerve injury. This paper focuses on this new therapeutic approach highlighting its direct translational and clinical utility in promoting regeneration of not only acute but perhaps also chronic cases of peripheral nerve damage.

  12. Targeted knock-down of cellular prion protein expression in myelinating Schwann cells does not alter mouse prion pathogenesis.

    Science.gov (United States)

    Halliez, Sophie; Chesnais, Nathalie; Mallucci, Giovanna; Vilotte, Marthe; Langevin, Christelle; Jaumain, Emilie; Laude, Hubert; Vilotte, Jean-Luc; Béringue, Vincent

    2013-06-01

    In naturally acquired transmissible spongiform encephalopathies, the pathogenic agents or prions spread from the sites of initial peripheral uptake or replication to the brain where they cause progressive and fatal neurodegeneration. Routing via the peripheral nervous system is considered to be one of the main pathways to the central nervous system. Replication of prions in Schwann cells is viewed as a potentially important mechanism for efficient prion spread along nerves. Here we used a Cre-loxP mouse transgenetic approach to disrupt host-encoded prion protein (PrP(C)) specifically in myelinating Schwann cells. Despite the use of infection routes targeting highly myelinated nerves, there was no alteration in mouse prion pathogenesis, suggesting that conversion-dependent, centripetal spread of prions does not crucially rely on PrP(C) expressed by myelinating Schwann cells.

  13. Data in support on the shape of Schwann cells and sympathetic neurons onto microconically structured silicon surfaces

    Directory of Open Access Journals (Sweden)

    C. Simitzi

    2015-09-01

    Full Text Available This article contains data related to the research article entitled “Laser fabricated discontinuous anisotropic microconical substrates as a new model scaffold to control the directionality of neuronal network outgrowth” in the Biomaterials journal [1]. Scanning electron microscopy (SEM analysis is performed to investigate whether Schwann cells and sympathetic neurons alter their morphology according to the underlying topography, comprising arrays of silicon microcones with anisotropic geometrical characteristics [1]. It is observed that although soma of sympathetic neurons always preserves its round shape, this is not the case for Schwann cells that become highly polarized in high roughness microconical substrates.

  14. The Proliferation Enhancing Effects of Salidroside on Schwann Cells In Vitro

    Directory of Open Access Journals (Sweden)

    Hui Liu

    2017-01-01

    Full Text Available Derived from Rhodiola rosea L., which is a popular plant in Eastern Europe and Asia, salidroside has pharmacological properties including antiviral, anticancer, hepatoprotective, antidiabetic, and antioxidative effects. Recent studies show that salidroside has neurotrophic and neuroprotective effects. However, the effect of salidroside on Schwann cells (SCs and the underlying mechanisms of the salidroside-induced neurotrophin secretion have seldom been studied. In this study, the effect of salidroside on the survival, proliferation, and gene expression of Schwann cells lineage (RSC96 was studied through the examinations of the cell viability, proliferation, morphology, and expression of neurotrophic factor related genes including BDNF, GDNF, and CDNF at 2, 4, and 6 days, respectively. These results showed that salidroside significantly enhanced survival and proliferation of SCs. The underlying mechanism might involve that salidroside affected SCs growth through the modulation of several neurotrophic factors including BDNF, GDNF, and CDNF. As for the concentration, 0.4 mM, 0.2 mM, and 0.1 mM of salidroside were recommended, especially 0.2 mM. This investigation indicates that salidroside is capable of enhancing SCs survival and function in vitro, which highlights the possibility that salidroside as a drug agent to promote nerve regeneration in cellular nerve scaffold through salidroside-induced neurotrophin secretion in SCs.

  15. The Proliferation Enhancing Effects of Salidroside on Schwann Cells In Vitro.

    Science.gov (United States)

    Liu, Hui; Lv, Peizhen; Wu, Huayu; Zhang, Kun; Xu, Fuben; Zheng, Li; Zhao, Jinmin

    2017-01-01

    Derived from Rhodiola rosea L., which is a popular plant in Eastern Europe and Asia, salidroside has pharmacological properties including antiviral, anticancer, hepatoprotective, antidiabetic, and antioxidative effects. Recent studies show that salidroside has neurotrophic and neuroprotective effects. However, the effect of salidroside on Schwann cells (SCs) and the underlying mechanisms of the salidroside-induced neurotrophin secretion have seldom been studied. In this study, the effect of salidroside on the survival, proliferation, and gene expression of Schwann cells lineage (RSC96) was studied through the examinations of the cell viability, proliferation, morphology, and expression of neurotrophic factor related genes including BDNF, GDNF, and CDNF at 2, 4, and 6 days, respectively. These results showed that salidroside significantly enhanced survival and proliferation of SCs. The underlying mechanism might involve that salidroside affected SCs growth through the modulation of several neurotrophic factors including BDNF, GDNF, and CDNF. As for the concentration, 0.4 mM, 0.2 mM, and 0.1 mM of salidroside were recommended, especially 0.2 mM. This investigation indicates that salidroside is capable of enhancing SCs survival and function in vitro, which highlights the possibility that salidroside as a drug agent to promote nerve regeneration in cellular nerve scaffold through salidroside-induced neurotrophin secretion in SCs.

  16. mTORC1 is essential for early steps during Schwann cell differentiation of amniotic fluid stem cells and regulates lipogenic gene expression.

    Directory of Open Access Journals (Sweden)

    Andrea Preitschopf

    Full Text Available Schwann cell development is hallmarked by the induction of a lipogenic profile. Here we used amniotic fluid stem (AFS cells and focused on the mechanisms occurring during early steps of differentiation along the Schwann cell lineage. Therefore, we initiated Schwann cell differentiation in AFS cells and monitored as well as modulated the activity of the mechanistic target of rapamycin (mTOR pathway, the major regulator of anabolic processes. Our results show that mTOR complex 1 (mTORC1 activity is essential for glial marker expression and expression of Sterol Regulatory Element-Binding Protein (SREBP target genes. Moreover, SREBP target gene activation by statin treatment promoted lipogenic gene expression, induced mTORC1 activation and stimulated Schwann cell differentiation. To investigate mTORC1 downstream signaling we expressed a mutant S6K1, which subsequently induced the expression of the Schwann cell marker S100b, but did not affect lipogenic gene expression. This suggests that S6K1 dependent and independent pathways downstream of mTORC1 drive AFS cells to early Schwann cell differentiation and lipogenic gene expression. In conclusion our results propose that future strategies for peripheral nervous system regeneration will depend on ways to efficiently induce the mTORC1 pathway.

  17. Epi/perineural and Schwann Cells as Well as Perineural Sheath Integrity are Affected Following 2,4-D Exposure.

    Science.gov (United States)

    Sharifi Pasandi, Marzieh; Hosseini Shirazi, Farshad; Gholami, Mohammad Reza; Salehi, Hossein; Najafzadeh, Nowruz; Mazani, Mohammad; Ghasemi Hamidabadi, Hatef; Niapour, Ali

    2017-07-11

    2,4-dicholorophenoxy acetic acid (2,4-D) is a worldwide-known hormone herbicide. However, there are increasing concerns about its exposure and risks of developing pathological conditions for the peripheral nervous system. The aim of this study was to investigate the mechanism(s) involved in the toxicity of 2,4-D on peripheral nerve's cellular components. The epi/perineural and Schwann cells and a total of three cell lines were treated with 2,4-D. The viability of cells at different doses of 2,4-D was measured by MTT assay. The cell cycle analyses, cumulative cell counting, fluorescent staining, antioxidant and caspase enzymes activity were examined on epi/perineural and Schwann cells. The epi/perineural cells were assessed as having biological macromolecular changes. Some tight junction-related genes and proteins were also tested on explants of 2,4-D treated epi/perineural tissue. The viability of 2,4-D treated cells was reduced in a dose-dependent manner. Reduced growth rate and G1 cell cycle arrest were verified in 2,4-D treated epi/perineural and Schwann cells. The use of staining methods (acridine orange/ethidium bromide and DAPI) and caspase 3/7 activity assay along with malondialdehyde, glutathione peroxidase, and superoxide dismutase activity assays indicated the apoptotic and oxidant effects of 2,4-D on epi/perineural and Schwann cells. Data obtained from FTIR revealed changes in epi/perineural proteins and cell membrane lipids. Additionally, claudin-1, occludin, and ZO-1 gene/protein expression profiles were significantly reduced in 2,4-D-treated epi/perineural pieces. Our data indicated that oxidative stress, apoptosis of epi/perineural and Schwann cell and impaired blood-nerve barrier may have contributed to nerve damage following 2,4-D exposure.

  18. Coseeded Schwann cells myelinate neurites from differentiated neural stem cells in neurotrophin-3-loaded PLGA carriers

    Science.gov (United States)

    Xiong, Yi; Zhu, Ji-Xiang; Fang, Zheng-Yu; Zeng, Cheng-Guang; Zhang, Chao; Qi, Guo-Long; Li, Man-Hui; Zhang, Wei; Quan, Da-Ping; Wan, Jun

    2012-01-01

    Biomaterials and neurotrophic factors represent promising guidance for neural repair. In this study, we combined poly-(lactic acid-co-glycolic acid) (PLGA) conduits and neurotrophin-3 (NT-3) to generate NT-3-loaded PLGA carriers in vitro. Bioactive NT-3 was released stably and constantly from PLGA conduits for up to 4 weeks. Neural stem cells (NSCs) and Schwann cells (SCs) were coseeded into an NT-releasing scaffold system and cultured for 14 days. Immunoreactivity against Map2 showed that most of the grafted cells (>80%) were differentiated toward neurons. Double-immunostaining for synaptogenesis and myelination revealed the formation of synaptic structures and myelin sheaths in the coculture, which was also observed under electron microscope. Furthermore, under depolarizing conditions, these synapses were excitable and capable of releasing synaptic vesicles labeled with FM1-43 or FM4-64. Taken together, coseeding NSCs and SCs into NT-3-loaded PLGA carriers increased the differentiation of NSCs into neurons, developed synaptic connections, exhibited synaptic activities, and myelination of neurites by the accompanying SCs. These results provide an experimental basis that supports transplantation of functional neural construction in spinal cord injury. PMID:22619535

  19. Nestin-Expressing Stem Cells Promote Nerve Growth in Long-Term 3-Dimensional Gelfoam®-Supported Histoculture.

    Directory of Open Access Journals (Sweden)

    Sumiyuki Mii

    Full Text Available We have previously reported that hair follicles contain multipotent stem cells which express nestin. The nestin-expressing cells form the hair follicle sensory nerve. In vitro, the nestin-expressing hair follicle cells can differentiate into neurons, Schwann cells, and other cell types. In the present study, the sciatic nerve was excised from transgenic mice in which the nestin promoter drives green fluorescent protein (ND-GFP mice. The ND-GFP cells of the sciatic nerve were also found to be multipotent as the ND-GFP cells in the hair follicle. When the ND-GFP cells in the mouse sciatic nerve cultured on Gelfoam® and were imaged by confocal microscopy, they were observed forming fibers extending the nerve. The fibers consisted of ND-GFP-expressing spindle cells, which co-expressed the neuron marker β-III tubulin, the immature Schwann-cell marker p75(NTR and TrkB which is associated with neurons. The fibers also contain nestin-negative spherical cells expressing GFAP, a Schwann-cell marker. The β-III tubulin-positive fibers had growth cones on their tips expressing F-actin, indicating they are growing axons. When the sciatic nerve from mice ubiquitously expressing red fluorescent protein (RFP was co-cultured on Gelfoam® with the sciatic nerve from ND-GFP transgenic mice, the interaction of nerves was observed. Proliferating nestin-expressing cells in the injured sciatic nerve were also observed in vivo. Nestin-expressing cells were also observed in posterior nerves but not in the spinal cord itself, when placed in 3-D Gelfoam® culture. The results of the present report suggest a critical function of nestin-expressing cells in peripheral nerve growth and regeneration.

  20. Loss of Fig4 in both Schwann cells and motor neurons contributes to CMT4J neuropathy

    Science.gov (United States)

    Vaccari, Ilaria; Carbone, Antonietta; Previtali, Stefano Carlo; Mironova, Yevgeniya A.; Alberizzi, Valeria; Noseda, Roberta; Rivellini, Cristina; Bianchi, Francesca; Del Carro, Ubaldo; D'Antonio, Maurizio; Lenk, Guy M.; Wrabetz, Lawrence; Giger, Roman J.; Meisler, Miriam H.; Bolino, Alessandra

    2015-01-01

    Mutations of FIG4 are responsible for Yunis-Varón syndrome, familial epilepsy with polymicrogyria, and Charcot-Marie-Tooth type 4J neuropathy (CMT4J). Although loss of the FIG4 phospholipid phosphatase consistently causes decreased PtdIns(3,5)P2 levels, cell-specific sensitivity to partial loss of FIG4 function may differentiate FIG4-associated disorders. CMT4J is an autosomal recessive neuropathy characterized by severe demyelination and axonal loss in human, with both motor and sensory involvement. However, it is unclear whether FIG4 has cell autonomous roles in both motor neurons and Schwann cells, and how loss of FIG4/PtdIns(3,5)P2-mediated functions contribute to the pathogenesis of CMT4J. Here, we report that mice with conditional inactivation of Fig4 in motor neurons display neuronal and axonal degeneration. In contrast, conditional inactivation of Fig4 in Schwann cells causes demyelination and defects in autophagy-mediated degradation. Moreover, Fig4-regulated endolysosomal trafficking in Schwann cells is essential for myelin biogenesis during development and for proper regeneration/remyelination after injury. Our data suggest that impaired endolysosomal trafficking in both motor neurons and Schwann cells contributes to CMT4J neuropathy. PMID:25187576

  1. Merlin controls the repair capacity of Schwann cells after injury by regulating Hippo/YAP activity.

    Science.gov (United States)

    Mindos, Thomas; Dun, Xin-Peng; North, Katherine; Doddrell, Robin D S; Schulz, Alexander; Edwards, Philip; Russell, James; Gray, Bethany; Roberts, Sheridan L; Shivane, Aditya; Mortimer, Georgina; Pirie, Melissa; Zhang, Nailing; Pan, Duojia; Morrison, Helen; Parkinson, David B

    2017-02-01

    Loss of the Merlin tumor suppressor and activation of the Hippo signaling pathway play major roles in the control of cell proliferation and tumorigenesis. We have identified completely novel roles for Merlin and the Hippo pathway effector Yes-associated protein (YAP) in the control of Schwann cell (SC) plasticity and peripheral nerve repair after injury. Injury to the peripheral nervous system (PNS) causes a dramatic shift in SC molecular phenotype and the generation of repair-competent SCs, which direct functional repair. We find that loss of Merlin in these cells causes a catastrophic failure of axonal regeneration and remyelination in the PNS. This effect is mediated by activation of YAP expression in Merlin-null SCs, and loss of YAP restores axonal regrowth and functional repair. This work identifies new mechanisms that control the regenerative potential of SCs and gives new insight into understanding the correct control of functional nerve repair in the PNS. © 2017 Mindos et al.

  2. The POU factor Oct-6 is required for the progression of Schwann cell differentiation in peripheral nerves.

    NARCIS (Netherlands)

    M.M. Jaegle (Martine); W.J. Mandemakers (Wim); L.A.M. Broos (Ludo); R. Zwart (Ronald); A. Karis (Alar); P. Visser (Pim); F.G. Grosveld (Frank); D.N. Meijer (Dies)

    1996-01-01

    textabstractThe POU transcription factor Oct-6, also known as SCIP or Tst-1, has been implicated as a major transcriptional regulator in Schwann cell differentiation. Microscopic and immunochemical analysis of sciatic nerves of Oct-6(-/-) mice at different stages of postnatal development reveals a

  3. Schwann Cell Migration Induced by Earthworm Extract via Activation of PAs and MMP2/9 Mediated through ERK1/2 and p38

    Science.gov (United States)

    Chang, Yung-Ming; Shih, Ying-Ting; Chen, Yueh-Sheng; Liu, Chien-Liang; Fang, Wen-Kuei; Tsai, Chang-Hai; Tsai, Fuu-Jen; Kuo, Wei-Wen; Lai, Tung-Yuan; Huang, Chih-Yang

    2011-01-01

    The earthworm, which has stasis removal and wound-healing functions, is a widely used Chinese herbal medicine in China. Schwann cell migration is critical for the regeneration of injured nerves. Schwann cells provide an essentially supportive activity for neuron regeneration. However, the molecular migration mechanisms induced by earthworms in Schwann cells remain unclear. Here, we investigate the roles of MAPK (ERK1/2, JNK and p38) pathways for earthworm-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production in Schwann cells. Moreover, earthworm induced phosphorylation of ERK1/2 and p38, but not JNK, activate the downstream signaling expression of PAs and MMPs in a time-dependent manner. Earthworm-stimulated ERK1/2 and p38 phosphorylation was attenuated by pretreatment with U0126 and SB203580, resulting in migration and uPA-related signal pathway inhibition. The results were confirmed using small interfering ERK1/2 and p38 RNA. These results demonstrated that earthworms can stimulate Schwann cell migration and up-regulate PAs and MMP2/9 expression mediated through the MAPK pathways, ERK1/2 and p38. Taken together, our data suggests the MAPKs (ERK1/2, p38)-, PAs (uPA, tPA)-, MMP (MMP2, MMP9) signaling pathway of Schwann cells regulated by earthworms might play a major role in Schwann cell migration and nerve regeneration. PMID:19808845

  4. Neuronal activity in the hub of extrasynaptic Schwann cell-axon interactions.

    Science.gov (United States)

    Samara, Chrysanthi; Poirot, Olivier; Domènech-Estévez, Enric; Chrast, Roman

    2013-01-01

    The integrity and function of neurons depend on their continuous interactions with glial cells. In the peripheral nervous system glial functions are exerted by Schwann cells (SCs). SCs sense synaptic and extrasynaptic manifestations of action potential propagation and adapt their physiology to support neuronal activity. We review here existing literature data on extrasynaptic bidirectional axon-SC communication, focusing particularly on neuronal activity implications. To shed light on underlying mechanisms, we conduct a thorough analysis of microarray data from SC-rich mouse sciatic nerve at different developmental stages and in neuropathic models. We identify molecules that are potentially involved in SC detection of neuronal activity signals inducing subsequent glial responses. We further suggest that alterations in the activity-dependent axon-SC crosstalk impact on peripheral neuropathies. Together with previously reported data, these observations open new perspectives for deciphering glial mechanisms of neuronal function support.

  5. Phenotypic changes of Schwann cells on the proximal stump of injured peripheral nerve during repair using small gap conduit tube

    Directory of Open Access Journals (Sweden)

    Shi-jun Zhang

    2017-01-01

    Full Text Available Dedifferentiation of Schwann cells is an important feature of the response to peripheral nerve injury and specific negative myelination regulators are considered to have a major role in this process. However, most experiments have focused on the distal nerve stump, where the Notch signaling pathway is strongly associated with Schwann cell dedifferentiation and repair of the nerve. We observed the phenotypic changes of Schwann cells and changes of active Notch signaling on the proximal stump during peripheral nerve repair using small gap conduit tubulization. Eighty rats, with right sciatic nerve section of 4 mm, were randomly assigned to conduit bridging group and control group (epineurium suture. Glial fibrillary acidic protein expression, in myelinating Schwann cells on the proximal stump, began to up-regulate at 1 day after injury and was still evident at 5 days. Compared with the control group, Notch1 mRNA was expressed at a higher level in the conduit bridging group during the first week on the proximal stump. Hes1 mRNA levels in the conduit bridging group significantly increased compared with the control group at 3, 5, 7 and 14 days post-surgery. The change of the Notch intracellular domain shared a similar trend as Hes1 mRNA expression. Our results confirmed that phenotypic changes of Schwann cells occurred in the proximal stump. The differences in these changes between the conduit tubulization and epineurium suture groups correlate with changes in Notch signaling. This suggests that active Notch signaling might be a key mechanism during the early stage of neural regeneration in the proximal nerve stump.

  6. Transplantation of neural stem cells, Schwann cells and olfactory ensheathing cells for spinal cord injury : A Web of Science-based literature analysis.

    Science.gov (United States)

    Zhang, Xing; Yin, Fei; Guo, Li; Zhao, Dongxu; Gong, Gu; Gao, Lei; Zhu, Qingsan

    2012-12-15

    To identify global research trends in transplantation of neural stem cells, Schwann cells and olfactory ensheathing cells for spinal cord injury. We performed a bibliometric analysis of studies on transplantation of neural stem cells, Schwann cells and olfactory ensheathing cells for spinal cord injury published from 2002 to 2011 and retrieved from the Web of Science, using the key words spinal cord injury along with either neural stem cell, Schwann cell or olfactory ensheathing cell. (a) peer-reviewed published articles on neural stem cells, Schwann cells or olfactory ensheathing cells for spinal cord injury indexed in the Web of Science; (b) original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial materials and news items; and (c) published between 2002 and 2011. (a) articles that required manual searching or telephone access; (b) documents that were not published in the public domain; and (c) corrected papers. (1) Annual publication output, distribution by journal, distribution by institution and top-cited articles on neural stem cells; (2) annual publication output, distribution by journal, distribution by institution and top-cited articles on Schwann cells; (3) annual publication output, distribution by journal, distribution by institution and top-cited articles on olfactory ensheathing cells. This analysis, based on articles indexed in the Web of Science, identified several research trends among studies published over the past 10 years in transplantation of neural stem cells, Schwann cells and olfactory ensheathing cells for spinal cord injury. The number of publications increased over the 10-year period examined. Most papers appeared in journals with a focus on neurology, such as Journal of Neurotrauma, Experimental Neurology and Glia. Research institutes publishing on the use of neural stem cells to repair spinal cord injury were mostly in the USA and Canada. Those publishing on the use of Schwann cells were

  7. Tead1 regulates the expression of Peripheral Myelin Protein 22 during Schwann cell development.

    Science.gov (United States)

    Lopez-Anido, Camila; Poitelon, Yannick; Gopinath, Chetna; Moran, John J; Ma, Ki Hwan; Law, William D; Antonellis, Anthony; Feltri, M Laura; Svaren, John

    2016-07-15

    Schwann cells are myelinating glia in the peripheral nervous system that form the myelin sheath. A major cause of peripheral neuropathy is a copy number variant involving the Peripheral Myelin Protein 22 (PMP22) gene, which is located within a 1.4-Mb duplication on chromosome 17 associated with the most common form of Charcot-Marie-Tooth Disease (CMT1A). Rodent models of CMT1A have been used to show that reducing Pmp22 overexpression mitigates several aspects of a CMT1A-related phenotype. Mechanistic studies of Pmp22 regulation identified enhancers regulated by the Sox10 (SRY sex determining region Y-box 10) and Egr2/Krox20 (Early growth response protein 2) transcription factors in myelinated nerves. However, relatively little is known regarding how other transcription factors induce Pmp22 expression during Schwann cell development and myelination. Here, we examined Pmp22 enhancers as a function of cell type-specificity, nerve injury and development. While Pmp22 enhancers marked by active histone modifications were lost or remodeled after injury, we found that these enhancers were permissive in early development prior to Pmp22 upregulation. Pmp22 enhancers contain binding motifs for TEA domain (Tead) transcription factors of the Hippo signaling pathway. We discovered that Tead1 and co-activators Yap and Taz are required for Pmp22 expression, as well as for the expression of Egr2 Tead1 directly binds Pmp22 and Egr2 enhancers early in development and Tead1 binding is induced during myelination, correlating with Pmp22 expression. The data identify Tead1 as a novel regulator of Pmp22 expression during development in concert with Sox10 and Egr2. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Mechanosensory organ regeneration in zebrafish depends on a population of multipotent progenitor cells kept latent by Schwann cells.

    Science.gov (United States)

    Sánchez, Mario; Ceci, Maria Laura; Gutiérrez, Daniela; Anguita-Salinas, Consuelo; Allende, Miguel L

    2016-04-07

    Regenerating damaged tissue is a complex process, requiring progenitor cells that must be stimulated to undergo proliferation, differentiation and, often, migratory behaviors and morphological changes. Multiple cell types, both resident within the damaged tissue and recruited to the lesion site, have been shown to participate. However, the cellular and molecular mechanisms involved in the activation of progenitor cell proliferation and differentiation after injury, and their regulation by different cells types, are not fully understood. The zebrafish lateral line is a suitable system to study regeneration because most of its components are fully restored after damage. The posterior lateral line (PLL) is a mechanosensory system that develops embryonically and is initially composed of seven to eight neuromasts distributed along the trunk and tail, connected by a continuous stripe of interneuromastic cells (INCs). The INCs remain in a quiescent state owing to the presence of underlying Schwann cells. They become activated during development to form intercalary neuromasts. However, no studies have described if INCs can participate in a regenerative event, for example, after the total loss of a neuromast. We used electroablation in transgenic larvae expressing fluorescent proteins in PLL components to completely ablate single neuromasts in larvae and adult fish. This injury results in discontinuity of the INCs, Schwann cells, and the PLL nerve. In vivo imaging showed that the INCs fill the gap left after the injury and can regenerate a new neuromast in the injury zone. Further, a single INC is able to divide and form all cell types in a regenerated neuromast and, during this process, it transiently expresses the sox2 gene, a neural progenitor cell marker. We demonstrate a critical role for Schwann cells as negative regulators of INC proliferation and neuromast regeneration, and that this inhibitory property is completely dependent on active ErbB signaling. The potential

  9. The insulin-like growth factors I and II stimulate proliferation of different types of Schwann cells

    DEFF Research Database (Denmark)

    Sondell, M; Svenningsen, Åsa Fex; Kanje, M

    1997-01-01

    A combination of immunocytochemistry for glial specific antigens and bromodeoxyuridine (BrdU) and teasing was used to identify proliferating cells in cultured rat sciatic nerve segments. The nerve segments were exposed to insulin, or the insulin-like growth factors IGF-I and IGF-II. Teasing in co......, truncated IGF-I promoted proliferation of Schwann cells of myelinated nerve fibres while insulin increased proliferation of both cell types....

  10. ErbB expressing Schwann cells control lateral line progenitor cells via non-cell-autonomous regulation of Wnt/β-catenin.

    Science.gov (United States)

    Lush, Mark E; Piotrowski, Tatjana

    2014-03-18

    Proper orchestration of quiescence and activation of progenitor cells is crucial during embryonic development and adult homeostasis. We took advantage of the zebrafish sensory lateral line to define niche-progenitor interactions to understand how integration of diverse signaling pathways spatially and temporally regulates the coordination of these processes. Our previous studies demonstrated that Schwann cells play a crucial role in negatively regulating lateral line progenitor proliferation. Here we demonstrate that ErbB/Neuregulin signaling is not only required for Schwann cell migration but that it plays a continued role in postmigratory Schwann cells. ErbB expressing Schwann cells inhibit lateral line progenitor proliferation and differentiation through non-cell-autonomous inhibition of Wnt/β-catenin signaling. Subsequent activation of Fgf signaling controls sensory organ differentiation, but not progenitor proliferation. In addition to the lateral line, these findings have important implications for understanding how niche-progenitor cells segregate interactions during development, and how they may go wrong in disease states. DOI: http://dx.doi.org/10.7554/eLife.01832.001.

  11. Essential and distinct roles for cdc42 and rac1 in the regulation of Schwann cell biology during peripheral nervous system development

    DEFF Research Database (Denmark)

    Benninger, Yves; Thurnherr, Tina; Pereira, Jorge A

    2007-01-01

    During peripheral nervous system (PNS) myelination, Schwann cells must interpret extracellular cues to sense their environment and regulate their intrinsic developmental program accordingly. The pathways and mechanisms involved in this process are only partially understood. We use tissue-specific...

  12. Schwann Cell and Axon: An Interlaced Unit-From Action Potential to Phenotype Expression.

    Science.gov (United States)

    Court, Felipe A; Alvarez, Jaime

    2016-01-01

    Here we propose a model of a peripheral axon with a great deal of autonomy from its cell body-the autonomous axon-but with a substantial dependence on its ensheathing Schwann cell (SC), the axon-SC unit. We review evidence in several fields and show that (i) axons can extend sprouts and grow without the concurrence of the cell body, but regulated by SCs; (ii) axons synthesize their proteins assisted by SCs that supply them with ribosomes and, probably, with mRNAs by way of exosomes; (iii) the molecular organization of the axoplasm, i.e., its phenotype, is regulated by the SC, as illustrated by the axonal microtubular content, which is down-regulated by the SC; and (iv) the axon has a program for self-destruction that is boosted by the SC. The main novelty of this model axon-SC unit is that it breaks with the notion that all proteins of the nerve cell are specified by its own nucleus. The notion of a collaborative specification of the axoplasm by more than one nucleus, which we present here, opens a new dimension in the understanding of the nervous system in health and disease and is also a frame of reference to understand other tissues or cell associations.

  13. Human autologous serum as a substitute for fetal bovine serum in human Schwann cell culture.

    Directory of Open Access Journals (Sweden)

    Parisa Goodarzi

    2014-04-01

    Full Text Available Nowadays, cell -based and tissue engineered products have opened new horizons in treatment of incurable nervous system disorders. The number of studies on the role of Schwann cells (SC in treating nervous disorders is higher than other cell types. Different protocols have been suggested for isolation and expansion of SC which most of them have used multiple growth factors, mitogens and fetal bovine sera (FBS in culture medium. Because of potential hazards of animal-derived reagents, this study was designed to evaluate the effect of replacing FBS with human autologous serum (HAS on SC's yield and culture parameters. Samples from 10 peripheral nerve biopsies were retrieved and processed under aseptic condition. The isolated cells cultured in FBS (1st group or autologous serum (2nd group. After primary culture the cells were seeded at 10000 cell/cm2 in a 12 wells cell culture plate for each group. At 100% confluency, the cell culture parameters (count, viability, purity and culture duration of 2 groups were compared using paired t-test. The average donors' age was 35.80 (SD=13.35 and except for 1 sample the others cultured successfully. In first group, the averages of cell purity, viability and culture duration were 97% (SD=1.32, 97/33% (SD=1.22 and 11.77 (SD=2.58 days respectively. This parameters were 97.33% (SD=1.00, 97.55% (SD=1.33 and 10.33 days (SD=1.65 in second group. The difference of cell count, purity and viability were not significant between 2 groups (P>0.05. The cells of second group reached to 100% confluency in shorter period of time (P=0.03. The results of this study showed that autologous serum can be a good substitute for FBS in human SC culture. This can reduce the costs and improve the safety of cell product for clinical application.

  14. Mycobacterium leprae downregulates the expression of PHEX in Schwann cells and osteoblasts

    Directory of Open Access Journals (Sweden)

    Sandra R Boiça Silva

    2010-08-01

    Full Text Available Neuropathy and bone deformities, lifelong sequelae of leprosy that persist after treatment, result in significant impairment to patients and compromise their social rehabilitation. Phosphate-regulating gene with homologies to endopeptidase on the X chromosome (PHEX is a Zn-metalloendopeptidase, which is abundantly expressed in osteoblasts and many other cell types, such as Schwann cells, and has been implicated in phosphate metabolism and X-linked rickets. Here, we demonstrate that Mycobacterium leprae stimulation downregulates PHEX transcription and protein expression in a human schwannoma cell line (ST88-14 and human osteoblast lineage. Modulation of PHEX expression was observed to a lesser extent in cells stimulated with other species of mycobacteria, but was not observed in cultures treated with latex beads or with the facultative intracellular bacterium Salmonella typhimurium. Direct downregulation of PHEX by M. leprae could be involved in the bone resorption observed in leprosy patients. This is the first report to describe PHEX modulation by an infectious agent.

  15. Preparation of graphene oxide/polyacrylamide composite hydrogel and its effect on Schwann cells attachment and proliferation.

    Science.gov (United States)

    Li, Guicai; Zhao, Yinxin; Zhang, Luzhong; Gao, Ming; Kong, Yan; Yang, Yumin

    2016-07-01

    Various hydrogel materials have been developed for improving the regeneration of peripheral nerve. Among which the graphene related hydrogels with excellent mechanical properties have attracted great attention. However, the effect of these hydrogels on peripheral nerve regeneration is still unclear. In the present study, the graphene oxide/polyacrylamide (GO/PAM) composite hydrogels were fabricated by in-situ free radical polymerization. The morphology, wettability, composition, swelling ratio, mechanical property and degradation behavior of the prepared GO/PAM composite hydrogels were separately characterized. The effect of GO/PAM hydrogel on the attachment and proliferation of Schwann cells was evaluated. Moreover, the release of biofactors by Schwann cells and adsorption of matrix proteins were further measured. The results showed that the color of the hydrogel became darker with the increased GO concentration, while the surface pore structure also displayed large variation when GO concentration was increased. The hydrophobicity and mechanical properties of hydrogel were increased with the ascending GO concentration. In addition, the variation of GO concentration displayed no obvious influence on the degradation of the composite hydrogel in different medium. The GO/PAM composite hydrogel with 0.4% GO (G0.4) could effectively enhance the attachment and proliferation of Schwann cells. Furthermore, the cells on G0.4 hydrogel displayed higher biofactors release and larger matrix adsorption than other samples. The results demonstrated that GO with suitable concentration in PAM hydrogel could effectively promote Schwann cell growth. The study may provide an important experimental basis for the design and development of new nerve grafts with potential application for peripheral nerve regeneration. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Schwann cells are activated by ATP released from neurons in an in vitro cellular model of Miller Fisher syndrome.

    Science.gov (United States)

    Rodella, Umberto; Negro, Samuele; Scorzeto, Michele; Bergamin, Elisanna; Jalink, Kees; Montecucco, Cesare; Yuki, Nobuhiro; Rigoni, Michela

    2017-05-01

    The neuromuscular junction is exposed to different types of insult, including mechanical trauma, toxins and autoimmune antibodies and, accordingly, has retained through evolution a remarkable ability to regenerate. Regeneration is driven by multiple signals that are exchanged among the cellular components of the junction. These signals are largely unknown. Miller Fisher syndrome is a variant of Guillain-Barré syndrome caused by autoimmune antibodies specific for epitopes of peripheral axon terminals. Using an animal model of Miller Fisher syndrome, we recently reported that a monoclonal anti-polysialoganglioside GQ1b antibody plus complement damages nerve terminals with production of mitochondrial hydrogen peroxide, which activates Schwann cells. Several additional signaling molecules are likely to be involved in the activation of the regeneration program in these cells. Using an in vitro cellular model consisting of co-cultured primary neurons and Schwann cells, we found that ATP is released by neurons injured by the anti-GQ1b antibody plus complement. Neuron-derived ATP acts as an alarm messenger for Schwann cells, where it induces the activation of intracellular pathways, including calcium signaling, cAMP and CREB, which, in turn, produce signals that promote nerve regeneration. These results contribute to defining the cross-talk taking place at the neuromuscular junction when it is attacked by anti-gangliosides autoantibodies plus complement, which is crucial for nerve regeneration and is also likely to be important in other peripheral neuropathies. © 2017. Published by The Company of Biologists Ltd.

  17. Schwann cells are activated by ATP released from neurons in an in vitro cellular model of Miller Fisher syndrome

    Directory of Open Access Journals (Sweden)

    Umberto Rodella

    2017-05-01

    Full Text Available The neuromuscular junction is exposed to different types of insult, including mechanical trauma, toxins and autoimmune antibodies and, accordingly, has retained through evolution a remarkable ability to regenerate. Regeneration is driven by multiple signals that are exchanged among the cellular components of the junction. These signals are largely unknown. Miller Fisher syndrome is a variant of Guillain–Barré syndrome caused by autoimmune antibodies specific for epitopes of peripheral axon terminals. Using an animal model of Miller Fisher syndrome, we recently reported that a monoclonal anti-polysialoganglioside GQ1b antibody plus complement damages nerve terminals with production of mitochondrial hydrogen peroxide, which activates Schwann cells. Several additional signaling molecules are likely to be involved in the activation of the regeneration program in these cells. Using an in vitro cellular model consisting of co-cultured primary neurons and Schwann cells, we found that ATP is released by neurons injured by the anti-GQ1b antibody plus complement. Neuron-derived ATP acts as an alarm messenger for Schwann cells, where it induces the activation of intracellular pathways, including calcium signaling, cAMP and CREB, which, in turn, produce signals that promote nerve regeneration. These results contribute to defining the cross-talk taking place at the neuromuscular junction when it is attacked by anti-gangliosides autoantibodies plus complement, which is crucial for nerve regeneration and is also likely to be important in other peripheral neuropathies.

  18. Ponatinib promotes a G1 cell-cycle arrest of merlin/NF2-deficient human schwann cells.

    Science.gov (United States)

    Petrilli, Alejandra M; Garcia, Jeanine; Bott, Marga; Klingeman Plati, Stephani; Dinh, Christine T; Bracho, Olena R; Yan, Denise; Zou, Bing; Mittal, Rahul; Telischi, Fred F; Liu, Xue-Zhong; Chang, Long-Sheng; Welling, D Bradley; Copik, Alicja J; Fernández-Valle, Cristina

    2017-05-09

    Neurofibromatosis type 2 (NF2) is a genetic syndrome that predisposes individuals to multiple benign tumors of the central and peripheral nervous systems, including vestibular schwannomas. Currently, there are no FDA approved drug therapies for NF2. Loss of function of merlin encoded by the NF2 tumor suppressor gene leads to activation of multiple mitogenic signaling cascades, including platelet-derived growth factor receptor (PDGFR) and SRC in Schwann cells. The goal of this study was to determine whether ponatinib, an FDA-approved ABL/SRC inhibitor, reduced proliferation and/or survival of merlin-deficient human Schwann cells (HSC). Merlin-deficient HSC had higher levels of phosphorylated PDGFRα/β, and SRC than merlin-expressing HSC. A similar phosphorylation pattern was observed in phospho-protein arrays of human vestibular schwannoma samples compared to normal HSC. Ponatinib reduced merlin-deficient HSC viability in a dose-dependent manner by decreasing phosphorylation of PDGFRα/β, AKT, p70S6K, MEK1/2, ERK1/2 and STAT3. These changes were associated with decreased cyclin D1 and increased p27Kip1levels, leading to a G1 cell-cycle arrest as assessed by Western blotting and flow cytometry. Ponatinib did not modulate ABL, SRC, focal adhesion kinase (FAK), or paxillin phosphorylation levels. These results suggest that ponatinib is a potential therapeutic agent for NF2-associated schwannomas and warrants further in vivo investigation.

  19. Exogenous schwann cells migrate, remyelinate and promote clinical recovery in experimental auto-immune encephalomyelitis.

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    Violetta Zujovic

    Full Text Available Schwann cell (SC transplantation is currently being discussed as a strategy that may promote functional recovery in patients with multiple sclerosis (MS and other inflammatory demyelinating diseases of the central nervous system (CNS. However this assumes they will not only survive but also remyelinate demyelinated axons in the chronically inflamed CNS. To address this question we investigated the fate of transplanted SCs in myelin oligodendrocyte glycoprotein (MOG-induced experimental autoimmune encephalomyelitis (EAE in the Dark Agouti rat; an animal model that reproduces the complex inflammatory demyelinating immunopathology of MS. We now report that SCs expressing green fluorescent protein (GFP-SCs allografted after disease onset not only survive but also migrate to remyelinate lesions in the inflamed CNS. GFP-SCs were detected more frequently in the parenchyma after direct injection into the spinal cord, than via intra-thecal delivery into the cerebrospinal fluid. In both cases the transplanted cells intermingled with astrocytes in demyelinated lesions, aligned with axons and by twenty one days post transplantation had formed Pzero protein immunoreactive internodes. Strikingly, GFP-SCs transplantation was associated with marked decrease in clinical disease severity in terms of mortality; all GFP-SCs transplanted animals survived whilst 80% of controls died within 40 days of disease.

  20. Exogenous Schwann Cells Migrate, Remyelinate and Promote Clinical Recovery in Experimental Auto-Immune Encephalomyelitis

    Science.gov (United States)

    Zujovic, Violetta; Doucerain, Cédric; Hidalgo, Antoine; Bachelin, Corinne; Lachapelle, François; Weissert, Robert; Stadelmann, Christine; Linington, Chris; Evercooren, Anne Baron-Van

    2012-01-01

    Schwann cell (SC) transplantation is currently being discussed as a strategy that may promote functional recovery in patients with multiple sclerosis (MS) and other inflammatory demyelinating diseases of the central nervous system (CNS). However this assumes they will not only survive but also remyelinate demyelinated axons in the chronically inflamed CNS. To address this question we investigated the fate of transplanted SCs in myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) in the Dark Agouti rat; an animal model that reproduces the complex inflammatory demyelinating immunopathology of MS. We now report that SCs expressing green fluorescent protein (GFP-SCs) allografted after disease onset not only survive but also migrate to remyelinate lesions in the inflamed CNS. GFP-SCs were detected more frequently in the parenchyma after direct injection into the spinal cord, than via intra-thecal delivery into the cerebrospinal fluid. In both cases the transplanted cells intermingled with astrocytes in demyelinated lesions, aligned with axons and by twenty one days post transplantation had formed Pzero protein immunoreactive internodes. Strikingly, GFP-SCs transplantation was associated with marked decrease in clinical disease severity in terms of mortality; all GFP-SCs transplanted animals survived whilst 80% of controls died within 40 days of disease. PMID:22984406

  1. Inhibition of SIRT2 in merlin/NF2-mutant Schwann cells triggers necrosis.

    Science.gov (United States)

    Petrilli, Alejandra; Bott, Marga; Fernández-Valle, Cristina

    2013-12-01

    Mutations in the NF2 gene cause Neurofibromatosis Type 2 (NF2), a disorder characterized by the development of schwannomas, meningiomas and ependymomas in the nervous system. Merlin, a tumor suppressor encoded by the NF2 gene, modulates activity of many essential signaling pathways. Yet despite increasing knowledge of merlin function, there are no NF2 drug therapies. In a pilot high-throughput screen of the Library of Pharmacologically Active Compounds, we assayed for compounds capable of reducing viability of mouse Schwann cells (MSC) with Nf2 inactivation as a cellular model for human NF2 schwannomas. AGK2, a SIRT2 (sirtuin 2) inhibitor, was identified as a candidate compound. SIRT2 is one of seven mammalian sirtuins that are NAD+-dependent protein deacetylases. We show that merlin-mutant MSC have higher expression levels of SIRT2 and lower levels of overall lysine acetylation than wild-type control MSC. Pharmacological inhibition of SIRT2 decreases merlin-mutant MSC viability in a dose dependent manner without substantially reducing wild-type MSC viability. Inhibition of SIRT2 activity in merlin-mutant MSC is accompanied by release of lactate dehydrogenase and high mobility group box 1 protein into the medium in the absence of significant apoptosis, autophagy, or cell cycle arrest. These findings suggest that SIRT2 inhibition triggers necrosis of merlin-mutant MSCs and that SIRT2 is a potential NF2 drug target.

  2. Schwann cell transplantation and descending propriospinal regeneration after spinal cord injury.

    Science.gov (United States)

    Deng, Ling-Xiao; Walker, Chandler; Xu, Xiao-Ming

    2015-09-04

    After spinal cord injury (SCI), poor ability of damaged axons of the central nervous system (CNS) to regenerate causes very limited functional recovery. Schwann cells (SCs) have been widely explored as promising donors for transplantation to promote axonal regeneration in the CNS including the spinal cord. Compared with other CNS axonal pathways, injured propriospinal tracts display the strongest regenerative response to SC transplantation. Even without providing additional neurotrophic factors, propriospinal axons can grow into the SC environment which is rarely seen in supraspinal tracts. Propriospinal tract has been found to respond to several important neurotrophic factors secreted by SCs. Therefore, the SC is considered to be one of the most promising candidates for cell-based therapies for SCI. Since many reviews have already appeared on topics of SC transplantation in SCI repair, this review will focus particularly on the rationale of SC transplantation in mediating descending propriospinal axonal regeneration as well as optimizing such regeneration by using different combinatorial strategies. This article is part of a Special Issue entitled SI: Spinal cord injury. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. A new electrospun graphene-silk fibroin composite scaffolds for guiding Schwann cells.

    Science.gov (United States)

    Zhao, Yahong; Gong, Jiahuan; Niu, Changmei; Wei, Ziwei; Shi, Jiaqi; Li, Guohui; Yang, Yumin; Wang, Hongbo

    2017-12-01

    Graphene (Gr) has been made of various forms used for repairing peripheral nerve injury with favorable electroactivity, however, graphene-based scaffolds in peripheral nerve regeneration are still rarely reported due to the difficulty of realizing uniform dispersion of graphene and electroactive materials at nanoscale as well as lacking biocompatibility. In this paper, graphene-silk fibroin (SF) composite nanofiber membranes with different mass ratios were prepared via electrospinning. Microscopic observation revealed that electrospun Gr/SF membranes had a nanofibrous structure. Electrochemical analysis provided electroactivity characterization of the Gr/SF membranes. The physiochemical results showed that the physiochemical properties of electrospun Gr/SF membranes could be changed by varying Gr concentration. Swelling ratio and contact angle measurements confirmed that electrospun Gr/SF membranes possessed large absorption capacity and hydrophilic surface, and the mechanical property was improved with increasing Gr concentration. Additionally, in-vitro cytotoxicity with L929 revealed that all the electrospun Gr/SF membranes are biocompatible. Moreover, the morphology and quantity showed that the membranes supported the survival and growth of the cultured Schwann cells. Collectively, all of the results suggest that the electrospun Gr/SF membranes combine the excellent electrically conductivity and mechanical strength of the graphene with biocompatibility property of silk to mimic the natural neural cell micro-environment for nerve development.

  4. Hierarchical thermoplastic rippled nanostructures regulate Schwann cell adhesion, morphology and spatial organization.

    Science.gov (United States)

    Masciullo, Cecilia; Dell'Anna, Rossana; Tonazzini, Ilaria; Böettger, Roman; Pepponi, Giancarlo; Cecchini, Marco

    2017-10-12

    Periodic ripples are a variety of anisotropic nanostructures that can be realized by ion beam irradiation on a wide range of solid surfaces. Only a few authors have investigated these surfaces for tuning the response of biological systems, probably because it is challenging to directly produce them in materials that well sustain long-term cellular cultures. Here, hierarchical rippled nanotopographies with a lateral periodicity of ∼300 nm are produced from a gold-irradiated germanium mold in polyethylene terephthalate (PET), a biocompatible polymer approved by the US Food and Drug Administration for clinical applications, by a novel three-step embossing process. The effects of nano-ripples on Schwann Cells (SCs) are studied in view of their possible use for nerve-repair applications. The data demonstrate that nano-ripples can enhance short-term SC adhesion and proliferation (3-24 h after seeding), drive their actin cytoskeleton spatial organization and sustain long-term cell growth. Notably, SCs are oriented perpendicularly with respect to the nanopattern lines. These results provide information about the possible use of hierarchical nano-rippled elements for nerve-regeneration protocols.

  5. Puerarin may protect against Schwann cell damage induced by glucose fluctuation.

    Science.gov (United States)

    Xue, Bing; Wang, Lin; Zhang, Zhe; Wang, Rui; Xia, Xin-Xin; Han, Ping-Ping; Cao, Li-Jun; Liu, Yong-Hui; Sun, Lian-Qing

    2017-07-01

    Puerarin is one of the major active ingredients in Gegen, a traditional Chinese herb that has been reported to have a wide variety of beneficial pharmacology functions. Previous studies have implicated that the damaging effects of hyperglycemia resulting from oxidative stress and glucose fluctuation may be more dangerous than constant high glucose in the development of diabetes-related complications. The present study focuses on the effects of puerarin on glucose fluctuation-induced oxidative stress-induced Schwann cell (SC) apoptosis in vitro. Primarily cultured SCs were exposed to different conditions and the effect of puerarin on cell viability was determined by MTT assays. Intracellular reactive oxygen species (ROS) generation and mitochondrial transmembrane potential were detected by flow cytometry analysis. Apoptosis was confirmed by the Annexin V-FITC/PI and TUNEL method. Quantitative real-time reverse transcriptase polymerase chain reaction was performed to analyze the expression levels of bax and bcl-2. Western blot was performed to analyze the expression levels of some important transcription factors and proteins. The results showed that incubating SCs with intermittent high glucose for 48 h decreased cell viability and increased the number of apoptotic cells whereas treating with puerarin protected SCs against glucose fluctuation-induced cell damage. Further study demonstrated that puerarin suppressed activation of apoptosis-related proteins including PARP and caspase-3, downregulation of bcl-2, and upregulation of intracellular distribution of bax from cytosol to mitochondria, which was induced by glucose fluctuation. Moreover, puerarin inhibited the elevation of intracellular ROS and mitochondrial depolarization induced by glucose fluctuation. These results suggest that puerarin may protect SCs against glucose fluctuation-induced cell injury through inhibiting apoptosis as well as oxidative stress.

  6. Lentiviral-mediated transfer of CNTF to schwann cells within reconstructed peripheral nerve grafts enhances adult retinal ganglion cell survival and axonal regeneration

    NARCIS (Netherlands)

    Hu, Ying; Leaver, Simone G; Plant, Giles W; Hendriks, William T J; Niclou, Simone P; Verhaagen, J.; Harvey, Alan R; Cui, Qi

    We recently described a method for reconstituting peripheral nerve (PN) sheaths using adult Schwann cells (SCs). Reconstructed PN tissue grafted onto the cut optic nerve supports the regeneration of injured adult rat retinal ganglion cell (RGC) axons. To determine whether genetic manipulation of

  7. Schwann cell-derived factors support serotoninergic neuron survival and promote neurite outgrowth

    Directory of Open Access Journals (Sweden)

    R Pellitteri

    2009-12-01

    Full Text Available During embryogenesis and the postnatal period, neurons and glia interact in the development and differentiation of specific populations of nerve cells. Both in the peripheral (PNS and in the central nervous system (CNS, glial cells have been shown in various experimental conditions to constitute a favorable substrate for neural adhesion, neural polarity, shape and axonal extension, while numerous soluble molecules secreted by neurons influence the survival and differentiation of the glial cells themselves. The aim of the present work was to investigate the influence of postnatal Schwann cells (SC on embryonic serotoninergic (5-HT neurons of the raphe, in order to study the possible influence of the peripheral glia on the CNS neurons. Cultures of SC from sciatic nerve of postnatal rats and neurons from rat embryonic rhombencephalon were successfully established and cells were immunocytochemically characterized. The number of 5-HT neurons, and the number and length of their branches were quantified in the cultures of 5-HT neurons, in cultures added with Nerve Growth Factor (NGF and Insulin-like Growth Factor I (IGF-I, in co-cultures with SC and in cultures added with conditioned medium obtained from SC cultures. The results indicated that SC have the capacity to promote the survival and growth of 5-HT neurons in culture, and that this activity is mediated by soluble factors. Although the precise nature and mechanism of action of the growth factor or factors produced by SC in the presence of 5-HT neurons was not identified, our results add more data on the possible activity of the peripheral glia in promoting and enhancing the survival and outgrowth of the CNS neurons.

  8. Mechanosensitivity of Embryonic Neurites Promotes Their Directional Extension and Schwann Cells Progenitors Migration

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    Gonzalo Rosso

    2017-11-01

    Full Text Available Background/Aims: Migration of Schwann cells (SCs progenitors and neurite outgrowth from embryonic dorsal root ganglions (DRGs are two central events during the development of the peripheral nervous system (PNS. How these two enthralling events preceding myelination are promoted is of great relevance from basic research and clinical aspects alike. Recent evidence demonstrates that biophysical cues (extracellular matrix stiffness and biochemical signaling act in concert to regulate PNS myelination. Microenvironment stiffness of SCs progenitors and embryonic neurites dynamically changes during development. Methods: DRG explants were isolated from day 12.5 to 13.5 mice embryos and plated on laminin-coated substrates with varied stiffness values. After 4 days in culture and immunostaining with specific markers, neurite outgrowth pattern, SCs progenitors migration, and growth cone shape and advance were analyzed with confocal fluorescence microscopy. Results: We found out that growing substrate stiffness promotes directional neurite outgrowth, SCs progenitors migration, growth cone advance and presumably axons fasciculation. Conclusions: DRG explants are in vitro models for the research of PNS development, myelination and regeneration. Consequently, we conclude the following: Our observations point out the importance of mechanosensitivity for the PNS. At the same time, they prompt the investigation of the important yet unclear links between PNS biomechanics and inherited neuropathies with myelination disorders such as Charcot-Marie-Tooth 1A and hereditary neuropathy with liability to pressure palsies. Finally, they encourage the consideration of mechanosensitivity in bioengineering of scaffolds to aid nerve regeneration after injury.

  9. Collagen nerve conduits promote enhanced axonal regeneration, schwann cell association, and neovascularization compared to silicone conduits.

    Science.gov (United States)

    Kemp, Stephen W P; Syed, Shahbaz; Walsh, Walsh; Zochodne, Douglas W; Midha, Rajiv

    2009-08-01

    Peripheral nerve regeneration within guidance conduits involves a critical association between regenerating axons, Schwann cells (SCs), and neovascularization. However, it is currently unknown if there is a greater association between these factors in nonpermeable versus semipermeable nerve guide conduits. We therefore examined this collaboration in both silicone- and collagen-based nerve conduits in both 5- and 10-mm-injury gaps in rat sciatic nerves. Results indicate that collagen conduits promoted enhanced axonal and SC regeneration and association when compared to silicone conduits in the shorter 5-mm-gap model. In addition, collagen tubes displayed enhanced neovascularization over silicone conduits, suggesting that these three factors are intimately related in successful peripheral nerve regeneration. At later time points (1- and 2-month analysis) in a 10-mm-gap model, collagen tubes displayed enhanced axonal regeneration, myelination, and vascularization when compared to silicone-based conduits. Results from these studies suggest that regenerating cables within collagen-based conduits are revascularized earlier and more completely, which in turn enhances peripheral nerve regeneration through these nerve guides as compared to silicone conduits.

  10. Schwann cell mitochondria as key regulators in the development and maintenance of peripheral nerve axons.

    Science.gov (United States)

    Ino, Daisuke; Iino, Masamitsu

    2017-03-01

    Formation of myelin sheaths by Schwann cells (SCs) enables rapid and efficient transmission of action potentials in peripheral axons, and disruption of myelination results in disorders that involve decreased sensory and motor functions. Given that construction of SC myelin requires high levels of lipid and protein synthesis, mitochondria, which are pivotal in cellular metabolism, may be potential regulators of the formation and maintenance of SC myelin. Supporting this notion, abnormal mitochondria are found in SCs of neuropathic peripheral nerves in both human patients and the relevant animal models. However, evidence for the importance of SC mitochondria in myelination has been limited, until recently. Several studies have recently used genetic approaches that allow SC-specific ablation of mitochondrial metabolic activity in living animals to show the critical roles of SC mitochondria in the development and maintenance of peripheral nerve axons. Here, we review current knowledge about the involvement of SC mitochondria in the formation and dysfunction of myelinated axons in the peripheral nervous system.

  11. Permissive Schwann cell graft/spinal cord interfaces for axon regeneration.

    Science.gov (United States)

    Williams, Ryan R; Henao, Martha; Pearse, Damien D; Bunge, Mary Bartlett

    2015-01-01

    The transplantation of autologous Schwann cells (SCs) to repair the injured spinal cord is currently being evaluated in a clinical trial. In support, this study determined properties of spinal cord/SC bridge interfaces that enabled regenerated brainstem axons to cross them, possibly leading to improvement in rat hindlimb movement. Fluid bridges of SCs and Matrigel were placed in complete spinal cord transections. Compared to pregelled bridges of SCs and Matrigel, they improved regeneration of brainstem axons across the rostral interface. The regenerating brainstem axons formed synaptophysin(+) bouton-like terminals and contacted MAP2A(+) dendrites at the caudal interface. Brainstem axon regeneration was directly associated with glial fibrillary acidic protein (GFAP(+)) astrocyte processes that elongated into the SC bridge. Electron microscopy revealed that axons, SCs, and astrocytes were enclosed together within tunnels bounded by a continuous basal lamina. Neuroglycan (NG2) expression was associated with these tunnels. One week after injury, the GFAP(+) processes coexpressed nestin and brain lipid-binding protein, and the tips of GFAP(+)/NG2(+) processes extended into the bridges together with the regenerating brainstem axons. Both brainstem axon regeneration and number of GFAP(+) processes in the bridges correlated with improvement in hindlimb locomotion. Following SCI, astrocytes may enter a reactive state that prohibits axon regeneration. Elongation of astrocyte processes into SC bridges, however, and formation of NG2(+) tunnels enable brainstem axon regeneration and improvement in function. It is important for spinal cord repair to define conditions that favor elongation of astrocytes into lesions/transplants.

  12. Implications of Schwann Cells Biomechanics and Mechanosensitivity for Peripheral Nervous System Physiology and Pathophysiology

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    Gonzalo Rosso

    2017-10-01

    Full Text Available The presence of bones around the central nervous system (CNS provides it with highly effective physiologically crucial mechanical protection. The peripheral nervous system (PNS, in contrast, lacks this barrier. Consequently, the long held belief is that the PNS is mechanically vulnerable. On the other hand, the PNS is exposed to a variety of physiological mechanical stresses during regular daily activities. This fact prompts us to question the dogma of PNS mechanical vulnerability. As a matter of fact, impaired mechanics of PNS nerves is associated with neuropathies with the liability to mechanical stresses paralleled by significant impairment of PNS physiological functions. Our recent biomechanical integrity investigations on nerve fibers from wild-type and neuropathic mice lend strong support in favor of natural mechanical protection of the PNS and demonstrate a key role of Schwann cells (SCs therein. Moreover, recent works point out that SCs can sense mechanical properties of their microenvironment and the evidence is growing that SCs mechanosensitivity is important for PNS development and myelination. Hence, SCs exhibit mechanical strength necessary for PNS mechanoprotection as well as mechanosensitivity necessary for PNS development and myelination. This mini review reflects on the intriguing dual ability of SCs and implications for PNS physiology and pathophysiology.

  13. Epalrestat increases intracellular glutathione levels in Schwann cells through transcription regulation

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    Keisuke Sato

    2014-01-01

    Full Text Available Epalrestat (EPS, approved in Japan, is the only aldose reductase inhibitor that is currently available for the treatment of diabetic neuropathy. Here we report that EPS at near-plasma concentration increases the intracellular levels of glutathione (GSH, which is important for protection against oxidative injury, through transcription regulation. Treatment of Schwann cells with EPS caused a dramatic increase in intracellular GSH levels. EPS increased the mRNA levels of γ-glutamylcysteine synthetase (γ-GCS, the enzyme catalyzing the first and rate-limiting step in de novo GSH synthesis. Nuclear factor erythroid 2-related factor 2 (Nrf2 is a key transcription factor that plays a central role in regulating the expression of γ-GCS. ELISA revealed that EPS increased nuclear Nrf2 levels. Knockdown of Nrf2 by siRNA suppressed the EPS-induced GSH biosynthesis. Furthermore, pretreatment with EPS reduced the cytotoxicity induced by H2O2, tert-butylhydroperoxide, 2,2'-azobis (2-amidinopropane dihydrochloride, and menadione, indicating that EPS plays a role in protecting against oxidative stress. This is the first study to show that EPS induces GSH biosynthesis via the activation of Nrf2. We suggest that EPS has new beneficial properties that may prevent the development and progression of disorders caused by oxidative stress.

  14. A history of plant biotechnology: from the Cell Theory of Schleiden and Schwann to biotech crops.

    Science.gov (United States)

    Vasil, Indra K

    2008-09-01

    Plant biotechnology is founded on the principles of cellular totipotency and genetic transformation, which can be traced back to the Cell Theory of Matthias Jakob Schleiden and Theodor Schwann, and the discovery of genetic transformation in bacteria by Frederick Griffith, respectively. On the 25th anniversary of the genetic transformation of plants, this review provides a historical account of the evolution of the theoretical concepts and experimental strategies that led to the production and commercialization of biotech (transformed or transgenic) plants expressing many useful genes, and emphasizes the beneficial effects of plant biotechnology on food security, human health, the environment, and conservation of biodiversity. In so doing, it celebrates and pays tribute to the contributions of scores of scientists who laid the foundation of modern plant biotechnology by their bold and unconventional thinking and experimentation. It highlights also the many important lessons to be learnt from the fascinating history of plant biotechnology, the significance of history in science teaching and research, and warns against the danger of the growing trends of ignoring history and historical illiteracy.

  15. Geometrical versus Random β-TCP Scaffolds: Exploring the Effects on Schwann Cell Growth and Behavior.

    Directory of Open Access Journals (Sweden)

    Lauren Sweet

    Full Text Available Numerous studies have demonstrated that Schwann cells (SCs play a role in nerve regeneration; however, their role in innervating a bioceramic scaffold for potential application in bone regeneration is still unknown. Here we report the cell growth and functional behavior of SCs on β-tricalcium phosphate (β-TCP scaffolds arranged in 3D printed-lattice (P-β-TCP and randomly-porous, template-casted (N-β-TCP structures. Our results indicate that SCs proliferated well and expressed the phenotypic markers p75LNGFR and the S100-β subunit of SCs as well as displayed growth morphology on both scaffolds, but SCs showed spindle-shaped morphology with a significant degree of SCs alignment on the P-β-TCP scaffolds, seen to a lesser degree in the N-β-TCP scaffold. The gene expressions of nerve growth factor (β-ngf, neutrophin-3 (nt-3, platelet-derived growth factor (pdgf-bb, and vascular endothelial growth factor (vegf-a were higher at day 7 than at day 14. While no significant differences in protein secretion were measured between these last two time points, the scaffolds promoted the protein secretion at day 3 compared to that on the cell culture plates. These results together imply that the β-TCP scaffolds can support SC cell growth and that the 3D-printed scaffold appeared to significantly promote the alignment of SCs along the struts. Further studies are needed to investigate the early and late stage relationship between gene expression and protein secretion of SCs on the scaffolds with refined characteristics, thus better exploring the potential of SCs to support vascularization and innervation in synthetic bone grafts.

  16. Promoting survival, migration, and integration of transplanted Schwann cells by over-expressing polysialic acid.

    Science.gov (United States)

    Luo, Juan; Bo, Xuenong; Wu, Dongsheng; Yeh, John; Richardson, Peter M; Zhang, Yi

    2011-03-01

    The poor survival and migration of transplanted Schwann cells (SCs) are major drawbacks for their clinical application in cell therapy for neurotrauma. To overcome such drawbacks we genetically modified SCs to over-express polysialic acid (PSA) by lentiviral delivery of polysialyltransferase (PST) to study whether over-expression of PSA could enhance their survival, migration, and integration when transplanted into the spinal cord. It was found that more PSA-expressing SCs (PST/SCs) survived than GFP-expressing SCs (GFP/SCs) after transplantation, although cell loss was still quite significant. PSA expression did not enhance the motility of transplanted SCs in uninjured spinal cord. However, in a spinal cord crush injury model PST/SCs transplanted caudal to the lesion showed that increased number of PST/SCs migrated to the injury site compared with that of GFP/SCs. Induced expression of PSA in spinal cord can further facilitate the infiltration of PST/SCs into the lesion site. PST/SCs were also shown to intermingle well with host spinal cells while GFP/SCs formed boundaries with host tissue. This was confirmed by an in vitro confrontation assay showing that more PST/SCs crossed over to astrocyte territory than GFP/SCs. Furthermore, PST/SCs induced much less expression of glial fibrillary acidic protein and chondroitin sulfate proteoglycan in the surrounding tissues than GFP/SCs, indicating that expression of PSA on SCs do not cause significant stress response of astrocytes. These results demonstrate that expression of PSA on SCs significantly changes their biological properties and makes them more feasible for neural repair after neurotrauma. Copyright © 2010 Wiley-Liss, Inc.

  17. Geometrical versus Random β-TCP Scaffolds: Exploring the Effects on Schwann Cell Growth and Behavior.

    Science.gov (United States)

    Sweet, Lauren; Kang, Yunqing; Czisch, Christopher; Witek, Lukasz; Shi, Yang; Smay, Jim; Plant, Giles W; Yang, Yunzhi

    2015-01-01

    Numerous studies have demonstrated that Schwann cells (SCs) play a role in nerve regeneration; however, their role in innervating a bioceramic scaffold for potential application in bone regeneration is still unknown. Here we report the cell growth and functional behavior of SCs on β-tricalcium phosphate (β-TCP) scaffolds arranged in 3D printed-lattice (P-β-TCP) and randomly-porous, template-casted (N-β-TCP) structures. Our results indicate that SCs proliferated well and expressed the phenotypic markers p75LNGFR and the S100-β subunit of SCs as well as displayed growth morphology on both scaffolds, but SCs showed spindle-shaped morphology with a significant degree of SCs alignment on the P-β-TCP scaffolds, seen to a lesser degree in the N-β-TCP scaffold. The gene expressions of nerve growth factor (β-ngf), neutrophin-3 (nt-3), platelet-derived growth factor (pdgf-bb), and vascular endothelial growth factor (vegf-a) were higher at day 7 than at day 14. While no significant differences in protein secretion were measured between these last two time points, the scaffolds promoted the protein secretion at day 3 compared to that on the cell culture plates. These results together imply that the β-TCP scaffolds can support SC cell growth and that the 3D-printed scaffold appeared to significantly promote the alignment of SCs along the struts. Further studies are needed to investigate the early and late stage relationship between gene expression and protein secretion of SCs on the scaffolds with refined characteristics, thus better exploring the potential of SCs to support vascularization and innervation in synthetic bone grafts.

  18. Transplantation of autologous Schwann cells for the repair of segmental peripheral nerve defects.

    Science.gov (United States)

    Hood, Brian; Levene, Howard B; Levi, Allan D

    2009-02-01

    Peripheral nerve injuries are a source of chronic disability. Incomplete recovery from such injuries results in motor and sensory dysfunction and the potential for the development of chronic pain. The repair of human peripheral nerve injuries with traditional surgical techniques has limited success, particularly when a damaged nerve segment needs to be replaced. An injury to a long segment of peripheral nerve is often repaired using autologous grafting of "noncritical" sensory nerve. Although extensive axonal regeneration can be observed extending into these grafts, recovery of function may be absent or incomplete if the axons fail to reach their intended target. The goal of this review was to summarize the progress that has occurred in developing an artificial neural prosthesis consisting of autologous Schwann cells (SCs), and to detail future directions required in translating this promising therapy to the clinic. In the authors' laboratory, methods are being explored to combine autologous SCs isolated using cell culture techniques with axon guidance channel (AGC) technology to develop the potential to repair critical gap length lesions within the peripheral nervous system. To test the clinical efficacy of such constructs, it is critically important to characterize the fate of the transplanted SCs with regard to cell survival, migration, differentiation, and myelin production. The authors sought to determine whether the use of SC-filled channels is superior or equivalent to strategies that are currently used clinically (for example, autologous nerve grafts). Finally, although many nerve repair paradigms demonstrate evidence of regeneration within the AGC, the authors further sought to determine if the regeneration observed was physiologically relevant by including electrophysiological, behavioral, and pain assessments. If successful, the development of this reparative approach will bring together techniques that are readily available for clinical use and should

  19. A systematic evaluation of Schwann cell injection into acellular cold-preserved nerve grafts.

    Science.gov (United States)

    Jesuraj, Nithya J; Santosa, Katherine B; Newton, Piyaraj; Liu, Z; Hunter, Daniel A; Mackinnon, Susan E; Sakiyama-Elbert, Shelly E; Johnson, Philip J

    2011-04-30

    Peripheral nerve regeneration after injury depends on environmental cues and trophic support. Schwann cells (SCs) secrete trophic factors that promote neuronal survival and help guide axons during regeneration. The addition of SCs to acellular nerve grafts is a promising strategy for enhancing peripheral nerve regeneration; however, inconsistencies in seeding parameters have led to varying results. The current work sought to establish a systematic approach to seeding SCs in cold-preserved acellular nerve grafts. Studies were undertaken to (1) determine the needle gauge for optimal cell survival and minimal epineurial disruption during injection, (2) track the seeded SCs using a commercially available dye, and (3) evaluate the seeding efficiency of SCs in nerve grafts. It was determined that seeding with a 27-gauge needle resulted in the highest viability of SCs with the least damage to the epineurium. In addition, Qtracker(®) dye, a commercially available quantum dot nanocrystal, was used to label SCs prior to transplantation, which allowed visualization of the seeded SCs in nerve grafts. Finally, stereological methods were used to evaluate the seeding efficiency of SCs in nerve grafts immediately after injection and following a 1- or 3-day in vitro incubation in SC growth media. Using a systematic approach, the best needle gauge and a suitable dye for SC visualization in acellular nerve grafts were identified. Seeding efficiency in these grafts was also determined. The findings will lead to improvements ability to assess injection of cells (including SCs) for use with acellular nerve grafts to promote nerve regeneration. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Changes in the Coding and Non-coding Transcriptome and DNA Methylome that Define the Schwann Cell Repair Phenotype after Nerve Injury.

    Science.gov (United States)

    Arthur-Farraj, Peter J; Morgan, Claire C; Adamowicz, Martyna; Gomez-Sanchez, Jose A; Fazal, Shaline V; Beucher, Anthony; Razzaghi, Bonnie; Mirsky, Rhona; Jessen, Kristjan R; Aitman, Timothy J

    2017-09-12

    Repair Schwann cells play a critical role in orchestrating nerve repair after injury, but the cellular and molecular processes that generate them are poorly understood. Here, we perform a combined whole-genome, coding and non-coding RNA and CpG methylation study following nerve injury. We show that genes involved in the epithelial-mesenchymal transition are enriched in repair cells, and we identify several long non-coding RNAs in Schwann cells. We demonstrate that the AP-1 transcription factor C-JUN regulates the expression of certain micro RNAs in repair Schwann cells, in particular miR-21 and miR-34. Surprisingly, unlike during development, changes in CpG methylation are limited in injury, restricted to specific locations, such as enhancer regions of Schwann cell-specific genes (e.g., Nedd4l), and close to local enrichment of AP-1 motifs. These genetic and epigenomic changes broaden our mechanistic understanding of the formation of repair Schwann cell during peripheral nervous system tissue repair. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Antioxidant and Anti-Senescence Effect of Metformin on Mouse Olfactory Ensheathing Cells (mOECs) May Be Associated with Increased Brain-Derived Neurotrophic Factor Levels-An Ex Vivo Study.

    Science.gov (United States)

    Śmieszek, Agnieszka; Stręk, Zuzanna; Kornicka, Katarzyna; Grzesiak, Jakub; Weiss, Christine; Marycz, Krzysztof

    2017-04-20

    Metformin, the popular anti-diabetic drug was shown to exert multiple biological effects. The most recent metformin gained attention as an agent that mobilizes endogenous progenitor cells and enhances regenerative potential of organisms, for example by promoting neurogenesis. In the present study, we examined the role of metformin on mouse olfactory ensheathing cells (mOECs) derived from animals receiving metformin for eight weeks at a concentration equal to 2.8 mg/day. The mOECs expanded ex vivo were characterized in terms of their cellular phenotype, morphology, proliferative activity, viability and accumulation of oxidative stress factors. Moreover, we determined the mRNA and protein levels of brain-derived neurotrophic factor (BDNF), distinguishing the secretion of BDNF by mOECs in cultures and circulating serum levels of BDNF. The mOECs used in the experiment were glial fibrillary acidic protein (GFAP) and p75 neurotrophin receptor (p75 NTR ) positive and exhibited both astrocyte-like and non-myelin Schwann cell-like morphologies. Our results revealed that the proliferation of OECs derived from mice treated with metformin was lowered, when compared to control group. Simultaneously, we noted increased cell viability, reduced expression of markers associated with cellular senescence and a decreased amount of reactive oxygen species. We observed increased mRNA expression of BDNF and its down-stream genes. Obtained results indicate that metformin may exert antioxidant, anti-apoptotic and senolytic action on OECs expanded ex vivo.

  2. Antioxidant and Anti-Senescence Effect of Metformin on Mouse Olfactory Ensheathing Cells (mOECs) May Be Associated with Increased Brain-Derived Neurotrophic Factor Levels—An Ex Vivo Study

    Science.gov (United States)

    Śmieszek, Agnieszka; Stręk, Zuzanna; Kornicka, Katarzyna; Grzesiak, Jakub; Weiss, Christine; Marycz, Krzysztof

    2017-01-01

    Metformin, the popular anti-diabetic drug was shown to exert multiple biological effects. The most recent metformin gained attention as an agent that mobilizes endogenous progenitor cells and enhances regenerative potential of organisms, for example by promoting neurogenesis. In the present study, we examined the role of metformin on mouse olfactory ensheathing cells (mOECs) derived from animals receiving metformin for eight weeks at a concentration equal to 2.8 mg/day. The mOECs expanded ex vivo were characterized in terms of their cellular phenotype, morphology, proliferative activity, viability and accumulation of oxidative stress factors. Moreover, we determined the mRNA and protein levels of brain-derived neurotrophic factor (BDNF), distinguishing the secretion of BDNF by mOECs in cultures and circulating serum levels of BDNF. The mOECs used in the experiment were glial fibrillary acidic protein (GFAP) and p75 neurotrophin receptor (p75NTR) positive and exhibited both astrocyte-like and non-myelin Schwann cell-like morphologies. Our results revealed that the proliferation of OECs derived from mice treated with metformin was lowered, when compared to control group. Simultaneously, we noted increased cell viability, reduced expression of markers associated with cellular senescence and a decreased amount of reactive oxygen species. We observed increased mRNA expression of BDNF and its down-stream genes. Obtained results indicate that metformin may exert antioxidant, anti-apoptotic and senolytic action on OECs expanded ex vivo. PMID:28425952

  3. Netrin-1 induces the migration of Schwann cells via p38 MAPK and PI3K-Akt signaling pathway mediated by the UNC5B receptor

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Jianwei [General Hospital of Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin 300052 (China); Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China); Sun, Xiaolei; Ma, Jianxiong [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China); Ma, Xinlong, E-mail: gengxiao502@163.com [General Hospital of Tianjin Medical University, No. 154, Anshan Road, Heping District, Tianjin 300052 (China); Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China); Zhang, Yang; Li, Fengbo; Li, Yanjun; Zhao, Zhihu [Tianjin Institute of Orthopedics in Traditional Chinese and Western Medicine, No. 155, Munan Road, Tianjin 300050 (China)

    2015-08-14

    Schwann cells (SCs) play an essentially supportive role in the regeneration of injured peripheral nerve system (PNS). As Netrin-1 is crucial for the normal development of nervous system (NS) and can direct the process of damaged PNS regeneration, our study was designed to determine the role of Netrin-1 in RSC96 Schwann cells (an immortalized rat Schwann cell line) proliferation and migration. Our studies demonstrated that Netrin-1 had no effect on RSC96 cells proliferation, while significantly promoted RSC96 cells migration. The Netrin-1-induced RSC96 cells migration was significantly attenuated by inhibition of p38 and PI3K through pretreatment with SB203580 and LY294002 respectively, but not inhibition of MEK1/2 and JNK by U0126-EtOH and SP600125 individually. Treatment with Netrin-1 enhanced the phosphorylation of p38 and Akt. QRT-PCR indicated that Netrin-1 and only its receptors Unc5a, Unc5b and Neogenin were expressed in RSC96 cells, among which Unc5b expressed the most. And UNC5B protein was significantly increased after stimulated by Netrin-1. In conclusion, we show here that Netrin-1-enhanced SCs migration is mediated by activating p38 MAPK and PI3K-Akt signal cascades via receptor UNC5B, which suggests that Netrin-1 could serve as a new therapeutic strategy and has potential application value for PNS regeneration. - Highlights: • Netrin-1 attracts RSC96 Schwann cells migration in a dose dependent manner. • Netrin-1 induced Schwann cells migration is p38 and PI3K-Akt signaling dependent. • UNC5B may be dominant receptor mediating Netrin-1′ effect on RSC96 cells motility. • Netrin-1 may promote peripheral nerve repair by enhancing Schwann cells motility.

  4. Cultured Schwann cells assemble normal-appearing basal lamina only when they ensheathe axons.

    Science.gov (United States)

    Clark, M B; Bunge, M B

    1989-06-01

    Previous work demonstrated that Schwann cells (SCs) must interact with nerve cells (NCs) in order to generate their basal lamina (BL) in culture (M. B. Bunge, A. K. Williams, and P. M. Wood, 1982, Dev. Biol. 92, 449-460). The present study was undertaken to determine if this interaction requires proximity of NCs to SCs. Coverslips carrying isolated SCs were placed into culture dishes containing normally contacting SCs + NCs, NCs alone, or SCs alone and were maintained in these dishes for 3-4 weeks in medium known to foster the differentiation of axon-related SCs (BL formation, myelination). The SCs on the coverslip were not allowed to contact the cells in the culture dish. In other experiments, SCs isolated on coverslips were simply cultured in medium conditioned by contacting SCs + NCs, NCs alone, or SCs alone. The accumulation of BL components was monitored by light microscopic immunocytochemistry and the assembly of BL structure assessed by electron microscopy. When SCs were cocultured with but not contacted by neurons, immunostaining for BL constituents revealed a patchy deposition of material in sharp contrast to the linear deposition observed on axon-related SCs. Electron microscopy of these isolated SCs revealed short segments of BL, strands or clumps of BL-like material extending away from the cell surface, and accumulation of this material between cells. A greater number of isolated SCs were immunostained when grown with contacting SCs + NCs than with NCs or SCs. The conditioned medium experiments yielded similar results; only patchy BL was observed and more immunostaining was detected on isolated SCs when the medium had been conditioned by contacting SCs + NCs than by NCs alone or SCs alone. Immunostaining was less overall in the conditioned medium experiments than in the cell coculture work. In addition, standard SC + NC cultures grown in differentiation-supporting medium were studied by electron microscopy. SCs that were not contacted by axons but were

  5. Schwann cell-derived Apolipoprotein D controls the dynamics of post-injury myelin recognition and degradation

    Directory of Open Access Journals (Sweden)

    Nadia eGarcía-Mateo

    2014-11-01

    Full Text Available Management of lipids, particularly signaling lipids that control neuroinflammation, is crucial for the regeneration capability of a damaged nervous system. Knowledge of pro- and anti-inflammatory signals after nervous system injury is extensive, most of them being proteins acting through well-known receptors and intracellular cascades. However, the role of lipid binding extracellular proteins able to modify the fate of lipids released after injury is not well understood.Apolipoprotein D (ApoD is an extracellular lipid binding protein of the Lipocalin family induced upon nervous system injury. Our previous study shows that axon regeneration is delayed without ApoD, and suggests its participation in early events during Wallerian degeneration. Here we demonstrate that ApoD is expressed by myelinating and non-myelinating Schwann cells and is induced early upon nerve injury. We show that ApoD, known to bind arachidonic acid (AA, also interacts with lysophosphatidylcholine (LPC in vitro. We use an in vivo model of nerve crush injury, a nerve explant injury model, and cultured macrophages exposed to purified myelin, to uncover that: (i ApoD regulates denervated Schwann cell-macrophage signaling, dampening MCP1- and Tnf-dependent macrophage recruitment and activation upon injury; (ii ApoD controls the over-expression of the phagocytosis activator Galectin-3 by infiltrated macrophages; (iii ApoD controls the basal and injury-triggered levels of LPC and AA; (iv ApoD modifies the dynamics of myelin-macrophage interaction, favoring the initiation of phagocytosis and promoting myelin degradation.Regulation of macrophage behaviour by Schwann-derived ApoD is therefore a key mechanism conditioning nerve injury resolution. These results place ApoD as a lipid binding protein controlling the signals exchanged between glia, neurons and blood-borne cells during nerve recovery after injury, and open the possibility for a therapeutic use of ApoD as a regeneration

  6. Association of Myosin Va and Schwann cells-derived RNA in mammal myelinated axons, analyzed by immunocytochemistry and confocal FRET microscopy.

    Science.gov (United States)

    Canclini, Lucía; Wallrabe, Horst; Di Paolo, Andrés; Kun, Alejandra; Calliari, Aldo; Sotelo-Silveira, José Roberto; Sotelo, José Roberto

    2014-03-15

    Evidence from multiple sources supports the hypothesis that Schwann cells in the peripheral nervous system transfer messenger RNA and ribosomes to the axons they ensheath. Several technical and methodological difficulties exist for investigators to unravel this process in myelinated axons - a complex two-cell unit. We present an experimental design to demonstrate that newly synthesized RNA is transferred from Schwann cells to axons in association with Myosin Va. The use of quantitative confocal FRET microscopy to track newly-synthesized RNA and determine the molecular association with Myosin Va, is described in detail. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Macrophage-derived microvesicles promote proliferation and migration of Schwann cell on peripheral nerve repair

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Chuan, E-mail: zhchuansy@163.com; Ma, Cheng-bin; Yuan, Hong-mou; Cao, Bao-yuan; Zhu, Jia-jun

    2015-12-04

    Background: Macrophages have been implicated in peripheral nerve regeneration. However, whether macrophages-derived microvesicles (MVs) are involved in this process remains unknown. In the present study, the effects of macrophages-derived MVs on proliferation and migration of Schwann cells (SCs) were evaluated in both in vitro and in vivo. Methods: Human monocytic leukaemia cell line (THP-1) was successfully driven to M1 and M2 phenotypes by delivery of either IFN-γ or IL-4, respectively. SCs incubated with M1 or M2 macrophages-derived MVs, the cell migration and proliferation were assessed, and expression levels of nerve growth factor (NGF) and Laminin were measured. A rat model of sciatic nerve was established and the effects of macrophages-derived MVs on nerve regeneration were investigated. Results: M2-derived MVs elevated migration, proliferation, NFG and Laminin protein levels of SCs compared with M1-or M0-derived MVs. The relative expression levels of miR-223 were also increased in M2 macrophages and M2-derived MVs. Transfected M2 macrophages with miR-223 inhibitor then co-incubated with SCs, an inhibition of cell migration and proliferation and a down-regulated levels of NFG and Laminin protein expression were observed. In vivo, M2-derived MVs significantly increased the infiltration and axon number of SCs. Conclusion: M2-derived MVs promoted proliferation and migration of SCs in vitro and in vivo, which provided a therapeutic strategy for nerve regeneration. - Highlights: • M2 macrophages-derived MVs elevated migration and proliferation of SCs. • M2 macrophages-derived MVs up-regulated NFG and Laminin expression of SCs. • MiR-223 expression was increased in M2 macrophages-derived MVs. • MiR-223 inhibitor reduced migration and proliferation of SCs co-incubated with MVs. • MiR-223 inhibitor down-regulated NFG and Laminin levels of SCs co-incubated with MVs.

  8. Enhanced Schwann cell attachment and alignment using one-pot "dual click" GRGDS and YIGSR derivatized nanofibers.

    Science.gov (United States)

    Zheng, Jukuan; Kontoveros, Dimitria; Lin, Fei; Hua, Geng; Reneker, Darrell H; Becker, Matthew L; Willits, Rebecca K

    2015-01-12

    Using metal-free click chemistry and oxime condensation methodologies, GRGDS and YIGSR peptides were coupled to random and aligned degradable nanofiber networks postelectrospinning in a one-pot reaction. The bound peptides are bioactive, as demonstrated by Schwann cell attachment and proliferation, and the inclusion of YIGSR with GRGDS alters the expression of the receptor for YIGSR. Additionally, aligned nanofibers act as a potential guidance cue by increasing the aspect ratio and aligning the actin filaments, which suggest that peptide-functionalized scaffolds would be useful to direct SCs for peripheral nerve regeneration.

  9. Schwann cell expressed Nogo-B modulates axonal branching of adult sensory neurons through the Nogo-B receptor NgBR

    Directory of Open Access Journals (Sweden)

    Christoph eEckharter

    2015-11-01

    Full Text Available In contrast to the central nervous system (CNS nerve fibers do regenerate in the peripheral nervous system (PNS although in a clinically unsatisfying manner. A major problem is excessive sprouting of regenerating axons which results in aberrant reinnervation of target tissue and impaired functional recovery. In the CNS, the reticulon protein Nogo-A has been identified as a prominent oligodendrocyte expressed inhibitor of long-distance growth of regenerating axons. We show here that the related isoform Nogo-B is abundantly expressed in Schwann cells in the PNS. Other than Nogo-A in oligodendrocytes, Nogo-B does not localize to the myelin sheath but is detected in the ER and the plasma membrane of Schwann cells. Adult sensory neurons that are cultured on nogo-a/b deficient Schwann cells form significantly fewer axonal branches versus those on wildtype Schwann cells, while their maximal axonal extension is unaffected. We demonstrate that this effect of Nogo-B on neuronal morphology is restricted to undifferentiated Schwann cells and is mediated by direct physical contact between these two cell types. Moreover, we show that blocking the Nogo-B specific receptor NgBR, which we find expressed on sensory neurons and to interact with Schwann cell expressed Nogo-B, produces the same branching phenotype as observed after deletion of Nogo-B. These data provide evidence for a novel function of the nogo gene that is implemented by the Nogo-B isoform. The remarkably specific effects of Nogo-B/ NgBR on axonal branching, while leaving axonal extension unaffected, are of potential clinical relevance in the context of excessive axonal sprouting after peripheral nerve injury.

  10. Requirement of cAMP signaling for Schwann cell differentiation restricts the onset of myelination.

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    Ketty Bacallao

    Full Text Available Isolated Schwann cells (SCs respond to cAMP elevation by adopting a differentiated post-mitotic state that exhibits high levels of Krox-20, a transcriptional enhancer of myelination, and mature SC markers such as the myelin lipid galactocerebroside (O1. To address how cAMP controls myelination, we performed a series of cell culture experiments which compared the differentiating responses of isolated and axon-related SCs to cAMP analogs and ascorbate, a known inducer of axon ensheathment, basal lamina formation and myelination. In axon-related SCs, cAMP induced the expression of Krox-20 and O1 without a concomitant increase in the expression of myelin basic protein (MBP and without promoting axon ensheathment, collagen synthesis or basal lamina assembly. When cAMP was provided together with ascorbate, a dramatic enhancement of MBP expression occurred, indicating that cAMP primes SCs to form myelin only under conditions supportive of basal lamina formation. Experiments using a combination of cell permeable cAMP analogs and type-selective adenylyl cyclase (AC agonists and antagonists revealed that selective transmembrane AC (tmAC activation with forskolin was not sufficient for full SC differentiation and that the attainment of an O1 positive state also relied on the activity of the soluble AC (sAC, a bicarbonate sensor that is insensitive to forskolin and GPCR activation. Pharmacological and immunological evidence indicated that SCs expressed sAC and that sAC activity was required for morphological differentiation and the expression of myelin markers such as O1 and protein zero. To conclude, our data indicates that cAMP did not directly drive myelination but rather the transition into an O1 positive state, which is perhaps the most critical cAMP-dependent rate limiting step for the onset of myelination. The temporally restricted role of cAMP in inducing differentiation independently of basal lamina formation provides a clear example of the

  11. Rat Nasal Respiratory Mucosa-Derived Ectomesenchymal Stem Cells Differentiate into Schwann-Like Cells Promoting the Differentiation of PC12 Cells and Forming Myelin In Vitro

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    Jian Zhang

    2015-01-01

    Full Text Available Schwann cell (SC transplantation as a cell-based therapy can enhance peripheral and central nerve repair experimentally, but it is limited by the donor site morbidity for clinical application. We investigated weather respiratory mucosa stem cells (REMSCs, a kind of ectomesenchymal stem cells (EMSCs, isolated from rat nasal septum can differentiate into functional Schwann-like cells (SC-like cells. REMSCs proliferated quickly in vitro and expressed the neural crest markers (nestin, vimentin, SOX10, and CD44. Treated with a mixture of glial growth factors for 7 days, REMSCs differentiated into SC-like cells. The differentiated REMSCs (dREMSCs exhibited a spindle-like morphology similar to SC cells. Immunocytochemical staining and Western blotting indicated that SC-like cells expressed the glial markers (GFAP, S100β, Galc, and P75 and CNPase. When cocultured with dREMSCs for 5 days, PC12 cells differentiated into mature neuron-like cells with long neurites. More importantly, dREMSCs could form myelin structures with the neurites of PC12 cells at 21 days in vitro. Our data indicated that REMSCs, a kind of EMSCs, could differentiate into SC-like cells and have the ability to promote the differentiation of PC12 cells and form myelin in vitro.

  12. Gene delivery to rat and human Schwann cells and nerve segments : a comparison of AAV 1-9 and lentiviral vectors

    NARCIS (Netherlands)

    Hoyng, S A; De Winter, F; Gnavi, S; van Egmond, L; Attwell, C L; Tannemaat, M R; Verhaagen, J; Malessy, M J A

    2015-01-01

    Schwann cells (SCs) in an injured peripheral nerve form pathways for regenerating axons. Although these cells initially support regeneration, SCs lose their pro-regenerative properties following a prolonged period of denervation. Gene transfer to SC can enhance their therapeutic potential. In this

  13. Gene delivery to rat and human Schwann cells and nerve segments: a comparison of AAV 1-9 and lentiviral vectors

    NARCIS (Netherlands)

    Hoyng, S.A.; de Winter, F.; Gnavi, S.; van Egmond, L.; Attwell, C.L.; Tannemaat, M.R.; Verhaagen, J.; Malessy, M.J.A.

    2015-01-01

    Schwann cells (SCs) in an injured peripheral nerve form pathways for regenerating axons. Although these cells initially support regeneration, SCs lose their pro-regenerative properties following a prolonged period of denervation. Gene transfer to SC can enhance their therapeutic potential. In this

  14. Tonsil-Derived Mesenchymal Stem Cells Differentiate into a Schwann Cell Phenotype and Promote Peripheral Nerve Regeneration

    Science.gov (United States)

    Jung, Namhee; Park, Saeyoung; Choi, Yoonyoung; Park, Joo-Won; Hong, Young Bin; Park, Hyun Ho Choi; Yu, Yeonsil; Kwak, Geon; Kim, Han Su; Ryu, Kyung-Ha; Kim, Jae Kwang; Jo, Inho; Choi, Byung-Ok; Jung, Sung-Chul

    2016-01-01

    Schwann cells (SCs), which produce neurotropic factors and adhesive molecules, have been reported previously to contribute to structural support and guidance during axonal regeneration; therefore, they are potentially a crucial target in the restoration of injured nervous tissues. Autologous SC transplantation has been performed and has shown promising clinical results for treating nerve injuries and donor site morbidity, and insufficient production of the cells have been considered as a major issue. Here, we performed differentiation of tonsil-derived mesenchymal stem cells (T-MSCs) into SC-like cells (T-MSC-SCs), to evaluate T-MSC-SCs as an alternative to SCs. Using SC markers such as CAD19, GFAP, MBP, NGFR, S100B, and KROX20 during quantitative real-time PCR we detected the upregulation of NGFR, S100B, and KROX20 and the downregulation of CAD19 and MBP at the fully differentiated stage. Furthermore, we found myelination of axons when differentiated SCs were cocultured with mouse dorsal root ganglion neurons. The application of T-MSC-SCs to a mouse model of sciatic nerve injury produced marked improvements in gait and promoted regeneration of damaged nerves. Thus, the transplantation of human T-MSCs might be suitable for assisting in peripheral nerve regeneration. PMID:27834852

  15. Tonsil-Derived Mesenchymal Stem Cells Differentiate into a Schwann Cell Phenotype and Promote Peripheral Nerve Regeneration

    Directory of Open Access Journals (Sweden)

    Namhee Jung

    2016-11-01

    Full Text Available Schwann cells (SCs, which produce neurotropic factors and adhesive molecules, have been reported previously to contribute to structural support and guidance during axonal regeneration; therefore, they are potentially a crucial target in the restoration of injured nervous tissues. Autologous SC transplantation has been performed and has shown promising clinical results for treating nerve injuries and donor site morbidity, and insufficient production of the cells have been considered as a major issue. Here, we performed differentiation of tonsil-derived mesenchymal stem cells (T-MSCs into SC-like cells (T-MSC-SCs, to evaluate T-MSC-SCs as an alternative to SCs. Using SC markers such as CAD19, GFAP, MBP, NGFR, S100B, and KROX20 during quantitative real-time PCR we detected the upregulation of NGFR, S100B, and KROX20 and the downregulation of CAD19 and MBP at the fully differentiated stage. Furthermore, we found myelination of axons when differentiated SCs were cocultured with mouse dorsal root ganglion neurons. The application of T-MSC-SCs to a mouse model of sciatic nerve injury produced marked improvements in gait and promoted regeneration of damaged nerves. Thus, the transplantation of human T-MSCs might be suitable for assisting in peripheral nerve regeneration.

  16. Reprogramming diminishes retention of Mycobacterium leprae in Schwann cells and elevates bacterial transfer property to fibroblasts [v2; ref status: indexed, http://f1000r.es/280

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    Toshihiro Masaki

    2013-11-01

    Full Text Available Background: Bacterial pathogens can manipulate or subvert host tissue cells to their advantage at different stages during infection, from initial colonization in primary host niches to dissemination. Recently, we have shown that Mycobacterium leprae (ML, the causative agent of human leprosy, reprogrammed its preferred host niche de-differentiated adult Schwann cells to progenitor/stem cell-like cells (pSLC which appear to facilitate bacterial spread. Here, we studied how this cell fate change influences bacterial retention and transfer properties of Schwann cells before and after reprogramming. Results: Using primary fibroblasts as bacterial recipient cells, we showed that non-reprogrammed Schwann cells, which preserve all Schwann cell lineage and differentiation markers, possess high bacterial retention capacity when co-cultured with skin fibroblasts; Schwann cells failed to transfer bacteria to fibroblasts at higher numbers even after co-culture for 5 days. In contrast, pSLCs, which are derived from the same Schwann cells but have lost Schwann cell lineage markers due to reprogramming, efficiently transferred bacteria to fibroblasts within 24 hours. Conclusions: ML-induced reprogramming converts lineage-committed Schwann cells with high bacterial retention capacity to a cell type with pSLC stage with effective bacterial transfer properties. We propose that such changes in cellular properties may be associated with the initial intracellular colonization, which requires long-term bacterial retention within Schwann cells, in order to spread the infection to other tissues, which entails efficient bacterial transfer capacity to cells like fibroblasts which are abundant in many tissues, thereby potentially maximizing bacterial dissemination. These data also suggest how pathogens could take advantage of multiple facets of host cell reprogramming according to their needs during infection.

  17. Reprogramming diminishes retention of Mycobacterium leprae in Schwann cells and elevates bacterial transfer property to fibroblasts [v3; ref status: indexed, http://f1000r.es/2ae

    Directory of Open Access Journals (Sweden)

    Toshihiro Masaki

    2013-11-01

    Full Text Available Background: Bacterial pathogens can manipulate or subvert host tissue cells to their advantage at different stages during infection, from initial colonization in primary host niches to dissemination. Recently, we have shown that Mycobacterium leprae (ML, the causative agent of human leprosy, reprogrammed its preferred host niche de-differentiated adult Schwann cells to progenitor/stem cell-like cells (pSLC which appear to facilitate bacterial spread. Here, we studied how this cell fate change influences bacterial retention and transfer properties of Schwann cells before and after reprogramming. Results: Using primary fibroblasts as bacterial recipient cells, we showed that non-reprogrammed Schwann cells, which preserve all Schwann cell lineage and differentiation markers, possess high bacterial retention capacity when co-cultured with skin fibroblasts; Schwann cells failed to transfer bacteria to fibroblasts at higher numbers even after co-culture for 5 days. In contrast, pSLCs, which are derived from the same Schwann cells but have lost Schwann cell lineage markers due to reprogramming, efficiently transferred bacteria to fibroblasts within 24 hours. Conclusions: ML-induced reprogramming converts lineage-committed Schwann cells with high bacterial retention capacity to a cell type with pSLC stage with effective bacterial transfer properties. We propose that such changes in cellular properties may be associated with the initial intracellular colonization, which requires long-term bacterial retention within Schwann cells, in order to spread the infection to other tissues, which entails efficient bacterial transfer capacity to cells like fibroblasts which are abundant in many tissues, thereby potentially maximizing bacterial dissemination. These data also suggest how pathogens could take advantage of multiple facets of host cell reprogramming according to their needs during infection.

  18. Engineered neural tissue with Schwann cell differentiated human dental pulp stem cells: potential for peripheral nerve repair?

    Science.gov (United States)

    Sanen, Kathleen; Martens, Wendy; Georgiou, Melanie; Ameloot, Marcel; Lambrichts, Ivo; Phillips, James

    2017-01-04

    Despite the spontaneous regenerative capacity of the peripheral nervous system, large gap peripheral nerve injuries (PNIs) require bridging strategies. The limitations and suboptimal results obtained with autografts or hollow nerve conduits in the clinic urge the need for alternative treatments. Recently, we have described promising neuroregenerative capacities of Schwann cells derived from differentiated human dental pulp stem cells (d-hDPSCs) in vitro. Here, we extended the in vitro assays to show the pro-angiogenic effects of d-hDPSCs, such as enhanced endothelial cell proliferation, migration and differentiation. In addition, for the first time we evaluated the performance of d-hDPSCs in an in vivo rat model of PNI. Eight weeks after transplantation of NeuraWrap™ conduits filled with engineered neural tissue (EngNT) containing aligned d-hDPSCs in 15-mm rat sciatic nerve defects, immunohistochemistry and ultrastructural analysis revealed ingrowing neurites, myelinated nerve fibres and blood vessels along the construct. Although further research is required to optimize the delivery of this EngNT, our findings suggest that d-hDPSCs are able to exert a positive effect in the regeneration of nerve tissue in vivo. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  19. Sam68 promotes Schwann cell proliferation by enhancing the PI3K/Akt pathway and acts on regeneration after sciatic nerve crush

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Weijie, E-mail: 459586768@qq.com; Liu, Yuxi, E-mail: 924013616@qq.com; Wang, Youhua, E-mail: wyouhua1516@163.com

    2016-05-13

    Sam68 (Src-associated in mitosis of 68 kD), a KH domain RNA-binding protein, is not only important in signaling transduction cascades, but crucial in a variety of cellular processes. Sam68 is reported to be involved in the phospoinositide3-kinase (PI3K) and nuclear factor-kappa B (NF-κB) signaling pathways, and it is closely associated with cell proliferation, RNA metabolism, and tumor progression. However, we know little about the role of Sam68 during peripheral nervous system injury and regeneration. In this study, we investigated the expression of Sam68 and its biological significances in sciatic nerve crush. Interestingly, we found Sam68 had a co-localization with S100 (Schwann cell marker). Moreover, after crush, Sam68 had a spatiotemporal protein expression, which was in parallel with proliferation cell nuclear antigen (PCNA). In vitro, we also observed increased expression of Sam68 during the process of TNF-α-induced Schwann cell proliferation model. Besides, flow cytometry analyses, CCK-8, and EDU were all performed with the purpose of investigating the role of Sam68 in the regulation of Schwann cell proliferation. Even more importantly, we discovered that Sam68 could enhance the phosphorylation of Akt while LY294002 (a PI3K inhibitor) obviously reversed Sam68-induced cell proliferation. Finally, we detected the variance during regeneration progress through the rat walk footprint test. In summary, all these evidences demonstrated that Sam68 might participate in Schwann cell proliferation partially via PI3K/Akt pathway and also regulate regeneration after sciatic nerve crush. -- Highlights: •The dynamic changes and location of Sam68 after sciatic nerve crush. •Sam68 promoted Schwann cell proliferation via PI3K/Akt pathway. •Sam68 modulated functional recovery after sciatic nerve crush.

  20. BD PuraMatrix peptide hydrogel as a culture system for human fetal Schwann cells in spinal cord regeneration.

    Science.gov (United States)

    Moradi, Fateme; Bahktiari, Mehrdad; Joghataei, Mohammad Taghi; Nobakht, Maliheh; Soleimani, Masoud; Hasanzadeh, Gholamreza; Fallah, Ali; Zarbakhsh, Sam; Hejazian, Leila Beigom; Shirmohammadi, Maryam; Maleki, Fatemeh

    2012-12-01

    BD PuraMatrix peptide hydrogel, a three-dimensional cell culture model of nanofiber scaffold derived from the self-assembling peptide RADA16, has been applied to regenerative tissue repair in order to develop novel nanomedicine systems. In this study with PuraMatrix, self-assembling nanofiber scaffold (SAPNS) and Schwann cells (SCs) were isolated from human fetal sciatic nerves, cultured within SAPNS, and then transplanted into the spinal cord after injury (SCI) in rats. First, the peptide nanofiber scaffold was evaluated via scanning electron microscopy and atomic force microscopy. With phase-contrast microscopy, the appearance of representative human fetal SCs encapsulated in PuraMatrix on days 3, 5, and 7 in 12-well plates was revealed. The Schwann cells in PuraMatrix were cultured for 2 days, and the SCs had active proliferative potential. Spinal cord injury was induced by placing a 35-g weight on the dura of T9-T10 segments for 15 min, followed by in vivo treatment with SAPNS and human fetal SCs (100,000 cells/10 μl/injection) grafted into spinal cord 7 days after SCI. After treatment, the recovery of motor function was assessed periodically using the Basso, Beattie, and Bresnahan scoring system. Eight weeks after grafting, animals were perfusion fixed, and the survival of implanted cells was analyzed with antibody recognizing SCs. Immunohistochemical analysis of grafted lumber segments at 8 weeks after grafting revealed reduced asterogliosis and considerably increased infiltration of endogenous S100(+) cells into the injury site, suggesting that PuraMatrix may play an important role in the repair observed after SAPNS and human fetal SC transplantation. Copyright © 2012 Wiley Periodicals, Inc.

  1. Tetramethylpyrazine protects Schwann cells from ischemia-like injury and increases cell survival in cold ischemic rat nerves

    Directory of Open Access Journals (Sweden)

    Ming-Ming Yang

    2015-03-01

    Full Text Available Tetramethylpyrazine (TMP, a major active ingredient of Ligusticum wallichi Franchat extract (a Chinese herb, exhibits neuroprotective properties in ischemia. In this study, we assessed its protective effects on Schwann cells (SCs by culturing them in the presence of oxygen glucose deprivation (OGD conditions and measuring cell survival in cold ischemic rat nerves. In the OGD-induced ischemic injury model of SCs, we demonstrated that TMP treatment not only reduced OGD-induced cell viability losses, cell death, and apoptosis of SCs in a dose-dependent manner, and inhibited LDH release, but also suppressed OGD-induced downregulation of Bcl-2 and upregulation of Bax and caspase-3, as well as inhibited the consequent activation of caspase-3. In the cold ischemic nerve model, we found that prolonged cold ischemic exposure for four weeks was markedly associated with the absence of SCs, a decrease in cell viability, and apoptosis in preserved nerve segments incubated in University of Wisconsin solution (UWS alone. However, TMP attenuated nerve segment damage by preserving SCs and antagonizing the decrease in nerve fiber viability and increase in TUNEL-positive cells in a dose-dependent manner. Collectively, our results indicate that TMP not only provides protective effects in an ischemia-like injury model of cultured rat SCs by regulating Bcl-2, Bax, and caspase-3, but also increases cell survival and suppresses apoptosis in the cold ischemic nerve model after prolonged ischemic exposure for four weeks. Therefore, TMP may be a novel and effective therapeutic strategy for preventing peripheral nervous system ischemic diseases and improving peripheral nerve storage.

  2. A distal Schwann cell-specific enhancer mediates axonal regulation of the Oct-6 transcription factor during peripheral nerve development and regeneration.

    NARCIS (Netherlands)

    W.J. Mandemakers (Wim); R. Zwart (Ronald); M.M. Jaegle (Martine); E.T. Walbeehm (Erik); P. Visser (Pim); F.G. Grosveld (Frank); D. Meijer (Daniëlle)

    2000-01-01

    textabstractThe POU domain transcription factor Oct-6 is a major regulator of Schwann cell differentiation and myelination. During nerve development and regeneration, expression of Oct-6 is under the control of axonal signals. Identification of the cis-acting elements

  3. [Effect of Draconis Sanguis-containing serum on NGF, BDNF, CNTF, LNGFR, TrkA, GDNF, GAP-43 and NF-H expressions in Schwann cells].

    Science.gov (United States)

    Gu, Jin; He, Xin-rong; Han, Ya-liang

    2015-04-01

    To observe the effect of Draconis Sanguis-containing serum on the expressions of NGF, BDNF, CNTF, LNG-FR, TrkA, GDNF, GAP-43 and NF-H in Schwann cells, and investigate the possible mechanism of Draconis Sanguis to promote peripheral nerve regeneration. SD rats were randomly divided into 2 groups: the Draconis Sanguis group (orally administered with Draconis Sanguis-containing balm solution) and the blank group (equivoluminal balm) to prepare Draconis Sanguis-containing serum and blank control serum. Schwann cells were extracted from double sciatic nerves of three-day-old SD rats, divided into 2 groups: the Draconis Sanguis group and the blank control group, and respectively cultured with 10% Draconis Sanguis-containing serum or blank control serum. The mRNA expressions of NGF, BDNF, CNTF and other genes in Schwann cells were measured by RT-PCR analysis 48 hours later. Most of the Schwann cells were bipolar spindle and arranged shoulder to shoulder or end to end under the microscope and identified to be positive with the immunocytochemical method. To compare with the blank group, mRNA expressions of NGF, LNGFR, GDNF and GAP-43 significantly increased (P Sanguis may show effect in nerve regeneration by up-regulating mRNA expressions of NGF, LNGFR, GDNF and GAP-43 and down-regulating mRNA expressions of TrkA, BDNF and CNTF.

  4. Lysophospholipid receptors are differentially expressed in rat terminal Schwann cells, as revealed by a single cell rt-PCR and in situ hybridization.

    Science.gov (United States)

    Kobashi, Hiroaki; Yaoi, Takeshi; Oda, Ryo; Okajima, Seiichiro; Fujiwara, Hiroyoshi; Kubo, Toshikazu; Fushiki, Shinji

    2006-04-22

    Terminal Schwann cells (TSCs) that cover motor neuron terminals, are known to play an important role in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, the molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. By using our previously reported method of selectively and efficiently collecting TSCs, we have analyzed the difference in expression patterns of lysophospholipid (LPL) receptor genes (LPA1, LPA2, LPA3, S1P1, S1P2, S1P3, S1P4, and S1P5) between TSCs and myelinating Schwann cells (MSCs). LPL, which includes lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), is the bioactive lipid that induces a myriad of cellular responses through specific members of G-protein coupled receptors for LPA. It turned out that LPA3 was expressed only in TSCs, whereas S1P1 was expressed in TSCs and skeletal muscle, but not in MSCs. Other types of LPL receptor genes, including LPA1, S1P2, S1P3, S1P4, were expressed in both types of Schwann cells. None of the LPL receptor gene family showed MSCs-specific expression.

  5. Motoneuron development influences dorsal root ganglia survival and Schwann cell development in a vertebrate model of spinal muscular atrophy.

    Science.gov (United States)

    Hao, Le Thi; Duy, Phan Q; Jontes, James D; Beattie, Christine E

    2015-01-15

    Low levels of the survival motor neuron protein (SMN) cause the disease spinal muscular atrophy. A primary characteristic of this disease is motoneuron dysfunction and paralysis. Understanding why motoneurons are affected by low levels of SMN will lend insight into this disease and to motoneuron biology in general. Motoneurons in zebrafish smn mutants develop abnormally; however, it is unclear where Smn is needed for motoneuron development since it is a ubiquitously expressed protein. We have addressed this issue by expressing human SMN in motoneurons in zebrafish maternal-zygotic (mz) smn mutants. First, we demonstrate that SMN is present in axons, but only during the period of robust motor axon outgrowth. We also conclusively demonstrate that SMN acts cell autonomously in motoneurons for proper motoneuron development. This includes the formation of both axonal and dendritic branches. Analysis of the peripheral nervous system revealed that Schwann cells and dorsal root ganglia (DRG) neurons developed abnormally in mz-smn mutants. Schwann cells did not wrap axons tightly and had expanded nodes of Ranvier. The majority of DRG neurons had abnormally short peripheral axons and later many of them failed to divide and died. Expressing SMN just in motoneurons rescued both of these cell types showing that their failure to develop was secondary to the developmental defects in motoneurons. Driving SMN just in motoneurons did not increase survival of the animal, suggesting that SMN is needed for motoneuron development and motor circuitry, but that SMN in other cells types factors into survival. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Concentrated growth factor increases Schwann cell proliferation and neurotrophic factor secretion and promotes functional nerve recovery in vivo.

    Science.gov (United States)

    Qin, Jie; Wang, Lin; Sun, Yue; Sun, Xiaolin; Wen, Chaoju; Shahmoradi, Mahdi; Zhou, Yanmin

    2016-02-01

    Concentrated growth factor (CGF) is a newly generated complex that comprises a fibrin matrix incorporating growth factors and plasmatic and leukocyte cytokines. It has been widely used in bone regenerative medicine. However, the effect of CGF on peripheral nerve regeneration had not been previously investigated. The aim of the present study was to evaluate the possibility of using CGF for nerve regeneration by i) investigating the effect of CGF on the proliferation of Schwann cells (SCs) and secretion of neurotrophic factors nerve growth factor (NGF) and glial cell line‑derived neurotrophic factor (GDNF) in vitro; and ii) analyzing the effect of CGF on functional nerve recovery after nerve injury in vivo. CGF was prepared from venous blood taken from rats, and using scanning electron microscopy (SEM) we noted that it featured a fiber‑like appearance with pore size ranging from 0.1 to 1.0 µm. The soluble component of CGF was used to produce conditioned media with which to treat the Schwann cell line. A cell counting kit-8 assay and cell cycle analysis were both used to study the proliferative effect of CGF on SCs. Reverse transcription-quantitative PCR and western blot analysis demonstrated that there was an increase in the mRNA and protein expression of NGF and GDNF, both of which are markers of SC neurotrophic secretion. A model of sciatic nerve crush injury was established for the in vivo experiment, and CGF was found to increase the sciatic functional index (indicative of nerve function). We noted that CGF increased SC proliferation and secretion of neurotrophic factors in vitro, and promoted functional recovery after peripheral nerve injuries in vivo. These results suggest that CGF is a promising candidate biomaterial for peripheral nerve regeneration, and may potentially be utilized to repair nerve injuries.

  7. Salidroside attenuates colistin-induced neurotoxicity in RSC96 Schwann cells through PI3K/Akt pathway.

    Science.gov (United States)

    Lu, Ziyin; Jiang, Guozheng; Chen, Ying; Wang, Jian; Muhammad, Ishfaq; Zhang, Ling; Wang, Rui; Liu, Fangping; Li, Rui; Qian, Feng; Li, Jichang

    2017-06-01

    Neurotoxicity is a key dose-limiting factor for colistin therapy. This study aimed to investigate the protective effect of Salidroside on colistin-induced neurotoxicity in RSC96 Schwann cells and the underlying mechanisms. After Salidroside (12.5, 25, 50 μg/mL) treatment for 2 h, the cells were cultured with 250 μg/mL colistin for 24 h. In order to investigate the role of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway, the cells were pre-treated with LY294002 (12.5 μmol/L, a specific inhibitor of PI3K phosphorylation) for 1 h before Salidroside (50 μg/mL) treatment, then were co-cultured with colistin (250 μg/mL) for 24 h. The results showed that colistin treatment could induce apoptotic cell death which was associated with oxidative stress injury. Salidroside could reduce colistin-induced neurotoxicity, decrease the effect of colistin on the reduced expression levels of p-Akt and Bcl-2, and increased the expresion of Bax, release of Cyt c, and activation of caspase-3. However, the protective effect of Salidroside against colistin-induced apoptosis was partly abolished by LY294002. These findings suggest that Salidroside could attenuate colistin-induced neurotoxicity in RSC96 Schwann cells via the PI3K/Akt pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Transfer of Vesicles From Schwann Cells to Axons: a Novel Mechanism of Communication in the Peripheral Nervous System

    Science.gov (United States)

    Lopez-Verrilli, M. Alejandra; Court, Felipe A.

    2012-01-01

    Schwann cells (SCs) are the glial component of the peripheral nervous system, with essential roles during development and maintenance of axons, as well as during regenerative processes after nerve injury. SCs increase conduction velocities by myelinating axons, regulate synaptic activity at presynaptic nerve terminals and are a source of trophic factors to neurons. Thus, development and maintenance of peripheral nerves are crucially dependent on local signaling between SCs and axons. In addition to the classic mechanisms of intercellular signaling, the possibility of communication through secreted vesicles has been poorly explored to date. Interesting recent findings suggest the occurrence of lateral transfer mediated by vesicles from glial cells to axons that could have important roles in axonal growth and axonal regeneration. Here, we review the role of vesicular transfer from SCs to axons and propose the advantages of this means in supporting neuronal and axonal maintenance and regeneration after nerve damage. PMID:22707941

  9. Transfer of vesicles from Schwann cell to axon: a novel mechanism of communication in the peripheral nervous system

    Directory of Open Access Journals (Sweden)

    María Alejandra eLopez-Verrilli

    2012-06-01

    Full Text Available Schwann cells (SCs are the glial component of the peripheral nervous system, with essential roles during development and maintenance of axons, as well as during regenerative processes after nerve injury. SCs increase conduction velocities by myelinating axons, regulate synaptic activity at presynaptic nerve terminals and are a source of trophic factors to neurons. Thus, development and maintenance of peripheral nerves are crucially dependent on local signalling between SCs and axons. In addition to the classic mechanisms of intercellular signalling, the possibility of communication through secreted vesicles has been poorly explored to date. Interesting recent findings suggest the occurrence of lateral transfer mediated by vesicles from glial cells to axons that could have important roles in axonal growth and axonal regeneration. Here, we review the role of vesicular transfer from SCs to axons and propose the benefits of this means in supporting neuronal and axonal maintenance and regeneration after nerve damage.

  10. Clinical grade cultivation of human Schwann cell, by the using of human autologous serum instead of fetal bovine serum and without growth factors.

    Science.gov (United States)

    Aghayan, Hamid-Reza; Arjmand, Babak; Norouzi-Javidan, Abbas; Saberi, Hooshang; Soleimani, Masoud; Tavakoli, Seyed Amir-Hossein; Khodadadi, Abbas; Tirgar, Niloufar; Mohammadi-Jahani, Fereshteh

    2012-06-01

    Clinical grade cultivation of human schwann cell by the utilization of human autologous serum instead of fetal bovine serum, and also avoiding any growth factors, can increase safety level of this procedure in cases of clinical cell transplantation. The aim of this study was demonstration of the feasibility of clinical grade schwann cell cultivation. In this experimental study after obtaining consent from close relatives we harvested 10 sural nerves from brain death donors and then cultured in 10 seperated culture media plus autologous serum. We also prepared autologous serum from donor's whole blood. Then cultured cells were evaluated by S100 antibody staining for both morphology and purity. Cell purity range was from 97% to 99% (mean=98.11 ± 0.782%). Mean of the cell count was 14,055.56 ± 2,480.479 per micro liter. There was not significant correlation between cell purity and either the culture period or the age of donors (P>0.05). The spearman correlation coefficient for the cell purity with the period or the age of donors was 0.21 and 0.09, respectively. We demonstrated the feasibility of clinical grade schwann cell cultivation by the using of human autologous serum instead of fetal bovine serum and also without the using of growth factors. We also recommended all cell preparation facilities to adhere to the GMP and other similar quality disciplines especially in the preparation of clinically-used cell products.

  11. Methylcobalamin promotes the differentiation of Schwann cells and remyelination in lysophosphatidylcholine-induced demyelination of the rat sciatic nerve

    Directory of Open Access Journals (Sweden)

    Shunsuke eNishimoto

    2015-08-01

    Full Text Available Schwann cells (SCs are constituents of the peripheral nervous system. The differentiation of SCs in injured peripheral nerves is critical for regeneration after injury. Methylcobalamin (MeCbl is a vitamin B12 analog that is necessary for the maintenance of the peripheral nervous system. In this study, we estimated the effect of MeCbl on SCs. We showed that MeCbl downregulated the activity of Erk1/2 and promoted the expression of the myelin basic protein in SCs. In a dorsal root ganglion neuron–SC coculture system, myelination was promoted by MeCbl. In a focal demyelination rat model, MeCbl promoted remyelination and motor and sensory functional regeneration. MeCbl promoted the in vitro differentiation of SCs and in vivo myelination in a rat demyelination model and may be a novel therapy for several types of nervous disorders.

  12. Rat Sciatic Nerve Reconstruction Across a 30 mm Defect Bridged by an Oriented Porous PHBV Tube With Schwann Cell as Artificial Nerve Graft

    OpenAIRE

    Karimi, Mina; Biazar, Esmaeil; Keshel, Saeed Heidari; Ronaghi, Abdolaziz; Doostmohamadpour, Jafar; Janfada, Alireza; Montazeri, Arash

    2014-01-01

    An oriented poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit has been used to evaluate its efficiency based on the promotion of peripheral nerve regeneration in rats. The oriented porous micropatterned artificial nerve conduit was designed onto the micropatterned silicon wafers, and then their surfaces were modified with oxygen plasma to increase cell adhesion. The designed conduits were investigated by cell culture analyses with Schwann cells (SCs). The conduits were implanted into...

  13. Cathepsin E generates a sumoylated intracellular fragment of the cell adhesion molecule L1 to promote neuronal and Schwann cell migration as well as myelination.

    Science.gov (United States)

    Lutz, David; Wolters-Eisfeld, Gerrit; Schachner, Melitta; Kleene, Ralf

    2014-03-01

    The cell adhesion molecule L1 regulates cellular responses in the developing and adult nervous system. Here, we show that stimulation of cultured mouse cerebellar neurons by a function-triggering L1 antibody leads to cathepsin E-mediated generation of a sumoylated 30 kDa L1 fragment (L1-30) and to import of L1-30 into the nucleus. Mutation of the sumoylation site at K1172 or the cathepsin E cleavage site at E1167 abolishes generation of L1-30, while mutation of the nuclear localization signal at K1147 prevents nuclear import of L1-30. Moreover, the aspartyl protease inhibitor pepstatin impairs the generation of L1-30 and inhibits L1-induced migration of cerebellar neurons and Schwann cells as well as L1-dependent in vitro myelination on axons of dorsal root ganglion neurons by Schwann cells. L1-stimulated migration of HEK293 cells expressing L1 with mutated cathepsin E cleavage site is diminished in comparison to migration of cells expressing non-mutated L1. In addition, L1-stimulated migration of HEK293 cells expressing non-mutated L1 is also abolished upon knock-down of cathepsin E expression and enhanced by over-expression of cathepsin E. The findings of the present study indicate that generation and nuclear import of L1-30 regulate neuronal and Schwann cell migration as well as myelination. Cell adhesion molecule L1 regulates cellular responses in the developing and adult nervous system. L1 stimulation triggers sumoylation and cleavage of L1, thus generating the L1-70 fragment (1) which is cleaved by cathepsin E (2) yielding the L1-30 fragment that is imported to the nucleus (3), may bind to DNA and/or nuclear proteins (4), to regulate diverse cellular functions. © 2013 International Society for Neurochemistry.

  14. The Effect of Electrospun Gelatin Fibers Alignment on Schwann Cell and Axon Behavior and Organization in the Perspective of Artificial Nerve Design

    Directory of Open Access Journals (Sweden)

    Sara Gnavi

    2015-06-01

    Full Text Available Electrospun fibrous substrates mimicking extracellular matrices can be prepared by electrospinning, yielding aligned fibrous matrices as internal fillers to manufacture artificial nerves. Gelatin aligned nano-fibers were prepared by electrospinning after tuning the collector rotation speed. The effect of alignment on cell adhesion and proliferation was tested in vitro using primary cultures, the Schwann cell line, RT4-D6P2T, and the sensory neuron-like cell line, 50B11. Cell adhesion and proliferation were assessed by quantifying at several time-points. Aligned nano-fibers reduced adhesion and proliferation rate compared with random fibers. Schwann cell morphology and organization were investigated by immunostaining of the cytoskeleton. Cells were elongated with their longitudinal body parallel to the aligned fibers. B5011 neuron-like cells were aligned and had parallel axon growth when cultured on the aligned gelatin fibers. The data show that the alignment of electrospun gelatin fibers can modulate Schwann cells and axon organization in vitro, suggesting that this substrate shows promise as an internal filler for the design of artificial nerves for peripheral nerve reconstruction.

  15. The Effect of Electrospun Gelatin Fibers Alignment on Schwann Cell and Axon Behavior and Organization in the Perspective of Artificial Nerve Design.

    Science.gov (United States)

    Gnavi, Sara; Fornasari, Benedetta Elena; Tonda-Turo, Chiara; Laurano, Rossella; Zanetti, Marco; Ciardelli, Gianluca; Geuna, Stefano

    2015-06-08

    Electrospun fibrous substrates mimicking extracellular matrices can be prepared by electrospinning, yielding aligned fibrous matrices as internal fillers to manufacture artificial nerves. Gelatin aligned nano-fibers were prepared by electrospinning after tuning the collector rotation speed. The effect of alignment on cell adhesion and proliferation was tested in vitro using primary cultures, the Schwann cell line, RT4-D6P2T, and the sensory neuron-like cell line, 50B11. Cell adhesion and proliferation were assessed by quantifying at several time-points. Aligned nano-fibers reduced adhesion and proliferation rate compared with random fibers. Schwann cell morphology and organization were investigated by immunostaining of the cytoskeleton. Cells were elongated with their longitudinal body parallel to the aligned fibers. B5011 neuron-like cells were aligned and had parallel axon growth when cultured on the aligned gelatin fibers. The data show that the alignment of electrospun gelatin fibers can modulate Schwann cells and axon organization in vitro, suggesting that this substrate shows promise as an internal filler for the design of artificial nerves for peripheral nerve reconstruction.

  16. Neurotrophin receptor-mediated death of misspecified neurons generated from embryonic stem cells lacking Pax6.

    Science.gov (United States)

    Nikoletopoulou, Vassiliki; Plachta, Nicolas; Allen, Nicolas D; Pinto, Luisa; Götz, Magdalena; Barde, Yves-Alain

    2007-11-01

    Pax6-positive radial glial (RG) cells are the progenitors of most glutamatergic neurons in the cortex, a lineage that can be recapitulated in vitro using embryonic stem (ES) cells. We show here that ES cells lacking Pax6, a transcription factor long known to be essential for cortical development, generate Mash1-positive RG cells that differentiate in GABAergic neurons. These neurons express high levels of the neurotrophin receptor p75NTR causing their rapid death. Pax6 function was also investigated following transplantation of ES cells in the developing chick telencephalon and in mice lacking both Pax6 and p75NTR. Taken together, our results indicate that reliable predictions can be made with cultured ES cells when used to explore the role of genes impacting early aspects of mammalian neurogenesis. They also provide a novel opportunity to compare the molecular constituents of glutamatergic with those of GABA-ergic neurons and to explore the mechanisms of their generation.

  17. Cultures of Schwann-like cells differentiated from adipose-derived stem cells on PDMS/MWNT sheets as a scaffold for peripheral nerve regeneration.

    Science.gov (United States)

    Han, In Ho; Sun, Fangfang; Choi, Yoon Ji; Zou, Fengming; Nam, Kyoung Hyup; Cho, Won Ho; Choi, Byung Kwan; Song, Geun Sung; Koh, Kwangnak; Lee, Jaebeom

    2015-11-01

    Carbon nanotubes (CNTs) are promising candidates as novel scaffolds for peripheral nerve regeneration. Schwann cells (SCs) are attractive therapeutic targets due to their pivotal role in peripheral nerve regeneration, but primary SCs have limitations for clinical application. However, adipose-derived stem cells (ASCs) may differentiate into Schwann-like cells. The present study assesses the potential applicability of multiwall CNTs (MWNTs) composited with polydimethylsiloxane (PDMS), which were then seeded with differentiated adipose-derived stem cells (dASCs) to promote neuronal differentiation and growth. Aqueous MWNT dispersion was filtered, and the PDMS/MWNT sheets were prepared using a simple printing-transfer method. Characterization of PDMS/MWNT sheets indicated their unique physical properties, such as superior mechanical strength and electroconductivity, compared with bare PDMS sheets. ASCs were differentiated into Schwann-like cells using a mixture of glial growth factors. Dorsal root ganglion (DRG) neurons were co-cultured with SCs and dASCs on PDMS/MWNTs sheets or noncoated dishes. An alamar blue proliferation assay of dASC and SCs showed significantly more dASC and SCs cultured on PDMS/MWNT sheets at 48 h and 72 h than when cultured on noncoated dishes (p proliferation of DRG neurons and the longest neurite outgrowth length per neuron were significantly greater than when DRG were cultured on PDMS/MWNT sheets alone or on noncoated dishes seeded with SCs or dASCs (p cells differentiated from ASCs. Seeding the dASCs on PDMS/MWNT sheets may produce synergistic effects in peripheral nerve regeneration, similarly to SCs. © 2015 Wiley Periodicals, Inc.

  18. Differential astroglial responses in the spinal cord of rats submitted to a sciatic nerve double crush treated with local injection of cultured Schwann cell suspension or lesioned spinal cord extract: implications on cell therapy for nerve repair Respostas astrocitárias na medula espinal do rato submetido ao esmagamento duplo do nervo ciático e tratado com injeção local de suspensão de células de Schwann cultivadas ou de extrato de medula espinal lesada: implicações na terapia celular para o reparo do nervo

    National Research Council Canada - National Science Library

    João Gabriel Martins Dallo; Bernardo Vergara Reichert; José Benedito Ramos Valladão Júnior; Camila Silva; Bianca Aparecida de Luca; Beatriz de Freitas Azevedo Levy; Gerson Chadi

    2007-01-01

    PURPOSE: Reactive astrocytes are implicated in several mechanisms after central or peripheral nervous system lesion, including neuroprotection, neuronal sprouting, neurotransmission and neuropathic pain. Schwann cells (SC...

  19. Characterization and Schwann Cell Seeding of up to 15.0 cm Long Spider Silk Nerve Conduits for Reconstruction of Peripheral Nerve Defects

    Directory of Open Access Journals (Sweden)

    Tim Kornfeld

    2016-11-01

    Full Text Available Nerve reconstruction of extended nerve defect injuries still remains challenging with respect to therapeutic options. The gold standard in nerve surgery is the autologous nerve graft. Due to the limitation of adequate donor nerves, surgical alternatives are needed. Nerve grafts made out of either natural or artificial materials represent this alternative. Several biomaterials are being explored and preclinical and clinical applications are ongoing. Unfortunately, nerve conduits with successful enhancement of axonal regeneration for nerve defects measuring over 4.0 cm are sparse and no conduits are available for nerve defects extending to 10.0 cm. In this study, spider silk nerve conduits seeded with Schwann cells were investigated for in vitro regeneration on defects measuring 4.0 cm, 10.0 cm and 15.0 cm in length. Schwann cells (SCs were isolated, cultured and purified. Cell purity was determined by immunofluorescence. Nerve grafts were constructed out of spider silk from Nephila edulis and decellularized ovine vessels. Finally, spider silk implants were seeded with purified Schwann cells. Cell attachment was observed within the first hour. After 7 and 21 days of culture, immunofluorescence for viability and determination of Schwann cell proliferation and migration throughout the conduits was performed. Analyses revealed that SCs maintained viable (>95% throughout the conduits independent of construct length. SC proliferation on the spider silk was determined from day 7 to day 21 with a proliferation index of 49.42% arithmetically averaged over all conduits. This indicates that spider silk nerve conduits represent a favorable environment for SC attachment, proliferation and distribution over a distance of least 15.0 cm in vitro. Thus spider silk nerve implants are a highly adequate biomaterial for nerve reconstruction.

  20. Characterization and Schwann Cell Seeding of up to 15.0 cm Long Spider Silk Nerve Conduits for Reconstruction of Peripheral Nerve Defects

    Science.gov (United States)

    Kornfeld, Tim; Vogt, Peter M.; Bucan, Vesna; Peck, Claas-Tido; Reimers, Kerstin; Radtke, Christine

    2016-01-01

    Nerve reconstruction of extended nerve defect injuries still remains challenging with respect to therapeutic options. The gold standard in nerve surgery is the autologous nerve graft. Due to the limitation of adequate donor nerves, surgical alternatives are needed. Nerve grafts made out of either natural or artificial materials represent this alternative. Several biomaterials are being explored and preclinical and clinical applications are ongoing. Unfortunately, nerve conduits with successful enhancement of axonal regeneration for nerve defects measuring over 4.0 cm are sparse and no conduits are available for nerve defects extending to 10.0 cm. In this study, spider silk nerve conduits seeded with Schwann cells were investigated for in vitro regeneration on defects measuring 4.0 cm, 10.0 cm and 15.0 cm in length. Schwann cells (SCs) were isolated, cultured and purified. Cell purity was determined by immunofluorescence. Nerve grafts were constructed out of spider silk from Nephila edulis and decellularized ovine vessels. Finally, spider silk implants were seeded with purified Schwann cells. Cell attachment was observed within the first hour. After 7 and 21 days of culture, immunofluorescence for viability and determination of Schwann cell proliferation and migration throughout the conduits was performed. Analyses revealed that SCs maintained viable (>95%) throughout the conduits independent of construct length. SC proliferation on the spider silk was determined from day 7 to day 21 with a proliferation index of 49.42% arithmetically averaged over all conduits. This indicates that spider silk nerve conduits represent a favorable environment for SC attachment, proliferation and distribution over a distance of least 15.0 cm in vitro. Thus spider silk nerve implants are a highly adequate biomaterial for nerve reconstruction. PMID:27916868

  1. GDNF Schwann cells in hydrogel scaffolds promote regional axon regeneration, remyelination and functional improvement after spinal cord transection in rats.

    Science.gov (United States)

    Chen, Bingkun K; Madigan, Nicolas N; Hakim, Jeffrey S; Dadsetan, Mahrokh; McMahon, Siobhan S; Yaszemski, Michael J; Windebank, Anthony J

    2017-03-10

    Positively-charged oligo[poly(ethylene glycol)fumarate] (OPF+ ) is a biodegradable hydrogel used for spinal cord injury repair. We compared scaffolds containing primary Schwann cells (SCs) to scaffolds delivering SCs genetically modified to secrete high concentrations of glial cell-derived neurotrophic factor (GDNF). Multichannel OPF+ scaffolds loaded with SCs or GDNF-SCs were implanted into transected rat spinal cords for 4 weeks. GDNF-SCs promoted regeneration of more axons into OPF+ scaffolds (2773.0 ± 396.0) than primary SC OPF+ scaffolds (1666.0 ± 352.2) (p = 0.0491). This increase was most significant in central and ventral-midline channels of the scaffold. Axonal remyelination was quantitated by stereologic analysis. Increased myelination of regenerating axons was observed in the GDNF-SC group. Myelinating cell and axon complexes were formed by host SCs and not by implanted cells or host oligodendrocytes. Fast Blue retrograde tracing studies determined the rostral-caudal directionality of axonal growth. The number of neurons that projected axons rostrally through the GDNF-SC scaffolds was higher (7929 ± 1670) than in animals with SC OPF+ scaffolds (1069 ± 241.5) (p OPF+ scaffolds partially recovered locomotor function at weeks 3 and 4 following surgery. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  2. Regulated viral BDNF delivery in combination with Schwann cells promotes axonal regeneration through capillary alginate hydrogels after spinal cord injury.

    Science.gov (United States)

    Liu, Shengwen; Sandner, Beatrice; Schackel, Thomas; Nicholson, LaShae; Chtarto, Abdelwahed; Tenenbaum, Liliane; Puttagunta, Radhika; Müller, Rainer; Weidner, Norbert; Blesch, Armin

    2017-09-15

    Grafting of cell-seeded alginate capillary hydrogels into a spinal cord lesion site provides an axonal bridge while physically directing regenerating axonal growth in a linear pattern. However, without an additional growth stimulus, bridging axons fail to extend into the distal host spinal cord. Here we examined whether a combinatory strategy would support regeneration of descending axons across a cervical (C5) lateral hemisection lesion in the rat spinal cord. Following spinal cord transections, Schwann cell (SC)-seeded alginate hydrogels were grafted to the lesion site and AAV5 expressing brain-derived neurotrophic factor (BDNF) under control of a tetracycline-regulated promoter was injected caudally. In addition, we examined whether SC injection into the caudal spinal parenchyma would further enhance regeneration of descending axons to re-enter the host spinal cord. Our data show that both serotonergic and descending axons traced by biotinylated dextran amine (BDA) extend throughout the scaffolds. The number of regenerating axons is significantly increased when caudal BDNF expression is activated and transient BDNF delivery is able to sustain axons after gene expression is switched off. Descending axons are confined to the caudal graft/host interface even with continuous BDNF expression for 8weeks. Only with a caudal injection of SCs, a pathway facilitating axonal regeneration through the host/graft interface is generated allowing axons to successfully re-enter the caudal spinal cord. Recovery from spinal cord injury is poor due to the limited regeneration observed in the adult mammalian central nervous system. Biomaterials, cell transplantation and growth factors that can guide axons across a lesion site, provide a cellular substrate, stimulate axon growth and have shown some promise in increasing the growth distance of regenerating axons. In the present study, we combined an alginate biomaterial with linear channels with transplantation of Schwann cells within

  3. Tumor-suppression functions of merlin are independent of its role as an organizer of the actin cytoskeleton in Schwann cells.

    Science.gov (United States)

    Lallemand, Dominique; Saint-Amaux, Aurelie Lampin; Giovannini, Marco

    2009-11-15

    Merlin is the product of the Nf2 tumor-suppressor gene, and inactivation of Nf2 leads to the development of neural tumors such as schwannomas and meningiomas in humans and mice. Merlin is a member of the ERM (ezrin, radixin and moesin) family of proteins that function as organizers of the actin cytoskeleton. Merlin structure is thought to be similar to that of the ERM proteins, and is held in a closed clamp conformation via intramolecular interactions of its N-terminal FERM (four-point-one, ERM) domain with an alpha-helical C-terminal domain. Like ERMs, merlin can remodel actin-rich cortical structures, yet merlin uniquely inhibits the proliferation of many different cell types. Here, we report that the F2 subdomain of the FERM domain and a domain close to the C-terminus that is defined by residues 532-579 are essential for merlin-mediated inhibition of primary Schwann cell proliferation. Furthermore, we demonstrate that the F1 subdomain of the merlin FERM domain is required for actin colocalization, proper regulation of merlin C-terminal phosphorylation and for remodeling the cytoskeleton, yet is not required for the inhibition of Schwann cell proliferation. Thus, tumor suppression by merlin is independent of its role as an organizer of the actin cytoskeleton in Schwann cells.

  4. A novel marker for terminal Schwann cells, homocysteine-responsive ER-resident protein, as isolated by a single cell PCR-differential display.

    Science.gov (United States)

    Oda, Ryo; Yaoi, Takeshi; Okajima, Seiichiro; Kobashi, Hiroaki; Kubo, Toshikazu; Fushiki, Shinji

    2003-09-05

    Terminal Schwann cells (TSCs) that cover motor neuron terminals are known to play important roles in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. We have established a method of selectively and efficiently collecting TSCs so that cDNA analysis can be done properly. The expression of 1-2% of whole mRNAs was compared between myelinating Schwann cells (MSCs) and TSCs, and it turned out that approximately one-third of the bands could be categorized as cell-type-specific bands. TSCs thus constitute a distinct entity from the viewpoint of gene expression. As one of the cDNA clones belonging to TSC-specific bands was identified homocysteine-responsive ER-resident protein (Herp), and in situ hybridization confirmed that Herp mRNA is expressed in TSCs on motor nerve terminals but not in MSCs, both in developing and adult rats. In conclusion, we have been able to identify Herp as a novel molecular marker for TSCs.

  5. The Use of Fiber-Reinforced Scaffolds Cocultured with Schwann Cells and Vascular Endothelial Cells to Repair Rabbit Sciatic Nerve Defect with Vascularization

    Directory of Open Access Journals (Sweden)

    Hongyang Gao

    2013-01-01

    Full Text Available To explore the feasibility of biodegradable fiber-reinforced 3D scaffolds with satisfactory mechanical properties for the repair of long-distance sciatic nerve defect in rabbits and effects of vascularized graft in early stage on the recovery of neurological function, Schwann cells and vascular endothelial cells were cocultured in the fiber-reinforced 3D scaffolds. Experiment group which used prevascularized nerve complex for the repair of sciatic nerve defect and control group which only cultured with Schwann cells were set. The animals in both groups underwent electromyography to show the status of the neurological function recovery at 4, 8, and 16 weeks after the surgery. Sciatic nerve regeneration and myelination were observed under the light microscope and electron microscope. Myelin sheath thickness, axonal diameter, and number of myelinated nerve fiber were quantitatively analyzed using image analysis system. The recovery of foot ulcer, the velocity of nerve conduction, the number of regenerating nerve fiber, and the recovery of ultrastructure were increased in the experimental group than those in the control group. Prevascularized tissue engineered fiber-reinforced 3D scaffolds for the repair of sciatic nerve defects in rabbits can effectively promote the recovery of neurological function.

  6. Salidroside promotes peripheral nerve regeneration based on tissue engineering strategy using Schwann cells and PLGA: in vitro and in vivo

    Science.gov (United States)

    Liu, Hui; Lv, Peizhen; Zhu, Yongjia; Wu, Huayu; Zhang, Kun; Xu, Fuben; Zheng, Li; Zhao, Jinmin

    2017-01-01

    Salidriside (SDS), a phenylpropanoid glycoside derived from Rhodiola rosea L, has been shown to be neuroprotective in many studies, which may be promising in nerve recovery. In this study, the neuroprotective effects of SDS on engineered nerve constructed by Schwann cells (SCs) and Poly (lactic-co-glycolic acid) (PLGA) were studied in vitro. We further investigated the effect of combinational therapy of SDS and PLGA/SCs based tissue engineering on peripheral nerve regeneration based on the rat model of nerve injury by sciatic transection. The results showed that SDS dramatically enhanced the proliferation and function of SCs. The underlying mechanism may be that SDS affects SCs growth through the modulation of neurotrophic factors (BDNF, GDNF and CNTF). 12 weeks after implantation with a 12 mm gap of sciatic nerve injury, SDS-PLGA/SCs achieved satisfying outcomes of nerve regeneration, as evidenced by morphological and functional improvements upon therapy by SDS, PLGA/SCs or direct suture group assessed by sciatic function index, nerve conduction assay, HE staining and immunohistochemical analysis. Our results demonstrated the significant role of introducing SDS into neural tissue engineering to promote nerve regeneration.

  7. Neuregulin1 displayed on motor axons regulates terminal Schwann cell-mediated synapse elimination at developing neuromuscular junctions

    Science.gov (United States)

    Li, Yue; Mikesh, Michelle; Smith, Ian; Nave, Klaus-Armin; Schwab, Markus H.; Thompson, Wesley J.

    2016-01-01

    Synaptic connections in the nervous system are rearranged during development and in adulthood as a feature of growth, plasticity, aging, and disease. Glia are implicated as active participants in these changes. Here we investigated a signal that controls the participation of peripheral glia, the terminal Schwann cells (SCs), at the neuromuscular junction (NMJ) in mice. Transgenic manipulation of the levels of membrane-tethered neuregulin1 (NRG1-III), a potent activator of SCs normally presented on motor axons, alters the rate of loss of motor inputs at NMJs during developmental synapse elimination. In addition, NMJs of adult transgenic mice that expressed excess axonal NRG1-III exhibited continued remodeling, in contrast to the more stable morphologies of controls. In fact, synaptic SCs of these adult mice with NRG1-III overexpression exhibited behaviors evident in wild type neonates during synapse elimination, including an affinity for the postsynaptic myofiber surface and phagocytosis of nerve terminals. Given that levels of NRG1-III expression normally peak during the period of synapse elimination, our findings identify axon-tethered NRG1 as a molecular determinant for SC-driven neuromuscular synaptic plasticity. PMID:26755586

  8. Cdc42 regulates Schwann cell radial sorting and myelin sheath folding through NF2/merlin-dependent and independent signaling.

    Science.gov (United States)

    Guo, Li; Moon, Chandra; Zheng, Yi; Ratner, Nancy

    2013-11-01

    The Rho family GTPase Cdc42 has been implicated in developmental Schwann cell (SC) proliferation, providing sufficient SCs for radial sorting of axons preceding SC differentiation in the peripheral nervous system. We generated Cdc42 conditional knockout (Cdc42-CKO) mice and confirmed aberrant axon sorting in Cdc42-CKO nerves. In adult Cdc42-CKO nerves, blood vessels were enlarged, and mature Remak bundles containing small axons were absent. Abnormal infoldings and outfoldings of myelin sheaths developed in Cdc42-CKO nerves, mimicking pathological features of Charcot-Marie-Tooth (CMT) disease. The NF2/merlin tumor suppressor has been implicated up- and down-stream of Cdc42. In Cdc42-CKO;NF2-del double mutant mice, radial sorting defects seen in Cdc42-CKO nerves were rescued, while changes in myelin sheaths in Cdc42-CKO nerves were not. Phosphorylation of Focal adhesion kinase (FAK) and P-GSK3β, as well as expression of β-catenin were decreased in Cdc42-CKO nerves, and these changes were rescued by NF2/merlin mutation in Cdc42-CKO;NF2-del double mutant mice. Thus, Cdc42 regulates SC radial sorting in vivo through NF2/merlin dependent signaling pathways, while Cdc42 modulation of myelin sheath folding is NF2/merlin independent. Copyright © 2013 Wiley Periodicals, Inc.

  9. Neurotropin® Accelerates the Differentiation of Schwann Cells and Remyelination in a Rat Lysophosphatidylcholine-Induced Demyelination Model

    Directory of Open Access Journals (Sweden)

    Hozo Matsuoka

    2018-02-01

    Full Text Available Neurotropin® (NTP, a non-protein extract of inflamed rabbit skin inoculated with vaccinia virus, is clinically used for the treatment of neuropathic pain in Japan and China, although its effect on peripheral nerve regeneration remains to be elucidated. The purpose of this study was to investigate the effects of NTP on Schwann cells (SCs in vitro and in vivo, which play an important role in peripheral nerve regeneration. In SCs, NTP upregulated protein kinase B (AKT activity and Krox20 and downregulated extracellular signal-regulated kinase1/2 activity under both growth and differentiation conditions, enhanced the expression of myelin basic protein and protein zero under the differentiation condition. In a co-culture of dorsal root ganglion neurons and SCs, NTP accelerated myelination of SCs. To further investigate the influence of NTP on SCs in vivo, lysophosphatidylcholine was injected into the rat sciatic nerve, leading to the focal demyelination. After demyelination, NTP was administered systemically with an osmotic pump for one week. NTP improved the ratio of myelinated axons and motor, sensory, and electrophysiological function. These findings reveal novel effects of NTP on SCs differentiation in vitro and in vivo, and indicate NTP as a promising treatment option for peripheral nerve injuries and demyelinating diseases.

  10. CXCL12α/SDF-1 from perisynaptic Schwann cells promotes regeneration of injured motor axon terminals.

    Science.gov (United States)

    Negro, Samuele; Lessi, Francesca; Duregotti, Elisa; Aretini, Paolo; La Ferla, Marco; Franceschi, Sara; Menicagli, Michele; Bergamin, Elisanna; Radice, Egle; Thelen, Marcus; Megighian, Aram; Pirazzini, Marco; Mazzanti, Chiara M; Rigoni, Michela; Montecucco, Cesare

    2017-08-01

    The neuromuscular junction has retained through evolution the capacity to regenerate after damage, but little is known on the inter-cellular signals involved in its functional recovery from trauma, autoimmune attacks, or neurotoxins. We report here that CXCL12α, also abbreviated as stromal-derived factor-1 (SDF-1), is produced specifically by perisynaptic Schwann cells following motor axon terminal degeneration induced by α-latrotoxin. CXCL12α acts via binding to the neuronal CXCR4 receptor. A CXCL12α-neutralizing antibody or a specific CXCR4 inhibitor strongly delays recovery from motor neuron degeneration in vivo Recombinant CXCL12α in vivo accelerates neurotransmission rescue upon damage and very effectively stimulates the axon growth of spinal cord motor neurons in vitro These findings indicate that the CXCL12α-CXCR4 axis plays an important role in the regeneration of the neuromuscular junction after motor axon injury. The present results have important implications in the effort to find therapeutics and protocols to improve recovery of function after different forms of motor axon terminal damage. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  11. Neuregulin1 displayed on motor axons regulates terminal Schwann cell-mediated synapse elimination at developing neuromuscular junctions.

    Science.gov (United States)

    Lee, Young Il; Li, Yue; Mikesh, Michelle; Smith, Ian; Nave, Klaus-Armin; Schwab, Markus H; Thompson, Wesley J

    2016-01-26

    Synaptic connections in the nervous system are rearranged during development and in adulthood as a feature of growth, plasticity, aging, and disease. Glia are implicated as active participants in these changes. Here we investigated a signal that controls the participation of peripheral glia, the terminal Schwann cells (SCs), at the neuromuscular junction (NMJ) in mice. Transgenic manipulation of the levels of membrane-tethered neuregulin1 (NRG1-III), a potent activator of SCs normally presented on motor axons, alters the rate of loss of motor inputs at NMJs during developmental synapse elimination. In addition, NMJs of adult transgenic mice that expressed excess axonal NRG1-III exhibited continued remodeling, in contrast to the more stable morphologies of controls. In fact, synaptic SCs of these adult mice with NRG1-III overexpression exhibited behaviors evident in wild type neonates during synapse elimination, including an affinity for the postsynaptic myofiber surface and phagocytosis of nerve terminals. Given that levels of NRG1-III expression normally peak during the period of synapse elimination, our findings identify axon-tethered NRG1 as a molecular determinant for SC-driven neuromuscular synaptic plasticity.

  12. Adult skin-derived precursor Schwann cell grafts form growths in the injured spinal cord of Fischer rats.

    Science.gov (United States)

    May, Zacnicte; Kumar, Ranjan; Führmann, Tobias; Tam, Roger; Vulic, Katarina; Forero, Juan; Lucas-Osma, Ana M; Fenrich, Keith; Assinck, Peggy; Lee, Michael J; Moulson, Aaron; Shoichet, Molly S; Tetzlaff, Wolfram; Biernaskie, Jeff; Fouad, Karim

    2017-10-25

    In this study, GFP+ skin-derived precursor Schwann cells (SKP-SCs) from adult rats were grafted into the injured spinal cord of immunosuppressed rats. Our goal was to improve grafted cell survival in the injured spinal cord, which is typically low. Cells were grafted in hyaluronan-methylcellulose hydrogel (HAMC) or hyaluronan-methylcellulose modified with laminin- and fibronectin-derived peptide sequences (eHAMC). The criteria for selection of hyaluronan was for its shear-thinning properties, making the hydrogel easy to inject, methylcellulose for its inverse thermal gelation, helping to keep grafted cells in situ, and fibronectin and laminin to improve cell attachment and, thus, prevent cell death due to dissociation from substrate molecules (i.e., anoikis). Post-mortem examination revealed large masses of GFP+ SKP-SCs in the spinal cords of rats that received cells in HAMC (5 out of n = 8) and eHAMC (6 out of n = 8). Cell transplantation in eHAMC caused significantly greater spinal lesions compared to lesion and eHAMC only control groups. A parallel study showed similar masses in the contused spinal cord of rats after transplantation of adult GFP+ SKP-SCs without a hydrogel or immunosuppression. These findings suggest that adult GFP+ SKP-SCs, cultured/transplanted under the conditions described here, have a capacity for uncontrolled proliferation. Growth-formation in pre-clinical research has also been documented after transplantation of: human induced pluripotent stem cell-derived neural stem cells (Itakura et al., 2015), embryonic stem cells and embryonic stem cell-derived neurons (Brederlau et al., 2006; Dressel et al., 2008), bone marrow derived mesenchymal stem cells (Jeong et al., 2011) and rat nerve-derived SCs following in vitro expansion for ˃11 passages (Funk et al., 2007; Langford et al., 1988; Morrissey et al., 1991). It is of upmost importance to define the precise culture/transplantation parameters for maintenance of normal cell function and safe

  13. PACAP interacts with PAC1 receptors to induce tissue plasminogen activator (tPA) expression and activity in schwann cell-like cultures.

    Science.gov (United States)

    Castorina, Alessandro; Waschek, James A; Marzagalli, Rubina; Cardile, Venera; Drago, Filippo

    2015-01-01

    Regeneration of peripheral nerves depends on the abilities of rejuvenating axons to migrate at the injury site through cellular debris and altered extracellular matrix, and then grow along the residual distal nerve sheath conduit and reinnervate synaptic targets. Considerable evidence suggest that glial cells participate in this process, although the mechanisms remain to be clarified. In cell culture, regenerating neurites secrete PACAP, a peptide shown to induce the expression of the protease tissue plasminogen activator (tPA) in neural cell types. In the present studies, we tested the hypothesis that PACAP can stimulate peripheral glial cells to produce tPA. More specifically, we addressed whether or not PACAP promoted the expression and activity of tPA in the Schwann cell line RT4-D6P2T, which shares biochemical and physical properties with Schwann cells. We found that PACAP dose- and time-dependently stimulated tPA expression both at the mRNA and protein level. Such effect was mimicked by maxadilan, a potent PAC1 receptor agonist, but not by the PACAP-related homolog VIP, suggesting a PAC1-mediated function. These actions appeared to be mediated at least in part by the Akt/CREB signaling cascade because wortmannin, a PI3K inhibitor, prevented peptide-driven CREB phosphorylation and tPA increase. Interestingly, treatment with BDNF mimicked PACAP actions on tPA, but acted through both the Akt and MAPK signaling pathways, while causing a robust increase in PACAP and PAC1 expression. PACAP6-38 totally blocked PACAP-driven tPA expression and in part hampered BDNF-mediated effects. We conclude that PACAP, acting through PAC1 receptors, stimulates tPA expression and activity in a Akt/CREB-dependent manner to promote proteolytic activity in Schwann-cell like cultures.

  14. PACAP interacts with PAC1 receptors to induce tissue plasminogen activator (tPA expression and activity in schwann cell-like cultures.

    Directory of Open Access Journals (Sweden)

    Alessandro Castorina

    Full Text Available Regeneration of peripheral nerves depends on the abilities of rejuvenating axons to migrate at the injury site through cellular debris and altered extracellular matrix, and then grow along the residual distal nerve sheath conduit and reinnervate synaptic targets. Considerable evidence suggest that glial cells participate in this process, although the mechanisms remain to be clarified. In cell culture, regenerating neurites secrete PACAP, a peptide shown to induce the expression of the protease tissue plasminogen activator (tPA in neural cell types. In the present studies, we tested the hypothesis that PACAP can stimulate peripheral glial cells to produce tPA. More specifically, we addressed whether or not PACAP promoted the expression and activity of tPA in the Schwann cell line RT4-D6P2T, which shares biochemical and physical properties with Schwann cells. We found that PACAP dose- and time-dependently stimulated tPA expression both at the mRNA and protein level. Such effect was mimicked by maxadilan, a potent PAC1 receptor agonist, but not by the PACAP-related homolog VIP, suggesting a PAC1-mediated function. These actions appeared to be mediated at least in part by the Akt/CREB signaling cascade because wortmannin, a PI3K inhibitor, prevented peptide-driven CREB phosphorylation and tPA increase. Interestingly, treatment with BDNF mimicked PACAP actions on tPA, but acted through both the Akt and MAPK signaling pathways, while causing a robust increase in PACAP and PAC1 expression. PACAP6-38 totally blocked PACAP-driven tPA expression and in part hampered BDNF-mediated effects. We conclude that PACAP, acting through PAC1 receptors, stimulates tPA expression and activity in a Akt/CREB-dependent manner to promote proteolytic activity in Schwann-cell like cultures.

  15. Behaviour of oligodendrocytes and Schwann cells in an experimental model of toxic demyelination of the central nervous system Comportamento de oligodendrócitos e células de Schwann em modelo experimental de desmielinização tóxica do sistema nervoso central

    Directory of Open Access Journals (Sweden)

    Dominguita Lühers Graça

    2001-06-01

    Full Text Available Oligodendrocytes and Schwann cells are engaged in myelin production, maintenance and repairing respectively in the central nervous system (CNS and the peripheral nervous system (PNS. Whereas oligodendrocytes act only within the CNS, Schwann cells are able to invade the CNS in order to make new myelin sheaths around demyelinated axons. Both cells have some limitations in their activities, i.e. oligodendrocytes are post-mitotic cells and Schwann cells only get into the CNS in the absence of astrocytes. Ethidium bromide (EB is a gliotoxic chemical that when injected locally within the CNS, induce demyelination. In the EB model of demyelination, glial cells are destroyed early after intoxication and Schwann cells are free to approach the naked central axons. In normal Wistar rats, regeneration of lost myelin sheaths can be achieved as early as thirteen days after intoxication; in Wistar rats immunosuppressed with cyclophosphamide the process is delayed and in rats administered cyclosporine it may be accelerated. Aiming the enlightening of those complex processes, all events concerning the myelinating cells in an experimental model are herein presented and discussed.Oligodendrócitos e células de Schwann realizam a produção e manutenção das bainhas de mielina, respectivamente no sistema nervoso central (SNC e periférico (SNP. As células de Schwann, à diferença dos oligodendrócitos, são capazes de invadir o SNC para remielinizar axônios desmielinizados, sempre que os astrócitos tenham sido destruídos. O brometo de etídio é uma droga gliotóxica usada para induzir desmielinização com o desaparecimento precoce de astrócitos, de modo que as células de Schwann têm liberdade para invadir o SNC. Em ratos Wistar normais, a remielinização é detectada treze dias após desmielinização; em ratos Wistar imunossuprimidos com ciclofosfamida a reparação do tecido é tardia, enquanto que em animais tratados com ciclosporina ela

  16. Basic fibroblast growth factor is a key factor that induces bone marrow mesenchymal stem cells towards cells with Schwann cell phenotype.

    Science.gov (United States)

    Zhu, Hui; Yang, Aizhen; Du, Jinfeng; Li, Donghui; Liu, Mei; Ding, Fei; Gu, Xiaosong; Liu, Yan

    2014-01-24

    Bone marrow mesenchymal stem cells (MSCs) can be differentiate towards a Schwann cells (SCs) lineage when exposed to pre-inducing reagents β-mercaptoethanol (BME) and retinoic acid (RA), followed by inducing factors: forskolin (FSK), basic fibroblast growth factor (bFGF), platelet derived growth factor (PDGF), and heregulin (HRG). However, the underlying mechanisms remain unclear. Here, we investigated the individual effects of these inducing factors on the differentiation of MSCs towards SC phenotype in rats. We show that the omission of either HRG or PDGF from the induction medium is not sufficient to change the SC-like phenotype or the expression level of the SC marker, S100β. However, the omission of bFGF from the induction medium effectively blocked neural induction of the MSCs. Moreover, only bFGF was found to inhibit MSC proliferation during differentiation. To clarify the mechanism responsible for the effect of bFGF, we also investigated the activation of the extracellular signal-regulated kinase (ERK) pathway in the induced cells. Our results suggest that morphological changes in MSCs induced by bFGF depend on the activation of ERK, and bFGF may be an indispensable factor that induces MSCs to differentiate into cells with SCs phenotype. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Human primordial germ cells migrate along nerve fibers and Schwann cells from the dorsal hind gut mesentery to the gonadal ridge

    DEFF Research Database (Denmark)

    Møllgård, Kjeld; Jespersen, Åse; Lutterodt, Melissa Catherine

    2010-01-01

    The aim of this study was to investigate the spatiotemporal development of autonomic nerve fibers and primordial germ cells (PGCs) along their migratory route from the dorsal mesentery to the gonadal ridges in human embryos using immunohistochemical markers and electron microscopy. Autonomic nerve...... and their intimate contact with PGCs. PGCs expressed GAGE, MAGE-A4, OCT4 and c-Kit. Serial paraffin sections showed that most PGCs were located inside bundles of autonomic nerve fibers with the majority adjacent to the most peripheral fibers (close to Schwann cells). We also show that both nerve fibers and PGCs...... arrive at the gonadal ridge between 29 and 33 days pc. In conclusion, our data suggest that PGCs in human embryos preferentially migrate along autonomic nerve fibers from the dorsal mesentery to the developing gonad where they are delivered via a fine nerve plexus....

  18. Proliferation- and migration-enhancing effects of ginseng and ginsenoside Rg1 through IGF-I- and FGF-2-signaling pathways on RSC96 Schwann cells.

    Science.gov (United States)

    Lu, Ming-Chin; Lai, Tung-Yuan; Hwang, Jin-Ming; Chen, Hsien-Te; Chang, Sheng-Huang; Tsai, Fuu-Jen; Wang, Hwai-Lee; Lin, Chien-Chung; Kuo, Wei-Wen; Huang, Chih-Yang

    2009-06-01

    The aim of the present study is to evaluate the proliferation- and migration-enhancing effects of ginseng and its component, ginsenoside (Rg1) on RSC96 Schwann cells. We investigated the molecular signaling pathways, which include: (1) survival signaling, IGFs-IGFIR-Akt-Bcl2 and proliferative signaling, cell cycle factors and mitogen-activated protein kinase (MAPK) pathways, (2) migrating and anti-scar signaling, FGF-2-uPA-MMPs.We treated RSC96 cells with different concentrations (100, 200, 300, 400, 500 microg ml(-1)) of ginseng and its constituent, Rg1 (5, 10, 15, 20, 25 microg ml(-1)). We observed a proliferative effect in a dose-dependent manner by PCNA western blotting assay, MTT assay, and wound healing test. Furthermore, we also found in the results of western blotting assay, ginseng and Rg1 enhance protein expression of IGF-I pathway regulators, cell cycle controlling proteins, and MAPK signaling pathways to promote the cell proliferation. In addition, ginseng and Rg1 also stimulated the FGF-2-uPA-MMP 9 migrating pathway to enhance the migration of RSC96 Schwann cells. Using MAPK chemical inhibitors, U0126, SB203580, and SP600125, the proliferative effects of ginseng and Rg1 on RSC96 cells were identified to be MAPK signaling-dependent. On the basis of the results, applying appropriate doses of ginseng and Rg1 with biomedical materials would be a potential approach for enhancing neuron regeneration. 2009 John Wiley & Sons, Ltd.

  19. Enhanced noradrenergic axon regeneration into schwann cell-filled PVDF-TrFE conduits after complete spinal cord transection.

    Science.gov (United States)

    Lee, Yee-Shuan; Wu, Siliang; Arinzeh, Treena Livingston; Bunge, Mary Bartlett

    2017-02-01

    Schwann cell (SC) transplantation has been utilized for spinal cord repair and demonstrated to be a promising therapeutic strategy. In this study, we investigated the feasibility of combining SC transplantation with novel conduits to bridge the completely transected adult rat spinal cord. This is the first and initial study to evaluate the potential of using a fibrous piezoelectric polyvinylidene fluoride trifluoroethylene (PVDF-TrFE) conduit with SCs for spinal cord repair. PVDF-TrFE has been shown to enhance neurite growth in vitro and peripheral nerve repair in vivo. In this study, SCs adhered and proliferated when seeded onto PVDF-TrFE scaffolds in vitro. SCs and PVDF-TrFE conduits, consisting of random or aligned fibrous inner walls, were transplanted into transected rat spinal cords for 3 weeks to examine early repair. Glial fibrillary acidic protein (GFAP)+ astrocyte processes and GFP (green fluorescent protein)-SCs were interdigitated at both rostral and caudal spinal cord/SC transplant interfaces in both types of conduits, indicative of permissivity to axon growth. More noradrenergic/DβH+ (dopamine-beta-hydroxylase) brainstem axons regenerated across the transplant when greater numbers of GFAP+ astrocyte processes were present. Aligned conduits promoted extension of DβH+ axons and GFAP+ processes farther into the transplant than random conduits. Sensory CGRP+ (calcitonin gene-related peptide) axons were present at the caudal interface. Blood vessels formed throughout the transplant in both conduits. This study demonstrates that PVDF-TrFE conduits harboring SCs are promising for spinal cord repair and deserve further investigation. Biotechnol. Bioeng. 2017;114: 444-456. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Sensory defects in Necdin deficient mice result from a loss of sensory neurons correlated within an increase of developmental programmed cell death

    Directory of Open Access Journals (Sweden)

    Fernandez Pierre-Alain

    2006-11-01

    Full Text Available Abstract Background The human NECDIN gene is involved in a neurodevelopmental disorder, Prader-Willi syndrome (PWS. Previously we reported a mouse Necdin knock-out model with similar defects to PWS patients. Despite the putative roles attributed to Necdin, mainly from in vitro studies, its in vivo function remains unclear. In this study, we investigate sensory-motor behaviour in Necdin deficient mice. We reveal cellular defects and analyse their cause. Results We report sensory differences in Necdin deficient mice compared to wild type animals. These differences led us to investigate sensory neuron development in Necdin deficient mouse embryos. First, we describe the expression pattern of Necdin in developing DRGs and report a reduction of one-third in specified sensory neurons in dorsal roots ganglia and show that this neuronal loss is achieved by E13.5, when DRGs sensory neurons are specified. In parallel, we observed an increase of 41% in neuronal apoptosis during the wave of naturally occurring cell death at E12.5. Since it is assumed that Necdin is a P75NTR interactor, we looked at the P75NTR-expressing cell population in Necdin knock-out embryos. Unexpectedly, Necdin loss of function has no effect on p75NTR expressing neurons suggesting no direct genetic interaction between Necdin and P75NTR in this context. Although we exclude a role of Necdin in axonal outgrowth from spinal sensory neurons in early developmental stages; such a role could occur later in neuronal differentiation. Finally we also exclude an anti-proliferative role of Necdin in developing sensory neurons. Conclusion Overall, our data show clearly that, in early development of the nervous system, Necdin is an anti-apoptotic or survival factor.

  1. Contribution of p75NTR to Schwannoma Growth and Therapeutic Responses

    Science.gov (United States)

    2017-05-01

    Proliferation, Association for Research in Otolaryngology Mid-Winter Meeting, Feb. 2017 Website(s) or other Internet site(s)- Nothing to report...Received Oct 21, 2013, Accepted for publication June 6, 2014. Address correspondence to Marlan R. Hansen, Department of Otolaryngology -Head and Neck...Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, USA. E-mail: marlan-hansen@uiowa.edu Department of Otolaryngology -Head and Neck

  2. Contribution of p75NTR to Schwannoma Growth and Therapeutic Responses

    Science.gov (United States)

    2016-05-01

    pathways ( Bosco et al., 2010; Chadee and Kyriakis, 2004; Chadee et al., 2006; Flaiz et al., 2009; Fraenzer et al., 2003; Houshmandi et al., 2009; James et al...transcript levels. A student’s non-paired, two-tailed t- test was used to determine statistical differences of transcript levels. Western Blots Western blots of...with a student’s nonpaired, two-tailed t- test . NF-jB Assay Protein lysates were prepared 2 h following treatment of primary VS cultures with proNGF

  3. A Combination Tissue Engineering Strategy for Schwann Cell-Induced Spinal Cord Repair

    Science.gov (United States)

    2016-10-01

    evaporated before using for cell culture studies. For in vitro experiments, the scaffolds were cut into 6mm disks and sterilized by ultraviolet ...of the PVDF-TrFE conduit in situ to understand if and how piezoelectricity may contribute to trans- planted SC distribution and axon regeneration. In...Barry J, Vertegel A, Ray S, et al. Spinal Cord Injury: A Review of Current Therapy, Future Treatments, and Basic Science Frontiers. Neurochem Res

  4. The analgesic effect on neuropathic pain of retrogradely transported botulinum neurotoxin A involves Schwann cells and astrocytes.

    Directory of Open Access Journals (Sweden)

    Sara Marinelli

    Full Text Available In recent years a growing debate is about whether botulinum neurotoxins are retrogradely transported from the site of injection. Immunodetection of cleaved SNAP-25 (cl-SNAP-25, the protein of the SNARE complex targeted by botulinum neurotoxin serotype A (BoNT/A, could represent an excellent approach to investigate the mechanism of action on the nociceptive pathways at peripheral and/or central level. After peripheral administration of BoNT/A, we analyzed the expression of cl-SNAP-25, from the hindpaw's nerve endings to the spinal cord, together with the behavioral effects on neuropathic pain. We used the chronic constriction injury of the sciatic nerve in CD1 mice as animal model of neuropathic pain. We evaluated immunostaining of cl-SNAP-25 in the peripheral nerve endings, along the sciatic nerve, in dorsal root ganglia and in spinal dorsal horns after intraplantar injection of saline or BoNT/A, alone or colocalized with either glial fibrillar acidic protein, GFAP, or complement receptor 3/cluster of differentiation 11b, CD11b, or neuronal nuclei, NeuN, depending on the area investigated. Immunofluorescence analysis shows the presence of the cl-SNAP-25 in all tissues examined, from the peripheral endings to the spinal cord, suggesting a retrograde transport of BoNT/A. Moreover, we performed in vitro experiments to ascertain if BoNT/A was able to interact with the proliferative state of Schwann cells (SC. We found that BoNT/A modulates the proliferation of SC and inhibits the acetylcholine release from SC, evidencing a new biological effect of the toxin and further supporting the retrograde transport of the toxin along the nerve and its ability to influence regenerative processes. The present results strongly sustain a combinatorial action at peripheral and central neural levels and encourage the use of BoNT/A for the pathological pain conditions difficult to treat in clinical practice and dramatically impairing patients' quality of life.

  5. Nerve Regeneration Potential of Protocatechuic Acid in RSC96 Schwann Cells by Induction of Cellular Proliferation and Migration through IGF-IR-PI3K-Akt Signaling.

    Science.gov (United States)

    Ju, Da-Tong; Liao, Hung-En; Shibu, Marthandam Asokan; Ho, Tsung-Jung; Padma, Viswanadha Vijaya; Tsai, Fuu-Jen; Chung, Li-Chin; Day, Cecilia Hsuan; Lin, Chien-Chung; Huang, Chih-Yang

    2015-12-31

    Peripheral nerve injuries, caused by accidental trauma, acute compression or surgery, often result in temporary or life-long neuronal dysfunctions and inflict great economic or social burdens on the patients. Nerve cell proliferation is an essential process to restore injured nerves of adults. Schwann cells play a crucial role in endogenous repair of peripheral nerves due to their ability to proliferate, migrate and provide trophic support to axons via expression of various neurotrophic factors, such as the nerve growth factor (NGF), especially after nerve injury. Protocatechuic acid (PCA) is a dihydroxybenzoic acid, a type of phenolic acid, isolated from the kernels of Alpinia oxyphylla Miq (AOF), a traditional Chinese herbal medicine the fruits of which are widely used as a tonic, aphrodisiac, anti-salivation and anti-diarrheatic. This study investigated the molecular mechanisms by which PCA induces Schwann cell proliferation by activating IGF-IR-PI3K-Akt pathway. Treatment with PCA induces phosphorylation of the insulin-like growth factor-I (IGF-I)-mediated phosphatidylinositol 3 kinase/serine - threonine kinase (PI3K/Akt) pathway, and activates expression of cell nuclear antigen (PCNA) in a dose-dependent manner. Cell cycle analysis after 18 h of treatment showed that proliferation of the RSC96 cells was enhanced by PCA treatment. The PCA induced proliferation was accompanied by modulation in the expressions of cell cycle proteins cyclin D1, cyclin E and cyclin A. Knockdown of PI3K using small interfering RNA (siRNA) and inhibition of IGF-IR receptor resulted in the reduction in cell survival proteins. The results collectively showed that PCA treatment promoted cell proliferation and cell survival via IGF-I signaling.

  6. Time-Dependent Nerve Growth Factor Signaling Changes in the Rat Retina During Optic Nerve Crush-Induced Degeneration of Retinal Ganglion Cells

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    Louise A. Mesentier-Louro

    2017-01-01

    Full Text Available Nerve growth factor (NGF is suggested to be neuroprotective after nerve injury; however, retinal ganglion cells (RGC degenerate following optic-nerve crush (ONC, even in the presence of increased levels of endogenous NGF. To further investigate this apparently paradoxical condition, a time-course study was performed to evaluate the effects of unilateral ONC on NGF expression and signaling in the adult retina. Visually evoked potential and immunofluorescence staining were used to assess axonal damage and RGC loss. The levels of NGF, proNGF, p75NTR, TrkA and GFAP and the activation of several intracellular pathways were analyzed at 1, 3, 7 and 14 days after crush (dac by ELISA/Western Blot and PathScan intracellular signaling array. The progressive RGC loss and nerve impairment featured an early and sustained activation of apoptotic pathways; and GFAP and p75NTR enhancement. In contrast, ONC-induced reduction of TrkA, and increased proNGF were observed only at 7 and 14 dac. We propose that proNGF and p75NTR contribute to exacerbate retinal degeneration by further stimulating apoptosis during the second week after injury, and thus hamper the neuroprotective effect of the endogenous NGF. These findings might aid in identifying effective treatment windows for NGF-based strategies to counteract retinal and/or optic-nerve degeneration.

  7. Combination Therapy with c-Met and Src Inhibitors Induces Caspase-Dependent Apoptosis of Merlin-Deficient Schwann Cells and Suppresses Growth of Schwannoma Cells.

    Science.gov (United States)

    Fuse, Marisa A; Plati, Stephani Klingeman; Burns, Sarah S; Dinh, Christine T; Bracho, Olena; Yan, Denise; Mittal, Rahul; Shen, Rulong; Soulakova, Julia N; Copik, Alicja J; Liu, Xue Zhong; Telischi, Fred F; Chang, Long-Sheng; Franco, Maria Clara; Fernandez-Valle, Cristina

    2017-11-01

    Neurofibromatosis type 2 (NF2) is a nervous system tumor disorder caused by inactivation of the merlin tumor suppressor encoded by the NF2 gene. Bilateral vestibular schwannomas are a diagnostic hallmark of NF2. Mainstream treatment options for NF2-associated tumors have been limited to surgery and radiotherapy; however, off-label uses of targeted molecular therapies are becoming increasingly common. Here, we investigated drugs targeting two kinases activated in NF2-associated schwannomas, c-Met and Src. We demonstrated that merlin-deficient mouse Schwann cells (MD-MSC) treated with the c-Met inhibitor, cabozantinib, or the Src kinase inhibitors, dasatinib and saracatinib, underwent a G 1 cell-cycle arrest. However, when MD-MSCs were treated with a combination of cabozantinib and saracatinib, they exhibited caspase-dependent apoptosis. The combination therapy also significantly reduced growth of MD-MSCs in an orthotopic allograft mouse model by greater than 80% of vehicle. Moreover, human vestibular schwannoma cells with NF2 mutations had a 40% decrease in cell viability when treated with cabozantinib and saracatinib together compared with the vehicle control. This study demonstrates that simultaneous inhibition of c-Met and Src signaling in MD-MSCs triggers apoptosis and reveals vulnerable pathways that could be exploited to develop NF2 therapies. Mol Cancer Ther; 16(11); 2387-98. ©2017 AACR . ©2017 American Association for Cancer Research.

  8. The Glia Response after Peripheral Nerve Injury: A Comparison between Schwann Cells and Olfactory Ensheathing Cells and Their Uses for Neural Regenerative Therapies.

    Science.gov (United States)

    Barton, Matthew J; John, James St; Clarke, Mary; Wright, Alison; Ekberg, Jenny

    2017-01-29

    The peripheral nervous system (PNS) exhibits a much larger capacity for regeneration than the central nervous system (CNS). One reason for this difference is the difference in glial cell types between the two systems. PNS glia respond rapidly to nerve injury by clearing debris from the injury site, supplying essential growth factors and providing structural support; all of which enhances neuronal regeneration. Thus, transplantation of glial cells from the PNS is a very promising therapy for injuries to both the PNS and the CNS. There are two key types of PNS glia: olfactory ensheathing cells (OECs), which populate the olfactory nerve, and Schwann cells (SCs), which are present in the rest of the PNS. These two glial types share many similar morphological and functional characteristics but also exhibit key differences. The olfactory nerve is constantly turning over throughout life, which means OECs are continuously stimulating neural regeneration, whilst SCs only promote regeneration after direct injury to the PNS. This review presents a comparison between these two PNS systems in respect to normal physiology, developmental anatomy, glial functions and their responses to injury. A thorough understanding of the mechanisms and differences between the two systems is crucial for the development of future therapies using transplantation of peripheral glia to treat neural injuries and/or disease.

  9. From transplanting Schwann cells in experimental rat spinal cord injury to their transplantation into human injured spinal cord in clinical trials.

    Science.gov (United States)

    Bunge, Mary B; Monje, Paula V; Khan, Aisha; Wood, Patrick M

    2017-01-01

    Among the potential therapies designed to repair the injured spinal cord is cell transplantation, notably the use of autologous adult human Schwann cells (SCs). Here, we detail some of the critical research accomplished over the last four decades to establish a foundation that enables these cells to be tested in clinical trials. New culture systems allowed novel information to be gained about SCs, including discovering ways to stimulate their proliferation to acquire adequately large numbers for transplantation into the injured human spinal cord. Transplantation of rat SCs into rat models of spinal cord injury has demonstrated that SCs promote repair of injured spinal cord. Additional work required to gain approval from the Food and Drug Administration for the first SC trial in the Miami Project is disclosed. This trial and a second one now underway are described. © 2017 Elsevier B.V. All rights reserved.

  10. Chitosan Degradation Products Promote Nerve Regeneration by Stimulating Schwann Cell Proliferation via miR-27a/FOXO1 Axis.

    Science.gov (United States)

    Wang, Yongjun; Zhao, Yahong; Sun, Cheng; Hu, Wen; Zhao, Jing; Li, Guicai; Zhang, Luzhong; Liu, Mei; Liu, Yan; Ding, Fei; Yang, Yumin; Gu, Xiaosong

    2016-01-01

    Natural polysaccharides are biomaterials widely used for constructing scaffolds in tissue engineering. While natural polysaccharides have been shown to robustly promote tissue regeneration, the underlying molecular mechanism remains largely unknown. Here, we show that chitooligosaccharides (COS), the intermediate products of chitosan degradation, stimulate peripheral nerve regeneration in rats. Our experiment also shows that COS stimulate the proliferation of Schwann cells (SCs) during nerve regeneration. By analyzing the transcriptome and gene regulatory network, we identified the miR-27a/FOXO1 axis as the main signaling pathway for mediating the proliferative effects of COS on SCs. COS increase the expression level of miR-27a and cause a reduction of FOXO1, which subsequently accelerates the cell cycle and stimulates SC proliferation to stimulate nerve regeneration. These findings define a basic pathway for oligosaccharides-mediated cell proliferation and reveal a novel aspect of polysaccharide biomaterials in tissue engineering.

  11. A Novel Growth-Promoting Pathway Formed by GDNF-Overexpressing Schwann Cells Promotes Propriospinal Axonal Regeneration, Synapse formation, and Partial Recovery of Function after Spinal Cord Injury

    Science.gov (United States)

    Deng, Lingxiao; Deng, Ping; Ruan, Yiwen; Xu, Zao Cheng; Liu, Naikui; Wen, Xuejun; Smith, George M.; Xu, Xiao-Ming

    2013-01-01

    Descending propriospinal neurons (DPSN) are known to establish functional relays for supraspinal signals, and they display a greater growth response after injury than do the long projecting axons. However, their regenerative response is still deficient due to their failure to depart from growth supportive cellular transplants back into the host spinal cord, which contains numerous impediments to axon growth. Here we report the construction of a continuous growth-promoting pathway in adult rats, formed by grafted Schwann cells (SCs) overexpressing glial cell line-derived neurotrophic factor (GDNF). We demonstrate that such a growth-promoting pathway, extending from the axonal cut ends to the site of innervation in the distal spinal cord, promoted regeneration of DPSN axons through and beyond the lesion gap of a spinal cord hemisection. Within the distal host spinal cord, regenerated DPSN axons formed synapses with host neurons leading to the restoration of action potentials and partial recovery of function. PMID:23536080

  12. A novel growth-promoting pathway formed by GDNF-overexpressing Schwann cells promotes propriospinal axonal regeneration, synapse formation, and partial recovery of function after spinal cord injury.

    Science.gov (United States)

    Deng, Ling-Xiao; Deng, Ping; Ruan, Yiwen; Xu, Zao Cheng; Liu, Nai-Kui; Wen, Xuejun; Smith, George M; Xu, Xiao-Ming

    2013-03-27

    Descending propriospinal neurons (DPSN) are known to establish functional relays for supraspinal signals, and they display a greater growth response after injury than do the long projecting axons. However, their regenerative response is still deficient due to their failure to depart from growth supportive cellular transplants back into the host spinal cord, which contains numerous impediments to axon growth. Here we report the construction of a continuous growth-promoting pathway in adult rats, formed by grafted Schwann cells overexpressing glial cell line-derived neurotrophic factor (GDNF). We demonstrate that such a growth-promoting pathway, extending from the axonal cut ends to the site of innervation in the distal spinal cord, promoted regeneration of DPSN axons through and beyond the lesion gap of a spinal cord hemisection. Within the distal host spinal cord, regenerated DPSN axons formed synapses with host neurons leading to the restoration of action potentials and partial recovery of function.

  13. Co- transplantation of Bone Marrow Stromal Cells with Schwann Cells Evokes Mechanical Allodynia in the Contusion Model of Spinal Cord Injury in Rats

    Science.gov (United States)

    Pourheydar, Bagher; Joghataei, Mohammad Taghi; Bakhtiari, Mehrdad; Mehdizadeh, Mehdi; Yekta, Zahra; Najafzadeh, Norooz

    2012-01-01

    Objective: Several studies have shown that, although transplantation of neural stem cells into the contusion model of spinal cord injury (SCI) promotes locomotor function and improves functional recovery, it induces a painful response, Allodynia. Different studies indicate that bone marrow stromal cells (BMSCs) and Schwann cells (SCs) can improve locomotor recovery when transplanted into the injured rat spinal cord. Since these cells are commonly used in cell therapy, we investigated whether co-transplantation of these cells leads to the development of Allodynia. Materials and Methods: In this experimental research, the contusion model of SCI was induced by laminectomy at the T8-T9 level of the spinal cord in adult female wistar rats (n=40) weighting (250-300g) using the New York University Device. BMSCs and SCs were cultured and prelabeled with 5-bromo-2-deoxyuridine (BrdU) and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) respectively. The rats were divided into five groups of 8 including: a control group (laminectomy only), three experimental groups (BMSC, SC and Co-transplant) and a sham group. The experimental groups received BMSCs, SCs, and BMSCs and SCs respectively by intraspinal injection 7 days after injury and the sham group received serum only. Locomotion was assessed using Basso, Beattie and Bresnahan (BBB) test and Allodynia by the withdrawal threshold test using Von Frey Filaments at 1, 7, 14, 21, 28, 35, 42, 49 and 56 days after SCI. The statistical comparisons between groups were carried out by using repeated measures analysis of variances (ANOVA). Results: Significant differences were observed in BBB scores in the Co- transplant group compared to the BMSC and SC groups (pspinal cord can improve functional recovery, it leads to the development of mechanical Allodynia. This finding indicates that strategies to reduce Allodynia in cell transplantation studies are required. PMID:23508042

  14. Schwann cell-specific JAM-C-deficient mice reveal novel expression and functions for JAM-C in peripheral nerves

    Science.gov (United States)

    Colom, Bartomeu; Poitelon, Yannick; Huang, Wenlong; Woodfin, Abigail; Averill, Sharon; Del Carro, Ubaldo; Zambroni, Desirée; Brain, Susan D.; Perretti, Mauro; Ahluwalia, Amrita; Priestley, John V.; Chavakis, Triantafyllos; Imhof, Beat A.; Feltri, M. Laura; Nourshargh, Sussan

    2012-01-01

    Junctional adhesion molecule-C (JAM-C) is an adhesion molecule expressed at junctions between adjacent endothelial and epithelial cells and implicated in multiple inflammatory and vascular responses. In addition, we recently reported on the expression of JAM-C in Schwann cells (SCs) and its importance for the integrity and function of peripheral nerves. To investigate the role of JAM-C in neuronal functions further, mice with a specific deletion of JAM-C in SCs (JAM-C SC KO) were generated. Compared to wild-type (WT) controls, JAM-C SC KO mice showed electrophysiological defects, muscular weakness, and hypersensitivity to mechanical stimuli. In addressing the underlying cause of these defects, nerves from JAM-C SC KO mice were found to have morphological defects in the paranodal region, exhibiting increased nodal length as compared to WTs. The study also reports on previously undetected expressions of JAM-C, namely on perineural cells, and in line with nociception defects of the JAM-C SC KO animals, on finely myelinated sensory nerve fibers. Collectively, the generation and characterization of JAM-C SC KO mice has provided unequivocal evidence for the involvement of SC JAM-C in the fine organization of peripheral nerves and in modulating multiple neuronal responses.—Colom, B., Poitelon, Y., Huang, W., Woodfin, A., Averill, S., Del Carro, U., Zambroni, D., Brain, S. D., Perretti, M., Ahluwalia, A., Priestley, J. V., Chavakis, T., Imhof, B. A., Feltri, M. L., Nourshargh, S. Schwann cell-specific JAM-C-deficient mice reveal novel expression and functions for JAM-C in peripheral nerves. PMID:22090315

  15. Schwann cells and mesenchymal stem cells in laminin- or fibronectin-aligned matrices and regeneration across a critical size defect of 15 mm in the rat sciatic nerve.

    Science.gov (United States)

    Gonzalez-Perez, Francisco; Hernández, Joaquim; Heimann, Claudia; Phillips, James B; Udina, Esther; Navarro, Xavier

    2018-01-01

    OBJECTIVE Artificial nerve guides are being developed to substitute for autograft repair after peripheral nerve injuries. However, the use of conduits is limited by the length of the gap that needs to be bridged, with the success of regeneration highly compromised in long gaps. Addition of aligned proregenerative cells and extracellular matrix (ECM) components inside the conduit can be a good strategy to achieve artificial grafts that recreate the natural environment offered by a nerve graft. The purpose of this study was to functionalize chitosan devices with different cell types to support regeneration in limiting gaps in the rat peripheral nerve. METHODS The authors used chitosan devices combined with proteins of the ECM and cells in a rat model of sciatic nerve injury. Combinations of fibronectin and laminin with mesenchymal stem cells (MSCs) or Schwann cells (SCs) were aligned within tethered collagen-based gels, which were placed inside chitosan tubes that were then used to repair a critical-size gap of 15 mm in the rat sciatic nerve. Electrophysiology and algesimetry tests were performed to analyze functional recovery during the 4 months after injury and repair. Histological analysis was performed at the midlevel and distal level of the tubes to assess the number of regenerated myelinated fibers. RESULTS Functional analysis demonstrated that SC-aligned scaffolds resulted in 100% regeneration success in a 15-mm nerve defect in this rat model. In contrast, animals that underwent repair with MSC-aligned constructs had only 90% regeneration success, and those implanted with acellular bridges had only 75% regeneration success. CONCLUSIONS These results indicate that the combination of chitosan conduits with ECM-enriched cellular gels represents a good alternative to the use of autografts for repairing long nerve gaps.

  16. Synchronous Quadruple Primary Neoplasms: Colon Adenocarcinoma, Collision Tumor of Neuroendocrine Tumor and Schwann Cell Hamartoma and Sessile Serrated Adenoma of the Appendix.

    Science.gov (United States)

    Meeks, Marshall W; Grace, Shane; Chen, Yongxin; Petterchak, James; Bolesta, Edward; Zhou, Yihua; Lai, Jin-Ping

    2016-08-01

    Quadruple synchronous primary neoplasms are very rare with only three cases reported in the English-speaking literature to date. Collision tumors are also rare entities, especially of the appendix. We herein report a case of synchronous quadruple primary neoplasm in a 95-year-old female. She was diagnosed with colon adenocarcinoma, sessile serrated adenoma of the appendix and a collision tumor composed of a well-differentiated neuroendocrine tumor and Schwann cell hamartoma. Histological examination and immunohistochemistry supported these four lesions as separate entities. This case is unique because we report the diagnosis of quadruple synchronous primary, an extremely rare occurrence, in addition to a collision tumor of the appendix. We also provide a review of the literature for synchronous neoplasms and collision tumors. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  17. Tyrosine phosphatases epsilon and alpha perform specific and overlapping functions in regulation of voltage-gated potassium channels in Schwann cells

    DEFF Research Database (Denmark)

    Tiran, Zohar; Peretz, Asher; Sines, Tal

    2006-01-01

    + channels and Src were analyzed in vivo in mice lacking either or both PTPs. Lack of either PTP increases Kv channel activity and phosphorylation in Schwann cells, indicating these PTPs inhibit Kv current amplitude in vivo. Open probability and unitary conductance of Kv channels are unchanged, suggesting......Tyrosine phosphatases (PTPs) epsilon and alpha are closely related and share several molecular functions, such as regulation of Src family kinases and voltage-gated potassium (Kv) channels. Functional interrelationships between PTPepsilon and PTPalpha and the mechanisms by which they regulate K...... an effect on channel number or organization. PTPalpha inhibits Kv channels more strongly than PTPepsilon; this correlates with constitutive association of PTPalpha with Kv2.1, driven by membranal localization of PTPalpha. PTPalpha, but not PTPepsilon, activates Src in sciatic nerve extracts, suggesting Src...

  18. Tang-Luo-Ning, a Traditional Chinese Medicine, Inhibits Endoplasmic Reticulum Stress-Induced Apoptosis of Schwann Cells under High Glucose Environment

    Directory of Open Access Journals (Sweden)

    Weijie Yao

    2017-01-01

    Full Text Available Tang-Luo-Ning (TLN has a definite effect in the clinical treatment of diabetic peripheral neuropathy (DPN. Schwann cells (SCs apoptosis induced by endoplasmic reticulum stress (ER stress is one of the main pathogeneses of DPN. This study investigates whether TLN can inhibit SCs apoptosis by inhibiting ER stress-induced apoptosis. Our previous researches have demonstrated that TLN could increase the expression of ER stress marker protein GRP78 and inhibited the expression of apoptosis marker protein CHOP in ER stress. In this study, the results showed that TLN attenuated apoptosis by decreasing Ca2+ level in SCs and maintaining ER morphology. TLN could decrease downstream proteins of CHOP including GADD34 and Ero1α, while it increased P-eIF2α and decreased the upstream proteins of CHOP including P-IRE1α/IRE1α and XBP-1, thereby reducing ER stress-induced apoptosis.

  19. An animal model of Miller Fisher syndrome: Mitochondrial hydrogen peroxide is produced by the autoimmune attack of nerve terminals and activates Schwann cells.

    Science.gov (United States)

    Rodella, Umberto; Scorzeto, Michele; Duregotti, Elisa; Negro, Samuele; Dickinson, Bryan C; Chang, Christopher J; Yuki, Nobuhiro; Rigoni, Michela; Montecucco, Cesare

    2016-12-01

    The neuromuscular junction is a tripartite synapse composed of the presynaptic nerve terminal, the muscle and perisynaptic Schwann cells. Its functionality is essential for the execution of body movements and is compromised in a number of disorders, including Miller Fisher syndrome, a variant of Guillain-Barré syndrome: this autoimmune peripheral neuropathy is triggered by autoantibodies specific for the polysialogangliosides GQ1b and GT1a present in motor axon terminals, including those innervating ocular muscles, and in sensory neurons. Their binding to the presynaptic membrane activates the complement cascade, leading to a nerve degeneration that resembles that caused by some animal presynaptic neurotoxins. Here we have studied the intra- and inter-cellular signaling triggered by the binding and complement activation of a mouse monoclonal anti-GQ1b/GT1a antibody to primary cultures of spinal cord motor neurons and cerebellar granular neurons. We found that a membrane attack complex is rapidly assembled following antibody binding, leading to calcium accumulation, which affects mitochondrial functionality. Consequently, using fluorescent probes specific for mitochondrial hydrogen peroxide, we found that this reactive oxygen species is rapidly produced by mitochondria of damaged neurons, and that it triggers the activation of the MAP kinase pathway in Schwann cells. These results throw light on the molecular and cellular pathogenesis of Miller Fisher syndrome, and may well be relevant to other pathologies of the motor axon terminals, including some subtypes of the Guillain Barré syndrome. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Species-specific control of cellular proliferation and the impact of large animal models for the use of olfactory ensheathing cells and Schwann cells in spinal cord repair.

    Science.gov (United States)

    Wewetzer, Konstantin; Radtke, Christine; Kocsis, Jeffery; Baumgärtner, Wolfgang

    2011-05-01

    Autologous transplantation of olfactory ensheathing cells (OECs) and Schwann cells (SCs) is considered a promising option to promote axonal regrowth and remyelination after spinal cord injury in humans. However, if the experimental data from the rodent model can be directly extrapolated to humans, as widely believed, remains to be established. While limitations of the rodent system have recently been discussed with regard to the distinct organization of the motor systems, the question whether OECs and SCs may display species-specific properties has not been fully addressed. Prompted by recent studies on canine and porcine glia, we performed a detailed analysis of the in vitro and in vivo properties of OECs and SCs and show that rodent but not human, monkey, porcine, and canine glia require mitogens for in vitro expansion, display a complex response to elevated intracellular cAMP, and undergo spontaneous immortalization upon prolonged mitogen stimulation. These data indicate fundamental inter-species differences of the control of cellular proliferation. Whether OECs and SCs from large animals and humans share growth-promoting in vivo properties with their rodent counterpart is not yet clear. Autologous implantation studies in humans did not reveal adverse effects of cell transplantation so far. However, in vivo studies of large animal or human glia and rodent recipients mainly focused on the remyelinating potential of the transplanted cells. Thus, further experimental in vivo studies in large animals are essential to fully define the axonal growth-promoting potential of OECs and SCs. Based on the homology of the in vitro growth control between porcine, canine and human glia, it is concluded that these species may serve as valuable translational models for scaling up human procedures. This article is part of a Special Issue entitled: Understanding olfactory ensheathing glia and their prospect for nervous system repair. Copyright © 2010 Elsevier Inc. All rights

  1. Gamma-secretase represents a therapeutic target for the treatment of invasive glioma mediated by the p75 neurotrophin receptor.

    Directory of Open Access Journals (Sweden)

    LiMei Wang

    2008-11-01

    Full Text Available The multifunctional signaling protein p75 neurotrophin receptor (p75(NTR is a central regulator and major contributor to the highly invasive nature of malignant gliomas. Here, we show that neurotrophin-dependent regulated intramembrane proteolysis (RIP of p75(NTR is required for p75(NTR-mediated glioma invasion, and identify a previously unnamed process for targeted glioma therapy. Expression of cleavage-resistant chimeras of p75(NTR or treatment of animals bearing p75(NTR-positive intracranial tumors with clinically applicable gamma-secretase inhibitors resulted in dramatically decreased glioma invasion and prolonged survival. Importantly, proteolytic processing of p75(NTR was observed in p75(NTR-positive patient tumor specimens and brain tumor initiating cells. This work highlights the importance of p75(NTR as a therapeutic target, suggesting that gamma-secretase inhibitors may have direct clinical application for the treatment of malignant glioma.

  2. Acute Putrescine Supplementation with Schwann Cell Implantation Improves Sensory and Serotonergic Axon Growth and Functional Recovery in Spinal Cord Injured Rats.

    Science.gov (United States)

    Iorgulescu, J Bryan; Patel, Samik P; Louro, Jack; Andrade, Christian M; Sanchez, Andre R; Pearse, Damien D

    2015-01-01

    Schwann cell (SC) transplantation exhibits significant potential for spinal cord injury (SCI) repair and its use as a therapeutic modality has now progressed to clinical trials for subacute and chronic human SCI. Although SC implants provide a receptive environment for axonal regrowth and support functional recovery in a number of experimental SCI models, axonal regeneration is largely limited to local systems and the behavioral improvements are modest without additional combinatory approaches. In the current study we investigated whether the concurrent delivery of the polyamine putrescine, started either 30 min or 1 week after SCI, could enhance the efficacy of SCs when implanted subacutely (1 week after injury) into the contused rat spinal cord. Polyamines are ubiquitous organic cations that play an important role in the regulation of the cell cycle, cell division, cytoskeletal organization, and cell differentiation. We show that the combination of putrescine with SCs provides a significant increase in implant size, an enhancement in axonal (sensory and serotonergic) sparing and/or growth, and improved open field locomotion after SCI, as compared to SC implantation alone. These findings demonstrate that polyamine supplementation can augment the effectiveness of SCs when used as a therapeutic approach for subacute SCI repair.

  3. Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Lihua [Department of Biomedical Engineering, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Center of Molecular Medicine, School of Medicine, Hubei University of Arts and Sciences, Xiangyang 441053 (China); Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan [Department of Biomedical Engineering, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Wang, Xiong; Huselstein, Celine [Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS – Université de Lorraine, Biopôle, 54500 Vandoeuvre-lès-Nancy (France); Chen, Yun, E-mail: yunchen@whu.edu.cn [Department of Biomedical Engineering, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China)

    2015-02-20

    Regeneration and functional reconstruction of peripheral nerve defects remained a significant clinical challenge. Nerve guide conduits, with seed cells or neurotrophic factors (NTFs), had been widely used to improve the repair and regeneration of injured peripheral nerve. Pyrroloquinoline quinone (PQQ) was an antioxidant that can stimulate nerve growth factors (NGFs) synthesis and accelerate the Schwann cells (SCs) proliferation and growth. In present study, three kinds of nerve guide conduits were constructed: one from cellulose/SPI hollow tube (CSC), another from CSC combined with SCs (CSSC), and the third one from CSSC combined with PQQ (CSSPC), respectively. And then they were applied to bridge and repair the sciatic nerve defect in rats, using autograft as control. Effects of different nerve guide conduits on the nerve regeneration were comparatively evaluated by general analysis, sciatic function index (SFI) and histological analysis (HE and TEM). Newly-formed regenerative nerve fibers were observed and running through the transparent nerve guide conduits 12 weeks after surgery. SFI results indicated that the reconstruction of motor function in CSSPC group was better than that in CSSC and CSC groups. HE images from the cross-sections and longitudinal-sections of the harvested regenerative nerve indicated that regenerative nerve fibers had been formed and accompanied with new blood vessels and matrix materials in the conduits. TEM images also showed that lots of fresh myelinated and non-myelinated nerve fibers had been formed. Parts of vacuolar, swollen and abnormal axons occurred in CSC and CSSC groups, while the vacuolization and swell of axons was the least serious in CSSPC group. These results indicated that CSSPC group had the most ability to repair and reconstruct the nerve structure and functions due to the comprehensive contributions from hollow CSC tube, SCs and PQQ. As a result, the CSSPC may have the potential for the applications as nerve guide

  4. [Down-regulation of miR-21 expression enhances the radiosensitivity of TE-1 cells in vitro].

    Science.gov (United States)

    Li, Xiaoqing; Chen, Xin; Huang, Shan; Che, Shaomin; Zhang, Xiaozhi

    2012-11-01

    To study the effect of miR-21 down-regulation on the radiosensitivity of TE-1 cells in vitro. TE-1 cells were transfected via lentivirus with a vector containing the antisense oligonucleotides of miR21, and the subclones with stable down-regulation of miR21 expression were selected with puromycin and designated as TE-1-miR21(-), whose expression level of miR21 was determined using real-time quantitative PCR. The radiosensitivity of TE-1 and TE-1-miR21(-) cells were evaluated with colony formation assay, and the expressions of β-catenin was determined using Western blotting and RT-PCR. Flow cytometry was used to analyze the proportion of p75NTR(+) cells in TE-1 and TE-1-miR21(-) cells. A cell subclone stably expressing a low level of miR21 was obtained and verified by real-time quantitative PCR. Colony formation assay showed an enhanced the radiosensitivity of TE-1-miR21(-) cells compared to parental TE-1 cells. RT-PCR revealed no significant changes in β-catenin mRNA expression in TE-1-miR21(-) cells, whereas its β-catenin protein expression was markedly suppressed by high-dose (8 and 10 Gy) irradiation. Flow cytometry assay showed a decreased proportion of p75NTR(+) cells in TE-1-miR21(-) cells compared to that in TE-1 cells. Down-regulation of miR21 can enhance the radiosensitivity of TE-1 cells, which might result from the inactivation of wnt/β-catenin signal pathway and a decreased p75NTR(+) cell proportion.

  5. Activity-induced Ca2+ signaling in perisynaptic Schwann cells of the early postnatal mouse is mediated by P2Y1 receptors and regulates muscle fatigue

    Science.gov (United States)

    Heredia, Dante J; Feng, Cheng-Yuan; Hennig, Grant W; Renden, Robert B

    2018-01-01

    Perisynaptic glial cells respond to neural activity by increasing cytosolic calcium, but the significance of this pathway is unclear. Terminal/perisynaptic Schwann cells (TPSCs) are a perisynaptic glial cell at the neuromuscular junction that respond to nerve-derived substances such as acetylcholine and purines. Here, we provide genetic evidence that activity-induced calcium accumulation in neonatal TPSCs is mediated exclusively by one subtype of metabotropic purinergic receptor. In P2ry1 mutant mice lacking these responses, postsynaptic, rather than presynaptic, function was altered in response to nerve stimulation. This impairment was correlated with a greater susceptibility to activity-induced muscle fatigue. Interestingly, fatigue in P2ry1 mutants was more greatly exacerbated by exposure to high potassium than in control mice. High potassium itself increased cytosolic levels of calcium in TPSCs, a response which was also reduced P2ry1 mutants. These results suggest that activity-induced calcium responses in TPSCs regulate postsynaptic function and muscle fatigue by regulating perisynaptic potassium. PMID:29384476

  6. Ginsenoside Re Promotes Nerve Regeneration by Facilitating the Proliferation, Differentiation and Migration of Schwann Cells via the ERK- and JNK-Dependent Pathway in Rat Model of Sciatic Nerve Crush Injury.

    Science.gov (United States)

    Wang, Lei; Yuan, Damin; Zhang, Dongmei; Zhang, Weidong; Liu, Chun; Cheng, Hongbing; Song, Yan; Tan, Qian

    2015-08-01

    Exploring effective drugs that are capable of promoting nerve regeneration has gained much attention. Ginsenoside Re (Re) is the main ingredient of ginseng berries and roots. Research in the area has shown that ginsenoside Re exhibits multiple pharmacological activities via different mechanisms both in vivo and in vitro. But the potential therapeutic effects of Re on sciatic nerve crush injury (SNC) have been little investigated. Herein, we investigated the protect effect of Re on peripheral nerve regeneration in a rat SNC model. Walking track analysis revealed that Re treatment significantly promoted functional recovery of crushed sciatic nerve in rats. The expression of PCNA in rat sciatic nerve was up-regulated by Re treatment, and peaked when the concentration of Re was 2.0 mg/kg. Using immunofluorescent staining, we found that Re greatly increased the expression of GAP-43 and S100 in injured rat sciatic nerve. Furthermore, we evaluated the effects of Re on proliferation, differentiation, and migration of Schwann cells in SNC rat models. Our studies reveal that Re promotes nerve regeneration is depend on ERK1/2 and JNK1/2 signaling pathway. Elevated Oct-6 expression and featured morphological changes indicated that Re facilitated the differentiation of Schwann cells following SNC. Also, transwell and wound-healing assay demonstrated that the migration capabilities of Schwann cell were significantly enhanced after Re treatment.

  7. Cotransplant of neural stem cells and NT-3 gene modified Schwann cells promote the recovery of transected spinal cord injury.

    Science.gov (United States)

    Guo, J-S; Zeng, Y-S; Li, H-B; Huang, W-L; Liu, R-Y; Li, X-B; Ding, Y; Wu, L-Z; Cai, D-Z

    2007-01-01

    An animal model of transected spinal cord injury (SCI) was used to test the hypothesis that cografted neural stem cells (NSCs) and NT-3-SCs promote morphologic and functional recoveries of injured spinal cord. To explore whether cotransplant of NSCs and NT-3-SCs could promote the injured spinal cord repair. Zhongshan Medical College, Sun Yat-sen University, PR China. Female Sprague-Dawley (SD) rats weighing on 200-220 g were used to prepare SCI models. The spinal cord was transected between T(9) and T(10), then NSCs, SCs+NSCs, LacZ-SCs+NSCs, or NT-3-SCs+NSCs were grafted into the transected site. (1) Part of NSCs could differentiate to neuron-like cells in the transected site and the percentage of differentiation was NT-3-SCs+NSCs group>SCs+NSCs group>NSCs group. (2) In the grafted groups, there were 5-HT, CGRP, and SP positive nerve fibres within the transected site. Some fluorogold (FG)-labeled cells were found in the spinal cord rostral to the transected site, the red nuclei and the inner pyramidal layer of sensorimotor cortex. (3) The cells grafted could enhance the injured neurons survival in inner pyramidal layer of sensorimotor cortex, red nuclei of midbrain, and Clark's nuclei of spinal cord's L1 segment, could decrease the latency and increase the amplitude of cortical somatosensory evoked potential (CSEP) and cortical motor evoked potential (CMEP), and could promote partly structural and functional recovery of the SCI rats. These results demonstrate that cografted NT-3-SCs and NSCs is a potential therapy for SCI. This research was supported by Chinese National Key Project for Basic Research (G1999054009), Chinese National Natural Science Foundation (30270700) and Social Developmental Foundation of Guangdong Province (2003C33808) to YS Zeng; Natural Science Foundation of Guangdong Province (04300468) and Medical Science Research Grant of Guangdong Province (A2004081) to JS Guo.

  8. Characterization of p75{sup +} ectomesenchymal stem cells from rat embryonic facial process tissue

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Xiujie; Liu, Luchuan; Deng, Manjing; Zhang, Li; Liu, Rui; Xing, Yongjun; Zhou, Xia [Department of Stomatology, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042 (China); Nie, Xin, E-mail: dr.xinnie@gmail.com [Department of Stomatology, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042 (China)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer Ectomesenchymal stem cells (EMSCs) were found to migrate to rat facial processes at E11.5. Black-Right-Pointing-Pointer We successfully sorted p75NTR positive EMSCs (p75{sup +} EMSCs). Black-Right-Pointing-Pointer p75{sup +} EMSCs up to nine passages showed relative stable proliferative activity. Black-Right-Pointing-Pointer We examined the in vitro multilineage potential of p75{sup +} EMSCs. Black-Right-Pointing-Pointer p75{sup +}EMSCs provide an in vitro model for tooth morphogenesis. -- Abstract: Several populations of stem cells, including those from the dental pulp and periodontal ligament, have been isolated from different parts of the tooth and periodontium. The characteristics of such stem cells have been reported as well. However, as a common progenitor of these cells, ectomesenchymal stem cells (EMSCs), derived from the cranial neural crest have yet to be fully characterized. The aim of this study was to better understand the characteristics of EMSCs isolated from rat embryonic facial processes. Immunohistochemical staining showed that EMSCs had migrated to rat facial processes at E11.5, while the absence of epithelial invagination or tooth-like epithelium suggested that any epithelial-mesenchymal interactions were limited at this stage. The p75 neurotrophin receptor (p75NTR), a typical neural crest marker, was used to select p75NTR-positive EMSCs (p75{sup +} EMSCs), which were found to show a homogeneous fibroblast-like morphology and little change in the growth curve, proliferation capacity, and cell phenotype during cell passage. They also displayed the capacity to differentiate into diverse cell types under chemically defined conditions in vitro. p75{sup +} EMSCs proved to be homogeneous, stable in vitro and potentially capable of multiple lineages, suggesting their potential for application in dental or orofacial tissue engineering.

  9. Gene delivery to rat and human Schwann cells and nerve segments: a comparison of AAV 1-9 and lentiviral vectors.

    Science.gov (United States)

    Hoyng, S A; De Winter, F; Gnavi, S; van Egmond, L; Attwell, C L; Tannemaat, M R; Verhaagen, J; Malessy, M J A

    2015-10-01

    Schwann cells (SCs) in an injured peripheral nerve form pathways for regenerating axons. Although these cells initially support regeneration, SCs lose their pro-regenerative properties following a prolonged period of denervation. Gene transfer to SC can enhance their therapeutic potential. In this article, we compared adeno-associated viral (AAV) vectors based on serotypes 1-9 for their capability to transduce cultured primary rat and human SCs and nerve segments. AAV1 is the best serotype to transduce rat SCs, whereas AAV2 and AAV6 performed equally well in human SCs. Transduction of monolayers of cultured rat and human SCs did not accurately predict the transduction efficiency in nerve segments. Rat nerve segments could be genetically modified equally well by a set of four AAV vectors (AAV1, AAV5, AAV7, AAV9), whereas AAV2 was superior in human nerve segments. The current experiments were undertaken as a first step towards future clinical implementation of ex vivo AAV-based gene therapy in surgical nerve repair. The transduction of rat and human SCs and nerve segments by entirely different AAV serotypes, as documented here, highlights one of the challenges of translating gene therapy from experimental animals to human patients.

  10. Exposure to Nerve Growth Factor Worsens Nephrotoxic Effect Induced by Cyclosporine A in HK-2 Cells

    Science.gov (United States)

    Lofaro, Danilo; Toteda, Giuseppina; Lupinacci, Simona; Leone, Francesca; Gigliotti, Paolo; Papalia, Teresa; Bonofiglio, Renzo

    2013-01-01

    Nerve growth factor is a neurotrophin that promotes cell growth, differentiation, survival and death through two different receptors: TrkANTR and p75NTR. Nerve growth factor serum concentrations increase during many inflammatory and autoimmune diseases, glomerulonephritis, chronic kidney disease, end-stage renal disease and, particularly, in renal transplant. Considering that nerve growth factor exerts beneficial effects in the treatment of major central and peripheral neurodegenerative diseases, skin and corneal ulcers, we asked whether nerve growth factor could also exert a role in Cyclosporine A-induced graft nephrotoxicity. Our hypothesis was raised from basic evidence indicating that Cyclosporine A-inhibition of calcineurin-NFAT pathway increases nerve growth factor expression levels. Therefore, we investigated the involvement of nerve growth factor and its receptors in the damage exerted by Cyclosporine A in tubular renal cells, HK-2. Our results showed that in HK-2 cells combined treatment with Cyclosporine A + nerve growth factor induced a significant reduction in cell vitality concomitant with a down-regulation of Cyclin D1 and up-regulation of p21 levels respect to cells treated with Cyclosporine A alone. Moreover functional experiments showed that the co-treatment significantly up-regulated human p21promoter activity by involvement of the Sp1 transcription factor, whose nuclear content was negatively regulated by activated NFATc1. In addition we observed that the combined exposure to Cyclosporine A + nerve growth factor promoted an up-regulation of p75 NTR and its target genes, p53 and BAD leading to the activation of intrinsic apoptosis. Finally, the chemical inhibition of p75NTR down-regulated the intrinsic apoptotic signal. We describe two new mechanisms by which nerve growth factor promotes growth arrest and apoptosis in tubular renal cells exposed to Cyclosporine A. PMID:24244623

  11. Exposure to nerve growth factor worsens nephrotoxic effect induced by Cyclosporine A in HK-2 cells.

    Directory of Open Access Journals (Sweden)

    Donatella Vizza

    Full Text Available Nerve growth factor is a neurotrophin that promotes cell growth, differentiation, survival and death through two different receptors: TrkA(NTR and p75(NTR. Nerve growth factor serum concentrations increase during many inflammatory and autoimmune diseases, glomerulonephritis, chronic kidney disease, end-stage renal disease and, particularly, in renal transplant. Considering that nerve growth factor exerts beneficial effects in the treatment of major central and peripheral neurodegenerative diseases, skin and corneal ulcers, we asked whether nerve growth factor could also exert a role in Cyclosporine A-induced graft nephrotoxicity. Our hypothesis was raised from basic evidence indicating that Cyclosporine A-inhibition of calcineurin-NFAT pathway increases nerve growth factor expression levels. Therefore, we investigated the involvement of nerve growth factor and its receptors in the damage exerted by Cyclosporine A in tubular renal cells, HK-2. Our results showed that in HK-2 cells combined treatment with Cyclosporine A + nerve growth factor induced a significant reduction in cell vitality concomitant with a down-regulation of Cyclin D1 and up-regulation of p21 levels respect to cells treated with Cyclosporine A alone. Moreover functional experiments showed that the co-treatment significantly up-regulated human p21promoter activity by involvement of the Sp1 transcription factor, whose nuclear content was negatively regulated by activated NFATc1. In addition we observed that the combined exposure to Cyclosporine A + nerve growth factor promoted an up-regulation of p75 (NTR and its target genes, p53 and BAD leading to the activation of intrinsic apoptosis. Finally, the chemical inhibition of p75(NTR down-regulated the intrinsic apoptotic signal. We describe two new mechanisms by which nerve growth factor promotes growth arrest and apoptosis in tubular renal cells exposed to Cyclosporine A.

  12. Transplantation of Schwann Cells Inside PVDF-TrFE Conduits to Bridge Transected Rat Spinal Cord Stumps to Promote Axon Regeneration Across the Gap.

    Science.gov (United States)

    Lee, Yee-Shuan; Wu, Siliang; Arinzeh, Treena Livingston; Bunge, Mary Bartlett

    2017-11-03

    Among various models for spinal cord injury in rats, the contusion model is the most often used because it is the most common type of human spinal cord injury. The complete transection model, although not as clinically relevant as the contusion model, is the most rigorous method to evaluate axon regeneration. In the contusion model, it is difficult to distinguish regenerated from sprouted or spared axons due to the presence of remaining tissue post injury. In the complete transection model, a bridging method is necessary to fill the gap and create continuity from the rostral to the caudal stumps in order to evaluate the effectiveness of the treatments. A reliable bridging surgery is essential to test outcome measures by reducing the variability due to the surgical method. The protocols described here are used to prepare Schwann cells (SCs) and conduits prior to transplantation, complete transection of the spinal cord at thoracic level 8 (T8), insert the conduit, and transplant SCs into the conduit. This approach also uses in situ gelling of an injectable basement membrane matrix with SC transplantation that allows improved axon growth across the rostral and caudal interfaces with the host tissue.

  13. CD44 is expressed in non-myelinating Schwann cells of the adult rat, and may play a role in neurodegeneration-induced glial plasticity at the neuromuscular junction.

    Science.gov (United States)

    Gorlewicz, Adam; Wlodarczyk, Jakub; Wilczek, Ewa; Gawlak, Maciej; Cabaj, Anna; Majczynski, Henryk; Nestorowicz, Klaudia; Herbik, Magdalena Aneta; Grieb, Pawel; Slawinska, Urszula; Kaczmarek, Leszek; Wilczynski, Grzegorz M

    2009-05-01

    CD44 is a multifunctional cell surface glycoprotein which regulates cell-cell and cell-matrix interactions in a variety of tissues. In particular, the protein was found to be expressed in glial cells of developing, but not adult, peripheral nerves, where it takes part in signaling mediated by ErbB class of receptors for neuregulins. Here, we demonstrate, using high resolution morphological methods, tissue fractionation and RT-PCR, that CD44 is strongly expressed in terminal Schwann cell (TSC) at the neuromuscular junction (NMJ) of the adult rat skeletal muscle. As CD44 is also expressed by Schwann cells of the non-myelinated Remak bundles of the proximal peripheral nerves, it appears to be a marker of non-myelinating Schwann cell subpopulation. The analysis of transgenic rats bearing a mutated superoxide-dismutase gene (SOD1(G93A)) causing familial amyotrophic lateral sclerosis (ALS) revealed that TSC activation and morphological plasticity at the NMJ, caused by ongoing denervation-reinnervation is associated with a strong increase in CD44 expression therein. Notably, CD44 immunoreactivity is present in fine axon-escheating processes of the glial cells that guide reinnervation. In addition, we found that both in normal and SOD1(G93A) muscle, CD44 expressed in TSC partially colocalizes with immunoreactivities of neuregulin receptors ErbB2 and ErbB3. The colocalization appears to reflect a physical interaction, as evidenced by co-immunoprecipitation and fluorescence resonance energy transfer (FRET) analysis between CD44 and ErbB3. Importantly, TSC activation upon ALS-like neurodegeneration results in significant increase in molecular proximity of CD44 and ErbB3, which may have an impact on glial plasticity at the NMJ.

  14. Design of super-elastic biodegradable scaffolds with longitudinally oriented microchannels and optimization of the channel size for Schwann cell migration

    Directory of Open Access Journals (Sweden)

    Koichiro Uto, Takanari Muroya, Michio Okamoto, Hiroyuki Tanaka, Tsuyoshi Murase, Mitsuhiro Ebara and Takao Aoyagi

    2012-01-01

    Full Text Available We newly designed super-elastic biodegradable scaffolds with longitudinally oriented microchannels for repair and regeneration of peripheral nerve defects. Four-armed poly(ε-caprolactone-co-D,L-lactides (P(CL-co-DLLAs were synthesized by ring-opening copolymerization of CL and DLLA from terminal hydroxyl groups of pentaerythritol, and acryloyl chloride was then reacted with the ends of the chains. The end-functionalized P(CL-co-DLLA was crosslinked in a cylindrical mold in the presence of longitudinally oriented silica fibers as the templates, which were later dissolved by hydrofluoric acid. The elastic moduli of the crosslinked P(CL-co-DLLAs were controlled between 10−1 and 102 MPa at 37 °C, depending on the composition. The scaffolds could be elongated to 700% of their original size without fracture or damage ('super-elasticity'. Scanning electron microscopy images revealed that well-defined and highly aligned multiple channels consistent with the mold design were produced in the scaffolds. Owing to their elastic nature, the microchannels in the scaffolds did not collapse when they were bent to 90°. To evaluate the effect of the channel diameter on Schwann cell migration, microchannels were also fabricated in transparent poly(dimethylsiloxane, allowing observation of cell migration. The migration speed increased with channel size, but the Young's modulus of the scaffold decreased as the channel diameter increased. These findings may serve as the basis for designing tissue-engineering scaffolds for nerve regeneration and investigating the effects of the geometrical and dimensional properties on axonal outgrowth.

  15. The p75 neurotrophin receptor localization in blood-CSF barrier: expression in choroid plexus epithelium.

    Science.gov (United States)

    Spuch, Carlos; Carro, Eva

    2011-05-11

    The presence of neurotrophins and their receptors Trk family has been reported in the choroid plexus. High levels of Nerve Growth Factor (NGF), Neurotrophin-4 (NT-4) and TrkB receptor were detected, while nothing was know about p75 neurotrophin receptor (p75NTR) in the choroid plexus epithelial cells. In neurons, p75NTR receptor has a dual function: promoting survival together with TrkA in response to NGF, and inducing apoptotic signaling through p75NTR. We postulated that p75NTR may also affect the survival pathways in the choroid plexus and also undergoes regulated proteolysis with metalloproteases. Here, we demonstrated the presence of p75NTR receptor in the choroid plexus epithelial cells. The p75NTR receptor would be involved in cell death mechanisms and in the damaged induced by amyloid beta (Aβ) in the choroid plexus and finally, we propose an essential role of p75NTR in the Aβ transcytosis through out choroid plexus barrier. The presence analysis reveals the new localization of p75NTR in the choroid plexus and, the distribution mainly in the cytoplasm and cerebrospinal fluid (CSF) side of the epithelial cells. We propose that p75NTR receptor plays a role in the survival pathways and Aβ-induced cell death. These data suggest that p75NTR dysfunction play an important role in the pathogenesis of brain diseases. The importance and novelty of this expression expands a new role of p75NTR.

  16. The p75 neurotrophin receptor localization in blood-CSF barrier: expression in choroid plexus epithelium

    Science.gov (United States)

    2011-01-01

    Background The presence of neurotrophins and their receptors Trk family has been reported in the choroid plexus. High levels of Nerve Growth Factor (NGF), Neurotrophin-4 (NT-4) and TrkB receptor were detected, while nothing was know about p75 neurotrophin receptor (p75NTR) in the choroid plexus epithelial cells. In neurons, p75NTR receptor has a dual function: promoting survival together with TrkA in response to NGF, and inducing apoptotic signaling through p75NTR. We postulated that p75NTR may also affect the survival pathways in the choroid plexus and also undergoes regulated proteolysis with metalloproteases. Results Here, we demonstrated the presence of p75NTR receptor in the choroid plexus epithelial cells. The p75NTR receptor would be involved in cell death mechanisms and in the damaged induced by amyloid beta (Aβ) in the choroid plexus and finally, we propose an essential role of p75NTR in the Aβ transcytosis through out choroid plexus barrier. Conclusions The presence analysis reveals the new localization of p75NTR in the choroid plexus and, the distribution mainly in the cytoplasm and cerebrospinal fluid (CSF) side of the epithelial cells. We propose that p75NTR receptor plays a role in the survival pathways and Aβ-induced cell death. These data suggest that p75NTR dysfunction play an important role in the pathogenesis of brain diseases. The importance and novelty of this expression expands a new role of p75NTR. PMID:21569322

  17. Immunohistochemical, ultrastructural and functional analysis of axonal regeneration through peripheral nerve grafts containing Schwann cells expressing BDNF, CNTF or NT3.

    Directory of Open Access Journals (Sweden)

    Maria João Godinho

    Full Text Available We used morphological, immunohistochemical and functional assessments to determine the impact of genetically-modified peripheral nerve (PN grafts on axonal regeneration after injury. Grafts were assembled from acellular nerve sheaths repopulated ex vivo with Schwann cells (SCs modified to express brain-derived neurotrophic factor (BDNF, a secretable form of ciliary neurotrophic factor (CNTF, or neurotrophin-3 (NT3. Grafts were used to repair unilateral 1 cm defects in rat peroneal nerves and 10 weeks later outcomes were compared to normal nerves and various controls: autografts, acellular grafts and grafts with unmodified SCs. The number of regenerated βIII-Tubulin positive axons was similar in all grafts with the exception of CNTF, which contained the fewest immunostained axons. There were significantly lower fiber counts in acellular, untransduced SC and NT3 groups using a PanNF antibody, suggesting a paucity of large caliber axons. In addition, NT3 grafts contained the greatest number of sensory fibres, identified with either IB4 or CGRP markers. Examination of semi- and ultra-thin sections revealed heterogeneous graft morphologies, particularly in BDNF and NT3 grafts in which the fascicular organization was pronounced. Unmyelinated axons were loosely organized in numerous Remak bundles in NT3 grafts, while the BDNF graft group displayed the lowest ratio of umyelinated to myelinated axons. Gait analysis revealed that stance width was increased in rats with CNTF and NT3 grafts, and step length involving the injured left hindlimb was significantly greater in NT3 grafted rats, suggesting enhanced sensory sensitivity in these animals. In summary, the selective expression of BDNF, CNTF or NT3 by genetically modified SCs had differential effects on PN graft morphology, the number and type of regenerating axons, myelination, and locomotor function.

  18. Sciatic nerve regeneration by transplantation of Schwann cells via erythropoietin controlled-releasing polylactic acid/multiwalled carbon nanotubes/gelatin nanofibrils neural guidance conduit.

    Science.gov (United States)

    Salehi, Majid; Naseri-Nosar, Mahdi; Ebrahimi-Barough, Somayeh; Nourani, Mohammdreza; Khojasteh, Arash; Hamidieh, Amir-Ali; Amani, Amir; Farzamfar, Saeed; Ai, Jafar

    2017-07-04

    The current study aimed to enhance the efficacy of peripheral nerve regeneration using an electrically conductive biodegradable porous neural guidance conduit for transplantation of allogeneic Schwann cells (SCs). The conduit was produced from polylactic acid (PLA), multiwalled carbon nanotubes (MWCNTs), and gelatin nanofibrils (GNFs) coated with the recombinant human erythropoietin-loaded chitosan nanoparticles (rhEpo-CNPs). The PLA/MWCNTs/GNFs/rhEpo-CNPs conduit had the porosity of 85.78 ± 0.70%, the contact angle of 77.65 ± 1.91° and the ultimate tensile strength and compressive modulus of 5.51 ± 0.13 MPa and 2.66 ± 0.34 MPa, respectively. The conduit showed the electrical conductivity of 0.32 S cm(-1) and lost about 11% of its weight after 60 days in normal saline. The produced conduit was able to release the rhEpo for at least 2 weeks and exhibited favorable cytocompatibility towards SCs. For functional analysis, the conduit was seeded with 1.5 × 10(4) SCs and implanted into a 10 mm sciatic nerve defect of Wistar rat. After 14 weeks, the results of sciatic functional index, hot plate latency, compound muscle action potential amplitude, weight-loss percentage of wet gastrocnemius muscle and Histopathological examination using hematoxylin-eosin and Luxol fast blue staining demonstrated that the produced conduit had comparable nerve regeneration to the autograft, as the gold standard to bridge the nerve gaps. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

  19. Three-tier regulation of cell number plasticity by neurotrophins and Tolls inDrosophila.

    Science.gov (United States)

    Foldi, Istvan; Anthoney, Niki; Harrison, Neale; Gangloff, Monique; Verstak, Brett; Nallasivan, Mohanakarthik Ponnadai; AlAhmed, Samaher; Zhu, Bangfu; Phizacklea, Mark; Losada-Perez, Maria; Moreira, Marta; Gay, Nicholas J; Hidalgo, Alicia

    2017-05-01

    Cell number plasticity is coupled to circuitry in the nervous system, adjusting cell mass to functional requirements. In mammals, this is achieved by neurotrophin (NT) ligands, which promote cell survival via their Trk and p75 NTR receptors and cell death via p75 NTR and Sortilin. Drosophila NTs (DNTs) bind Toll receptors instead to promote neuronal survival, but whether they can also regulate cell death is unknown. In this study, we show that DNTs and Tolls can switch from promoting cell survival to death in the central nervous system (CNS) via a three-tier mechanism. First, DNT cleavage patterns result in alternative signaling outcomes. Second, different Tolls can preferentially promote cell survival or death. Third, distinct adaptors downstream of Tolls can drive either apoptosis or cell survival. Toll-6 promotes cell survival via MyD88-NF-κB and cell death via Wek-Sarm-JNK. The distribution of adaptors changes in space and time and may segregate to distinct neural circuits. This novel mechanism for CNS cell plasticity may operate in wider contexts. © 2017 Foldi et al.

  20. Human papillomavirus 16 infection predicts poor outcome in patients with esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Xi R

    2015-03-01

    Full Text Available Ruxing Xi,1 Xiaozhi Zhang,1 Xin Chen,1 Shupei Pan,1 Beina Hui,1 Li Zhang,1 Shenbo Fu,1 Xiaolong Li,2 Xuanwei Zhang,1 Tuotuo Gong,1 Jia Guo,1 Shaomin Che1 1Department of Radiotherapy, The First Affiliated Hospital of Xi’an Jiao Tong University, 2Department of Radiotherapy, The People’s Liberation Army 323 Hospital, Xi’an, People’s Republic of China Background: Previous studies indicate that human papillomavirus 16 (HPV16 infection plays a pivotal role in the etiology of esophageal squamous cell carcinoma (ESCC. We aim to detect the influence of HPV16 infection on ESCC patient prognosis. Patients and methods: Immunohistochemical staining for HPV16 E6 oncoprotein, the low-affinity p75 neurotrophin receptor (p75NTR, and phosphatidylinositol 3-kinase (PI3K was performed on 103 archived surgical specimens from patients with ESCC and 54 control samples from patients with benign esophageal tumor or inflammatory lesions. All patients were from the Shaan Xi Province, People’s Republic of China. Results: HPV16 E6 expression was significantly higher in the ESCC group (P<0.05. HPV16 E6 expression was significantly higher in men than in women (P<0.05. p75NTR expression was higher in those aged >56 years (P<0.05. PI3K expression was higher in those with a more advanced histopathological grade (P<0.05. There was a positive correlation between HPV16 E6 and p75NTR expression (r=0.547, P<0.001 and between p75NTR and PI3K expression (r=0.364, P<0.001. In 100 evaluable patients, the 5-year overall survival (OS rate was 11%. In patients with ESCC, HPV16 E6 and PI3K expression were negatively correlated with the 3-year OS (P<0.05, 5-year OS (P<0.05, and progression-free survival (P<0.05. Conclusion: HPV16 infection likely contributes to the etiology of ESCC patients in Shaan Xi, People’s Republic of China. HPV16 infection status and PI3K expression levels could be useful for predicting prognosis in patients with ESCC. Keywords: low-affinity p75

  1. Co-transplantation of autologous bone marrow mesenchymal stem cells and Schwann cells through cerebral spinal fluid for the treatment of patients with chronic spinal cord injury: safety and possible outcome.

    Science.gov (United States)

    Oraee-Yazdani, S; Hafizi, M; Atashi, A; Ashrafi, F; Seddighi, A-S; Hashemi, S M; Seddighi, A; Soleimani, M; Zali, A

    2016-02-01

    This is a clinical trial (phase 1). The objective of this study was to asses the safety and feasibility of bone marrow mesenchymal stem cell (MSC) and Schwann cell (SC) co-injection through cerebral spinal fluid (CSF) for the treatment of patients with chronic spinal cord injury. Six subjects with complete spinal cord injury due to trauma according to International Standard of Neurological Classification for Spinal Cord Injury (ISNCSCI) developed by the American Spinal Injury Association were enrolled. They received autologous co-transplantation of MSC and SC through lumbar puncture. Neurological status of the patients was determined by ISNCSCI, as well as by assessment of functional status by Spinal Cord Independent Measure. Before and after cell transplantation, magnetic resonance imaging (MRI) was performed for all the patients. Before the procedure, all the patients underwent electromyography, urodynamic study (UDS) and MRI tractograghy. After transplantation, these assessments were performed in special cases when the patients reported any changes in motor function or any changes in urinary sensation. Over the mean 30 months of follow-up, the radiological findings were unchanged without any evidence of neoplastic tissue overgrowth. American Spinal Injury Association class in one patient was changed from A to B, in addition to the improvement in indexes of UDS, especially bladder compliance, which was congruous with axonal regeneration detected in MRI tractography. No motor score improvement was observed among the patients. No adverse findings were detected at a mean of 30 months after autologous transplantation of the combination of MSCs and SCs through CSF. It may suggest the safety of this combination of cells for spinal cord regeneration.

  2. In vitro cementoblast-like differentiation of postmigratory neural crest-derived p75{sup +} stem cells with dental follicle cell conditioned medium

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Xiujie; Liu, Luchuan; Deng, Manjing; Liu, Rui; Zhang, Li; Nie, Xin, E-mail: dr.xinnie@gmail.com

    2015-09-10

    Cranial neural crest-derived cells (CNCCs) play important role in epithelial–mesenchymal interactions during tooth morphogenesis. However, the heterogeneity of CNCCs and their tendency to spontaneously differentiate along smooth muscle or osteoblast lineages in vitro limit further understanding of their biological properties. We studied the differentiation properties of isolated rat embryonic postmigratory CNCCs, expressing p75 neurotrophin receptor (p75NTR). These p75NTR positive (p75{sup +}) CNCCs, isolated using fluorescence activated cell sorter, exhibited fibroblast-like morphology and characteristics of mesenchymal stem cells. Incubation of p75{sup +} CNCCs in dental follicle cell conditioned medium (DFCCM) combined with dentin non-collagenous proteins (dNCPs), altered their morphological features to cementoblast-like appearance. These cells also showed low proliferative activity, high ALP activity and significantly increased calcified nodule formation. Markers related to mineralization or specific to cementoblast lineage were highly expressed in dNCPs/DFCCM-treated p75{sup +} cells, suggesting their differentiation along cementoblast-like lineage. p75{sup +} stem cells selected from postmigratory CNCCs represent a pure stem cell population and could be used as a stem cell model for in vitro studies due to their intrinsic ability to differentiate to neuronal cells and transform from neuroectoderm to ectomesenchyme. They can provide a potential stem cell resource for tooth engineering studies and help to further investigate mechanisms of epithelial–mesenchymal interactions in tooth morphogenesis. - Highlights: • Cranial neural crest-derived cells (CNCCs) take part in tooth morphogenesis. • positive (p75{sup +}) CNCCs are fibroblast-like and resemble mesenchymal stem cells. • p75{sup +} CNCCs in dental follicle cell medium (DFCCM/dNCP) appear like cementoblasts. • DFCCM/dNCP-treated p75{sup +} cells express cementoblast specific mineralization

  3. Signalling Pathways of Cooperative Oncogenes and Their Effects on the Transcriptional Control of Cell Cycle Genes in Schwann Cell Transformation (Neurofibromatosis).

    Science.gov (United States)

    1996-10-01

    Elledge, S.J., Keyomarsi, K., Dynlacht, B., Tsai, L.H., Zhang, P., Dobrowolski, S., Bai, C., Connell, C.L., Swindell , E. and et, a.l. 1995. Inhibition of...Exp Cell Res 211: 90-98. Ohtsubo, M., Theodoras, A.M., Schumacher, J., Roberts , J.M. and Pagano, M. 1995. Human cyclin E, a nuclear protein essential...J.Y., Solomon, M.J., Sherr, C.J., Massague, J., Roberts , J.M. and Koff, A. 1994. p27Kipl, a cyclin-Cdk inhibitor, links transforming growth factor

  4. Adipose stromal cells contain phenotypically distinct adipogenic progenitors derived from neural crest.

    Directory of Open Access Journals (Sweden)

    Yoshihiro Sowa

    Full Text Available Recent studies have shown that adipose-derived stromal/stem cells (ASCs contain phenotypically and functionally heterogeneous subpopulations of cells, but their developmental origin and their relative differentiation potential remain elusive. In the present study, we aimed at investigating how and to what extent the neural crest contributes to ASCs using Cre-loxP-mediated fate mapping. ASCs harvested from subcutaneous fat depots of either adult P0-Cre/or Wnt1-Cre/Floxed-reporter mice contained a few neural crest-derived ASCs (NCDASCs. This subpopulation of cells was successfully expanded in vitro under standard culture conditions and their growth rate was comparable to non-neural crest derivatives. Although NCDASCs were positive for several mesenchymal stem cell markers as non-neural crest derivatives, they exhibited a unique bipolar or multipolar morphology with higher expression of markers for both neural crest progenitors (p75NTR, Nestin, and Sox2 and preadipocytes (CD24, CD34, S100, Pref-1, GATA2, and C/EBP-delta. NCDASCs were able to differentiate into adipocytes with high efficiency but their osteogenic and chondrogenic potential was markedly attenuated, indicating their commitment to adipogenesis. In vivo, a very small proportion of adipocytes were originated from the neural crest. In addition, p75NTR-positive neural crest-derived cells were identified along the vessels within the subcutaneous adipose tissue, but they were negative for mural and endothelial markers. These results demonstrate that ASCs contain neural crest-derived adipocyte-restricted progenitors whose phenotype is distinct from that of non-neural crest derivatives.

  5. Genetic Dissection of Neurotrophin Signaling through the p75 Neurotrophin Receptor

    Directory of Open Access Journals (Sweden)

    Ioannis Charalampopoulos

    2012-12-01

    Full Text Available Structural determinants underlying signaling specificity in the tumor necrosis factor receptor superfamily (TNFRSF are poorly characterized, and it is unclear whether different signaling outputs can be genetically dissociated. The p75 neurotrophin receptor (p75NTR, also known as TNFRSF16, is a key regulator of trophic and injury responses in the nervous system. Here, we describe a genetic approach for dissecting p75NTR signaling and deciphering its underlying logic. Structural determinants important for regulation of cell death, NF-κB, and RhoA pathways were identified in the p75NTR death domain (DD. Proapoptotic and prosurvival pathways mapped onto nonoverlapping epitopes, demonstrating that different signaling outputs can be genetically separated in p75NTR. Dissociation of c-Jun kinase (JNK and caspase-3 activities indicated that JNK is necessary but not sufficient for p75NTR-mediated cell death. RIP2 recruitment and RhoGDI release were mechanistically linked, indicating that competition for DD binding underlies crosstalk between NF-κB and RhoA pathways in p75NTR signaling. These results provide insights into the logic of p75NTR signaling and pave the way for a genetic dissection of p75NTR function and physiology.

  6. La célula de Schwann

    Directory of Open Access Journals (Sweden)

    Adriana del Pilar López Lombana

    1993-12-01

    Full Text Available La célula de Schwann que constituye la glía del SNP, además de ser el soporte estructural para los axones en dicho sistema, tiene la función de producir la mielina, una organela de gran importancia en los procesos de neuroconducción. De la integridad de esta célula dependen el desarrollo estructural y metabólico del axón, así mismo se ha reconocido desde hace varios anos el papel primordial que juega ella, en los procesos de regeneración del SPN posterior a una injuria, en cuyo caso reinician la proliferación para producir una guía de regeneración del nervio periférico. En esta revisión se contemplarán algunos de los puntos relacionados con su origen, desarrollo, estructura, relación con el axon y el tipo de patologías que pueden alterarla; igualmente se resalta la utilidad de los cultivos de celulas de Schwann para el estudio de los procesos de mielinización, desmielinización, regeneración post-traumatica y respuesta a agentes infecciosos.

  7. S100ß e fator de crescimento de fibroblasto-2 estão presentes nas células de Schwann cultivadas e exercem ações parácrinas na lesão do nervo

    OpenAIRE

    Tatiana Duobles; Thais de Sousa Lima; Beatriz de Freitas Azevedo Levy; Gerson Chadi

    2008-01-01

    PURPOSE: The neurotrophic factor fibroblast growth factor-2 (FGF-2, bFGF) and Ca++ binding protein S100ß are expressed by the Schwann cells of the peripheral nerves and by the satellite cells of the dorsal root ganglia (DRG). Recent studies have pointed out the importance of the molecules in the paracrine mechanisms related to neuronal maintenance and plasticity of lesioned motor and sensory peripheral neurons. Moreover, cultured Schwann cells have been employed experimentally in the treatmen...

  8. Structural Characterization of the p75 Neurotrophin Receptor: A Stranger in the TNFR Superfamily.

    Science.gov (United States)

    Vilar, M

    2017-01-01

    Although p75 neurotrophin receptor (p75NTR) was the founding member of the tumor necrosis factor (TNF) receptor superfamily (TNFRSF), it is an atypical TNFRSF protein. p75NTR like TNF-R1 and Fas-R contain an extracellular domain with four cysteine-rich domains (CRD) and a death domain (DD) in the intracellular region. While TNFRSF proteins are activated by trimeric TNFSF ligands, p75NTR forms dimers activated by dimeric neurotrophins that are structurally unrelated to TNFSF proteins. In addition, although p75NTR shares with other members the interaction with the TNF receptor-associated factors to activate the NF-κB and cell death pathways, p75NTR does not interact with the DD-containing proteins FADD, TRADD, or MyD88. By contrast, the DD of p75NTR is able to recruit several protein interactors via a full catalog of DD interactions not described before in the TNFRSF. p75-DD forms homotypic symmetrical DD-DD complexes with itself and with the related p45-DD; forms heterotypic DD-CARD interactions with the RIP2-CARD domain, and forms a new interaction between a DD and RhoGDI. All these features, in addition to its promiscuous interactions with several ligands and coreceptors, its processing by α- and γ-secretases, the dimeric nature of its transmembrane domain and its "special" juxtamembrane region, make p75NTR a truly stranger in the TNFR superfamily. In this chapter, I will summarize the known structural aspects of p75NTR and I will analyze from a structural point of view, the similitudes and differences between p75NTR and the other members of the TNFRSF. © 2017 Elsevier Inc. All rights reserved.

  9. Sox10 is required for Schwann cell identity and progression beyond the immature Schwann cell stage

    NARCIS (Netherlands)

    M. Finzsch (Markus); S. Schreiner (Silke); T. Kichko (Tatjana); P. Reeh (Peter); E.R. Tamm (Ernst); M.R. Bösl (Michael); D.N. Meijer (Dies); M. Wegner (Michael)

    2010-01-01

    textabstractMutations in the transcription factor SOX10 cause neurocristopathies, including Waardenburg-Hirschsprung syndrome and peripheral neuropathies in humans. This is partly attributed to a requirement for Sox10 in early neural crest for survival, maintenance of pluripotency, and specification

  10. Expression of cytokine and extracellular matrix mRNAs in fetal hepatic stellate cells.

    Science.gov (United States)

    Tan, Keai Sinn; Kulkeaw, Kasem; Nakanishi, Yoichi; Sugiyama, Daisuke

    2017-09-01

    In mouse fetal liver, hepatoblasts, sinusoidal endothelial cells and macrophages (or erythroblastic islands) promote differentiation and proliferation of hematopoietic cells through cell-cell interactions and secretion of cytokines and extracellular matrix factors. Until now, we have had little knowledge of the hematopoietic cytokines or extracellular matrix mRNAs expressed in hepatic stellate cells. Using p75 neurotrophin receptor (p75NTR) to mark this cell population, we sorted 12.5, 14.5 and 16.5 dpc hepatic stellate cells and analyzed expression of cytokines and extracellular matrix mRNAs. Among cytokines, insulin-like growth factor 2 (Igf2) was highly expressed at all three stages analyzed. The extracellular matrix molecule fibronectin (Fn1) was highly expressed in 12.5 dpc cells, whereas vitronectin (Vtn) was highly expressed in 14.5 and 16.5 dpc hepatic stellate cells. Among liver cells, Igf2 was predominantly expressed in hepatoblast-like cells at all three stages examined, suggesting that hepatoblast-like cells are an essential part of the niche that maintains homeostasis of hematopoietic cells in embryonic mouse liver. Defining these expression patterns could facilitate our understanding of cross talk between cytokine and extracellular matrix molecules in hepatic stellate cells and benefit research in developmental hematopoiesis as well as the study of liver biology. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

  11. Differential astroglial responses in the spinal cord of rats submitted to a sciatic nerve double crush treated with local injection of cultured Schwann cell suspension or lesioned spinal cord extract: implications on cell therapy for nerve repair Respostas astrocitárias na medula espinal do rato submetido ao esmagamento duplo do nervo ciático e tratado com injeção local de suspensão de células de Schwann cultivadas ou de extrato de medula espinal lesada: implicações na terapia celular para o reparo do nervo

    Directory of Open Access Journals (Sweden)

    João Gabriel Martins Dallo

    2007-12-01

    Full Text Available PURPOSE: Reactive astrocytes are implicated in several mechanisms after central or peripheral nervous system lesion, including neuroprotection, neuronal sprouting, neurotransmission and neuropathic pain. Schwann cells (SC, a peripheral glia, also react after nerve lesion favoring wound/repair, fiber outgrowth and neuronal regeneration. We investigated herein whether cell therapy for repair of lesioned sciatic nerve may change the pattern of astroglial activation in the spinal cord ventral or dorsal horn of the rat. METHODS: Injections of a cultured SC suspension or a lesioned spinal cord homogenized extract were made in a reservoir promoted by a contiguous double crush of the rat sciatic nerve. Local injection of phosphate buffered saline (PBS served as control. One week later, rats were euthanized and spinal cord astrocytes were labeled by immunohistochemistry and quantified by means of quantitative image analysis. RESULTS: In the ipsilateral ventral horn, slight astroglial activations were seen after PBS or SC injections, however, a substantial activation was achieved after cord extract injection in the sciatic nerve reservoir. Moreover, SC suspension and cord extract injections were able to promote astroglial reaction in the spinal cord dorsal horn bilaterally. Conclusion: Spinal cord astrocytes react according to repair processes of axotomized nerve, which may influence the functional outcome. The event should be considered during the neurosurgery strategies.OBJETIVO: Astrócitos reativos participam de vários mecanismos após lesões do sistema nervoso central e periférico, os quais incluem neuroproteção, brotamento neuronal, neurotransmissão e dor neuropática. As células de Schwann (CS, um tipo de glia periférica, também reagem com a lesão do nervo, podendo interferir com o reparo e cicatrização, crescimento de fibras e regeneração neuronais. Investigamos aqui a possibilidade da terapia celular para o reparo do nervo ci

  12. The p75 neurotrophin receptor is a central regulator of glioma invasion.

    Directory of Open Access Journals (Sweden)

    Angela L M Johnston

    2007-08-01

    Full Text Available The invasive nature of cancers in general, and malignant gliomas in particular, is a major clinical problem rendering tumors incurable by conventional therapies. Using a novel invasive glioma mouse model established by serial in vivo selection, we identified the p75 neurotrophin receptor (p75(NTR as a critical regulator of glioma invasion. Through a series of functional, biochemical, and clinical studies, we found that p75(NTR dramatically enhanced migration and invasion of genetically distinct glioma and frequently exhibited robust expression in highly invasive glioblastoma patient specimens. Moreover, we found that p75(NTR-mediated invasion was neurotrophin dependent, resulting in the activation of downstream pathways and producing striking cytoskeletal changes of the invading cells. These results provide the first evidence for p75(NTR as a major contributor to the highly invasive nature of malignant gliomas and identify a novel therapeutic target.

  13. Cartilage stem/progenitor cells are activated in osteoarthritis via interleukin-1β/nerve growth factor signaling.

    Science.gov (United States)

    Jiang, Yangzi; Hu, Changchang; Yu, Shuting; Yan, Junwei; Peng, Hsuan; Ouyang, Hong Wei; Tuan, Rocky S

    2015-11-17

    Interleukin-1β (IL-1β) and nerve growth factor (NGF) are key regulators in the pathogenesis of inflammatory arthritis; specifically, IL-1β is involved in tissue degeneration and NGF is involved in joint pain. However, the cellular and molecular interactions between IL-1β and NGF in articular cartilage are not known. Cartilage stem/progenitor cells (CSPCs) have recently been identified in osteoarthritic (OA) cartilage on the basis of their migratory properties. Here we hypothesize that IL-1β/NGF signaling is involved in OA cartilage degeneration by targeting CSPCs. NGF and NGF receptor (NGFR: TrkA and p75NTR) expression in healthy and OA human articular cartilage and isolated chondrocytes was determined by immunostaining, qRT-PCR, flow cytometry and western blot. Articular cartilage derived stem/progenitor cells were collected and identified by stem/progenitor cell characteristics. 3D-cultured CSPC pellets and cartilage explants were treated with NGF and NGF neutralizing antibody, and extracellular matrix changes were examined by sulfated glycosaminoglycan (GAG) release and MMP expression and activity. Expression of NGF, TrkA and p75NTR was found to be elevated in human OA cartilage. Cellular changes upon IL-1β and/or NGF treatment were then examined. NGF mRNA and NGFR proteins levels were upregulated in cultured chondrocytes exposed to IL-1β. NGF was chemotactic for cells isolated from OA cartilage. Cells isolated on the basis of their chemotactic migration towards NGF demonstrated stem/progenitor cell characteristics, including colony-forming ability, multi-lineage differentiation potential, and stem cell surface markers. The effects of NGF perturbation in cartilage explants and 3D-cultured CSPCs were next analyzed. NGF treatment resulted in extracellular matrix catabolism indicated by increased sGAG release and MMP expression and activity; conversely, treatment with NGF neutralizing antibody inhibited increased MMP levels, and enhanced tissue inhibitor of

  14. Glial Cells: The Other Cells of the Nervous System

    Indian Academy of Sciences (India)

    conduction is restored within a few days. This is probably because at this stage the spinal cord lacks myelin and has few glial cells. Thus the inhibitory signals are absent and the regeneration is possible. 2. Transplantation of Schwann cells (either a graft of sciatic nerve or cultured Schwann cells) into the lesioned area of the.

  15. Cryopreservation of Hair-Follicle Associated Pluripotent (HAP) Stem Cells Maintains Differentiation and Hair-Growth Potential.

    Science.gov (United States)

    Hoffman, Robert M; Kajiura, Satoshi; Cao, Wenluo; Liu, Fang; Amoh, Yasuyuki

    2016-01-01

    Hair follicles contain nestin-expressing pluripotent stem cells which originate above the bulge area of the follicle, below the sebaceous gland. We have termed these cells hair follicle-associated pluripotent (HAP) stem cells. We have established efficient cryopreservation methods of the hair follicle that maintain the pluripotency of HAP stem cells as well as hair growth. We cryopreserved the whole hair follicle by slow-rate cooling in TC-Protector medium or in DMSO-containing medium and storage in liquid nitrogen or at -80 °C. After thawing and culture of the cryopreserved whisker follicles, growing HAP stem cells formed hair spheres. The hair spheres contained cells that differentiated to neurons, glial cells, and other cell types. The hair spheres derived from slow-cooling cryopreserved hair follicles were as pluripotent as hair spheres from fresh hair follicles. We have also previously demonstrated that cryopreserved mouse whisker hair follicles maintain their hair-growth potential. DMSO better cryopreserved mouse whisker follicles compared to glycerol. DMSO-cryopreserved hair follicles also maintained the HAP stem cells, evidenced by P75ntr expression. Subcutaneous transplantation of DMSO-cryopreserved hair follicles in nude mice resulted in extensive hair fiber growth over 8 weeks, indicating the functional recovery of hair-shaft growth of cryopreserved hair follicles. HAP stem cells can be used for nerve and spinal-cord repair. This biobanking of hair follicles can allow each patient the potential for their own stem cell use for regenerative medicine or hair transplantation.

  16. LINGO-1 protein interacts with the p75 neurotrophin receptor in intracellular membrane compartments.

    Science.gov (United States)

    Meabon, James S; De Laat, Rian; Ieguchi, Katsuaki; Wiley, Jesse C; Hudson, Mark P; Bothwell, Mark

    2015-04-10

    Axon outgrowth inhibition in response to trauma is thought to be mediated via the binding of myelin-associated inhibitory factors (e.g. Nogo-66, myelin-associated glycoprotein, oligodendrocyte myelin glycoprotein, and myelin basic protein) to a putative tripartite LINGO-1·p75(NTR)·Nogo-66 receptor (NgR) complex at the cell surface. We found that endogenous LINGO-1 expression in neurons in the cortex and cerebellum is intracellular. Mutation or truncation of the highly conserved LINGO-1 C terminus altered this intracellular localization, causing poor intracellular retention and increased plasma membrane expression. p75(NTR) associated predominantly with natively expressed LINGO-1 containing immature N-glycans, characteristic of protein that has not completed trans-Golgi-mediated processing, whereas mutant forms of LINGO-1 with enhanced plasma membrane expression did not associate with p75(NTR). Co-immunoprecipitation experiments demonstrated that LINGO-1 and NgR competed for binding to p75(NTR) in a manner that is difficult to reconcile with the existence of a LINGO-1·p75(NTR)·NgR ternary complex. These findings contradict models postulating functional LINGO-1·p75(NTR)·NgR complexes in the plasma membrane. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Wallerian degeneration and axonal regeneration after sciatic nerve crush are altered in ICAM-1-deficient mice.

    Science.gov (United States)

    Kirsch, Matthias; Campos Friz, Marianella; Vougioukas, Vassilios I; Hofmann, Hans-Dieter

    2009-10-01

    The intercellular cell adhesion molecule-1 (ICAM-1) has been implicated in the recruitment of immune cells during inflammatory processes. Previous studies investigating its involvement in the process of Wallerian degeneration and focusing on its potential role in macrophage recruitement have come to controversial conclusions. To examine whether Wallerian degeneration is altered in the absence of ICAM-1, we have analyzed changes in the expression of axonal and Schwann cell markers following sciatic nerve crush in wildtype and ICAM-1-deficient mice. We report that the lack of ICAM-1 leads to impaired axonal degeneration and regeneration and to alterations in Schwann cell responses following sciatic nerve crush. Degradation of neurofilament protein, the collapse of axonal profiles, and the re-expression of neurofilament proteins are substantially delayed in the distal nerve segment of ICAM-1(-/-) mice. In contrast, the degradation of myelin, as determined by immunostaining for myelin protein zero, is unaltered in the mutants. Upregulation of GAP-43 and p75 neurotrophin receptor (p75(NTR)) expression, characteristic for Schwann cells dedifferentiating in response to nerve injury, is differentially altered in the mutant animals. These results indicate that ICAM-1 is essential for the normal progression of axonal degeneration and regeneration in distal segments of injured peripheral nerves.

  18. Genetically modified mesenchymal stem cells (MSCs) promote axonal regeneration and prevent hypersensitivity after spinal cord injury.

    Science.gov (United States)

    Kumagai, Gentaro; Tsoulfas, Pantelis; Toh, Satoshi; McNiece, Ian; Bramlett, Helen M; Dietrich, W Dalton

    2013-10-01

    Neurotrophins and the transplantation of bone marrow-derived stromal cells (MSCs) are both candidate therapies targeting spinal cord injury (SCI). While some studies have suggested the ability of MSCs to transdifferentiate into neural cells, other SCI studies have proposed anti-inflammatory and other mechanisms underlying established beneficial effects. We grafted rat MSCs genetically modified to express MNTS1, a multineurotrophin that binds TrkA, TrkB and TrkC, and p75(NTR) receptors or MSC-MNTS1/p75(-) that binds mainly to the Trk receptors. Seven days after contusive SCI, PBS-only, GFP-MSC, MSC-MNTS1/GFP or MSC-MNTS1/p75(-)/GFP were delivered into the injury epicenter. All transplanted groups showed reduced inflammation and cystic cavity size compared to control SCI rats. Interestingly, transplantation of the MSC-MNTS1 and MSC-MNTS1/p75(-), but not the naïve MSCs, enhanced axonal growth and significantly prevented cutaneous hypersensitivity after SCI. Moreover, transplantation of MSC-MNTS1/p75(-) promoted angiogenesis and modified glial scar formation. These findings suggest that MSCs transduced with a multineurotrophin are effective in promoting cell growth and improving sensory function after SCI. These novel data also provide insight into the neurotrophin-receptor dependent mechanisms through which cellular transplantation leads to functional improvement after experimental SCI. © 2013.

  19. Peroxisome proliferator-activated receptor gamma is a novel target of the nerve growth factor signaling pathway in PC12 cells.

    Science.gov (United States)

    Fuenzalida, Karen M; Aguilera, Mauricio C; Piderit, Daniela G; Ramos, Patricio C; Contador, David; Quiñones, Verónica; Rigotti, Atilio; Bronfman, Francisca C; Bronfman, Miguel

    2005-03-11

    Peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the nuclear receptor superfamily, is subject to considerable interest because of its role in adipocyte differentiation, metabolic control, and anti-inflammatory action. PPARgamma research in brain cells is presently focused on glial PPARgamma because of its potential as a pharmacological target in the treatment of neurodegenerative diseases with an inflammatory component. In neurons PPARgamma function is far from clear, and PPARgamma agonist-dependent and -independent effects on cell survival or differentiation have been reported. We used PC12 cells, widely used to study neuronal signaling, such as nerve growth factor (NGF)-induced differentiation and survival or epidermal growth factor-dependent cell proliferation to dissect the possible involvement of PPARgamma in these pathways. We show that NGF but not epidermal growth factor increases the transcriptional activity of PPARgamma, and modulates the expression of this transcription factor. Because NGF signals through the tyrosine kinase (TrkA) NGF receptor and/or the p75NTR receptor, we used rescue experiments with a PC12 cell mutant lacking TrkA to show that NGF-induced PPARgamma activation is dependent on TrkA activation. Our results point out PPARgamma as a novel target of the TrkA-mediated neuronal cell survival and differentiating pathway and suggest a potential new inflammatory-independent therapeutic approach for pharmacological intervention in neurological disorders.

  20. Nitration and Glycation Turn Mature NGF into a Toxic Factor for Motor Neurons: A Role for p75NTRand RAGE Signaling in ALS.

    Science.gov (United States)

    Kim, Mi Jin; Vargas, Marcelo R; Harlan, Benjamin A; Killoy, Kelby M; Ball, Lauren E; Comte-Walters, Susana; Gooz, Monika; Yamamoto, Yasuhiko; Beckman, Joseph S; Barbeito, Luis; Pehar, Mariana

    2017-06-26

    Glycating stress can occur together with oxidative stress during neurodegeneration and contribute to the pathogenic mechanism. Nerve growth factor (NGF) accumulates in several neurodegenerative diseases. Besides promoting survival, NGF can paradoxically induce cell death by signaling through the p75 neurotrophin receptor (p75 NTR ). The ability of NGF to induce cell death is increased by nitration of its tyrosine residues under conditions associated with increased peroxynitrite formation. Here we investigated whether glycation also changes the ability of NGF to induce cell death and assessed the ability of post-translational modified NGF to signal through the receptor for advanced glycation end products (RAGEs). We also explored the potential role of RAGE-p75 NTR interaction in the motor neuron death occurring in amyotrophic lateral sclerosis (ALS) models. Glycation promoted NGF oligomerization and ultimately allowed the modified neurotrophin to signal through RAGE and p75 NTR to induce motor neuron death at low physiological concentrations. A similar mechanism was observed for nitrated NGF. We provide evidence for the interaction of RAGE with p75 NTR at the cell surface. Moreover, we observed that post-translational modified NGF was present in the spinal cord of an ALS mouse model. In addition, NGF signaling through RAGE and p75 NTR was involved in astrocyte-mediated motor neuron toxicity, a pathogenic feature of ALS. Oxidative modifications occurring under stress conditions can enhance the ability of mature NGF to induce neuronal death at physiologically relevant concentrations, and RAGE is a new p75 NTR coreceptor contributing to this pathway. Our results indicate that NGF-RAGE/p75 NTR signaling may be a therapeutic target in ALS. Antioxid. Redox Signal. 00, 000-000.

  1. In vivo transplantation of fetal human gut-derived enteric neural crest cells.

    Science.gov (United States)

    Cooper, J E; Natarajan, D; McCann, C J; Choudhury, S; Godwin, H; Burns, A J; Thapar, N

    2017-01-01

    The prospect of using neural cell replacement for the treatment of severe enteric neuropathies has seen significant progress in the last decade. The ability to harvest and transplant enteric neural crest cells (ENCCs) that functionally integrate within recipient intestine has recently been confirmed by in vivo murine studies. Although similar cells can be harvested from human fetal and postnatal gut, no studies have as yet verified their functional viability upon in vivo transplantation. We sought to determine whether ENCCs harvested from human fetal bowel are capable of engraftment and functional integration within recipient intestine following in vivo transplantation into postnatal murine colon. Enteric neural crest cells selected and harvested from fetal human gut using the neurotrophin receptor p75(NTR) were lentivirally labeled with either GFP or calcium-sensitive GCaMP and transplanted into the hindgut of Rag2(-) /γc(-) /C5(-) -immunodeficient mice at postnatal day 21. Transplanted intestines were assessed immunohistochemically for engraftment and differentiation of donor cells. Functional viability and integration with host neuromusculature was assessed using calcium imaging. Transplanted human fetal gut-derived ENCC showed engraftment within the recipient postnatal colon in 8/15 mice (53.3%). At 4 weeks posttransplantation, donor cells had spread from the site of transplantation and extended projections over distances of 1.2 ± 0.6 mm (n = 5), and differentiated into enteric nervous system (ENS) appropriate neurons and glia. These cells formed branching networks located with the myenteric plexus. Calcium transients (change in intensity F/F0 = 1.25 ± 0.03; 15 cells) were recorded in transplanted cells upon stimulation of the recipient endogenous ENS demonstrating their viability and establishment of functional connections. © 2016 The Authors. Neurogastroenterology & Motility Published by John Wiley & Sons Ltd.

  2. Cultivo de células Schwann y efecto de la neurregulina sobre el mismo

    OpenAIRE

    Pedraza Hueso, María Isabel

    2012-01-01

    Las Células de Schwann forman parte del tejido glial del sistema nervioso periférico. Su principal función es la participación en la regeneración del mimo cuando ha sufrido una lesión. Por ello,es importante llevar a cabo estudios para perfeccionar la regeneración de las mismas in vitro, aumentando su rendimiento para su posterior aplicación en la terapéutica de enfermedades que afectan al adulto. Llevamos a cabo el cultivo de células de Schwann procedentes del Nervio Ciático de una rata ...

  3. Cultivo de células de Schwann, un modelo del microambiente del sistema nervioso

    OpenAIRE

    Vilma C. Muñetón; Zayra V. Garavito; Hernán Hurtado

    1998-01-01

    Algunos aspectos de la fisiopatología del sistema nervioso periférico pueden ser ampliamente estudiados en un modelo celular in vitro, enriquecido en células de Schwann. La célula de Schwann como glía del sistema nervioso periférico produce la mielina responsable de la transmisión saltatoria del impulso, influye en la actividad neuronal y da soporte y protección axonal. A su vez es blanco de procesos que alteran la normalidad del sistema nervioso periférico como neuropatías congénitas y 10 de...

  4. Switchable cell trapping using superparamagnetic beads

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, M. T.; Smith, K. H.; Real, M. E.; Bashir, M. A.; Fry, P. W.; Fischer, P.; Im, M.-Y.; Schrefl, T.; Allwood, D. A.; Haycock, J. W.

    2010-04-30

    Ni{sub 81}Fe{sub 19} microwires are investigated as the basis of a switchable template for positioning magnetically-labeled neural Schwann cells. Magnetic transmission X-ray microscopy and micromagnetic modeling show that magnetic domain walls can be created or removed in zigzagged structures by an applied magnetic field. Schwann cells containing superparamagnetic beads are trapped by the field emanating from the domain walls. The design allows Schwann cells to be organized on a surface to form a connected network and then released from the surface if required. As aligned Schwann cells can guide nerve regeneration, this technique is of value for developing glial-neuronal co-culture models in the future treatment of peripheral nerve injuries.

  5. Characterization of glial cell models and in vitro manipulation of the neuregulin1/ErbB system

    NARCIS (Netherlands)

    Pascal, Davide; Giovannelli, Alessia; Gnavi, Sara; Hoyng, Stefan Adriaan; de Winter, Fred; Morano, Michela; Fregnan, Federica; Dell'Albani, Paola; Zaccheo, Damiano; Perroteau, Isabelle; Pellitteri, Rosalia; Gambarotta, Giovanna

    2014-01-01

    The neuregulin1/ErbB system plays an important role in Schwann cell behavior both in normal and pathological conditions. Upon investigation of the expression of the neuregulin1/ErbB system in vitro, we explored the possibility to manipulate the system in order to increase the migration of Schwann

  6. Therapeutic effects of neurotrophic factors in experimental spinal cord injury models

    Directory of Open Access Journals (Sweden)

    Enomoto M

    2016-03-01

    Full Text Available Mitsuhiro Enomoto1,21Department of Orthopaedic and Spinal Surgery, Graduate School, 2Hyperbaric Medical Center, Tokyo Medical and Dental University, Tokyo, JapanAbstract: Neurotrophic factors (NFs play important roles in regenerative medicine approaches to mitigate primary and secondary damage after spinal cord injury (SCI because their receptors are still present in the injured spinal cord even though the expression of the NFs themselves is decreased. Several reports have shown that NF administration increases regenerative signaling after SCI, particularly by stimulating axonal growth. However, few NFs cross the blood–brain barrier, and most of them show low stability and limited diffusion within the central nervous system. To overcome this problem, transplantation strategies using genetically modified NF-secreting Schwann cells, neural and glial progenitor cells, and mesenchymal stem cells have been applied to animal models of SCI. In particular, multifunctional NFs that bind to TrkB, TrkC, and p75NTR receptors have been discovered in the last decade and utilized in preclinical cell therapies for spinal cord repair. To achieve functional recovery after SCI, it is important to consider the different effects of each NF on axonal regeneration, and strategies should be established to specifically harness the multifunctional properties of NFs. This review provides an overview of multifunctional NFs combined with cell therapy in experimental SCI models and a proposal to implement their use as a clinically viable therapy.Keywords: spinal cord injury, neurotrophic factor, multineurotrophin, regeneration, cell transplantation

  7. Cultivo de células de Schwann, un modelo del microambiente del sistema nervioso

    Directory of Open Access Journals (Sweden)

    Vilma C. Muñetón

    1998-03-01

    Full Text Available Algunos aspectos de la fisiopatología del sistema nervioso periférico pueden ser ampliamente estudiados en un modelo celular in vitro, enriquecido en células de Schwann. La célula de Schwann como glía del sistema nervioso periférico produce la mielina responsable de la transmisión saltatoria del impulso, influye en la actividad neuronal y da soporte y protección axonal. A su vez es blanco de procesos que alteran la normalidad del sistema nervioso periférico como neuropatías congénitas y 10 desmielinizantes, lesiones nerviosas, respuesta a patógenos neurotrópicos, etc., eventos más frecuentes y discapacitantes en individuos adultos. De ahí la importancia de obtener células a partir de animales adultos. Sin embargo, estas células son mitóticamente ""lentas"" y su obtención en cultivo requiere de condiciones específicas que estimulen su proliferación y actividad. Describimos a continuación, un modelo in vitro mediante el cual se obtienen cultivos enriquecidos en células de Schwann de ratón adulto, las cuales conservan características de las células in vivo, lo cual permite estudiar diversos fenómenos específicos del sistema nervioso periférico.

  8. Cerebellar Expression of the Neurotrophin Receptor p75 in Naked-Ataxia Mutant Mouse.

    Science.gov (United States)

    Rahimi Balaei, Maryam; Jiao, Xiaodan; Ashtari, Niloufar; Afsharinezhad, Pegah; Ghavami, Saeid; Marzban, Hassan

    2016-01-15

    Spontaneous mutation in the lysosomal acid phosphatase 2 (Acp2) mouse (nax--naked-ataxia mutant mouse) correlates with severe cerebellar defects including ataxia, reduced size and abnormal lobulation as well as Purkinje cell (Pc) degeneration. Loss of Pcs in the nax cerebellum is compartmentalized and harmonized to the classic pattern of gene expression of the cerebellum in the wild type mouse. Usually, degeneration starts in the anterior and posterior zones and continues to the central and nodular zones of cerebellum. Studies have suggested that the p75 neurotrophin receptor (NTR) plays a role in Pc degeneration; thus, in this study, we investigated the p75NTR pattern and protein expression in the cerebellum of the nax mutant mouse. Despite massive Pc degeneration that was observed in the nax mouse cerebellum, p75NTR pattern expression was similar to the HSP25 pattern in nax mice and comparable with wild type sibling cerebellum. In addition, immunoblot analysis of p75NTR protein expression did not show any significant difference between nax and wild type sibling (p > 0.5). In comparison with wild type counterparts, p75NTR pattern expression is aligned with the fundamental cytoarchitecture organization of the cerebellum and is unchanged in the nax mouse cerebellum despite the severe neurodevelopmental disorder accompanied with Pc degeneration.

  9. Cerebellar Expression of the Neurotrophin Receptor p75 in Naked-Ataxia Mutant Mouse

    Directory of Open Access Journals (Sweden)

    Maryam Rahimi Balaei

    2016-01-01

    Full Text Available Spontaneous mutation in the lysosomal acid phosphatase 2 (Acp2 mouse (nax—naked-ataxia mutant mouse correlates with severe cerebellar defects including ataxia, reduced size and abnormal lobulation as well as Purkinje cell (Pc degeneration. Loss of Pcs in the nax cerebellum is compartmentalized and harmonized to the classic pattern of gene expression of the cerebellum in the wild type mouse. Usually, degeneration starts in the anterior and posterior zones and continues to the central and nodular zones of cerebellum. Studies have suggested that the p75 neurotrophin receptor (NTR plays a role in Pc degeneration; thus, in this study, we investigated the p75NTR pattern and protein expression in the cerebellum of the nax mutant mouse. Despite massive Pc degeneration that was observed in the nax mouse cerebellum, p75NTR pattern expression was similar to the HSP25 pattern in nax mice and comparable with wild type sibling cerebellum. In addition, immunoblot analysis of p75NTR protein expression did not show any significant difference between nax and wild type sibling (p > 0.5. In comparison with wild type counterparts, p75NTR pattern expression is aligned with the fundamental cytoarchitecture organization of the cerebellum and is unchanged in the nax mouse cerebellum despite the severe neurodevelopmental disorder accompanied with Pc degeneration.

  10. Granular Cell Tumor

    African Journals Online (AJOL)

    ultrastructure and immunochemical staining. 4 strongly suggest Schwann cell derivation . hyperplasia at the edges of the tumor. Necrosis within the tumor was absent, no mitosis was. Granular cell tumors are seldom diagnosed identified in the section and the edges of the accurately clinically. The lesion in this case was.

  11. Glial Cells: The Other Cells of the Nervous System

    Indian Academy of Sciences (India)

    Purified 5chwann cells from monkey sciatic nerve grown in culture. Note the typical bipolar spindle shaped appearance of the cells (x 200). shaped appearance when grown in isolation in tissue culture. (Figure 2), stretch in cords around the axons. While one Schwann cell can enclose several small unmyelinated axons, one ...

  12. Effects of nerve cells and adhesion molecules on nerve conduit for peripheral nerve regeneration.

    Science.gov (United States)

    Chung, Joo-Ryun; Choi, Jong-Won; Fiorellini, Joseph P; Hwang, Kyung-Gyun; Park, Chang-Joo

    2017-09-01

    For peripheral nerve regeneration, recent attentions have been paid to the nerve conduits made by tissue-engineering technique. Three major elements of tissue-engineering are cells, molecules, and scaffolds. In this study, the attachments of nerve cells, including Schwann cells, on the nerve conduit and the effects of both growth factor and adhesion molecule on these attachments were investigated. The attachment of rapidly-proliferating cells, C6 cells and HS683 cells, on nerve conduit was better than that of slowly-proliferating cells, PC12 cells and Schwann cells, however, the treatment of nerve growth factor improved the attachment of slowly-proliferating cells. In addition, the attachment of Schwann cells on nerve conduit coated with fibronectin was as good as that of Schwann cells treated with glial cell line-derived neurotrophic factor (GDNF). Growth factor changes nerve cell morphology and affects cell cycle time. And nerve growth factor or fibronectin treatment is indispensable for Schwann cell to be used for implantation in artificial nerve conduits.

  13. Glial cell biology in the Great Lakes region.

    Science.gov (United States)

    Feinstein, Douglas L; Skoff, Robert P

    2016-03-31

    We report on the tenth bi-annual Great Lakes Glial meeting, held in Traverse City, Michigan, USA, September 27-29 2015. The GLG meeting is a small conference that focuses on current research in glial cell biology. The array of functions that glial cells (astrocytes, microglia, oligodendrocytes, Schwann cells) play in health and disease is constantly increasing. Despite this diversity, GLG meetings bring together scientists with common interests, leading to a better understanding of these cells. This year's meeting included two keynote speakers who presented talks on the regulation of CNS myelination and the consequences of stress on Schwann cell biology. Twenty-two other talks were presented along with two poster sessions. Sessions covered recent findings in the areas of microglial and astrocyte activation; age-dependent changes to glial cells, Schwann cell development and pathology, and the role of stem cells in glioma and neural regeneration.

  14. Combination of Acellular Nerve Graft and Schwann Cells-Like Cells for Rat Sciatic Nerve Regeneration

    OpenAIRE

    Songtao Gao; Yan Zheng; Qiqing Cai; Zhansheng Deng; Weitao Yao; Jiaqiang Wang; Xin Wang; Peng Zhang

    2014-01-01

    Objective. To investigate the effect of tissue engineering nerve on repair of rat sciatic nerve defect. Methods. Forty-five rats with defective sciatic nerve were randomly divided into three groups. Rats in group A were repaired by acellular nerve grafts only. Rats in group B were repaired by tissue engineering nerve. In group C, rats were repaired by autogenous nerve grafts. After six and twelve weeks, sciatic nerve functional index (SFI), neural electrophysiology (NEP), histological and tra...

  15. Enhanced peripheral nerve regeneration by the combination of a polycaprolactone tubular prosthesis and a scaffold of collagen with supramolecular organization.

    Science.gov (United States)

    Maturana, Luiz G; Pierucci, Amauri; Simões, Gustavo F; Vidigal, Mateus; Duek, Eliana A R; Vidal, Benedicto C; Oliveira, Alexandre L R

    2013-07-01

    The purpose of this study was to investigate the influence of implanting collagen with a supramolecular organization on peripheral nerve regeneration, using the sciatic nerve tubulization technique. For this purpose, adult female Sprague Dawley rats were divided into five groups: (1) TP - sciatic nerve repaired with empty polyethylene tubular prothesis (n = 10), (2) TPCL - nerve repair with empty polycaprolactone (PCL) tubing (n = 8), (3) TPCLF - repair with PCL tubing filled with an implant of collagen with a supramolecular organization (n = 10), (4) AG - animals that received a peripheral nerve autograft (n = 8), and (5) Normal nerves (n = 8). The results were assessed by quantification of the regenerated fibers, nerve morphometry, and transmission electron microscopy, 60 days after surgery. Immunohistochemistry and polarization microscopy were also used to analyze the regenerated nerve structure and cellular elements. The results showed that the AG group presented a larger number of regenerated axons. However, the TPCL and TPCLF groups presented more compact regenerated fibers with a morphometric profile closer to normal, both at the tube midpoint and 2 mm distal to the prosthesis. These findings were reinforced by polarization microscopy, which indicated a better collagen/axons suprastructural organization in the TPCLF derived samples. In addition, the immunohistochemical results obtained using the antibody anti-p75NTR as a Schwann cell reactivity marker demonstrated that the Schwann cells were more reactive during the regenerative process in the TPCLF group as compared to the TPCL group and the normal sciatic nerve. Altogether, the results of this study indicated that the implant of collagen with a supramolecular organization positively influenced and stimulated the regeneration process through the nerve gap, resulting in the formation of a better morphologically arranged tissue.

  16. Nonyloxytryptamine Mimics Polysialic Acid and Modulates Neuronal and Glial Functions in Cell Culture

    Science.gov (United States)

    2014-01-01

    Schwann cellswere prepared from 7-day-old C57BL/6J or NCAM-deficient mice (Loers et al. 2005; Mehanna et al. 2009); motoneurons were prepared from...adhesion molecule (NCAM) independent manner, but it stimulates neurite outgrowth of motoneurons and process formation of Schwann cells in an NCAM...dependent manner. Neurite outgrowth of wild-type (black bars, left) and NCAM-deficient (gray bars, right) hippocampal neurons (a), motoneurons (b) or

  17. Cell autonomy of the mouse claw paw mutation.

    Science.gov (United States)

    Darbas, Aysel; Jaegle, Martine; Walbeehm, Erik; van den Burg, Hans; Driegen, Siska; Broos, Ludo; Uyl, Matthijs; Visser, Pim; Grosveld, Frank; Meijer, Dies

    2004-08-15

    Mice homozygous for the autosomal recessive mutation claw paw (clp) are characterized by limb posture abnormalities and congenital hypomyelination, with delayed onset of myelination of the peripheral nervous system but not the central nervous system. Although this combination of limb and peripheral nerve abnormalities in clp/clp mice might suggest a common neurogenic origin of the syndrome, it is not clear whether the clp gene acts primarily in the neurone, the Schwann cell or both. In the work described here, we address this question of cell autonomy of the clp mutation through reciprocal nerve grafting experiments between wild-type and clp/clp animals. Our results demonstrate that the clp mutation affects the Schwann cell compartment and possibly also the neuronal compartment. These data suggest that the clp gene product is expressed in Schwann cells as well as neurones and is likely to be involved in direct axon--Schwann cell interactions. Within the Schwann cell, clp affects a myelin-related signaling pathway that regulates periaxin and Krox-20 expression, but not Oct-6.

  18. Neurotrophin receptors expression and JNK pathway activation in human astrocytomas

    Directory of Open Access Journals (Sweden)

    Maraziotis Theodore

    2007-10-01

    Full Text Available Abstract Background Neurotrophins are growth factors that regulate cell growth, differentiation and apoptosis in the nervous system. Their diverse actions are mediated through two different transmembrane – receptor signaling systems: Trk receptor tyrosine kinases (TrkA, TrkB, TrkC and p75NTR neurotrophin receptor. Trk receptors promote cell survival and differentiation while p75NTR induces, in most cases, the activity of JNK-p53-Bax apoptosis pathway or suppresses intracellular survival signaling cascades. Robust Trk activation blocks p75NTR -induced apoptosis by suppressing the JNK-p53-Bax pathway. The aim of this exploratory study was to investigate the expression levels of neurotrophin receptors, Trks and p75NTR, and the activation of JNK pathway in human astrocytomas and in adjacent non-neoplastic brain tissue. Methods Formalin-fixed paraffin-embedded serial sections from 33 supratentorial astrocytomas (5 diffuse fibrillary astrocytomas, WHO grade II; 6 anaplastic astrocytomas, WHO grade III; 22 glioblastomas multiforme, WHO grade IV were immunostained following microwave pretreatment. Polyclonal antibodies against TrkA, TrkB, TrkC and monoclonal antibodies against p75NTR and phosphorylated forms of JNK (pJNK and c-Jun (pc-Jun were used. The labeling index (LI, defined as the percentage of positive (labeled cells out of the total number of tumor cells counted, was determined. Results Moderate to strong, granular cytoplasmic immunoreactivity for TrkA, TrkB and TrkC receptors was detected in greater than or equal to 10% of tumor cells in the majority of tumors independently of grade; on the contrary, p75NTR receptor expression was found in a small percentage of tumor cells (~1% in some tumors. The endothelium of tumor capillaries showed conspicuous immunoreactivity for TrkB receptor. Trk immunoreactivity seemed to be localized in some neurons and astrocytes in non-neoplastic tissue. Phosphorylated forms of JNK (pJNK and c-Jun (pc-Jun were

  19. Neural Stem Cells (NSCs in 3D Collagen Scaffolds: developing pharmacologically monitored neuroimplants for Spinal Cord Injury (SCI

    Directory of Open Access Journals (Sweden)

    Alexandra Kourgiantaki

    2014-06-01

    Full Text Available Spinal cord injury, a traumatic disease characterised by a massive degeneration of neural tissue, was recently targeted for neuroregenerative interventions. Our approach is the development of pharmacologically pulsed neuroimplants using 3D collagen scaffolds hosting NSCs. We aim to monitor the properties of NSCs ex vivo and in vivo, using synthetic small molecules with neuroprotective and neurogenic properties. Synthetic, highly lipophilic CNS bioavailable small molecules, synthesized by our group (microneurotrophins, bind to neurotrophins receptors (Gravanis et al, Science Signaling, 2012, Calogeropoulou et al., J Med Chem., 2009. BNN27 can specifically interact with TrkA and p75NTR receptors activating specific signalling pathways controlling neuronal cell survival and neurogenesis (Charalampopoulos et al, PNAS, 2004, Lazaridis et al., PLoS Biol., 2011. We are seeding embryonic and adult mouse NSC on collagen 3D scaffolds of different composition (collagen, chondroitin-6-sulphate and gelatin and construction (size of pores and stiffness, testing cell behaviour (survival, proliferation or differentiation in basal conditions or pulsed with neurotrophins and/or microneurotrophins. Using the knock in sox2-egfp mice strain and fluorescence activated cell sorting (FACS analysis, we obtain NSCs cultures with a sox2-positive population more than 90% pure. We evaluate specific markers of proliferation (ki67 and/or differentiation (GFAP for glial cells, Tuj1 for mature neurons and O4 for oligodendrocytes: we are currently testing the possible effect of BNN27 on proliferation of cortical NSCs in 2D cultures (increased numbers of ki67 positive cells up to 12%. The composition and the structure of 3D scaffolds seem to play a significant functional role: scaffolds with a combined composition such as 50% collagen/50% gelatin and 92% collagen/8% chondroitin-6-sulphate support NSC survival since they sustain sox2 expression and propagate neurosphere formation

  20. Activation of Schwann cells in vitro by magnetic nanocomposites via applied magnetic field

    OpenAIRE

    Liu Z; Huang L; Liu L.; Luo B.; Liang M; Sun Z; Zhu S.; Quan X.; Yang Y.; Ma T.; Huang J; Luo Z

    2014-01-01

    Zhongyang Liu,1,* Liangliang Huang,1,* Liang Liu,1,* Beier Luo,2,* Miaomiao Liang,3 Zhen Sun,1 Shu Zhu,1 Xin Quan,1 Yafeng Yang,1 Teng Ma,1 Jinghui Huang,1 Zhuojing Luo1 1Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, 2Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, 3Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi’an, People’s Republic of Ch...

  1. A Combination Tissue Engineering Strategy for Schwann Cell-Induced Spinal Cord Repair

    Science.gov (United States)

    2015-10-01

    100ms ON and 400ms OFF cycles were applied to the PZT beam to produce displacements in the 0-50um range. During the ON cycle , the beam goes down...insulated batteries in the medullary canal of canine femora caused substantial formation of endosteum near the cathode in a 14–21 day period [49]. Even...in the absence of external electrical stimulation, implanting poled sintered hydrox- yapatite disks in canine cortical bone resulted in the filling of

  2. Fourth Ventricular Schwannoma: Identical Clinicopathologic Features as Schwann Cell-Derived Schwannoma with Unique Etiopathologic Origins

    Directory of Open Access Journals (Sweden)

    Tiffany R. Hodges

    2011-01-01

    Full Text Available Background. To our knowledge, this is the sixth reported case in the literature of fourth ventricular schwannoma. The etiology and natural history of intraventricular schwannomas is not well understood. A thorough review of potential etiopathogenic mechanisms is provided in this case report. Case Description. A 69-year-old man presented with an incidentally found fourth ventricular tumor during an evaluation for generalized weakness, gait instability, and memory disturbance. Magnetic resonance imaging (MRI revealed a heterogeneously enhancing lesion in the fourth ventricle. A suboccipital craniotomy was performed to resect the lesion. Histopathological examination confirmed the diagnosis of schwannoma (WHO grade I. Conclusions. Schwannomas should be considered in the differential diagnosis of intraventricular tumors. Although the embryologic origins may be different from nerve sheath-derived schwannomas, the histologic, clinical, and natural history appear identical and thus should be managed similarly.

  3. Permissive Schwann Cell Graft/Spinal Cord Interfaces for Axon Regeneration

    National Research Council Canada - National Science Library

    Williams, Ryan R; Henao, Martha; Pearse, Damien D; Bunge, Mary Bartlett

    2015-01-01

    .... Fluid bridges of SCs and Matrigel were placed in complete spinal cord transections. Compared to pregelled bridges of SCs and Matrigel, they improved regeneration of brainstem axons across the rostral interface...

  4. Structural and functional analysis of the Oct-6 Schwann cell enhancer

    NARCIS (Netherlands)

    M. Ghazvini (Mehrnaz)

    2004-01-01

    textabstractA defining feature in the biology of higher vertebrates is their extended and complex nervous system that allows them to rapidly integrate and process environmental information, control body posture, regulate homeostasis of their internal organs and develop complex behaviour. The

  5. Dicer in Schwann cells is required for myelination and axonal integrity

    DEFF Research Database (Denmark)

    Pereira, Jorge A.; Baumann, Reto; Norrmén, Camilla

    2010-01-01

    remarkable differentiation both in morphology and gene expression patterns throughout lineage progression to myelinating and nonmyelinating phenotypes. Gene expression in SCs is particularly tightly regulated and critical for the organism, as highlighted by the fact that a 50% decrease or an increase to 150...

  6. Extracellular matrix from human umbilical cord-derived mesenchymal stem cells as a scaffold for peripheral nerve regeneration.

    Science.gov (United States)

    Xiao, Bo; Rao, Feng; Guo, Zhi-Yuan; Sun, Xun; Wang, Yi-Guo; Liu, Shu-Yun; Wang, Ai-Yuan; Guo, Quan-Yi; Meng, Hao-Ye; Zhao, Qing; Peng, Jiang; Wang, Yu; Lu, Shi-Bi

    2016-07-01

    The extracellular matrix, which includes collagens, laminin, or fibronectin, plays an important role in peripheral nerve regeneration. Recently, a Schwann cell-derived extracellular matrix with classical biomaterial was used to mimic the neural niche. However, extensive clinical use of Schwann cells remains limited because of the limited origin, loss of an autologous nerve, and extended in vitro culture times. In the present study, human umbilical cord-derived mesenchymal stem cells (hUCMSCs), which are easily accessible and more proliferative than Schwann cells, were used to prepare an extracellular matrix. We identified the morphology and function of hUCMSCs and investigated their effect on peripheral nerve regeneration. Compared with a non-coated dish tissue culture, the hUCMSC-derived extracellular matrix enhanced Schwann cell proliferation, upregulated gene and protein expression levels of brain-derived neurotrophic factor, glial cell-derived neurotrophic factor, and vascular endothelial growth factor in Schwann cells, and enhanced neurite outgrowth from dorsal root ganglion neurons. These findings suggest that the hUCMSC-derived extracellular matrix promotes peripheral nerve repair and can be used as a basis for the rational design of engineered neural niches.

  7. cAMP is involved in the differentiation of human teratocarcinoma cells

    NARCIS (Netherlands)

    de Jonge, R. R.; van Schaik, I. N.; Vermeulen, M.; Kwa, M. S.; Baas, F.

    2001-01-01

    The generation of fully differentiated post-mitotic human neuronal cells from stem cells (human teratocarcinoma (hNT2) cells) might enable the development of a co-culture model of human neurons with human Schwann cells (SCs). This co-culture model is an important tool to study formation of myelin

  8. Valoración cuantitativa del crecimiento del cultivo de células de Schwann de rata

    OpenAIRE

    Rodríguez Blanco, María

    2014-01-01

    Estudios recientes han demostrado que las células de Schwann (SCs) son necesarias en la regeneración en el sistema nervioso periférico (SNP) y podrían también dar soporte a la regeneración en el sistema nervioso central (SNC). Por esto, el trasplante autólogo de SCs es uno de los tratamientos propuestos para la reparación de lesiones nerviosas y en nervios y médula espinal, siendo, por tanto, necesario desarrollar un método seguro y eficaz para la obtención de SCs en una can...

  9. Neuroblastoma GOTO cells are hypersensitive to disruption of lipid rafts.

    Science.gov (United States)

    Tomioka, Ryosaku; Minami, Natsumi; Kushida, Ai; Horibe, Shiho; Izumi, Ippei; Kato, Akira; Fukushima, Keiko; Ideo, Hiroko; Yamashita, Katsuko; Hirose, Shigehisa; Saito, Yuji

    2009-11-06

    GOTO cells, a neuroblastoma cell line retaining the ability to differentiate into neuronal or Schwann cells, were found to be rich in membrane rafts containing ganglioside GM2 and hypersensitive to lipid raft-disrupting methyl-beta-cyclodextrin (MbetaCD); the GM2-rich rafts and sensitivity to MbetaCD were markedly diminished upon their differentiation into Schwann cells. We first raised a monoclonal antibody that specifically binds to GOTO cells but not to differentiated Schwann cells and determined its target antigen as ganglioside GM2, which was shown to be highly concentrated in lipid rafts by its colocalization with flotillin, a marker protein of rafts. Disturbance of normal structure of the lipid raft by depleting its major constituent, cholesterol, with MbetaCD resulted in acute apoptotic cell death of GOTO cells, but little effects were seen on differentiated Schwann cells. Until this study, GM2-rich rafts are poorly characterized and MbetaCD hypersensitivity, which may have clinical implications, has not been reported.

  10. APP regulates NGF receptor trafficking and NGF-mediated neuronal differentiation and survival.

    Directory of Open Access Journals (Sweden)

    Yun-wu Zhang

    Full Text Available β-Amyloid precursor protein (APP is a key factor in Alzheimer's disease (AD but its physiological function is largely undetermined. APP has been found to regulate retrograde transport of nerve growth factor (NGF, which plays a crucial role in mediating neuronal survival and differentiation. Herein, we reveal the mechanism underlying APP-mediated NGF trafficking, by demonstrating a direct interaction between APP and the two NGF receptors, TrkA and p75NTR. Downregulation of APP leads to reduced cell surface levels of TrkA/p75NTR and increased endocytosis of TrkA/p75NTR and NGF. In addition, APP-deficient cells manifest defects in neurite outgrowth and are more susceptible to Aβ-induced neuronal death at physiological levels of NGF. However, APP-deficient cells show better responses to NGF-stimulated differentiation and survival than control cells. This may be attributed to increased receptor endocytosis and enhanced activation of Akt and MAPK upon NGF stimulation in APP-deficient cells. Together, our results suggest that APP mediates endocytosis of NGF receptors through direct interaction, thereby regulating endocytosis of NGF and NGF-induced downstream signaling pathways for neuronal survival and differentiation.

  11. Predicted 3D Model of the Rabies Virus Glycoprotein Trimer

    OpenAIRE

    Bastida-González Fernando; Celaya-Trejo Yersin; Correa-Basurto José; Zárate-Segura Paola

    2016-01-01

    The RABVG ectodomain is a homotrimer, and trimers are often called spikes. They are responsible for the attachment of the virus through the interaction with nicotinic acetylcholine receptors, neural cell adhesion molecule (NCAM), and the p75 neurotrophin receptor (p75NTR). This makes them relevant in viral pathogenesis. The antigenic structure differs significantly between the trimers and monomers. Surfaces rich in hydrophobic amino acids are important for trimer stabilization in which the C-...

  12. A HaloTag® method for assessing the retrograde axonal transport of the p75 neurotrophin receptor and other proteins in compartmented cultures of rat sympathetic neurons.

    Science.gov (United States)

    Mok, Sue-Ann; Lund, Karen; Lapointe, Paul; Campenot, Robert B

    2013-03-30

    We have adapted HaloTag® (HT) technology for use in compartmented cultures of rat sympathetic neurons in order to provide a technique that can be broadly applied to studies of the retrograde transport of molecules that play roles in neurotrophin signaling. Transfected neurons expressing HT protein alone, HT protein fused to the p75 neurotrophin receptor (p75NTR) or HT protein fused to tubulin α-1B were maintained in compartmented cultures in which cell bodies and proximal axons of rat sympathetic neurons reside in proximal compartments and their distal axons extend into distal compartments. HT ligand containing a fluorescent tetramethylrhodamine (TMR) label was applied either in the distal compartments or the proximal compartments, and the transport of labeled proteins was assayed by gel fluorescence imaging and TMR immunoblot. HT protein expressed alone displayed little or no retrograde transport. HT protein fused to either the intracellular C-terminus or the extracellular N-terminus of p75NTR was retrogradely transported. The retrograde transport of p75NTR was augmented when the distal axons were provided with nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) or antibodies to BDNF. The anterograde transport of HT protein fused to the N-terminus of tubulin α-1B was also demonstrated. We conclude that retrograde transport of HT fusion proteins provides a powerful and novel approach in studies of axonal transport. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. LINGO-1 Protein Interacts with the p75 Neurotrophin Receptor in Intracellular Membrane Compartments*

    Science.gov (United States)

    Meabon, James S.; De Laat, Rian; Ieguchi, Katsuaki; Wiley, Jesse C.; Hudson, Mark P.; Bothwell, Mark

    2015-01-01

    Axon outgrowth inhibition in response to trauma is thought to be mediated via the binding of myelin-associated inhibitory factors (e.g. Nogo-66, myelin-associated glycoprotein, oligodendrocyte myelin glycoprotein, and myelin basic protein) to a putative tripartite LINGO-1·p75NTR·Nogo-66 receptor (NgR) complex at the cell surface. We found that endogenous LINGO-1 expression in neurons in the cortex and cerebellum is intracellular. Mutation or truncation of the highly conserved LINGO-1 C terminus altered this intracellular localization, causing poor intracellular retention and increased plasma membrane expression. p75NTR associated predominantly with natively expressed LINGO-1 containing immature N-glycans, characteristic of protein that has not completed trans-Golgi-mediated processing, whereas mutant forms of LINGO-1 with enhanced plasma membrane expression did not associate with p75NTR. Co-immunoprecipitation experiments demonstrated that LINGO-1 and NgR competed for binding to p75NTR in a manner that is difficult to reconcile with the existence of a LINGO-1·p75NTR·NgR ternary complex. These findings contradict models postulating functional LINGO-1·p75NTR·NgR complexes in the plasma membrane. PMID:25666623

  14. New Aspects of the Pathogenesis of Canine Distemper Leukoencephalitis

    Directory of Open Access Journals (Sweden)

    Charlotte Lempp

    2014-07-01

    Full Text Available Canine distemper virus (CDV is a member of the genus morbillivirus, which is known to cause a variety of disorders in dogs including demyelinating leukoencephalitis (CDV-DL. In recent years, substantial progress in understanding the pathogenetic mechanisms of CDV-DL has been made. In vivo and in vitro investigations provided new insights into its pathogenesis with special emphasis on axon-myelin-glia interaction, potential endogenous mechanisms of regeneration, and astroglial plasticity. CDV-DL is characterized by lesions with a variable degree of demyelination and mononuclear inflammation accompanied by a dysregulated orchestration of cytokines as well as matrix metalloproteinases and their inhibitors. Despite decades of research, several new aspects of the neuropathogenesis of CDV-DL have been described only recently. Early axonal damage seems to represent an initial and progressive lesion in CDV-DL, which interestingly precedes demyelination. Axonopathy may, thus, function as a potential trigger for subsequent disturbed axon-myelin-glia interactions. In particular, the detection of early axonal damage suggests that demyelination is at least in part a secondary event in CDV-DL, thus challenging the dogma of CDV as a purely primary demyelinating disease. Another unexpected finding refers to the appearance of p75 neurotrophin (NTR-positive bipolar cells during CDV-DL. As p75NTR is a prototype marker for immature Schwann cells, this finding suggests that Schwann cell remyelination might represent a so far underestimated endogenous mechanism of regeneration, though this hypothesis still remains to be proven. Although it is well known that astrocytes represent the major target of CDV infection in CDV-DL, the detection of infected vimentin-positive astrocytes in chronic lesions indicates a crucial role of this cell population in nervous distemper. While glial fibrillary acidic protein represents the characteristic intermediate filament of mature

  15. Distribuição das celulas de Schwann na junção neuromuscular de camundongos distroficos da linhagem mdx

    OpenAIRE

    Candida Luiza Tonizza de Carvalho

    2003-01-01

    Resumo: O objetivo do presente trabalho foi verificar possíveis alterações no padrão de distribuição das células de Schwann nas junções neuromusculares de camundongos distróficos comparando-se com a distribuição observada em animais normais controle, desnervados ou não. Sabe-se que as células de Schwann induzem e guiam os brotamentos do terminal nervoso. Nos animais distróficos, os quais apresentam ausência de distrofina, bem como ciclos de degeneração-regeneração da fibra muscular, há aument...

  16. Expression of polysialylated neural cell adhesion molecules on adult stem cells after neuronal differentiation of inner ear spiral ganglion neurons

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyoung Ho [Department of Otolaryngology Head and Neck Surgery, College of Medicine, Catholic University, Seoul (Korea, Republic of); Yeo, Sang Won, E-mail: swyeo@catholic.ac.kr [Department of Otolaryngology Head and Neck Surgery, College of Medicine, Catholic University, Seoul (Korea, Republic of); Troy, Frederic A., E-mail: fatroy@ucdavis.edu [Department of Biochemistry and Molecular Medicine, University of California, School of Medicine, Davis, CA 95616 (United States); Xiamen University, School of Medicine, Xiamen City (China)

    2014-10-17

    Highlights: • PolySia expressed on neurons primarily during early stages of neuronal development. • PolySia–NCAM is expressed on neural stem cells from adult guinea pig spiral ganglion. • PolySia is a biomarker that modulates neuronal differentiation in inner ear stem cells. - Abstract: During brain development, polysialylated (polySia) neural cell adhesion molecules (polySia–NCAMs) modulate cell–cell adhesive interactions involved in synaptogenesis, neural plasticity, myelination, and neural stem cell (NSC) proliferation and differentiation. Our findings show that polySia–NCAM is expressed on NSC isolated from adult guinea pig spiral ganglion (GPSG), and in neurons and Schwann cells after differentiation of the NSC with epidermal, glia, fibroblast growth factors (GFs) and neurotrophins. These differentiated cells were immunoreactive with mAb’s to polySia, NCAM, β-III tubulin, nestin, S-100 and stained with BrdU. NSC could regenerate and be differentiated into neurons and Schwann cells. We conclude: (1) polySia is expressed on NSC isolated from adult GPSG and on neurons and Schwann cells differentiated from these NSC; (2) polySia is expressed on neurons primarily during the early stage of neuronal development and is expressed on Schwann cells at points of cell–cell contact; (3) polySia is a functional biomarker that modulates neuronal differentiation in inner ear stem cells. These new findings suggest that replacement of defective cells in the inner ear of hearing impaired patients using adult spiral ganglion neurons may offer potential hope to improve the quality of life for patients with auditory dysfunction and impaired hearing disorders.

  17. Unravelling crucial biomechanical resilience of myelinated peripheral nerve fibres provided by the Schwann cell basal lamina and PMP22

    Science.gov (United States)

    Rosso, Gonzalo; Liashkovich, Ivan; Gess, Burkhard; Young, Peter; Kun, Alejandra; Shahin, Victor

    2014-01-01

    There is an urgent need for the research of the close and enigmatic relationship between nerve biomechanics and the development of neuropathies. Here we present a research strategy based on the application atomic force and confocal microscopy for simultaneous nerve biomechanics and integrity investigations. Using wild-type and hereditary neuropathy mouse models, we reveal surprising mechanical protection of peripheral nerves. Myelinated peripheral wild-type fibres promptly and fully recover from acute enormous local mechanical compression while maintaining functional and structural integrity. The basal lamina which enwraps each myelinated fibre separately is identified as the major contributor to the striking fibre's resilience and integrity. In contrast, neuropathic fibres lacking the peripheral myelin protein 22 (PMP22), which is closely connected with several hereditary human neuropathies, fail to recover from light compression. Interestingly, the structural arrangement of the basal lamina of Pmp22−/− fibres is significantly altered compared to wild-type fibres. In conclusion, the basal lamina and PMP22 act in concert to contribute to a resilience and integrity of peripheral nerves at the single fibre level. Our findings and the presented technology set the stage for a comprehensive research of the links between nerve biomechanics and neuropathies. PMID:25446378

  18. Complement regulatory proteins (CD46, 55 and 59) expressed on Schwann cells: immune targets in demyelinating neuropathies?

    Science.gov (United States)

    Miyaji, Kazuki; Paul, Friedemann; Shahrizaila, Nortina; Umapathi, Thirugnanam; Yuki, Nobuhiro

    2014-11-15

    Given their localization and important role in regulating complement, complement regulatory proteins may act as target antigens and their antibodies as biomarkers in demyelinating neuropathies. We investigated the binding of autoantibodies to complement regulatory proteins (CD46, 55 and 59) in demyelinating diseases. In 42 acute inflammatory demyelinating polyneuropathy, 23 chronic inflammatory demyelinating polyneuropathy, 13 acute motor axonal neuropathy, 71 multiple sclerosis, and 19 neuromyelitis optica patients as well as 55 healthy controls, we were unable to detect significant titers of antibodies to CD46, CD55 and CD59. These autoantibodies are unlikely to be biomarkers in acute and chronic inflammatory demyelinating polyneuropathies. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Peripheral Nerve Injury: Stem Cell Therapy and Peripheral Nerve Transfer

    Directory of Open Access Journals (Sweden)

    Robert Sullivan

    2016-12-01

    Full Text Available Peripheral nerve injury can lead to great morbidity in those afflicted, ranging from sensory loss, motor loss, chronic pain, or a combination of deficits. Over time, research has investigated neuronal molecular mechanisms implicated in nerve damage, classified nerve injury, and developed surgical techniques for treatment. Despite these advancements, full functional recovery remains less than ideal. In this review, we discuss historical aspects of peripheral nerve injury and introduce nerve transfer as a therapeutic option, as well as an adjunct therapy to transplantation of Schwann cells and their stem cell derivatives for repair of the damaged nerve. This review furthermore, will provide an elaborated discussion on the sources of Schwann cells, including sites to harvest their progenitor and stem cell lines. This reflects the accessibility to an additional, concurrent treatment approach with nerve transfers that, predicated on related research, may increase the efficacy of the current approach. We then discuss the experimental and clinical investigations of both Schwann cells and nerve transfer that are underway. Lastly, we provide the necessary consideration that these two lines of therapeutic approaches should not be exclusive, but conversely, should be pursued as a combined modality given their mutual role in peripheral nerve regeneration.

  20. Peripheral Nerve Injury: Stem Cell Therapy and Peripheral Nerve Transfer.

    Science.gov (United States)

    Sullivan, Robert; Dailey, Travis; Duncan, Kelsey; Abel, Naomi; Borlongan, Cesario V

    2016-12-14

    Peripheral nerve injury can lead to great morbidity in those afflicted, ranging from sensory loss, motor loss, chronic pain, or a combination of deficits. Over time, research has investigated neuronal molecular mechanisms implicated in nerve damage, classified nerve injury, and developed surgical techniques for treatment. Despite these advancements, full functional recovery remains less than ideal. In this review, we discuss historical aspects of peripheral nerve injury and introduce nerve transfer as a therapeutic option, as well as an adjunct therapy to transplantation of Schwann cells and their stem cell derivatives for repair of the damaged nerve. This review furthermore, will provide an elaborated discussion on the sources of Schwann cells, including sites to harvest their progenitor and stem cell lines. This reflects the accessibility to an additional, concurrent treatment approach with nerve transfers that, predicated on related research, may increase the efficacy of the current approach. We then discuss the experimental and clinical investigations of both Schwann cells and nerve transfer that are underway. Lastly, we provide the necessary consideration that these two lines of therapeutic approaches should not be exclusive, but conversely, should be pursued as a combined modality given their mutual role in peripheral nerve regeneration.

  1. Combining Gene and Stem Cell Therapy for Peripheral Nerve Tissue Engineering.

    Science.gov (United States)

    Busuttil, Francesca; Rahim, Ahad A; Phillips, James B

    2017-02-15

    Despite a substantially increased understanding of neuropathophysiology, insufficient functional recovery after peripheral nerve injury remains a significant clinical challenge. Nerve regeneration following injury is dependent on Schwann cells, the supporting cells in the peripheral nervous system. Following nerve injury, Schwann cells adopt a proregenerative phenotype, which supports and guides regenerating nerves. However, this phenotype may not persist long enough to ensure functional recovery. Tissue-engineered nerve repair devices containing therapeutic cells that maintain the appropriate phenotype may help enhance nerve regeneration. The combination of gene and cell therapy is an emerging experimental strategy that seeks to provide the optimal environment for axonal regeneration and reestablishment of functional circuits. This review aims to summarize current preclinical evidence with potential for future translation from bench to bedside.

  2. An Injectable Method for Posterior Lateral Spine Fusion

    Science.gov (United States)

    2014-09-01

    29. Cosgaya JM, Chan JR, Shooter EM 2002 The neurotrophin receptor p75NTR as a positive modulator of myelination. Science 298(5596):1245-8. 30...inducible caspase 9 (icasp9M), which when activated will induce apoptosis within the transduced cells. Further, the hydrogel will also possess an...with CID Days * * * * * * * p<.05R LU s Figure 3: BMP2 activity in the presence and absence of CID. W20- 17 cells were exposed for 3 days with media

  3. Cell autonomy of the mouse claw paw mutation

    OpenAIRE

    Darbas, Aysel; Jaegle, Martine; Walbeehm, Erik; van den Burg, Hans; Driegen, Siska; Broos, Ludo; Uyl, Matthijs; Visser, Pim; Grosveld, Frank; Meijer, Dies

    2004-01-01

    textabstractMice homozygous for the autosomal recessive mutation claw paw (clp) are characterized by limb posture abnormalities and congenital hypomyelination, with delayed onset of myelination of the peripheral nervous system but not the central nervous system. Although this combination of limb and peripheral nerve abnormalities in clp/clp mice might suggest a common neurogenic origin of the syndrome, it is not clear whether the clp gene acts primarily in the neurone, the Schwann cell or bot...

  4. Non-viral gene therapy that targets motor neurons in vivo

    Directory of Open Access Journals (Sweden)

    Mary-Louise eRogers

    2014-10-01

    Full Text Available A major challenge in neurological gene therapy is safe delivery of transgenes to sufficient cell numbers from the circulation or periphery. This is particularly difficult for diseases involving spinal cord motor neurons such as amyotrophic lateral sclerosis (ALS. We have examined the feasibility of non-viral gene delivery to spinal motor neurons from intraperitoneal injections of plasmids carried by ‘immunogene’ nanoparticles targeted for axonal retrograde transport using antibodies. PEGylated polyethylenimine (PEI-PEG12 as DNA carrier was conjugated to an antibody (MLR2 to the neurotrophin receptor p75 (p75NTR. We used a plasmid (pVIVO2 designed for in vivo gene delivery that produces minimal immune responses, has improved nuclear entry into post mitotic cells and also expresses green fluorescent protein (GFP. MLR2-PEI-PEG12 carried pVIVO2 and was specific for mouse motor neurons in mixed cultures containing astrocytes. While only 8% of motor neurons expressed GFP 72 h post transfection in vitro, when the immunogene was given intraperitonealy to neonatal C57BL/6J mice GFP specific motor neuron expression was observed in 25.4% of lumbar, 18.3% of thoracic and 17.0 % of cervical motor neurons, 72 h post transfection. PEI-PEG12 carrying pVIVO2 by itself did not transfect motor neurons in vivo, demonstrating the need for specificity via the p75NTR antibody MLR2. This is the first time that specific transfection of spinal motor neurons has been achieved from peripheral delivery of plasmid DNA as part of a non-viral gene delivery agent. These results stress the specificity and feasibility of immunogene delivery targeted for p75NTR expressing motor neurons, but suggests that further improvements are required to increase the transfection efficiency of motor neurons in vivo.

  5. Safrole-2',3'-oxide induces atherosclerotic plaque vulnerability in apolipoprotein E-knockout mice.

    Science.gov (United States)

    Su, Le; Zhang, Haiyan; Zhao, Jing; Zhang, Shangli; Zhang, Yun; Zhao, Baoxiang; Miao, Junying

    2013-02-27

    Safrole-2',3'-oxide (SFO) is the major electrophilic metabolite of safrole (4-allyl-1, 2-methylenedioxybenzene), a natural plant constituent found in essential oils of numerous edible herbs and spices and in food containing these herbs, such as pesto sauce, cola beverages and bologna sausages. The effects of SFO in mammalian systems, especially the cardiovascular system, are little known. Disruption of vulnerable atherosclerotic plaques in atherosclerosis, a chronic inflammatory disease, is the main cause of cardiovascular events. In this study, we investigated SFO-induced atherosclerotic plaque vulnerability (possibility of rupture) in apolipoprotein E-knockout (apoE(-/-)) mice. Lipid area in vessel wall reached 59.8% in high dose SFO (SFO-HD) treated group, which is only 31.2% in control group. SFO treatment changed the lesion composition to an unstable phenotype, increased the number of apoptotic cells in plaque and the endothelium in plaques was damaged after SFO treatment. Furthermore, compared with control groups, the plaque endothelium level of p75(NTR) was 3-fold increased and the liver level of p75(NTR) was 17.4-fold increased by SFO-HD. Meanwhile, the serum level of KC (a functional homolog of IL-8 and the main proinflammatory alpha chemokine in mice) in apoE(-/-) mice was up to 357pg/ml in SFO-HD treated group. Thus, SFO contributes to the instability of atherosclerotic plaque in apoE(-/-) mice through activating p75(NTR) and IL-8 and cell apoptosis in plaque. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. O oxido nitrico na plasticidade das celulas de Schwann terminais e dos terminais nervosos da junção neuromuscular

    OpenAIRE

    Elaine Cristina Leite Pereira

    2005-01-01

    Resumo: Músculos distróficos apresentam alterações no complexo distrofinaglicoproteínas, bem como ausência da enzima óxido nítrico sintase neuronal, associada a alterações na estrutura da junção neuromuscular. No presente trabalho, estudamos as respostas dos terminais nervosos e das células de Schwann terminais após lesão nervosa, na ausência de óxido nítrico (NO). Nove dias após lesão nervosa por esmagamento, 24% das junções controle (n=200) apresentaram brotamentos ultraterminais. Na ausênc...

  7. Oxidative stress and neurodegenerative diseases: a neurotrophic approach.

    Science.gov (United States)

    Espinet, Carme; Gonzalo, Hugo; Fleitas, Catherine; Menal, Maria Jose; Egea, Joaquim

    2015-01-01

    Neurotrophins are important neurotrophic factors involved in the survival, differentiation and function of a wide variety of neuron populations. A common feature for most neurotrophins is that they are synthesized as precursor proteins (pro-neurotrophins) that upon being processed by proteolysis render the mature active form responsible for most of their trophic functions. However, some of the pro-neurotrophin form of these proteins, such as the precursor form of NGF (pro-NGF), have been shown to induce opposite effects and trigger apoptosis on neurons through the p75NTR receptor. This suggests that the balance between the levels of proneurotrophin and neurotrophin must be tightly controlled. In this context, it has been shown that in conditions of oxidative stress due for instance to aging or the development of some neurodegenerative disease, neurotrophins are oxidatively modified at least by advanced glycation/lipoxidation end products (AGE/ALEs) which makes pro-NGF refractary to be processed. The lack of maturation and the imbalance in favor of the precursor form may change the pattern of active signaling pathways towards cell death, thus exacerbating the deleterious alterations, for instance during the development of neurodegenerative diseases. Besides that, AGE/ALEs also induce the processing of the pro-NGF receptor p75NTR by α- secretase which is followed by the processing by γ -secretase and the release of the intracellular domain of p75NTR (p75NTRICD). Once cleaved, p75NTRICD recruits two intracellular interactors, NRIF and TRAF6, which allows NRIF phosphorylation by JNK. The phosphorylated form of NRIF then translocates to the nucleus and induces the expression of pro-apoptotic proteins. In this chapter we will summarize the mechanisms by which ROS- induce protein modifications, which proteins are susceptible to be modified, how these modifications affect function and signaling and, finally, how they can be related to neurodegenerative diseases.

  8. Induction of invasion in an organotypic oral cancer model by CoCl2, a hypoxia mimetic.

    Science.gov (United States)

    Brusevold, Ingvild J; Husvik, Camilla; Schreurs, Olav; Schenck, Karl; Bryne, Magne; Søland, Tine M

    2010-04-01

    Invasion is a hallmark of malignancy. The aim of this study was to develop an in vitro model that can be used for experimental studies of cancer cell invasion. The organotypic oral cancer model was constructed by growing oral squamous cell carcinoma (OSCC) cells on a collagen matrix in which normal human fibroblasts were incorporated. Immunohistochemical staining of the model showed that the expression of invasion-related molecules such as phosphorylated extracellular signal-regulated kinases 1 and 2 (p-ERK1/2), cyclooxygenase-2 (COX-2), p75(NTR), and hepatocyte growth factor receptor (Met) was similar to that seen in OSCC. Treatment of the model with cobalt chloride (CoCl(2)) to mimic hypoxic conditions increased cancer cell invasion, defined as the appearance of cancer cell islands protruding into the matrix. Models treated with CoCl(2) showed increased expression of p75(NTR) and laminin-5 in the cancer cells, and a more pronounced fragmentation of collagen IV in the basal membrane area, in contrast to models that were left untreated. The results indicate that the present model is well suited for studies on cancer cell invasion in the matrix and that the addition of CoCl(2) on day 3 of the experiment is indicated because it markedly increases the invasion and improves the model.

  9. Obtención, cultivo y caracterización de células de Schwann: un modelo de terapia celular

    Directory of Open Access Journals (Sweden)

    Clara Spinel

    2000-02-01

    Full Text Available

    Numerosos estudios han demostrado que las células de Schwann son importantes para la regeneración del sistema nervioso. Esta célula produce una serie de moléculas que favorecen el crecimiento de las fibras nerviosas. Estas moléculas pueden ser solubles como el NGF (Factor de crecimiento Nervioso, el LIF (Factor Inhibidor de la Leucemia, el BDNF (factor de crecimiento derivado del cerebro y otros factores de crecimiento o moléculas asociadas con la adhesión celular como N-CAM (Molécula de Adhesión Neuronal, L1 y a la matriz extracelular, especialmente a la lámina basal como el complejo proteoglicano-laminina. Estas características han permitido a los investigadores utilizar estas células para estimular la regeneración, tanto del sistema nervioso central (SNC como del sistema nervioso periférico (SNP.

    Dentro de la línea de investigación de regeneración y del sistema nervioso del Laboratorio de Neurociencias del Instituto Nacional de Salud, se han obtenido, cultivado y caracterizado células de Schwann de ratón, rata y humano adultos, con el fin de desarrollar prótesis celulares que podrían soportar la regeneración. En este trabajo se muestran resultados obtenidos en el proceso de obtención, cultivo y caracterización de estas células.

    La obtención, el cultivo y la caracterización se han realizado por diferentes metodologías. Para la obtención, hemos usado y estandarizado el cultivo a partir de dos fuentes de células, nervio periférico y ganglio tanto sensorial en el caso de ratón, como autonómico en el caso de células humanas. Estas técnicas nos han permitido obtener cultivos altamente enriquecidos en células de Schwann que en ratón alcanzan el 90%, en rata el 85% y en humano entre el 70

  10. Characterization of novel biomarkers in selecting for subtype specific medulloblastoma phenotypes.

    Science.gov (United States)

    Liang, Lisa; Aiken, Christopher; McClelland, Robyn; Morrison, Ludivine Coudière; Tatari, Nazanin; Remke, Marc; Ramaswamy, Vijay; Issaivanan, Magimairajan; Ryken, Timothy; Del Bigio, Marc R; Taylor, Michael D; Werbowetski-Ogilvie, Tamra E

    2015-11-17

    Major research efforts have focused on defining cell surface marker profiles for characterization and selection of brain tumor stem/progenitor cells. Medulloblastoma is the most common primary malignant pediatric brain cancer and consists of 4 molecular subgroups: WNT, SHH, Group 3 and Group 4. Given the heterogeneity within and between medulloblastoma variants, surface marker profiles may be subtype-specific. Here, we employed a high throughput flow cytometry screen to identify differentially expressed cell surface markers in self-renewing vs. non-self-renewing SHH medulloblastoma cells. The top 25 markers were reduced to 4, CD271/p75NTR/NGFR, CD106/VCAM1, EGFR and CD171/NCAM-L1, by evaluating transcript levels in SHH tumors relative to samples representing the other variants. However, only CD271/p75NTR/NGFR and CD171/NCAM-L1 maintain differential expression between variants at the protein level. Functional characterization of CD271, a low affinity neurotrophin receptor, in cell lines and primary cultures suggested that CD271 selects for lower self-renewing progenitors or stem cells. Moreover, CD271 levels were negatively correlated with expression of SHH pathway genes. Our study reveals a novel role for CD271 in SHH medulloblastoma and suggests that targeting CD271 pathways could lead to the design of more selective therapies that lessen the broad impact of current treatments on developing nervous systems.

  11. The discovery of oligodendroglia cells by Rio-Hortega: his original articles. 1921.

    Science.gov (United States)

    Iglesias-Rozas, José R; Garrosa, Manuel

    2012-01-01

    Comment on: del Río-Hortega P. Glia with very few processes (oligodendroglia). Clin Neuropathol. 2012; 31: 440-459, originally published in Archivos de Neurobiología. 1921; 2: 16-43 and del Río-Hortega P. Are the glia with very few processes homologous with Schwann cells? Clin Neuropathol. 2012; 31: 460-462, originally published in Bol de la Soc Esp de Biol. 1922; X: 25-28.

  12. A cell type-specific allele of the POU gene Oct-6 reveals Schwann cell autonomous function in nerve development and regeneration

    NARCIS (Netherlands)

    M. Ghazvini (Mehrnaz); W.J. Mandemakers (Wim); M.M. Jaegle (Martine); M. Piirsoo (Marko); M. Koutsourakis (Manousos); X. Smit (Xander); D.N. Meijer (Dies); M.J.F. Driegen (Siska); F.G. Grosveld (Frank)

    2002-01-01

    textabstractWhile an important role for the POU domain transcription factor Oct-6 in the developing peripheral nerve has been well established, studies into its exact role in nerve development and regeneration have been hampered by the high mortality rate of newborn Oct-6 mutant

  13. A cell type-specific allele of the POU gene Oct-6 reveals Schwann cell autonomous function in nerve development and regeneration.

    NARCIS (Netherlands)

    M. Ghazvini (Mehrnaz); W.J. Mandemakers (Wim); M.M. Jaegle (Martine); M. Piirsoo (Marko); M. Koutsourakis (Manousos); X. Smit (Xander); F.G. Grosveld (Frank); D.N. Meijer (Dies); M.J.F. Driegen (Siska)

    2002-01-01

    textabstractWhile an important role for the POU domain transcription factor Oct-6 in the developing peripheral nerve has been well established, studies into its exact role in nerve development and regeneration have been hampered by the high mortality rate of newborn Oct-6 mutant animals. In this

  14. Seizure-induced neuronal death is suppressed in the absence of the endogenous lectin Galectin-1.

    Science.gov (United States)

    Bischoff, Vincent; Deogracias, Rubén; Poirier, Françoise; Barde, Yves-Alain

    2012-10-31

    Pilocarpine injection induces epileptic seizures in rodents, an experimental paradigm extensively used to model temporal lobe epilepsy in humans. It includes conspicuous neuronal death in the forebrain and previous work has demonstrated an involvement of the neurotrophin receptor p75(NTR) in this process. Following the identification of Galectin-1 (Gal-1) as a downstream effector of p75(NTR), we examine here the role of this endogenous lectin in pilocarpine-induced cell death in adult mice. We found that most somatostatin-positive neurons also express Gal-1 and that in mice lacking the corresponding gene Lgals1, pilocarpine-induced neuronal death was essentially abolished in the forebrain. We also found that the related lectin Galectin-3 (Gal-3) was strongly upregulated by pilocarpine in microglial cells. This upregulation was absent in Lgals1 mutants and our results with Lgals3-null animals show that Gal-3 is not required for neuronal death in the hippocampus. These findings provide new insights into the roles and regulation of endogenous lectins in the adult CNS and a surprisingly selective proapoptotic role of Gal-1 for a subpopulation of GABAergic interneurons.

  15. Amine-functionalized polypyrrole: Inherently cell adhesive conducting polymer.

    Science.gov (United States)

    Lee, Jae Y; Schmidt, Christine E

    2015-06-01

    Electrically conducting polymers (CPs) have been recognized as novel biomaterials that can electrically communicate with biological systems. For their tissue engineering applications, CPs have been modified to promote cell adhesion for improved interactions between biomaterials and cells/tissues. Conventional approaches to improve cell adhesion involve the surface modification of CPs with biomolecules, such as physical adsorption of cell adhesive proteins and polycationic polymers, or their chemical immobilization; however, these approaches require additional multiple modification steps with expensive biomolecules. In this study, as a simple and effective alternative to such additional biomolecule treatment, we synthesized amine-functionalized polypyrrole (APPy) that inherently presents cell adhesion-supporting positive charges under physiological conditions. The synthesized APPy provides electrical activity in a moderate range and a hydrophilic surface compared to regular polypyrrole (PPy) homopolymers. Under both serum and serum-free conditions, APPy exhibited superior attachment of human dermal fibroblasts and Schwann cells compared to PPy homopolymer controls. Moreover, Schwann cell adhesion onto the APPy copolymer was at least similar to that on poly-l-lysine treated PPy controls. Our results indicate that amine-functionalized CP substrates will be useful to achieve good cell adhesion and potentially electrically stimulate various cells. In addition, amine functionality present on CPs can further serve as a novel and flexible platform to chemically tether various bioactive molecules, such as growth factors, antibodies, and chemical drugs. © 2014 Wiley Periodicals, Inc.

  16. The leucine-rich repeats of LINGO-1 are not required for self-interaction or interaction with the amyloid precursor protein.

    Science.gov (United States)

    Stein, Thomas; Walmsley, Adrian Robert

    2012-02-10

    LINGO-1 (leucine rich repeat and Ig domain containing Nogo receptor interacting protein-1) is a central nervous system transmembrane protein which simultaneously interacts with the Nogo-66 receptor and p75(NTR) or TROY on neurons to form a receptor complex responsible for myelin-mediated neurite outgrowth inhibition. On oligodendroglial cells, LINGO-1 interacts with p75(NTR) to constitutively inhibit multiple aspects of oligodendrocyte differentiation. Recently, LINGO-1 was identified as an in vivo interacting partner of the amyloid precursor protein (APP) and, correspondingly, cellular LINGO-1 expression was found to augment the release of the Abeta peptide, the potential causative agent of Alzheimer's disease. In addition, the recombinant LINGO-1 ectodomain has been shown to self-interact in solution and after crystallisation. Here, we have used deletional mutagenesis to identify the regions on LINGO-1 that are involved in homo- and heterotypic interactions. We have found that the N-terminal region containing the leucine-rich repeats along with the transmembrane and cytoplasmic domains of LINGO-1 are not required for self-interaction or interaction with APP. Copyright © 2012. Published by Elsevier Ireland Ltd.

  17. Promoting Nerve Regeneration in a Neurotmesis Rat Model Using Poly(DL-lactide-ε-caprolactone) Membranes and Mesenchymal Stem Cells from the Wharton's Jelly: In Vitro and In Vivo Analysis

    OpenAIRE

    Pereira, T.; Gärtner, A; Amorim, I; Almeida, A.; Caseiro, A.R.; Armada-da-Silva, Paulo A. S.; Sandra Amado; Federica Fregnan; Varejão, A. S. P.; Santos, J. D.; Bartolo, P. J.; Geuna, S; Luís, A. L.; Mauricio, A. C.

    2014-01-01

    In peripheral nerves MSCs can modulate Wallerian degeneration and the overall regenerative response by acting through paracrine mechanisms directly on regenerating axons or upon the nerve-supporting Schwann cells. In the present study, the effect of human MSCs from Wharton’s jelly (HMSCs), differentiated into neuroglial-like cells associated to poly (DL-lactide-ε-caprolactone) membrane, on nerve regeneration, was evaluated in the neurotmesis injury rat sciatic nerve model. Results in vitro sh...

  18. Benign gastrointestinal mesenchymal BUMPS: a brief review of some spindle cell polyps with published names.

    Science.gov (United States)

    Rittershaus, Ahren C; Appelman, Henry D

    2011-10-01

    There are several benign, predominantly spindle cell, mesenchymal proliferations involving the mucosa and/or submucosa in the gut, which present as polyps and pathologists see as polypectomy specimens. These include perineuriomas, Schwann cell nodules, ganglioneuromas, leiomyomas of the muscularis mucosae, inflammatory fibroid polyps, and granular cell tumors. To evaluate these mesenchymal polyps for their morphologic, immunohistochemical, ultrastructural, and molecular characteristics and to determine some of their associations. Personal observations based on years of analyzing endoscopic biopsies and a review of the world's literature. These polyps do surface every so often. There is significant literature covering inflammatory fibroid polyps and granular cell tumors, but there is little literature about the other entities.

  19. Cultivo purificado de células de Schwann provenientes de ganglios de la raíz dorsal de Ratón adulto

    Directory of Open Access Journals (Sweden)

    Spinel Clara M.

    2006-06-01

    Full Text Available Las células de Schwann (CS son la glía del sistema nervioso periférico. Se encargan de apoyar la función
    neuronal y ayudan a la conducción del impulso nervioso. Estas células juegan un papel muy importante en el
    crecimiento axonal, no solo durante el desarrollo embrional sino durante los procesos de regeneración nerviosa. Las CS secretan un gran número de factores que promueven la regeneración y esto las ha convertido en blanco para el diseño de prótesis artificiales. Para estos estudios es necesario establecer cultivos enriquecidos de CS los cuales son realizados en general a partir de nervios periféricos, sin embargo, ciertos estudios muestran a los ganglios de la raíz dorsal (GRD como una buena fuente para la obtención de estas células. En este estudio se estableció un protocolo para la obtención de CS a partir de GRD de ratones adultos. Mediante técnicas de descapsulación, disociación enzimática y disociación mecánica fue posible establecer cultivos de CS con una pureza del 98%. Los cultivos fueron realizados sobre plástico sin afectar esto la pureza de los mismos. Este protocolo permitió la obtención de grandes poblaciones de CS (3 x 106 células/animal en tan solo un mes. Estos resultados mejoran las perspectivas del uso de los GRD como fuente para la obtención de este tipo celular.

  20. Current state of stem cell-mediated therapies for facial nerve injury.

    Science.gov (United States)

    Wang, Tiffany V; Delaney, Sean; Pepper, Jon-Paul

    2016-08-01

    Interest in the application of stem cell therapy to nerve injury has grown exponentially in recent years, as the armamentarium of potential stem cell sources has increased. This article reviews literature on the recent developments in the application of stem cell therapy for facial nerve injury. Current stem cell therapy for the treatment of peripheral nerve injury can be generalized into those that either enhance native neural regeneration via an anti-inflammatory effect or growth factor secretion, replace Schwann cells, or replace motor neurons. Animal studies have shown that nerve conduits seeded with stem cells (either undifferentiated or differentiated into Schwann-like cells) in sciatic and facial nerve injury models can promote nerve regeneration with similar efficacy to autologous nerve autografts. In-vivo studies have also shown that induced pluripotent stem cell-derived motor neurons, when transplanted into transected mouse tibial nerves, can form functional neuromuscular junctions with the denervated mouse triceps surae. The authors believe that induced pluripotent stem cells have significant therapeutic potential. This source of human stem cells can be harvested with little morbidity, is isogenic to the donor, and has fewer ethical concerns compared with embryonic cellular sources. Further research is required to determine stem cell efficacy and safety. Questions of stem cell fate unpredictability and possible tumorigenesis must be addressed prior to human trials.

  1. Secretion of nerve growth factor, brain-derived neurotrophic factor, and glial cell-line derived neurotrophic factor in co-culture of four cell types in cerebrospinal fluid-containing medium.

    Science.gov (United States)

    Feng, Sanjiang; Zhuang, Minghua; Wu, Rui

    2012-12-25

    The present study co-cultured human embryonic olfactory ensheathing cells, human Schwann cells, human amniotic epithelial cells and human vascular endothelial cells in complete culture medium-containing cerebrospinal fluid. Enzyme linked immunosorbent assay was used to detect nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor secretion in the supernatant of co-cultured cells. Results showed that the number of all cell types reached a peak at 7-10 days, and the expression of nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor peaked at 9 days. Levels of secreted nerve growth factor were four-fold higher than brain-derived neurotrophic factor, which was three-fold higher than glial cell line-derived neurotrophic factor. Increasing concentrations of cerebrospinal fluid (10%, 20% and 30%) in the growth medium caused a decrease of neurotrophic factor secretion. Results indicated co-culture of human embryonic olfactory ensheathing cells, human Schwann cells, human amniotic epithelial cells and human vascular endothelial cells improved the expression of nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor. The reduction of cerebrospinal fluid extravasation at the transplant site after spinal cord injury is beneficial for the survival and secretion of neurotrophic factors from transplanted cells.

  2. Claudin k is specifically expressed in cells that form myelin during development of the nervous system and regeneration of the optic nerve in adult zebrafish.

    Science.gov (United States)

    Münzel, Eva Jolanda; Schaefer, Karin; Obirei, Barbara; Kremmer, Elisabeth; Burton, Edward A; Kuscha, Veronika; Becker, Catherina G; Brösamle, Christian; Williams, Anna; Becker, Thomas

    2012-02-01

    The zebrafish has become an important model organism to study myelination during development and after a lesion of the adult central nervous system (CNS). Here, we identify Claudin k as a myelin-associated protein in zebrafish and determine its localization during development and adult optic nerve regeneration. We find Claudin k in subcellular compartments consistent with location in autotypic tight junctions of oligodendrocytes and myelinating Schwann cells. Expression starts in the hindbrain at 2 days (mRNA) and 3 days (protein) postfertilization and is maintained in adults. A newly generated claudin k:green fluorescent protein (GFP) reporter line allowed us to characterize oligodendrocytes in the adult retina that express Claudin k and olig2, but not P0 and uniquely only form loose wraps of membrane around axons. After a crush of the adult optic nerve, Claudin k protein levels were first reduced and then recovered within 4 weeks postlesion, concomitant with optic nerve myelin de- and regeneration. During optic nerve regeneration, oligodendrocytes, many of which were newly generated, repopulated the lesion site and exhibited increasing morphological complexity over time. Thus, Claudin k is a novel myelin-associated protein expressed by oligodendrocytes and Schwann cells from early stages of wrapping and myelin formation in zebrafish development and adult regeneration, suggesting important functions of the gene for myelin formation and maintenance. Our Claudin k antibodies and claudin k:GFP reporter line represent excellent ways to visualize oligodendrocyte and Schwann cell differentiation in vivo. Copyright © 2011 Wiley Periodicals, Inc.

  3. Eukaryotic cells and their cell bodies: Cell Theory revised.

    Science.gov (United States)

    Baluska, Frantisek; Volkmann, Dieter; Barlow, Peter W

    2004-07-01

    Cell Theory, also known as cell doctrine, states that all eukaryotic organisms are composed of cells, and that cells are the smallest independent units of life. This Cell Theory has been influential in shaping the biological sciences ever since, in 1838/1839, the botanist Matthias Schleiden and the zoologist Theodore Schwann stated the principle that cells represent the elements from which all plant and animal tissues are constructed. Some 20 years later, in a famous aphorism Omnis cellula e cellula, Rudolf Virchow annunciated that all cells arise only from pre-existing cells. General acceptance of Cell Theory was finally possible only when the cellular nature of brain tissues was confirmed at the end of the 20th century. Cell Theory then rapidly turned into a more dogmatic cell doctrine, and in this form survives up to the present day. In its current version, however, the generalized Cell Theory developed for both animals and plants is unable to accommodate the supracellular nature of higher plants, which is founded upon a super-symplasm of interconnected cells into which is woven apoplasm, symplasm and super-apoplasm. Furthermore, there are numerous examples of multinucleate coenocytes and syncytia found throughout the eukaryote superkingdom posing serious problems for the current version of Cell Theory. To cope with these problems, we here review data which conform to the original proposal of Daniel Mazia that the eukaryotic cell is composed of an elemental Cell Body whose structure is smaller than the cell and which is endowed with all the basic attributes of a living entity. A complement to the Cell Body is the Cell Periphery Apparatus, which consists of the plasma membrane associated with other periphery structures. Importantly, boundary structures of the Cell Periphery Apparatus, although capable of some self-assembly, are largely produced and maintained by Cell Body activities and can be produced from it de novo. These boundary structures serve not only as

  4. Dynamics of degeneration and regeneration in developing zebrafish peripheral axons reveals a requirement for extrinsic cell types

    Directory of Open Access Journals (Sweden)

    Villegas Rosario

    2012-06-01

    Full Text Available Abstract Background Understanding the cellular mechanisms regulating axon degeneration and regeneration is crucial for developing treatments for nerve injury and neurodegenerative disease. In neurons, axon degeneration is distinct from cell body death and often precedes or is associated with the onset of disease symptoms. In the peripheral nervous system of both vertebrates and invertebrates, after degeneration of detached fragments, axons can often regenerate to restore function. Many studies of axonal degeneration and regeneration have used in vitro approaches, but the influence of extrinsic cell types on these processes can only be fully addressed in live animals. Because of its simplicity and superficial location, the larval zebrafish posterior lateral line (pLL nerve is an ideal model system for live studies of axon degeneration and regeneration. Results We used laser axotomy and time-lapse imaging of pLL axons to characterize the roles of leukocytes, Schwann cells and target sensory hair cells in axon degeneration and regeneration in vivo. Immune cells were essential for efficient removal of axonal debris after axotomy. Schwann cells were required for proper fasciculation and pathfinding of regenerating axons to their target cells. Intact target hair cells were not themselves required for regeneration, but chemical ablation of neuromasts caused axons to transiently deviate from their normal paths. Conclusions Macrophages, Schwann cells, and target sensory organs are required for distinct aspects of pLL axon degeneration or regeneration in the zebrafish larva. Our work introduces a powerful vertebrate model for analyzing axonal degeneration and regeneration in the living animal and elucidating the role of extrinsic cell types in these processes.

  5. Systemic administration of erythropoietin inhibits retinopathy in RCS rats.

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    Weiyong Shen

    Full Text Available OBJECTIVE: Royal College of Surgeons (RCS rats develop vasculopathy as photoreceptors degenerate. The aim of this study was to examine the effect of erythropoietin (EPO on retinopathy in RCS rats. METHODS: Fluorescein angiography was used to monitor retinal vascular changes over time. Changes in retinal glia and vasculature were studied by immunostaining. To study the effects of EPO on retinal pathology, EPO (5000 IU/kg was injected intraperitoneally in 14 week old normal and RCS rats twice a week for 4 weeks. Changes in the retinal vasculature, glia and microglia, photoreceptor apoptosis, differential expression of p75 neurotrophin receptor (p75NTR, pro-neurotrophin 3 (pro-NT3, tumour necrosis factor-α (TNFα, pigment epithelium derived factor (PEDF and vascular endothelial growth factor-A (VEGF-A, the production of CD34(+ cells and mobilization of CD34(+/VEGF-R2(+ cells as well as recruitment of CD34(+ cells into the retina were examined after EPO treatment. RESULTS: RCS rats developed progressive capillary dropout and subretinal neovascularization which were accompanied by retinal gliosis. Systemic administration of EPO stabilized the retinal vasculature and inhibited the development of focal vascular lesions. Further studies showed that EPO modulated retinal gliosis, attenuated photoreceptor apoptosis and p75NTR and pro-NT3 upregulation, promoted the infiltration of ramified microglia and stimulated VEGF-A expression but had little effect on TNFα and PEDF expression. EPO stimulated the production of red and white blood cells and CD34(+ cells along with effective mobilization of CD34(+/VEGF-R2(+ cells. Immunofluorescence study demonstrated that EPO enhanced the recruitment of CD34+ cells into the retina. CONCLUSIONS: Our results suggest that EPO has therapeutic potentials in treatment of neuronal and vascular pathology in retinal disease. The protective effects of EPO on photoreceptors and the retinal vasculature may involve multiple

  6. Diabetes and overexpression of proNGF cause retinal neurodegeneration via activation of RhoA pathway.

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    Mohammed M H Al-Gayyar

    Full Text Available Our previous studies showed positive correlation between accumulation of proNGF, activation of RhoA and neuronal death in diabetic models. Here, we examined the neuroprotective effects of selective inhibition of RhoA kinase in the diabetic rat retina and in a model that stably overexpressed the cleavage-resistance proNGF plasmid in the retina. Male Sprague-Dawley rats were rendered diabetic using streptozotocin or stably express cleavage-resistant proNGF plasmid. The neuroprotective effects of the intravitreal injection of RhoA kinase inhibitor Y27632 were examined in vivo. Effects of proNGF were examined in freshly isolated primary retinal ganglion cell (RGC cultures and RGC-5 cell line. Retinal neurodegeneration was assessed by counting TUNEL-positive and Brn-3a positive retinal ganglion cells. Expression of proNGF, p75(NTR, cleaved-PARP, caspase-3 and p38MAPK/JNK were examined by Western-blot. Activation of RhoA was assessed by pull-down assay and G-LISA. Diabetes and overexpression of proNGF resulted in retinal neurodegeneration as indicated by 9- and 6-fold increase in TUNEL-positive cells, respectively. In vitro, proNGF induced 5-fold cell death in RGC-5 cell line, and it induced >10-fold cell death in primary RGC cultures. These effects were associated with significant upregulation of p75(NTR and activation of RhoA. While proNGF induced TNF-α expression in vivo, it selectively activated RhoA in primary RGC cultures and RGC-5 cell line. Inhibiting RhoA kinase with Y27632 significantly reduced diabetes- and proNGF-induced activation of proapoptotic p38MAPK/JNK, expression of cleaved-PARP and caspase-3 and prevented retinal neurodegeneration in vivo and in vitro. Taken together, these results provide compelling evidence for a causal role of proNGF in diabetes-induced retinal neurodegeneration through enhancing p75(NTR expression and direct activation of RhoA and p38MAPK/JNK apoptotic pathways.

  7. A Role for the p75 Neurotrophin Receptor in Axonal Degeneration and Apoptosis Induced by Oxidative Stress*

    Science.gov (United States)

    Kraemer, Bradley R.; Snow, John P.; Vollbrecht, Peter; Pathak, Amrita; Valentine, William M.; Deutch, Ariel Y.; Carter, Bruce D.

    2014-01-01

    The p75 neurotrophin receptor (p75NTR) mediates the death of specific populations of neurons during the development of the nervous system or after cellular injury. The receptor has also been implicated as a contributor to neurodegeneration caused by numerous pathological conditions. Because many of these conditions are associated with increases in reactive oxygen species, we investigated whether p75NTR has a role in neurodegeneration in response to oxidative stress. Here we demonstrate that p75NTR signaling is activated by 4-hydroxynonenal (HNE), a lipid peroxidation product generated naturally during oxidative stress. Exposure of sympathetic neurons to HNE resulted in neurite degeneration and apoptosis. However, these effects were reduced markedly in neurons from p75NTR−/− mice. The neurodegenerative effects of HNE were not associated with production of neurotrophins and were unaffected by pretreatment with a receptor-blocking antibody, suggesting that oxidative stress activates p75NTR via a ligand-independent mechanism. Previous studies have established that proteolysis of p75NTR by the metalloprotease TNFα-converting enzyme and γ-secretase is necessary for p75NTR-mediated apoptotic signaling. Exposure of sympathetic neurons to HNE resulted in metalloprotease- and γ-secretase-dependent cleavage of p75NTR. Pharmacological blockade of p75NTR proteolysis protected sympathetic neurons from HNE-induced neurite degeneration and apoptosis, suggesting that cleavage of p75NTR is necessary for oxidant-induced neurodegeneration. In vivo, p75NTR−/− mice exhibited resistance to axonal degeneration associated with oxidative injury following administration of the neurotoxin 6-hydroxydopamine. Together, these data suggest a novel mechanism linking oxidative stress to ligand-independent cleavage of p75NTR, resulting in axonal fragmentation and neuronal death. PMID:24939843

  8. Dual mTORC1/2 inhibition induces anti-proliferative effect in NF1-associated plexiform neurofibroma and malignant peripheral nerve sheath tumor cells

    Science.gov (United States)

    Hivelin, Mikael; Nusbaum, Patrick; Hubas, Arnaud; Laurendeau, Ingrid; Lantieri, Laurent; Wolkenstein, Pierre; Vidaud, Michel; Pasmant, Eric; Chapuis, Nicolas; Parfait, Béatrice

    2016-01-01

    Approximately 30-50% of individuals with Neurofibromatosis type 1 develop benign peripheral nerve sheath tumors, called plexiform neurofibromas (PNFs). PNFs can undergo malignant transformation to highly metastatic malignant peripheral nerve sheath tumors (MPNSTs) in 5-10% of NF1 patients, with poor prognosis. No effective systemic therapy is currently available for unresectable tumors. In tumors, the NF1 gene deficiency leads to Ras hyperactivation causing the subsequent activation of the AKT/mTOR and Raf/MEK/ERK pathways and inducing multiple cellular responses including cell proliferation. In this study, three NF1-null MPNST-derived cell lines (90-8, 88-14 and 96-2), STS26T sporadic MPNST cell line and PNF-derived primary Schwann cells were used to test responses to AZD8055, an ATP-competitive “active-site” mTOR inhibitor. In contrast to rapamycin treatment which only partially affected mTORC1 signaling, AZD8055 induced a strong inhibition of mTORC1 and mTORC2 signaling in MPNST-derived cell lines and PNF-derived Schwann cells. AZD8055 induced full blockade of mTORC1 leading to an efficient decrease of global protein synthesis. A higher cytotoxic effect was observed with AZD8055 compared to rapamycin in the NF1-null MPNST-derived cell lines with IC50 ranging from 70 to 140 nM and antiproliferative effect was confirmed in PNF-derived Schwann cells. Cell migration was impaired by AZD8055 treatment and cell cycle analysis showed a G0/G1 arrest. Combined effects of AZD8055 and PD0325901 MEK inhibitor as well as BRD4 (BromoDomain-containing protein 4) inhibitors showed a synergistic antiproliferative effect. These data suggest that NF1-associated peripheral nerve sheath tumors are an ideal target for AZD8055 as a single molecule or in combined therapies. PMID:26840085

  9. Conditional beta1-integrin gene deletion in neural crest cells causes severe developmental alterations of the peripheral nervous system

    DEFF Research Database (Denmark)

    Pietri, Thomas; Eder, Olivier; Breau, Marie Anne

    2004-01-01

    Integrins are transmembrane receptors that are known to interact with the extracellular matrix and to be required for migration, proliferation, differentiation and apoptosis. We have generated mice with a neural crest cell-specific deletion of the beta1-integrin gene to analyse the role of beta1-....... There was an almost complete absence of Schwann cells and sensory axon segregation and defective maturation in neuromuscular synaptogenesis. Thus, beta1-integrins are important for the control of embryonic and postnatal peripheral nervous system development....

  10. Stereological quantification of immune-competent cells in baseline biopsy specimens from achilles tendons

    DEFF Research Database (Denmark)

    Kragsnaes, Maja Skov; Fredberg, Ulrich; Stribolt, Katrine

    2014-01-01

    BACKGROUND: Limited data exist on the presence and function of immune-competent cells in chronic tendinopathic tendons and their potential role in inflammation and tissue healing as well as in predicting long-term outcome. PURPOSE: To quantify subtypes of immune-competent cells in biopsy specimens...... immunohistochemically by quantifying the presence of macrophages (CD68-PGM1(+), CD68-KP1(+)), hemosiderophages (Perls blue), T lymphocytes (CD2(+), CD3(+), CD4(+), CD7(+), CD8(+)), B lymphocytes (CD20(+)), natural killer cells (CD56(+)), mast cells (NaSDCl(+)), Schwann cells (S100(+)), and endothelial cells (CD34......(+)) using a stereological technique. A follow-up examination was conducted more than 4 years (range, 4-9 years) after the biopsy procedure to evaluate the long-term presence of Achilles tendon symptoms. RESULTS: Macrophages, T lymphocytes, mast cells, and natural killer cells were observed in the majority...

  11. Mesenchymal Stem Cell-Like Cells Derived from Mouse Induced Pluripotent Stem Cells Ameliorate Diabetic Polyneuropathy in Mice

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    Tatsuhito Himeno

    2013-01-01

    Full Text Available Background. Although pathological involvements of diabetic polyneuropathy (DPN have been reported, no dependable treatment of DPN has been achieved. Recent studies have shown that mesenchymal stem cells (MSCs ameliorate DPN. Here we demonstrate a differentiation of induced pluripotent stem cells (iPSCs into MSC-like cells and investigate the therapeutic potential of the MSC-like cell transplantation on DPN. Research Design and Methods. For induction into MSC-like cells, GFP-expressing iPSCs were cultured with retinoic acid, followed by adherent culture for 4 months. The MSC-like cells, characterized with flow cytometry and RT-PCR analyses, were transplanted into muscles of streptozotocin-diabetic mice. Three weeks after the transplantation, neurophysiological functions were evaluated. Results. The MSC-like cells expressed MSC markers and angiogenic/neurotrophic factors. The transplanted cells resided in hindlimb muscles and peripheral nerves, and some transplanted cells expressed S100β in the nerves. Impairments of current perception thresholds, nerve conduction velocities, and plantar skin blood flow in the diabetic mice were ameliorated in limbs with the transplanted cells. The capillary number-to-muscle fiber ratios were increased in transplanted hindlimbs of diabetic mice. Conclusions. These results suggest that MSC-like cell transplantation might have therapeutic effects on DPN through secreting angiogenic/neurotrophic factors and differentiation to Schwann cell-like cells.

  12. Death Receptors in the Selective Degeneration of Motoneurons in Amyotrophic Lateral Sclerosis

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    Julianne Aebischer

    2013-01-01

    Full Text Available While studies on death receptors have long been restricted to immune cells, the last decade has provided a strong body of evidence for their implication in neuronal death and hence neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS. ALS is a fatal paralytic disorder that primarily affects motoneurons in the brain and spinal cord. A neuroinflammatory process, associated with astrocyte and microglial activation as well as infiltration of immune cells, accompanies motoneuron degeneration and supports the contribution of non-cell-autonomous mechanisms in the disease. Hallmarks of Fas, TNFR, LT-βR, and p75NTR signaling have been observed in both animal models and ALS patients. This review summarizes to date knowledge of the role of death receptors in ALS and the link existing between the selective loss of motoneurons and neuroinflammation. It further suggests how this recent evidence could be included in an ultimate multiapproach to treat patients.

  13. Human umbilical cord mesenchymal stem cells promote peripheral nerve repair via paracrine mechanisms

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    Zhi-yuan Guo

    2015-01-01

    Full Text Available Human umbilical cord-derived mesenchymal stem cells (hUCMSCs represent a promising young-state stem cell source for cell-based therapy. hUCMSC transplantation into the transected sciatic nerve promotes axonal regeneration and functional recovery. To further clarify the paracrine effects of hUCMSCs on nerve regeneration, we performed human cytokine antibody array analysis, which revealed that hUCMSCs express 14 important neurotrophic factors. Enzyme-linked immunosorbent assay and immunohistochemistry showed that brain-derived neurotrophic factor, glial-derived neurotrophic factor, hepatocyte growth factor, neurotrophin-3, basic fibroblast growth factor, type I collagen, fibronectin and laminin were highly expressed. Treatment with hUCMSC-conditioned medium enhanced Schwann cell viability and proliferation, increased nerve growth factor and brain-derived neurotrophic factor expression in Schwann cells, and enhanced neurite growth from dorsal root ganglion explants. These findings suggest that paracrine action may be a key mechanism underlying the effects of hUCMSCs in peripheral nerve repair.

  14. HLA-DR-expressing cells and T-lymphocytes in sural nerve biopsies

    DEFF Research Database (Denmark)

    Schrøder, H D; Olsson, T; Solders, G

    1988-01-01

    was confirmed. HLA-DR expression was found in all biopsies and thus was not restricted to any particular type of neuropathy. The HLA-DR expression appeared to correlate with severity and activity of the neuropathy. HLA-DR-expressing macrophages wrapping myelinated fibers were prominent in primary demyelinating......Thirty-five sural nerve biopsies were stained immunohistochemically for HLA-DR antigen. HLA-DR was expressed on nonmyelinating Schwann cells, macrophages, vascular endothelium, and perineurium. By means of double immunofluorescence staining the identity of the HLA-DR presenting structures...

  15. Effects of sciatic-conditioned medium on neonatal rat retinal cells in vitro

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    Torres P.M.M.

    1998-01-01

    Full Text Available Schwann cells produce and release trophic factors that induce the regeneration and survival of neurons following lesions in the peripheral nerves. In the present study we examined the in vitro ability of developing rat retinal cells to respond to factors released from fragments of sciatic nerve. Treatment of neonatal rat retinal cells with sciatic-conditioned medium (SCM for 48 h induced an increase of 92.5 ± 8.8% (N = 7 for each group in the amount of total protein. SCM increased cell adhesion, neuronal survival and glial cell proliferation as evaluated by morphological criteria. This effect was completely blocked by 2.5 µM chelerythrine chloride, an inhibitor of protein kinase C (PKC. These data indicate that PKC activation is involved in the effect of SCM on retinal cells and demonstrate that fragments of sciatic nerve release trophic factors having a remarkable effect on neonatal rat retinal cells in culture.

  16. In vivo introduction of transgenes into mouse sciatic nerve cells in situ using viral vectors.

    Science.gov (United States)

    Gonzalez, Sergio; Fernando, Ruani N; Perrin-Tricaud, Claire; Tricaud, Nicolas

    2014-05-01

    The myelin sheath is essential for the rapid and efficient propagation of action potentials. However, our understanding of the basic molecular mechanisms that regulate myelination, demyelination and remyelination is limited. Schwann cells produce myelin in the peripheral nervous system and remain associated with the axons of peripheral neurons throughout axonal migration to the target. Owing to the intimate relationship between these cell types it is difficult to fully reproduce their function in vitro. For this reason, we developed an approach based on the injection of an engineered virus into the sciatic nerve of mice to locally transduce peripheral nerve cells. This approach can be used as an alternative to germline transgenesis to facilitate the investigation of peripheral nerve biology in vivo. The detailed protocol, described here, requires 3 weeks to complete. In comparison with genetic modification strategies, this protocol is a fast, reproducible and straightforward method for introducing exogenous factors into myelinating Schwann cells and myelinated axons in vivo to investigate specific molecular mechanisms.

  17. Inhibitory effects of brain-derived neurotrophic factor precursor on viability and neurite growth of murine hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Jia CHEN

    2014-10-01

    Full Text Available Objective To explore the mediation effect of p75 neurotrophin receptor (p75NTR in the effect of brainderived neurotrophic factor precursor (proBDNF on viability and neurite growth of murine hippocampal neurons. Methods  Hippocampal neurons were obtained from p75NTR+/+ and p75NTR-/- 18-day mice and primarily cultured. For p75NTR+/+ neurons, three experimental groups were set, i.e. control, proBDNF (30ng/ml, and proBDNF (30ng/ml+p75/Fc (30µg/ml groups. For p75NTR-/- neurons, two experimental groups were set, i.e. control and proBDNF (30ng/ml groups. MTT assays were performed after 24h to examine the viability of neonatal primary neurons. Immunofluorescent staining was conducted after 72h to investigate the neurite length. Results With MAP2 and DAPI double fluorescent staining it was identified that the neonatal hippocampal neurons were successfully cultured in vitro with high purity. For viability assay of p75NTR+/+ neurons, it was found that the absorbance value at 570nm (A570 in proBDNF group was significantly lower than that in control group (P0.05. With neurite growth assay of p75NTR+/+ neurons, it was found that the neurite length in proBDNF group was significantly shorter than that in control group (P0.05. With neurite growth assay of p75NTR-/- neurons, no difference in neurite length was observed between proBDNF group and control group. Conclusion proBDNF may inhibit the neuronal viability and neurite growth via p75NTR. DOI: 10.11855/j.issn.0577-7402.2014.09.03

  18. Mechanotransduction in epidermal Merkel cells.

    Science.gov (United States)

    Nakatani, Masashi; Maksimovic, Srdjan; Baba, Yoshichika; Lumpkin, Ellen A

    2015-01-01

    The cellular and molecular basis of vertebrate touch reception remains least understood among the traditional five senses. Somatosensory afferents that innervate the skin encode distinct tactile qualities, such as flutter, slip, and pressure. Gentle touch is thought to be transduced by somatosensory afferents whose tactile end organs selectively filter mechanical stimuli. These tactile end organs comprise afferent terminals in association with non-neuronal cell types such as Merkel cells, keratinocytes, and Schwann cells. An open question is whether these non-neuronal cells serve primarily as passive mechanical filters or whether they actively participate in mechanosensory transduction. This question has been most extensively studied in Merkel cells, which are epidermal cells that complex with sensory afferents in regions of high tactile acuity such as fingertips, whisker follicles, and touch domes. Merkel cell-neurite complexes mediate slowly adapting type I (SAI) responses, which encode sustained pressure and represent object features with high fidelity. How Merkel cells contribute to unique SAI firing patterns has been debated for decades; however, three recent studies in rodent models provide some direct answers. First, whole-cell recordings demonstrate that Merkel cells are touch-sensitive cells with fast, mechanically activated currents that require Piezo2. Second, optogenetics and intact recordings show that Merkel cells mediate sustained SAI firing. Finally, loss-of-function studies in transgenic mouse models reveal that SAI afferents are also touch sensitive. Together, these studies identify molecular mechanisms of mechanotransduction in Merkel cells, reveal unexpected functions for these cells in touch, and support a revised, two-receptor site model of mechanosensory transduction.

  19. The Possible Roles of the Dentate Granule Cell’s Leptin and Other Ciliary Receptors in Alzheimer’s Neuropathology

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    James F. Whitfield

    2015-07-01

    Full Text Available Dentate-gyral granule cells in the hippocampus plus dentate gyrus memory-recording/retrieving machine, unlike most other neurons in the brain, are continuously being generated in the adult brain with the important task of separating overlapping patterns of data streaming in from the outside world via the entorhinal cortex. This “adult neurogenesis” is driven by tools in the mature granule cell’s cilium. Here we report our discovery of leptin’s LepRb receptor in this cilium. In addition, we discuss how ciliary LepRb signaling might be involved with ciliary p75NTR and SSTR3 receptors in adult neurogenesis and memory formation as well as attenuation of Alzheimer’s neuropathology by reducing the production of its toxic amyloid-β-derived drivers.

  20. Segmental neurofibromatosis follows blaschko's lines or dermatomes depending on the cell line affected: case report and literature review.

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    Redlick, Fara P; Shaw, James C

    2004-01-01

    Segmental neurofibromatosis type 1 (NF-1) has the characteristic features of generalized NF-1 but is isolated to a particular segment of the body. Segmental NF-1 results from a postzygotic mutation during embryogenesis in the NF-1 gene on chromosome 17. The embryologic timing of the mutation and cell types affected predict the clinical phenotype. We present a case of a 52-year-old woman with segmental neurofibromas isolated to the right cheek and neck. We review the recent literature on the genetic and cellular differences between the various clinical manifestations of segmental NF-1. A MEDLINE search for cases of segmental neurofibromatosis was conducted. In patients with segmental NF-1 presenting as neurofibromas-only, the distribution follows a neural distribution in dermatomes because the genetic mutation appears to be limited to Schwann cells. In patients with pigmentary changes only, the NF-1 mutation has been shown to occur in fibroblasts and the distribution tends to follow the lines of Blaschko. Our patient's neurofibromas were secondary to a postzygotic mutation in the NF-1 gene of neural crest-derived cells. This mutation most likely occurred later in embryogenesis in cells that had already differentiated to Schwann cells and were committed to the dermatomal distribution of the right neck and cheek region (C2).

  1. LDL receptor-related protein-1 is a sialic-acid-independent receptor for myelin-associated glycoprotein that functions in neurite outgrowth inhibition by MAG and CNS myelin.

    Science.gov (United States)

    Stiles, Travis L; Dickendesher, Travis L; Gaultier, Alban; Fernandez-Castaneda, Anthony; Mantuano, Elisabetta; Giger, Roman J; Gonias, Steven L

    2013-01-01

    In the injured adult mammalian central nervous system (CNS), products are generated that inhibit neuronal sprouting and regeneration. In recent years, most attention has focused on the myelin-associated inhibitory proteins (MAIs) Nogo-A, OMgp, and myelin-associated glycoprotein (MAG). Binding of MAIs to neuronal cell-surface receptors leads to activation of RhoA, growth cone collapse, and neurite outgrowth inhibition. In the present study, we identify low-density lipoprotein (LDL) receptor-related protein-1 (LRP1) as a high-affinity, endocytic receptor for MAG. In contrast with previously identified MAG receptors, binding of MAG to LRP1 occurs independently of terminal sialic acids. In primary neurons, functional inactivation of LRP1 with receptor-associated protein, depletion by RNA interference (RNAi) knock-down, or LRP1 gene deletion is sufficient to significantly reverse MAG and myelin-mediated inhibition of neurite outgrowth. Similar results are observed when LRP1 is antagonized in PC12 and N2a cells. By contrast, inhibiting LRP1 does not attenuate inhibition of neurite outgrowth caused by chondroitin sulfate proteoglycans. Mechanistic studies in N2a cells showed that LRP1 and p75NTR associate in a MAG-dependent manner and that MAG-mediated activation of RhoA may involve both LRP1 and p75NTR. LRP1 derivatives that include the complement-like repeat clusters CII and CIV bind MAG and other MAIs. When CII and CIV were expressed as Fc-fusion proteins, these proteins, purified full-length LRP1 and shed LRP1 all attenuated the inhibition of neurite outgrowth caused by MAG and CNS myelin in primary neurons. Collectively, our studies identify LRP1 as a novel MAG receptor that functions in neurite outgrowth inhibition.

  2. High-plasticity mesenchymal stem cells isolated from adult-retained primary teeth and autogenous adult tooth pulp--A potential source for regenerative therapies?

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    Kushnerev, E; Shawcross, S G; Hillarby, M C; Yates, J M

    2016-02-01

    The objective of this study was to compare the growth rate, morphology, immunohistology and plasticity of autogenous adult-retained SHEDs (arSHEDs) and adult dental pulp stem cells (DPSCs) obtained from the same donor. Expression of the mesenchymal stem cell markers CD44, CD90, CD105, caspase-3 and GAPDH were assessed using RT-PCR. Caspase-3 and CD44 were also evaluated at the protein level by western blotting of cell lysates. Plasticity of DPSCs and arSHEDs were tested by culture in adipogenic, chondrogenic, osteogenic and Schwann cells induction media. DPSCs and arSHEDs were isolated by explant culturing and were similarly positive for growth rate and all tested markers. Furthermore, DPSCs and arSHEDs could be driven to adipocyte, chondrocyte, osteocyte and Schwann cells lineages thus indicating similar plasticity as precursor cells. This study demonstrates the similarities between DPSCs and arSHEDs in a unique situation, where both stem cells (SC) types were obtained from a single patient and thus represent an alternative source of SC's for tissue engineering and regeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. A Single-Cell Transcriptomic Map of the Human and Mouse Pancreas Reveals Inter- and Intra-cell Population Structure.

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    Baron, Maayan; Veres, Adrian; Wolock, Samuel L; Faust, Aubrey L; Gaujoux, Renaud; Vetere, Amedeo; Ryu, Jennifer Hyoje; Wagner, Bridget K; Shen-Orr, Shai S; Klein, Allon M; Melton, Douglas A; Yanai, Itai

    2016-10-26

    Although the function of the mammalian pancreas hinges on complex interactions of distinct cell types, gene expression profiles have primarily been described with bulk mixtures. Here we implemented a droplet-based, single-cell RNA-seq method to determine the transcriptomes of over 12,000 individual pancreatic cells from four human donors and two mouse strains. Cells could be divided into 15 clusters that matched previously characterized cell types: all endocrine cell types, including rare epsilon-cells; exocrine cell types; vascular cells; Schwann cells; quiescent and activated stellate cells; and four types of immune cells. We detected subpopulations of ductal cells with distinct expression profiles and validated their existence with immuno-histochemistry stains. Moreover, among human beta- cells, we detected heterogeneity in the regulation of genes relating to functional maturation and levels of ER stress. Finally, we deconvolved bulk gene expression samples using the single-cell data to detect disease-associated differential expression. Our dataset provides a resource for the discovery of novel cell type-specific transcription factors, signaling receptors, and medically relevant genes. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Nerve growth factor has a modulatory role on human primary fibroblast cultures derived from vernal keratoconjunctivitis-affected conjunctiva

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    Micera, Alessandra; Lambiase, Alessandro; Stampachiacchiere, Barbara; Sgrulletta, Roberto; Normando, Eduardo Maria; Bonini, Sergio

    2007-01-01

    Purpose To evaluate the role of nerve growth factor (NGF) in remodeling processes of vernal keratoconjunctivitis (VKC). VKC is a chronic inflammatory disorder of the conjunctiva and is characterized by marked tissue remodeling. NGF, a pleiotrophic factor with documented profibrogenic activities, is produced by inflammatory and structural cells populating the VKC conjunctiva and is increased in the serum and tears of VKC patients. Methods Primary cultures of VKC-derived fibroblasts (VKC-FBs) were exposed to increasing NGF concentrations (1-500 ng/ml) to evaluate and compare the expression of α-smooth muscle actin (αSMA, a defining myofibroblast marker), collagens (types I and IV), and metalloproteinases and tissue inhibitors (MMP9/TIMP1, MMP2/TIMP2) at the biochemical as well as molecular levels. Results Endogenous NGF was increased in the VKC-FB supernatant, as compared to healthy-FB supernatant. VKC-FBs expressed αSMA and increased types I and IV collagens. VKC-FBs, and in particular all αSMA positive cells, expressed both trkANGFR and p75NTR, while healthy-FBs only expressed trkANGFR. Exogenous NGF did not change αSMA expression, while αSMA expression was enhanced by specific neutralization of p75NTR. NGF (10 ng/ml) exposure significantly decreased type I collagen expression, without affecting type IV collagen, and increased MMP9mRNA and protein. Conclusions The autocrine modulation of differentiation and response of VKC-FBs to NGF exposure with downregulation of type I collagen and upregulation of MMP9 expression supports a relevant role for NGF in tissue remodeling of VKC. PMID:17653039

  5. Mesenchymal Stem Cell-Derived Factors Restore Function to Human Frataxin-Deficient Cells.

    Science.gov (United States)

    Kemp, Kevin; Dey, Rimi; Cook, Amelia; Scolding, Neil; Wilkins, Alastair

    2017-08-01

    Friedreich's ataxia is an inherited neurological disorder characterised by mitochondrial dysfunction and increased susceptibility to oxidative stress. At present, no therapy has been shown to reduce disease progression. Strategies being trialled to treat Friedreich's ataxia include drugs that improve mitochondrial function and reduce oxidative injury. In addition, stem cells have been investigated as a potential therapeutic approach. We have used siRNA-induced knockdown of frataxin in SH-SY5Y cells as an in vitro cellular model for Friedreich's ataxia. Knockdown of frataxin protein expression to levels detected in patients with the disorder was achieved, leading to decreased cellular viability, increased susceptibility to hydrogen peroxide-induced oxidative stress, dysregulation of key anti-oxidant molecules and deficiencies in both cell proliferation and differentiation. Bone marrow stem cells are being investigated extensively as potential treatments for a wide range of neurological disorders, including Friedreich's ataxia. The potential neuroprotective effects of bone marrow-derived mesenchymal stem cells were therefore studied using our frataxin-deficient cell model. Soluble factors secreted by mesenchymal stem cells protected against cellular changes induced by frataxin deficiency, leading to restoration in frataxin levels and anti-oxidant defences, improved survival against oxidative stress and stimulated both cell proliferation and differentiation down the Schwann cell lineage. The demonstration that mesenchymal stem cell-derived factors can restore cellular homeostasis and function to frataxin-deficient cells further suggests that they may have potential therapeutic benefits for patients with Friedreich's ataxia.

  6. The Role of Rab Proteins in Neuronal Cells and in the Trafficking of Neurotrophin Receptors

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    Cecilia Bucci

    2014-10-01

    Full Text Available Neurotrophins are a family of proteins that are important for neuronal development, neuronal survival and neuronal functions. Neurotrophins exert their role by binding to their receptors, the Trk family of receptor tyrosine kinases (TrkA, TrkB, and TrkC and p75NTR, a member of the tumor necrosis factor (TNF receptor superfamily. Binding of neurotrophins to receptors triggers a complex series of signal transduction events, which are able to induce neuronal differentiation but are also responsible for neuronal maintenance and neuronal functions. Rab proteins are small GTPases localized to the cytosolic surface of specific intracellular compartments and are involved in controlling vesicular transport. Rab proteins, acting as master regulators of the membrane trafficking network, play a central role in both trafficking and signaling pathways of neurotrophin receptors. Axonal transport represents the Achilles' heel of neurons, due to the long-range distance that molecules, organelles and, in particular, neurotrophin-receptor complexes have to cover. Indeed, alterations of axonal transport and, specifically, of axonal trafficking of neurotrophin receptors are responsible for several human neurodegenerative diseases, such as Huntington’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis and some forms of Charcot-Marie-Tooth disease. In this review, we will discuss the link between Rab proteins and neurotrophin receptor trafficking and their influence on downstream signaling pathways.

  7. Abnormalities in spinal neurons and dorsal root ganglion cells in Tangier disease presenting with a syringomyelia-like syndrome.

    Science.gov (United States)

    Schmalbruch, H; Stender, S; Boysen, G

    1987-09-01

    A woman with homozygous Tangier disease had progressive syringomyelia-like neuropathy. She died with cardiac failure at age 61. A sural nerve biopsy taken at age 60 had shown lipid storage in Schwann and interstitial cells, and a pronounced loss of unmyelinated fibers. The neurons of the L5 spinal ganglion and, to a lesser extent, all neurons of the sacral spinal cord, contained large lipid inclusions which in electron micrographs differed from those in Schwann and satellite cells. There was no storage material in glial cells. The neuronal inclusions were membrane-bound and consisted of electron-dense and electron-lucent components. There was evidence of neuronal death in the spinal ganglion, and a diameter histogram showed that small cytons had preferentially been lost. The inclusions probably were secondary lysosomes or residual bodies, and resembled giant lipofuscin granules. Nevertheless, they were uncolored and displayed weak autofluorescence as compared to the aging pigment in control ganglia. It is tentatively suggested that the syringomyelia-like neuropathy in Tangier disease represents a lysosomal storage disorder preferentially affecting small dorsal root ganglion cells.

  8. Large enhancement in neurite outgrowth on a cell membrane-mimicking conducting polymer

    Science.gov (United States)

    Zhu, Bo; Luo, Shyh-Chyang; Zhao, Haichao; Lin, Hsing-An; Sekine, Jun; Nakao, Aiko; Chen, Chi; Yamashita, Yoshiro; Yu, Hsiao-Hua

    2014-07-01

    Although electrically stimulated neurite outgrowth on bioelectronic devices is a promising means of nerve regeneration, immunogenic scar formation can insulate electrodes from targeted cells and tissues, thereby reducing the lifetime of the device. Ideally, an electrode material capable of electrically interfacing with neurons selectively and efficiently would be integrated without being recognized by the immune system and minimize its response. Here we develop a cell membrane-mimicking conducting polymer possessing several attractive features. This polymer displays high resistance towards nonspecific enzyme/cell binding and recognizes targeted cells specifically to allow intimate electrical communication over long periods of time. Its low electrical impedance relays electrical signals efficiently. This material is capable to integrate biochemical and electrical stimulation to promote neural cellular behaviour. Neurite outgrowth is enhanced greatly on this new conducting polymer; in addition, electrically stimulated secretion of proteins from primary Schwann cells can also occur on it.

  9. Tight junction proteins and perineurial cells in neurofibromas.

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    Pummi, Kati P; Aho, Heikki J; Laato, Matti K; Peltonen, Juha T K; Peltonen, Sirkku A

    2006-01-01

    Cutaneous neurofibromas consist of axonal processes, Schwann cells, fibroblasts, perineurial cells, mast cells, and abundant extracellular matrix. The distribution and role of perineurial cells in neurofibromas has been uncertain, partly because there has not been a specific immunohistochemical marker for perineurial cells. In this study, tight junctions (TJs) of 16 neurofibromas from 12 patients with neurofibromatosis type 1 (NF1) were analyzed using electron microscopy, immunohistochemistry, and Western transfer analysis. Cell-cell contacts with typical ultrastructural morphology of TJs were seen between adjacent perineurial cells surrounding the small nerves and between contacting perineurial cell processes embedded in tumor stroma. Immunohistochemistry showed expression of claudin-1, claudin-3, and ZO-1 in the intercellular junctions of a subpopulation of tumor cells. Occludin was present mainly in perineurium and claudin-5 localized to the blood vessels. Double immunolabelings were used to identify the cell types expressing claudin-1. The results showed that claudin-1 positive cells were also positive for type IV collagen and epithelial membrane antigen but not for S-100 protein. This labeling pattern is consistent with perineurial cell phenotype. Using claudin-1 as a marker, our results showed that clusters of perineurial cells are distributed around the rudimentary nerves within cutaneous neurofibromas and at the periphery of some neurofibromas.

  10. Unchanged Neurotrophic Factors and Their Receptors Correlate With Sparing in Extraocular Muscles in Amyotrophic Lateral Sclerosis.

    Science.gov (United States)

    Harandi, Vahid M; Gaied, Aida R N; Brännström, Thomas; Pedrosa Domellöf, Fatima; Liu, Jing-Xia

    2016-12-01

    To investigate the impact of amyotrophic lateral sclerosis (ALS) on the extraocular muscles (EOMs) by examining the distribution of neurotrophic factors (NTFs) and their receptors in EOMs and limb muscles from ALS transgenic mice. Muscle samples collected from transgenic mice overexpressing human superoxide dismutase type 1 mutations (SOD1G93A, the most widely used mouse model of ALS) at 50 and 150 days as well as age-matched controls were analyzed with immunohistochemistry using antibodies against brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), neurotrophin-4/5 (NT-4), glial cell line-derived neurotrophic factor (GDNF), and the neurotrophin receptors p75NTR, tyrosine kinase (Trk) receptor TrkB and TrkC, and GDNF family receptor alpha-1 (GFRα-1). There was an intrinsic difference in NTF expression between EOMs and limb muscles in control mice: EOMs presented significantly lower number of neuromuscular junctions (NMJs) labeled for BDNF and NT-4 at 50 days, and for BDNF and GDNF at 150 days, compared with the control limb muscles of corresponding age. In ALS transgenic mice at 150 days, NTF expression in limb muscles was significantly changed but not in EOMs: the limb muscles presented a significant decline in the number of NMJs labeled for BDNF, NT-4, GDNF, p75NTR, TrkB, and TrkC, which was not observed in EOMs. The significant differences in expression of NTFs on NMJs between EOMs and limb muscles in both control and ALS transgenic mice suggest that NTF may be involved in the pathogenesis of ALS and the resistance of EOMs to the disease.

  11. Enhancement of primary neuronal cell proliferation using printing-transferred carbon nanotube sheets.

    Science.gov (United States)

    Kang, Dong-Wan; Sun, Fangfang; Choi, Yoon Ji; Zou, Fengming; Cho, Won-Ho; Choi, Byung-Kwan; Koh, Kwangnak; Lee, Jaebeom; Han, In Ho

    2015-05-01

    Artificial nerve guidance conduits (aNGCs) prepared from polymer scaffolds and carbon nanotubes (CNTs) possess unique chemical and physical properties, and have been widely used in preclinical trials to promote neuronal differentiation and growth. However, there have been only a few reports on the clinical applicability of CNT sheets for proliferation of primary neuronal cells due to safety concerns. The present study assesses the ability and potential applicability of multiwalled CNTs (MWNTs) composited with polydimethylsiloxane (PDMS) sheets to promote and enhance the proliferation of primary neuronal cells. In this study, the aqueous MWNT dispersion was filtered, and the PDMS/MWNT sheets were prepared using a simple printing transfer method. Characterization of PDMS/MWNT sheets demonstrated their unique physical properties such as superior mechanical strength and electroconductivity when compared with PDMS sheets. The effect of the PDMS/MWNT sheets on the neural cell proliferation and cytotoxicity was evaluated using MTT and alamar blue assays. Our results indicate the viability and proliferation of primary neuronal cells and Schwann cells in PDMS/MWNT sheets increased over twice when compared with a noncoated dish that is not usual in the primary neuronal cell growth control (p cells compared with poly-l-lysine coated dishes, which are most commonly used for improving cell adherence. Additionally, the PDMS/MWNT sheets exhibited excellent biocompatibility for culturing neuronal and Schwann cells. Overall, all assessments indicate that PDMS/MWNT sheets are ideal candidates for the development of artificial nerve conduits for clinical use following peripheral nerve injury. © 2014 Wiley Periodicals, Inc.

  12. The Effect of Glucocorticoid and Glucocorticoid Receptor Interactions on Brain, Spinal Cord, and Glial Cell Plasticity

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    Kathryn M. Madalena

    2017-01-01

    Full Text Available Stress, injury, and disease trigger glucocorticoid (GC elevation. Elevated GCs bind to the ubiquitously expressed glucocorticoid receptor (GR. While GRs are in every cell in the nervous system, the expression level varies, suggesting that diverse cell types react differently to GR activation. Stress/GCs induce structural plasticity in neurons, Schwann cells, microglia, oligodendrocytes, and astrocytes as well as affect neurotransmission by changing the release and reuptake of glutamate. While general nervous system plasticity is essential for adaptation and learning and memory, stress-induced plasticity is often maladaptive and contributes to neuropsychiatric disorders and neuropathic pain. In this brief review, we describe the evidence that stress/GCs activate GR to promote cell type-specific changes in cellular plasticity throughout the nervous system.

  13. Breast schwannoma in a patient with diffuse large B-cell lymphoma: a case report

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    Salihoglu Ayse

    2012-12-01

    Full Text Available Abstract Introduction Schwannomas are mostly benign tumors arising from Schwann cells of the nerve sheaths. Breast schwannomas are very rare and account for only 2.6% of cases. As far as we know this is the first reported case of breast schwannoma discovered in a patient with diffuse large B-cell lymphoma. The breast schwannoma was evaluated with positron emission tomography and it exhibited moderate 18F-fluorodeoxyglucose uptake. Case presentation We present the case of a breast schwannoma in a 63-year-old Caucasian woman who was diagnosed with diffuse large B-cell lymphoma. Conclusion Imaging modalities including positron emission tomography-computed tomography failed to distinguish breast schwannoma from diffuse large B-cell lymphoma involvement of the breast.

  14. Biodegradable chitin conduit tubulation combined with bone marrow mesenchymal stem cell transplantation for treatment of spinal cord injury by reducing glial scar and cavity formation.

    Science.gov (United States)

    Xue, Feng; Wu, Er-Jun; Zhang, Pei-Xun; Li-Ya, A; Kou, Yu-Hui; Yin, Xiao-Feng; Han, Na

    2015-01-01

    We examined the restorative effect of modified biodegradable chitin conduits in combination with bone marrow mesenchymal stem cell transplantation after right spinal cord hemisection injury. Immunohistochemical staining revealed that biological conduit sleeve bridging reduced glial scar formation and spinal muscular atrophy after spinal cord hemisection. Bone marrow mesenchymal stem cells survived and proliferated after transplantation in vivo, and differentiated into cells double-positive for S100 (Schwann cell marker) and glial fibrillary acidic protein (glial cell marker) at 8 weeks. Retrograde tracing showed that more nerve fibers had grown through the injured spinal cord at 14 weeks after combination therapy than either treatment alone. Our findings indicate that a biological conduit combined with bone marrow mesenchymal stem cell transplantation effectively prevented scar formation and provided a favorable local microenvironment for the proliferation, migration and differentiation of bone marrow mesenchymal stem cells in the spinal cord, thus promoting restoration following spinal cord hemisection injury.

  15. Biodegradable chitin conduit tubulation combined with bone marrow mesenchymal stem cell transplantation for treatment of spinal cord injury by reducing glial scar and cavity formation

    Directory of Open Access Journals (Sweden)

    Feng Xue

    2015-01-01

    Full Text Available We examined the restorative effect of modified biodegradable chitin conduits in combination with bone marrow mesenchymal stem cell transplantation after right spinal cord hemisection injury. Immunohistochemical staining revealed that biological conduit sleeve bridging reduced glial scar formation and spinal muscular atrophy after spinal cord hemisection. Bone marrow mesenchymal stem cells survived and proliferated after transplantation in vivo, and differentiated into cells double-positive for S100 (Schwann cell marker and glial fibrillary acidic protein (glial cell marker at 8 weeks. Retrograde tracing showed that more nerve fibers had grown through the injured spinal cord at 14 weeks after combination therapy than either treatment alone. Our findings indicate that a biological conduit combined with bone marrow mesenchymal stem cell transplantation effectively prevented scar formation and provided a favorable local microenvironment for the proliferation, migration and differentiation of bone marrow mesenchymal stem cells in the spinal cord, thus promoting restoration following spinal cord hemisection injury.

  16. Differentiation of Equine Mesenchymal Stromal Cells into Cells of Neural Lineage: Potential for Clinical Applications

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    Claudia Cruz Villagrán

    2014-01-01

    Full Text Available Mesenchymal stromal cells (MSCs are able to differentiate into extramesodermal lineages, including neurons. Positive outcomes were obtained after transplantation of neurally induced MSCs in laboratory animals after nerve injury, but this is unknown in horses. Our objectives were to test the ability of equine MSCs to differentiate into cells of neural lineage in vitro, to assess differences in morphology and lineage-specific protein expression, and to investigate if horse age and cell passage number affected the ability to achieve differentiation. Bone marrow-derived MSCs were obtained from young and adult horses. Following demonstration of stemness, MSCs were neurally induced and microscopically assessed at different time points. Results showed that commercially available nitrogen-coated tissue culture plates supported proliferation and differentiation. Morphological changes were immediate and all the cells displayed a neural crest-like cell phenotype. Expression of neural progenitor proteins, was assessed via western blot or immunofluorescence. In our study, MSCs generated from young and middle-aged horses did not show differences in their ability to undergo differentiation. The effect of cell passage number, however, is inconsistent and further experiments are needed. Ongoing work is aimed at transdifferentiating these cells into Schwann cells for transplantation into a peripheral nerve injury model in horses.

  17. Dental Pulp Stem Cells: Their Potential in Reinnervation and Angiogenesis by Using Scaffolds.

    Science.gov (United States)

    Lambrichts, Ivo; Driesen, Ronald B; Dillen, Yörg; Gervois, Pascal; Ratajczak, Jessica; Vangansewinkel, Tim; Wolfs, Esther; Bronckaers, Annelies; Hilkens, Petra

    2017-09-01

    Dental pulp is a highly vascularized and innervated tissue containing a heterogeneous stem cell population with multilineage differentiation potential. Current endodontic treatments focus on the preservation of the pulp tissue and the regeneration of dental pulp after pathological insults. Human dental pulp stem cells (hDPSCs) are currently investigated as stem cell-based therapy for pulp regeneration and for peripheral nerve injury in which neurons and Schwann cells display limited regenerative capacity. We have developed a neuronal differentiation protocol for hDPSCs that requires neurosphere formation before neuronal maturation. Moreover, Schwann cell differentiation of hDPSCs in our group revealed that differentiated hDPSCs have acquired the ability to myelinate and guide neurites from dorsal root ganglia. Besides their dynamic differentiation capacity, hDPSCs were shown to exert a paracrine effect on neural and endothelial cells. Analysis of hDPSC conditioned medium revealed the secretion of a broad spectrum of growth factors including brain-derived neurotrophic factor, nerve growth factor, vascular endothelial growth factor, and glial-derived neurotrophic factor. Application of the conditioned medium to endothelial cells promoted cell migration and tubulogenesis, indicating a paracrine proangiogenic effect. This hypothesis was enforced by the enhanced formation of blood vessels in the chorioallantoic membrane assay in the presence of hDPSCs. In addition, transplantation of 3-dimensional-printed hydroxyapatite scaffolds containing peptide hydrogels and hDPSCs into immunocompromised mice revealed blood vessel ingrowth, pulplike tissue formation, and osteodentin deposition suggesting osteogenic/odontogenic differentiation of hDPSCs. Future studies in our research group will focus on the pulp regeneration capacity of hDPSCs and the role of fibroblasts within the pulp extracellular matrix. Copyright © 2017 American Association of Endodontists. Published by

  18. Epalrestat increases glutathione, thioredoxin, and heme oxygenase-1 by stimulating Nrf2 pathway in endothelial cells

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    Kaori Yama

    2015-04-01

    Full Text Available Epalrestat (EPS is the only aldose reductase inhibitor that is currently available for the treatment of diabetic neuropathy. Recently, we found that EPS at near-plasma concentration increases the intracellular levels of glutathione (GSH in rat Schwann cells. GSH plays a crucial role in protecting endothelial cells from oxidative stress, thereby preventing vascular diseases. Here we show that EPS increases GSH levels in not only Schwann cells but also endothelial cells. Treatment of bovine aortic endothelial cells (BAECs, an in vitro model of the vascular endothelium, with EPS caused a dramatic increase in intracellular GSH levels. This was concomitant with the up-regulation of glutamate cysteine ligase, an enzyme catalyzing the first and rate-limiting step in de novo GSH synthesis. Moreover, EPS stimulated the expression of thioredoxin and heme oxygenase-1, which have important redox regulatory functions in endothelial cells. Nuclear factor erythroid 2-related factor 2 (Nrf2 is a key transcription factor that regulates the expression of antioxidant genes. EPS increased nuclear Nrf2 levels in BAECs. Nrf2 knockdown by siRNA suppressed the EPS-induced glutamate cysteine ligase, thioredoxin-1, and heme oxygenase-1 expression. Interestingly, LY294002, an inhibitor of phosphatidylinositol 3-kinase, abolished the EPS-stimulated GSH synthesis, suggesting that the kinase is associated with Nrf2 activation induced by EPS. Furthermore, EPS reduced the cytotoxicity induced by H2O2 and tert-butylhydroperoxide, indicating that EPS plays a role in protecting cells from oxidative stress. Taken together, the results provide evidence that EPS exerts new beneficial effects on endothelial cells by increasing GSH, thioredoxin, and heme oxygenase-1 levels through the activation of Nrf2. We suggest that EPS has the potential to prevent several vascular diseases caused by oxidative stress.

  19. Role of low-affinity nerve growth factor receptor inhibitory antibody in reducing pain behavior and calcitonin gene-related Peptide expression in a rat model of wrist joint inflammatory pain.

    Science.gov (United States)

    Iwakura, Nahoko; Ohtori, Seiji; Orita, Sumihisa; Yamashita, Masaomi; Takahashi, Kazuhisa; Kuniyoshi, Kazuki

    2010-02-01

    Nerve growth factor (NGF), via the high-affinity receptor, tyrosine kinase A, has been widely reported as a mediator of pain caused by inflammation. A clinical trial has suggested that anti-NGF antibody is effective for pain caused by osteoarthritis of the knee. However, adverse events such as headache (8.9%), upper respiratory tract infection (7.3%), and paresthesia (6.8%) were reported. We hypothesized that inhibition of the low-affinity NGF receptor, p75 neurotrophin receptor (p75NTR), is also effective for joint pain and may reduce side effects. This study examined suppression of pain behavior and expression of pain-inducing neuropeptides such as calcitonin gene-related peptide (CGRP) and p75NTR in dorsal root ganglia neurons by a p75NTR inhibitory antibody in a rat model of wrist joint inflammatory pain. We injected complete Freund's adjuvant (CFA) into the wrist joint of rats and used this as a model of inflammatory pain. We applied 10 microL of saline (CFA + saline group; n = 20) or 1, 10, or 50 microL of a p75NTR inhibitory antibody (CFA + p75NTR inhibitory antibody group; n = 40) directly to the inflamed joint in the rats. Mechanical hyperalgesia was measured for 2 weeks using von Frey filaments. We assessed CGRP and p75NTR expression in C8 dorsal root ganglia immunochemically. Adverse events such as loss of weight and/or appetite, constipation, and infection were examined. p75NTR inhibitory antibody reduced mechanical hyperalgesia caused by CFA (pwrist inflammation (p<.01). p75NTR inhibition may be a therapeutic target for inflamed joint pain treatment with reduced adverse events. Copyright 2010. Published by Elsevier Inc.

  20. Uridine 5'-triphosphate promotes in vitro Schwannoma cell migration through matrix metalloproteinase-2 activation.

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    Aloa Lamarca

    Full Text Available In response to peripheral nerve injury, Schwann cells adopt a migratory phenotype and modify the extracellular matrix to make it permissive for cell migration and axonal re-growth. Uridine 5'-triphosphate (UTP and other nucleotides are released during nerve injury and activate purinergic receptors expressed on the Schwann cell surface, but little is known about the involvement of purine signalling in wound healing. We studied the effect of UTP on Schwannoma cell migration and wound closure and the intracellular signaling pathways involved. We found that UTP treatment induced Schwannoma cell migration through activation of P2Y2 receptors and through the increase of extracellular matrix metalloproteinase-2 (MMP-2 activation and expression. Knockdown P2Y2 receptor or MMP-2 expression greatly reduced wound closure and MMP-2 activation induced by UTP. MMP-2 activation evoked by injury or UTP was also mediated by phosphorylation of all 3 major mitogen-activated protein kinases (MAPKs: JNK, ERK1/2, and p38. Inhibition of these MAPK pathways decreased both MMP-2 activation and cell migration. Interestingly, MAPK phosphorylation evoked by UTP exhibited a biphasic pattern, with an early transient phosphorylation 5 min after treatment, and a late and sustained phosphorylation that appeared at 6 h and lasted up to 24 h. Inhibition of MMP-2 activity selectively blocked the late, but not the transient, phase of MAPK activation. These results suggest that MMP-2 activation and late MAPK phosphorylation are part of a positive feedback mechanism to maintain the migratory phenotype for wound healing. In conclusion, our findings show that treatment with UTP stimulates in vitro Schwannoma cell migration and wound repair through a MMP-2-dependent mechanism via P2Y2 receptors and MAPK pathway activation.

  1. Co-cultures with stem cell-derived human sensory neurons reveal regulators of peripheral myelination.

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    Clark, Alex J; Kaller, Malte S; Galino, Jorge; Willison, Hugh J; Rinaldi, Simon; Bennett, David L H

    2017-04-01

    See Saporta and Shy (doi:10.1093/awx048) for a scientific commentary on this article.Effective bidirectional signalling between axons and Schwann cells is essential for both the development and maintenance of peripheral nerve function. We have established conditions by which human induced pluripotent stem cell-derived sensory neurons can be cultured with rat Schwann cells, and have produced for the first time long-term and stable myelinating co-cultures with human neurons. These cultures contain the specialized domains formed by axonal interaction with myelinating Schwann cells, such as clustered voltage-gated sodium channels at the node of Ranvier and Shaker-type potassium channel (Kv1.2) at the juxtaparanode. Expression of type III neuregulin-1 (TIIINRG1) in induced pluripotent stem cell-derived sensory neurons strongly enhances myelination, while conversely pharmacological blockade of the NRG1-ErbB pathway prevents myelination, providing direct evidence for the ability of this pathway to promote the myelination of human sensory axons. The β-secretase, BACE1 is a protease needed to generate active NRG1 from the full-length form. Due to the fact that it also cleaves amyloid precursor protein, BACE1 is a therapeutic target in Alzheimer's disease, however, consistent with its role in NRG1 processing we find that BACE1 inhibition significantly impairs myelination in our co-culture system. In order to exploit co-cultures to address other clinically relevant problems, they were exposed to anti-disialosyl ganglioside antibodies, including those derived from a patient with a sensory predominant, inflammatory neuropathy with mixed axonal and demyelinating electrophysiology. The co-cultures reveal that both mouse and human disialosyl antibodies target the nodal axolemma, induce acute axonal degeneration in the presence of complement, and impair myelination. The human, neuropathy-associated IgM antibody is also shown to induce complement-independent demyelination

  2. Assessment of citalopram and escitalopram on neuroblastoma cell lines. Cell toxicity and gene modulation.

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    Sakka, Laurent; Delétage, Nathalie; Chalus, Maryse; Aissouni, Youssef; Sylvain-Vidal, Valérie; Gobron, Stéphane; Coll, Guillaume

    2017-06-27

    Selective serotonin reuptake inhibitors (SSRI) are common antidepressants which cytotoxicity has been assessed in cancers notably colorectal carcinomas and glioma cell lines. We assessed and compared the cytotoxicity of 2 SSRI, citalopram and escitalopram, on neuroblastoma cell lines. The study was performed on 2 non-MYCN amplified cell lines (rat B104 and human SH-SY5Y) and 2 human MYCN amplified cell lines (IMR32 and Kelly). Citalopram and escitalopram showed concentration-dependent cytotoxicity on all cell lines. Citalopram was more cytotoxic than escitalopram. IMR32 was the most sensitive cell line. The absence of toxicity on human primary Schwann cells demonstrated the safety of both molecules for myelin. The mechanisms of cytotoxicity were explored using gene-expression profiles and quantitative real-time PCR (qPCR). Citalopram modulated 1 502 genes and escitalopram 1 164 genes with a fold change ≥ 2. 1 021 genes were modulated by both citalopram and escitalopram; 481 genes were regulated only by citalopram while 143 genes were regulated only by escitalopram. Citalopram modulated 69 pathways (KEGG) and escitalopram 42. Ten pathways were differently modulated by citalopram and escitalopram. Citalopram drastically decreased the expression of MYBL2, BIRC5 and BARD1 poor prognosis factors of neuroblastoma with fold-changes of -107 (pescitalopram.

  3. Assessment of citalopram and escitalopram on neuroblastoma cell lines: Cell toxicity and gene modulation

    Science.gov (United States)

    Sakka, Laurent; Delétage, Nathalie; Chalus, Maryse; Aissouni, Youssef; Sylvain-Vidal, Valérie; Gobron, Stéphane; Coll, Guillaume

    2017-01-01

    Selective serotonin reuptake inhibitors (SSRI) are common antidepressants which cytotoxicity has been assessed in cancers notably colorectal carcinomas and glioma cell lines. We assessed and compared the cytotoxicity of 2 SSRI, citalopram and escitalopram, on neuroblastoma cell lines. The study was performed on 2 non-MYCN amplified cell lines (rat B104 and human SH-SY5Y) and 2 human MYCN amplified cell lines (IMR32 and Kelly). Citalopram and escitalopram showed concentration-dependent cytotoxicity on all cell lines. Citalopram was more cytotoxic than escitalopram. IMR32 was the most sensitive cell line. The absence of toxicity on human primary Schwann cells demonstrated the safety of both molecules for myelin. The mechanisms of cytotoxicity were explored using gene-expression profiles and quantitative real-time PCR (qPCR). Citalopram modulated 1 502 genes and escitalopram 1 164 genes with a fold change ≥ 2. 1 021 genes were modulated by both citalopram and escitalopram; 481 genes were regulated only by citalopram while 143 genes were regulated only by escitalopram. Citalopram modulated 69 pathways (KEGG) and escitalopram 42. Ten pathways were differently modulated by citalopram and escitalopram. Citalopram drastically decreased the expression of MYBL2, BIRC5 and BARD1 poor prognosis factors of neuroblastoma with fold-changes of -107 (pescitalopram. PMID:28467792

  4. p75 neurotrophin receptor regulates energy balance in obesity

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    Baeza-Raja, Bernat; Sachs, Benjamin D.; Li, Pingping; Christian, Frank; Vagena, Eirini; Davalos, Dimitrios; Le Moan, Natacha; Ryu, Jae Kyu; Sikorski, Shoana L.; Chan, Justin P.; Scadeng, Miriam; Taylor, Susan S.; Houslay, Miles D.; Baillie, George S.; Saltiel, Alan R.; Olefsky, Jerrold M.; Akassoglou, Katerina

    2015-01-01

    Summary Obesity and metabolic syndrome reflect the dysregulation of molecular pathways that control energy homeostasis. Here we show that upon high-fat diet (HFD), the p75 neurotrophin receptor (p75NTR) controls energy expenditure in obese mice. Despite no changes in food intake, p75NTR-null mice were protected from HFD-induced obesity and remained lean due to increased energy expenditure, without developing insulin resistance or liver steatosis. p75NTR directly interacts with the catalytic subunit of protein kinase A (PKA) and regulates cAMP signaling in adipocytes, leading to decreased lipolysis and thermogenesis. Adipocyte-specific depletion of p75NTR or transplantation of p75NTR-null white adipose tissue (WAT) into wild-type mice fed a HFD protected against weight gain and insulin resistance. Our results reveal that signaling from p75NTR to cAMP/PKA regulates energy balance and suggest that non-neuronal functions of neurotrophin receptor signaling could be a new target for treating obesity and the metabolic syndrome. PMID:26748707

  5. Preferential and comprehensive reconstitution of severely damaged sciatic nerve using murine skeletal muscle-derived multipotent stem cells.

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    Tetsuro Tamaki

    Full Text Available Loss of vital functions in the somatic motor and sensory nervous systems can be induced by severe peripheral nerve transection with a long gap following trauma. In such cases, autologous nerve grafts have been used as the gold standard, with the expectation of activation and proliferation of graft-concomitant Schwann cells associated with their paracrine effects. However, there are a limited number of suitable sites available for harvesting of nerve autografts due to the unavoidable sacrifice of other healthy functions. To overcome this problem, the potential of skeletal muscle-derived multipotent stem cells (Sk-MSCs was examined as a novel alternative cell source for peripheral nerve regeneration. Cultured/expanded Sk-MSCs were injected into severely crushed sciatic nerve corresponding to serious neurotmesis. After 4 weeks, engrafted Sk-MSCs preferentially differentiated into not only Schwann cells, but also perineurial/endoneurial cells, and formed myelin sheath and perineurium/endoneurium, encircling the regenerated axons. Increased vascular formation was also observed, leading to a favorable blood supply and waste product excretion. In addition, engrafted cells expressed key neurotrophic and nerve/vascular growth factor mRNAs; thus, endocrine/paracrine effects for the donor/recipient cells were also expected. Interestingly, skeletal myogenic capacity of expanded Sk-MSCs was clearly diminished in peripheral nerve niche. The same differentiation and tissue reconstitution capacity of Sk-MSCs was sufficiently exerted in the long nerve gap bridging the acellular conduit, which facilitated nerve regeneration/reconnection. These effects represent favorable functional recovery in Sk-MSC-treated mice, as demonstrated by good corduroy walking. We also demonstrated that these differentiation characteristics of the Sk-MSCs were comparable to native peripheral nerve-derived cells, whereas the therapeutic capacities were largely superior in Sk

  6. Preferential and Comprehensive Reconstitution of Severely Damaged Sciatic Nerve Using Murine Skeletal Muscle-Derived Multipotent Stem Cells

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    Tamaki, Tetsuro; Hirata, Maki; Soeda, Shuichi; Nakajima, Nobuyuki; Saito, Kosuke; Nakazato, Kenei; Okada, Yoshinori; Hashimoto, Hiroyuki; Uchiyama, Yoshiyasu; Mochida, Joji

    2014-01-01

    Loss of vital functions in the somatic motor and sensory nervous systems can be induced by severe peripheral nerve transection with a long gap following trauma. In such cases, autologous nerve grafts have been used as the gold standard, with the expectation of activation and proliferation of graft-concomitant Schwann cells associated with their paracrine effects. However, there are a limited number of suitable sites available for harvesting of nerve autografts due to the unavoidable sacrifice of other healthy functions. To overcome this problem, the potential of skeletal muscle-derived multipotent stem cells (Sk-MSCs) was examined as a novel alternative cell source for peripheral nerve regeneration. Cultured/expanded Sk-MSCs were injected into severely crushed sciatic nerve corresponding to serious neurotmesis. After 4 weeks, engrafted Sk-MSCs preferentially differentiated into not only Schwann cells, but also perineurial/endoneurial cells, and formed myelin sheath and perineurium/endoneurium, encircling the regenerated axons. Increased vascular formation was also observed, leading to a favorable blood supply and waste product excretion. In addition, engrafted cells expressed key neurotrophic and nerve/vascular growth factor mRNAs; thus, endocrine/paracrine effects for the donor/recipient cells were also expected. Interestingly, skeletal myogenic capacity of expanded Sk-MSCs was clearly diminished in peripheral nerve niche. The same differentiation and tissue reconstitution capacity of Sk-MSCs was sufficiently exerted in the long nerve gap bridging the acellular conduit, which facilitated nerve regeneration/reconnection. These effects represent favorable functional recovery in Sk-MSC-treated mice, as demonstrated by good corduroy walking. We also demonstrated that these differentiation characteristics of the Sk-MSCs were comparable to native peripheral nerve-derived cells, whereas the therapeutic capacities were largely superior in Sk-MSCs. Therefore, Sk-MSCs can

  7. Cell transplantation for the treatment of spinal cord injury - bone marrow stromal cells and choroid plexus epithelial cells

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    Chizuka Ide

    2016-01-01

    Full Text Available Transplantation of bone marrow stromal cells (BMSCs enhanced the outgrowth of regenerating axons and promoted locomotor improvements of rats with spinal cord injury (SCI. BMSCs did not survive long-term, disappearing from the spinal cord within 2-3 weeks after transplantation. Astrocyte-devoid areas, in which no astrocytes or oligodendrocytes were found, formed at the epicenter of the lesion. It was remarkable that numerous regenerating axons extended through such astrocyte-devoid areas. Regenerating axons were associated with Schwann cells embedded in extracellular matrices. Transplantation of choroid plexus epithelial cells (CPECs also enhanced axonal regeneration and locomotor improvements in rats with SCI. Although CPECs disappeared from the spinal cord shortly after transplantation, an extensive outgrowth of regenerating axons occurred through astrocyte-devoid areas, as in the case of BMSC transplantation. These findings suggest that BMSCs and CPECs secret neurotrophic factors that promote tissue repair of the spinal cord, including axonal regeneration and reduced cavity formation. This means that transplantation of BMSCs and CPECs promotes "intrinsic" ability of the spinal cord to regenerate. The treatment to stimulate the intrinsic regeneration ability of the spinal cord is the safest method of clinical application for SCI. It should be emphasized that the generally anticipated long-term survival, proliferation and differentiation of transplanted cells are not necessarily desirable from the clinical point of view of safety.

  8. Delayed nerve stimulation promotes axon-protective neurofilament phosphorylation, accelerates immune cell clearance and enhances remyelination in vivo in focally demyelinated nerves.

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    Nikki A McLean

    Full Text Available Rapid and efficient axon remyelination aids in restoring strong electrochemical communication with end organs and in preventing axonal degeneration often observed in demyelinating neuropathies. The signals from axons that can trigger more effective remyelination in vivo are still being elucidated. Here we report the remarkable effect of delayed brief electrical nerve stimulation (ES; 1 hour @ 20 Hz 5 days post-demyelination on ensuing reparative events in a focally demyelinated adult rat peripheral nerve. ES impacted many parameters underlying successful remyelination. It effected increased neurofilament expression and phosphorylation, both implicated in axon protection. ES increased expression of myelin basic protein (MBP and promoted node of Ranvier re-organization, both of which coincided with the early reappearance of remyelinated axons, effects not observed at the same time points in non-stimulated demyelinated nerves. The improved ES-associated remyelination was accompanied by enhanced clearance of ED-1 positive macrophages and attenuation of glial fibrillary acidic protein expression in accompanying Schwann cells, suggesting a more rapid clearance of myelin debris and return of Schwann cells to a nonreactive myelinating state. These benefits of ES correlated with increased levels of brain derived neurotrophic factor (BDNF in the acute demyelination zone, a key molecule in the initiation of the myelination program. In conclusion, the tremendous impact of delayed brief nerve stimulation on enhancement of the innate capacity of a focally demyelinated nerve to successfully remyelinate identifies manipulation of this axis as a novel therapeutic target for demyelinating pathologies.

  9. Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

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    Cécile eCoste

    2015-06-01

    Full Text Available Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL12-abundant reticular (CAR cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs, which have been recently identified as neural crest-derived cells (NCSCs. Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-to-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system.

  10. Cell Therapy in Spinal Cord Injury: a Mini- Reivew

    Science.gov (United States)

    Mehrabi, Soraya; Eftekhari, Sanaz; Moradi, Fateme; Delaviz, Hamdollah; Pourheidar, Bagher; Azizi, Monir; Zendehdel, Adib; Shahbazi, Ali; Joghataei, Mohammad Taghi

    2013-01-01

    Spinal cord injury (SCI) is a debilitating disease which leads to progressive functional damages. Because of limited axonal regeneration in the central nervous system, there is no or little recovery expected in the patients. Different cellular and molecular approaches were investigated in SCI animal models. Cellular transplantation of stem cells can potentially replace damaged tissue and provide a suitable microenvironment for axons to regenerate. Here, we reviewed the last approaches applied by our colleagues and others in order to improve axonal regeneration following SCI. We used different types of stem cells via different methods. First, fetal olfactory mucosa, schwann, and bone marrow stromal cells were transplanted into the injury sites in SCI models. In later studies, was applied simultaneous transplantation of stem cells with chondroitinase ABC in SCI models with the aid of nanoparticles. Using these approaches, considerable functional recovery was observed. However, considering some challenges in stem cell therapy such as rejection, infection, and development of a new cancer, our more recent strategy was application of cytokines. We observed a significant improvement in motor function of rats when stromal derived factor-1 was used to attract innate stem cells to the injury site. In conclusion, it seems that co-transplantation of different cells accompanies with other factors like enzymes and growth factors via new delivery systems may yield better results in SCI. PMID:25337345

  11. CNPase Expression in Olfactory Ensheathing Cells

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    Christine Radtke

    2011-01-01

    Full Text Available A large body of work supports the proposal that transplantation of olfactory ensheathing cells (OECs into nerve or spinal cord injuries can promote axonal regeneration and remyelination. Yet, some investigators have questioned whether the transplanted OECs associate with axons and form peripheral myelin, or if they recruit endogenous Schwann cells that form myelin. Olfactory bulbs from transgenic mice expressing the enhanced green fluorescent protein (eGFP under the control of the 2-3-cyclic nucleotide 3-phosphodiesterase (CNPase promoter were studied. CNPase is expressed in myelin-forming cells throughout their lineage. We examined CNPase expression in both in situ in the olfactory bulb and in vitro to determine if OECs express CNPase commensurate with their myelination potential. eGFP was observed in the outer nerve layer of the olfactory bulb. Dissociated OECs maintained in culture had both intense eGFP expression and CNPase immunostaining. Transplantation of OECs into transected peripheral nerve longitudinally associated with the regenerated axons. These data indicate that OECs in the outer nerve layer of the olfactory bulb of CNPase transgenic mice express CNPase. Thus, while OECs do not normally form myelin on olfactory nerve axons, their expression of CNPase is commensurate with their potential to form myelin when transplanted into injured peripheral nerve.

  12. Transplantation of Nogo-66 receptor gene-silenced cells in a poly(D,L-lactic-co-glycolic acid) scaffold for the treatment of spinal cord injury★

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    Wang, Dong; Fan, Yuhong; Zhang, Jianjun

    2013-01-01

    Inhibition of neurite growth, which is in large part mediated by the Nogo-66 receptor, affects neural regeneration following bone marrow mesenchymal stem cell transplantation. The tissue engineering scaffold poly(D,L-lactide-co-glycolic acid) has good histocompatibility and can promote the growth of regenerating nerve fibers. The present study used small interfering RNA to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells and Schwann cells, which were subsequently transplanted with poly(D,L-lactide-co-glycolic acid) into the spinal cord lesion regions in rats. Simultaneously, rats treated with scaffold only were taken as the control group. Hematoxylin-eosin staining and immunohistochemistry revealed that at 4 weeks after transplantation, rats had good motor function of the hind limb after treatment with Nogo-66 receptor gene-silenced cells plus the poly(D,L-lactide-co-glycolic acid) scaffold compared with rats treated with scaffold only, and the number of bone marrow mesenchymal stem cells and neuron-like cells was also increased. At 8 weeks after transplantation, horseradish peroxidase tracing and transmission electron microscopy showed a large number of unmyelinated and myelinated nerve fibers, as well as intact regenerating axonal myelin sheath following spinal cord hemisection injury. These experimental findings indicate that transplantation of Nogo-66 receptor gene-silenced bone marrow mesenchymal stem cells and Schwann cells plus a poly(D,L-lactide-co-glycolic acid) scaffold can significantly enhance axonal regeneration of spinal cord neurons and improve motor function of the extremities in rats following spinal cord injury. PMID:25206713

  13. Transplantation of Nogo-66 receptor gene-silenced cells in a poly(D,L-lactic-co-glycolic acid) scaffold for the treatment of spinal cord injury.

    Science.gov (United States)

    Wang, Dong; Fan, Yuhong; Zhang, Jianjun

    2013-03-15

    Inhibition of neurite growth, which is in large part mediated by the Nogo-66 receptor, affects neural regeneration following bone marrow mesenchymal stem cell transplantation. The tissue engineering scaffold poly(D,L-lactide-co-glycolic acid) has good histocompatibility and can promote the growth of regenerating nerve fibers. The present study used small interfering RNA to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells and Schwann cells, which were subsequently transplanted with poly(D,L-lactide-co-glycolic acid) into the spinal cord lesion regions in rats. Simultaneously, rats treated with scaffold only were taken as the control group. Hematoxylin-eosin staining and immunohistochemistry revealed that at 4 weeks after transplantation, rats had good motor function of the hind limb after treatment with Nogo-66 receptor gene-silenced cells plus the poly(D,L-lactide-co-glycolic acid) scaffold compared with rats treated with scaffold only, and the number of bone marrow mesenchymal stem cells and neuron-like cells was also increased. At 8 weeks after transplantation, horseradish peroxidase tracing and transmission electron microscopy showed a large number of unmyelinated and myelinated nerve fibers, as well as intact regenerating axonal myelin sheath following spinal cord hemisection injury. These experimental findings indicate that transplantation of Nogo-66 receptor gene-silenced bone marrow mesenchymal stem cells and Schwann cells plus a poly(D,L-lactide-co-glycolic acid) scaffold can significantly enhance axonal regeneration of spinal cord neurons and improve motor function of the extremities in rats following spinal cord injury.

  14. Sciatic nerve repair with tissue engineered nerve: Olfactory ensheathing cells seeded poly(lactic-co-glygolic acid conduit in an animal model

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    C W Tan

    2013-01-01

    Full Text Available Background and Aim: Synthetic nerve conduits have been sought for repair of nerve defects as the autologous nerve grafts causes donor site morbidity and possess other drawbacks. Many strategies have been investigated to improve nerve regeneration through synthetic nerve guided conduits. Olfactory ensheathing cells (OECs that share both Schwann cell and astrocytic characteristics have been shown to promote axonal regeneration after transplantation. The present study was driven by the hypothesis that tissue-engineered poly(lactic-co-glycolic acid (PLGA seeded with OECs would improve peripheral nerve regeneration in a long sciatic nerve defect. Materials and Methods: Sciatic nerve gap of 15 mm was created in six adult female Sprague-Dawley rats and implanted with PLGA seeded with OECs. The nerve regeneration was assessed electrophysiologically at 2, 4 and 6 weeks following implantation. Histopathological examination, scanning electron microscopic (SEM examination and immunohistochemical analysis were performed at the end of the study. Results: Nerve conduction studies revealed a significant improvement of nerve conduction velocities whereby the mean nerve conduction velocity increases from 4.2 ΁ 0.4 m/s at week 2 to 27.3 ΁ 5.7 m/s at week 6 post-implantation ( P < 0.0001. Histological analysis revealed presence of spindle-shaped cells. Immunohistochemical analysis further demonstrated the expression of S100 protein in both cell nucleus and the cytoplasm in these cells, hence confirming their Schwann-cell-like property. Under SEM, these cells were found to be actively secreting extracellular matrix. Conclusion: Tissue-engineered PLGA conduit seeded with OECs provided a permissive environment to facilitate nerve regeneration in a small animal model.

  15. Nestin-GFP Transgene Reveals Neural Precursor Cells in Adult Skeletal Muscle

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    Birbrair, Alexander; Wang, Zhong-Min; Messi, Maria Laura; Enikolopov, Grigori N.; Delbono, Osvaldo

    2011-01-01

    Background Therapy for neural lesions or degenerative diseases relies mainly on finding transplantable active precursor cells. Identifying them in peripheral tissues accessible for biopsy, outside the central nervous system, would circumvent the serious immunological and ethical concerns impeding cell therapy. Methodology/Principal Findings In this study, we isolated neural progenitor cells in cultured adult skeletal muscle from transgenic mice in which nestin regulatory elements control GFP expression. These cells also expressed the early neural marker Tuj1 and light and heavy neurofilament but not S100β, indicating that they express typical neural but not Schwann cell markers. GFP+/Tuj1+ cells were also negative for the endothelial and pericyte markers CD31 and α-smooth muscle actin, respectively. We established their a) functional response to glutamate in patch-clamp recordings; b) interstitial mesenchymal origin; c) replicative capacity; and d) the environment necessary for their survival after fluorescence-activated cell sorting. Conclusions/Significance We propose that the decline in nestin-GFP expression in muscle progenitor cells and its persistence in neural precursor cells in muscle cultures provide an invaluable tool for isolating a population of predifferentiated neural cells with therapeutic potential. PMID:21304812

  16. Depletion of Neural Crest-Derived Cells Leads to Reduction in Plasma Noradrenaline and Alters B Lymphopoiesis.

    Science.gov (United States)

    Tsunokuma, Naoki; Yamane, Toshiyuki; Matsumoto, Chiaki; Tsuneto, Motokazu; Isono, Kana; Imanaka-Yoshida, Kyoko; Yamazaki, Hidetoshi

    2017-01-01

    Hematopoietic stem cells and their lymphoid progenitors are supported by the bone marrow (BM) microenvironmental niches composed of various stromal cells and Schwann cells and sympathetic nerve fibers. Although neural crest (NC) cells contribute to the development of all the three, their function in BM is not well understood. In this study, NC-derived cells were ablated with diphtheria toxin in double-transgenic mice expressing NC-specific Cre and Cre-driven diphtheria toxin receptor with yellow fluorescent protein reporter. We found that yellow fluorescent protein-expressing, NC-derived nonhematopoietic cells in BM expressed hematopoietic factors Cxcl12 and stem cell factor The ablation of NC-derived cells led to a significant decrease in B cell progenitors but not in hematopoietic stem cells or myeloid lineage cells in BM. Interestingly, plasma noradrenaline was markedly decreased in these mice. The i.p. administration of 6-hydroxydopamine, a known neurotoxin for noradrenergic neurons, led to a similar phenotype, whereas the administration of a noradrenaline precursor in NC-ablated mice partially rescued this phenotype. Additionally, the continuous administration of adrenergic receptor β antagonists partially decreased the number of B cell progenitors while preserving B lymphopoiesis in vitro. Taken together, our results indicate that NC-derived cell depletion leads to abnormal B lymphopoiesis partially through decreased plasma noradrenaline, suggesting this as a novel mechanism regulated by molecules released by the sympathetic neurons. Copyright © 2016 by The American Association of Immunologists, Inc.

  17. Biomaterial-Supported Cell Transplantation Treatments for Spinal Cord Injury: Challenges and Perspectives

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    Shengwen Liu

    2018-01-01

    Full Text Available Spinal cord injury (SCI, resulting in para- and tetraplegia caused by the partial or complete disruption of descending motor and ascending sensory neurons, represents a complex neurological condition that remains incurable. Following SCI, numerous obstacles comprising of the loss of neural tissue (neurons, astrocytes, and oligodendrocytes, formation of a cavity, inflammation, loss of neuronal circuitry and function must be overcome. Given the multifaceted primary and secondary injury events that occur with SCI treatment options are likely to require combinatorial therapies. While several methods have been explored, only the intersection of two, cell transplantation and biomaterial implantation, will be addressed in detail here. Owing to the constant advance of cell culture technologies, cell-based transplantation has come to the forefront of SCI treatment in order to replace/protect damaged tissue and provide physical as well as trophic support for axonal regrowth. Biomaterial scaffolds provide cells with a protected environment from the surrounding lesion, in addition to bridging extensive damage and providing physical and directional support for axonal regrowth. Moreover, in this combinatorial approach cell transplantation improves scaffold integration and therefore regenerative growth potential. Here, we review the advances in combinatorial therapies of Schwann cells (SCs, astrocytes, olfactory ensheathing cells (OECs, mesenchymal stem cells, as well as neural stem and progenitor cells (NSPCs with various biomaterial scaffolds.

  18. Roles of neural stem cells in the repair of peripheral nerve injury

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    Chong Wang

    2017-01-01

    Full Text Available Currently, researchers are using neural stem cell transplantation to promote regeneration after peripheral nerve injury, as neural stem cells play an important role in peripheral nerve injury repair. This article reviews recent research progress of the role of neural stem cells in the repair of peripheral nerve injury. Neural stem cells can not only differentiate into neurons, astrocytes and oligodendrocytes, but can also differentiate into Schwann-like cells, which promote neurite outgrowth around the injury. Transplanted neural stem cells can differentiate into motor neurons that innervate muscles and promote the recovery of neurological function. To promote the repair of peripheral nerve injury, neural stem cells secrete various neurotrophic factors, including brain-derived neurotrophic factor, fibroblast growth factor, nerve growth factor, insulin-like growth factor and hepatocyte growth factor. In addition, neural stem cells also promote regeneration of the axonal myelin sheath, angiogenesis, and immune regulation. It can be concluded that neural stem cells promote the repair of peripheral nerve injury through a variety of ways.

  19. Biomaterial-Supported Cell Transplantation Treatments for Spinal Cord Injury: Challenges and Perspectives

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    Liu, Shengwen; Schackel, Thomas; Weidner, Norbert; Puttagunta, Radhika

    2018-01-01

    Spinal cord injury (SCI), resulting in para- and tetraplegia caused by the partial or complete disruption of descending motor and ascending sensory neurons, represents a complex neurological condition that remains incurable. Following SCI, numerous obstacles comprising of the loss of neural tissue (neurons, astrocytes, and oligodendrocytes), formation of a cavity, inflammation, loss of neuronal circuitry and function must be overcome. Given the multifaceted primary and secondary injury events that occur with SCI treatment options are likely to require combinatorial therapies. While several methods have been explored, only the intersection of two, cell transplantation and biomaterial implantation, will be addressed in detail here. Owing to the constant advance of cell culture technologies, cell-based transplantation has come to the forefront of SCI treatment in order to replace/protect damaged tissue and provide physical as well as trophic support for axonal regrowth. Biomaterial scaffolds provide cells with a protected environment from the surrounding lesion, in addition to bridging extensive damage and providing physical and directional support for axonal regrowth. Moreover, in this combinatorial approach cell transplantation improves scaffold integration and therefore regenerative growth potential. Here, we review the advances in combinatorial therapies of Schwann cells (SCs), astrocytes, olfactory ensheathing cells (OECs), mesenchymal stem cells, as well as neural stem and progenitor cells (NSPCs) with various biomaterial scaffolds.

  20. Synchronized reconstitution of muscle fibers, peripheral nerves and blood vessels by murine skeletal muscle-derived CD34(-)/45 (-) cells.

    Science.gov (United States)

    Tamaki, Tetsuro; Okada, Yoshinori; Uchiyama, Yoshiyasu; Tono, Kayoko; Masuda, Maki; Wada, Mika; Hoshi, Akio; Akatsuka, Akira

    2007-10-01

    In order to establish the practical isolation and usage of skeletal muscle-derived stem cells (MDSCs), we determined reconstitution capacity of CD34(-)/CD45(-) (Sk-DN) cells as a candidate somatic stem cell source for transplantation. Sk-DN cells were enzymatically isolated from GFP transgenic mice (C57/BL6N) skeletal muscle and sorted using fluorescence activated cell sorting (FACS), and expanded by collagen gel-based cell culture with bFGF and EGF. The number of Sk-DN cells was small after sorting (2-8 x 10(4)); however, the number increased 10-20 fold (2-16 x 10(5)) after 6 days of expansion culture, and the cells maintained immature state and multipotency, expressing mRNAs for mesodermal and ectodermal cell lineages. Transplantation of expanded Sk-DN cells into the severe muscle damage model (C57/BL6N wild-type) resulted in the synchronized reconstitution of blood vessels, peripheral nerves and muscle fibers following significant recovery of total muscle mass (57%) and contractile function (55%), whereas the non-cell-transplanted control group showed around 20% recovery in both factors. These reconstitution capacities were supported by the intrinsic plasticity of Sk-DN cells that can differentiate into muscular (skeletal muscle), vascular (pericyte, endothelial cell and smooth muscle) and peripheral nerve (Schwann cells and perineurium) cell lineages that was revealed by transplantation to non-muscle tissue (beneath renal capsule) and fluorescence in situ hybridization (FISH) analysis.

  1. Cell-type specific segregation of transcriptional expression of glial genes in the rat peripheral neurotumor RT4 cell lines.

    Science.gov (United States)

    Hagiwara, N; Imada, S; Sueoka, N

    1993-12-15

    Four types of cells, RT4-AC (stem cell type), RT4-B and RT4-E (neuronal cell types), and RT4-D (glial cell type) were previously isolated from an ethylnitrosourea (ENU) induced rat peripheral neurotumor RT4. In a phenomenon termed cell-type conversion, RT4-AC spontaneously and permanently gives rise to the three other cell types in culture. In the RT4 system the expression of glial fibrillary acidic protein (GFAP) and S100 beta protein genes segregates in a cell-type specific manner. To further characterize the RT4 family, the expression of four myelin-forming glial genes--P0 glycoprotein, suppressed cAMP inducible POU (SCIP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP), and myelin basic protein (MBP)--has been studied in the RT4 cell lines. In addition to these genes, the expression of the low-affinity nerve growth factor (LNGF) receptor (expressed in immature Schwann cells) has been examined. We have found the following results. 1) The stem cell type RT4-AC and the glial cell type RT4-D express mRNA transcripts of P0, SCIP, and CNP (the larger form, 2.8 kb), and the amount of mRNA of these genes was increased by forskolin. 2) RT4-AC and RT4-D also express a low level of MBP mRNA upon forskolin treatment. 3) The neuronal cell types RT4-B and RT4-E do not express any of these myelin-forming glial genes with or without forskolin treatment. 4) The LNGF receptor mRNA is expressed in RT4-AC and RT4-D and at a lower level in RT4-B; its expression is stimulated by forskolin.

  2. Biological behavior of mesenchymal stem cells on poly-ε-caprolactone filaments and a strategy for tissue engineering of segments of the peripheral nerves.

    Science.gov (United States)

    Carrier-Ruiz, A; Evaristo-Mendonça, F; Mendez-Otero, R; Ribeiro-Resende, V T

    2015-07-07

    Peripheral nerves may fail to regenerate across tube implants because these lack the microarchitecture of native nerves. Bone marrow mesenchymal stem cells (MSC) secrete soluble factors that improve the regeneration of the peripheral nerves. Also, microstructured poly-caprolactone (PCL) filaments are capable of inducing bands of Büngner and promote regeneration in the peripheral nervous system (PNS). We describe here the interaction between PCL filaments and MSC, aiming to optimize PNS tubular implants. MSC were plated on PCL filaments for 48 h and the adhesion profile, viability, proliferation and paracrine capacity were evaluated. Also, Schwann cells were plated on PCL filaments covered with MSC for 24 h to analyze the feasibility of the co-culture system. Moreover, E16 dorsal root ganglia were plated in contact with PCL filaments for 4 days to analyze neurite extension. Right sciatic nerves were exposed and a 10 mm nerve segment was removed. Distal and proximal stumps were reconnected inside a 14-mm polyethylene tube, leaving a gap of approximately 13 mm between the two stumps. Animals then received phosphate-buffered saline 1×, PCL filaments or PCL filaments previously incubated with MSC and, after 12 weeks, functional gait performance and histological analyses were made. Statistical analyses were made using Student's unpaired t-test, one-way analysis of variance (ANOVA) or two-way ANOVA followed by Bonferroni post-test. MSC were confined to lateral areas and ridges of PCL filaments, aligning along the longitudinal. MSC showed high viability (90 %), and their proliferation and secretion capabilities were not completely inhibited by the filaments. Schwann cells adhered to filaments plated with MSC, maintaining high viability (90 %). Neurites grew and extended over the surface of PCL filaments, reaching greater distances when over MSC-plated filaments. Axons showed more organized and myelinized fibers and reinnervated significantly more muscle fibers when they

  3. Poly-3-hydroxybutyrate strips seeded with regenerative cells are effective promoters of peripheral nerve repair.

    Science.gov (United States)

    Schaakxs, Dominique; Kalbermatten, Daniel F; Pralong, Etienne; Raffoul, Wassim; Wiberg, Mikael; Kingham, Paul J

    2017-03-01

    Peripheral nerve injuries are often associated with loss of nerve tissue and require a graft to bridge the gap. Autologous nerve grafts are still the 'gold standard' in reconstructive surgery but have several disadvantages, such as sacrifice of a functional nerve, neuroma formation and loss of sensation at the donor site. Bioengineered grafts represent a promising approach to address this problem. In this study, poly-3-hydroxybutyrate (PHB) strips were used to bridge a 10 mm rat sciatic nerve gap and their effects on long-term (12 weeks) nerve regeneration were compared. PHB strips were seeded with different cell types, either primary Schwann cells (SCs) or SC-like differentiated adipose-derived stem cells (dASCs) suspended in a fibrin glue matrix. The control group was PHB and fibrin matrix without cells. Functional and morphological properties of the regenerated nerve were assessed using walking track analysis, EMGs, muscle weight ratios and muscle and nerve histology. The animals treated with PHB strips seeded with SCs or dASCs showed significantly better functional ability than the control group. This correlated with less muscle atrophy and greater axon myelination in the cell groups. These findings suggest that the PHB strip seeded with cells provides a beneficial environment for nerve regeneration. Furthermore, dASCs, which are abundant and easily accessible, constitute an attractive cell source for future applications of cell therapy for the clinical repair of traumatic nerve injuries. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  4. The Palmitoylation State of PMP22 Modulates Epithelial Cell Morphology and Migration

    Directory of Open Access Journals (Sweden)

    Susie J. Zoltewicz

    2012-11-01

    Full Text Available PMP22 (peripheral myelin protein 22, also known as GAS 3 (growth-arrest-specific protein 3, is a disease-linked tetraspan glycoprotein of peripheral nerve myelin and constituent of intercellular junctions in epithelia. To date, our knowledge of the post-translational modification of PMP22 is limited. Using the CSS-Palm 2.0 software we predicted that C85 (cysteine 85, a highly conserved amino acid located between the second and third transmembrane domains, is a potential site for palmitoylation. To test this, we mutated C85S (C85 to serine and established stable cells lines expressing the WT (wild-type or the C85S-PMP22. In Schwann and MDCK (Madin–Darby canine kidney cells mutating C85 blocked the palmitoylation of PMP22, which we monitored using 17-ODYA (17-octadecynoic acid. While palmitoylation was not necessary for processing the newly synthesized PMP22 through the secretory pathway, overexpression of C85S-PMP22 led to pronounced cell spreading and uneven monolayer thinning. To further investigate the functional significance of palmitoylated PMP22, we evaluated MDCK cell migration in a wound-healing assay. While WT-PMP22 expressing cells were resistant to migration, C85S cells displayed lamellipodial protrusions and migrated at a similar rate to vector control. These findings indicate that palmitoylation of PMP22 at C85 is critical for the role of the protein in modulating epithelial cell shape and motility.

  5. Characterizing Mystery Cell Lines: Student-driven Research Projects in an Undergraduate Neuroscience Laboratory Course.

    Science.gov (United States)

    Lemons, Michele L

    2012-01-01

    Inquiry-based projects promote discovery and retention of key concepts, increase student engagement, and stimulate interest in research. Described here are a series of lab exercises within an undergraduate upper level neuroscience course that train students to design, execute and analyze their own hypothesis-driven research project. Prior to developing their own projects, students learn several research techniques including aseptic cell culture, cell line maintenance, immunocytochemistry and fluorescent microscopy. Working in groups, students choose how to use these techniques to characterize and identify a "mystery" cell line. Each lab group is given a unique cell line with either a neural, astrocyte, or Schwann cell origin. Working together, students plan and execute experiments to determine the cellular origin and other unique characteristics of their mystery cell line. Students generate testable hypotheses, design interpretable experiments, generate and analyze data, and report their findings in both oral and written formats. Students receive instructor and peer feedback throughout the entire project. In summary, these labs train students the process of scientific research. This series of lab exercises received very strong positive feedback from the students. Reflections on student feedback and plans for future improvements are discussed.

  6. Sox10-Venus mice: a new tool for real-time labeling of neural crest lineage cells and oligodendrocytes.

    Science.gov (United States)

    Shibata, Shinsuke; Yasuda, Akimasa; Renault-Mihara, Francois; Suyama, Satoshi; Katoh, Hiroyuki; Inoue, Takayoshi; Inoue, Yukiko U; Nagoshi, Narihito; Sato, Momoka; Nakamura, Masaya; Akazawa, Chihiro; Okano, Hideyuki

    2010-10-31

    While several mouse strains have recently been developed for tracing neural crest or oligodendrocyte lineages, each strain has inherent limitations. The connection between human SOX10 mutations and neural crest cell pathogenesis led us to focus on the Sox10 gene, which is critical for neural crest development. We generated Sox10-Venus BAC transgenic mice to monitor Sox10 expression in both normal development and in pathological processes. Tissue fluorescence distinguished neural crest progeny cells and oligodendrocytes in the Sox10-Venus mouse embryo. Immunohistochemical analysis confirmed that Venus expression was restricted to cells expressing endogenous Sox10. Time-lapse imaging of various tissues in Sox10-Venus mice demonstrated that Venus expression could be visualized at the single-cell level in vivo due to the intense, focused Venus fluorescence. In the adult Sox10-Venus mouse, several types of mature and immature oligodendrocytes along with Schwann cells were clearly labeled with Venus, both before and after spinal cord injury. In the newly-developed Sox10-Venus transgenic mouse, Venus fluorescence faithfully mirrors endogenous Sox10 expression and allows for in vivo imaging of live cells at the single-cell level. This Sox10-Venus mouse will thus be a useful tool for studying neural crest cells or oligodendrocytes, both in development and in pathological processes.

  7. Sox10-Venus mice: a new tool for real-time labeling of neural crest lineage cells and oligodendrocytes

    Directory of Open Access Journals (Sweden)

    Shibata Shinsuke

    2010-10-01

    Full Text Available Abstract Background While several mouse strains have recently been developed for tracing neural crest or oligodendrocyte lineages, each strain has inherent limitations. The connection between human SOX10 mutations and neural crest cell pathogenesis led us to focus on the Sox10 gene, which is critical for neural crest development. We generated Sox10-Venus BAC transgenic mice to monitor Sox10 expression in both normal development and in pathological processes. Results Tissue fluorescence distinguished neural crest progeny cells and oligodendrocytes in the Sox10-Venus mouse embryo. Immunohistochemical analysis confirmed that Venus expression was restricted to cells expressing endogenous Sox10. Time-lapse imaging of various tissues in Sox10-Venus mice demonstrated that Venus expression could be visualized at the single-cell level in vivo due to the intense, focused Venus fluorescence. In the adult Sox10-Venus mouse, several types of mature and immature oligodendrocytes along with Schwann cells were clearly labeled with Venus, both before and after spinal cord injury. Conclusions In the newly-developed Sox10-Venus transgenic mouse, Venus fluorescence faithfully mirrors endogenous Sox10 expression and allows for in vivo imaging of live cells at the single-cell level. This Sox10-Venus mouse will thus be a useful tool for studying neural crest cells or oligodendrocytes, both in development and in pathological processes.

  8. Chopper Is Prodeath Regardless of the Effect of p75ICD on Sensitivity to Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Alliya Qazi

    2011-01-01

    Full Text Available Background. The intracellular domain (ICD of the neurotrophin receptor, p75NTR, exhibits variably pro- and antiapoptotic activity and has been implicated in neurodegenerative and neurodestructive disease. The molecular determinants of these cellular effects are not completely understood. The “Chopper” domain of p75ICD has been shown to be proapoptotic in in vitro systems in which p75ICD is proapoptotic. The effects of Chopper in systems in which p75ICD is antiapoptotic and, therefore, whether or not Chopper accounts for the variability of the cellular effects of p75ICD are not known. We therefore examined the effects of deletion of Chopper on the effects of p75ICD on in vitro cell culture systems in which p75ICD is pro- or antiapoptotic, respectively. Results. In HN33.11 murine neuroblastoma-hippocampal neuron hybrid cells, p75ICD is antiapoptotic. In NIH 3T3 cells, p75ICD is proapoptotic. In both cell lines deletion of the Chopper domain from p75ICD decreases the incidence of apoptosis resulting from oxidative stress. Thus, irrespective of the nature of the effects of p75ICD on the cell, its Chopper domain is proapoptotic. Conclusions. Expression of p75ICD can enhance or attenuate oxidative induction of apoptosis. Variability of the effects of p75ICD is not related to variability of the effects of its Chopper domain.

  9. NGF and Its Receptors in the Regulation of Inflammatory Response

    Science.gov (United States)

    Minnone, Gaetana; De Benedetti, Fabrizio; Bracci-Laudiero, Luisa

    2017-01-01

    There is growing interest in the complex relationship between the nervous and immune systems and how its alteration can affect homeostasis and result in the development of inflammatory diseases. A key mediator in cross-talk between the two systems is nerve growth factor (NGF), which can influence both neuronal cell function and immune cell activity. The up-regulation of NGF described in inflamed tissues of many diseases can regulate innervation and neuronal activity of peripheral neurons, inducing the release of immune-active neuropeptides and neurotransmitters, but can also directly influence innate and adaptive immune responses. Expression of the NGF receptors tropomyosin receptor kinase A (TrkA) and p75 neurotrophin receptor (p75NTR) is dynamically regulated in immune cells, suggesting a varying requirement for NGF depending on their state of differentiation and functional activity. NGF has a variety of effects that can be either pro-inflammatory or anti-inflammatory. This apparent contradiction can be explained by considering NGF as part of an endogenous mechanism that, while activating immune responses, also activates pathways necessary to dampen the inflammatory response and limit tissue damage. Decreases in TrkA expression, such as that recently demonstrated in immune cells of arthritis patients, might prevent the activation by NGF of regulatory feed-back mechanisms, thus contributing to the development and maintenance of chronic inflammation. PMID:28492466

  10. p21-Activated kinases are required for transformation in a cell-based model of neurofibromatosis type 2.

    Directory of Open Access Journals (Sweden)

    Hoi Yee Chow

    2010-11-01

    Full Text Available NF2 is an autosomal dominant disease characterized by development of bilateral vestibular schwannomas and other benign tumors in central nervous system. Loss of the NF2 gene product, Merlin, leads to aberrant Schwann cell proliferation, motility, and survival, but the mechanisms by which this tumor suppressor functions remain unclear. One well-defined target of Merlin is the group I family of p21-activated kinases, which are allosterically inhibited by Merlin and which, when activated, stimulate cell cycle progression, motility, and increased survival. Here, we examine the effect of Pak inhibition on cells with diminished Merlin function.Using a specific peptide inhibitor of group I Paks, we show that loss of Pak activity restores normal cell movement in cells lacking Merlin function. In addition, xenografts of such cells form fewer and smaller tumors than do cells without Pak inhibition. However, in tumors, loss of Pak activity does not reduce Erk or Akt activity, two signaling proteins that are thought to mediate Pak function in growth factor pathways.These results suggest that Pak functions in novel signaling pathways in NF2, and may serve as a useful therapeutic target in this disease.

  11. Characterization of developmental stage and neuronal potential of the rat PNS-derived stem cell line, RT4-AC.

    Science.gov (United States)

    Donahue, L M; Coates, P W; Reinhart, A J

    1996-06-14

    RT4 is a family of cell lines derived from a rat peripheral neurotumor and consists of a multipotential stem cell line that spontaneously gives rise to three derivative cell types: one glial-like and two neuronal-like. Previous studies have established that the RT4 glial derivative expresses many properties of Schwann cells; however, the neuronal designation of the other RT4 derivatives is less well substantiated. To further characterize the developmental stage and lineages represented by the RT4 stem cell and its derivatives we examined the expression of 16 marker genes whose expression is either specific to neurons or in some cases, neural tissue. Taken together our results indicate that (i) the RT4 neuronal-like derivatives express only immature neuronal properties, (ii) the RT4 cell lines most closely resemble neural crest derivatives from embryonic day 10 to 12 in the rat, (iii) treatment with cAMP and steroids, although capable of promoting process extension by the RT4 neuronal-like derivatives, did not affect the expression of any of the 16 marker genes examined, and (iv) when compared to other neural stem cell systems, RT4-AC generates the most immature neuronal derivatives.

  12. Reconstitution of experimental neurogenic bladder dysfunction using skeletal muscle-derived multipotent stem cells.

    Science.gov (United States)

    Nitta, Masahiro; Tamaki, Tetsuro; Tono, Kayoko; Okada, Yoshinori; Masuda, Maki; Akatsuka, Akira; Hoshi, Akio; Usui, Yukio; Terachi, Toshiro

    2010-05-15

    BACKGROUND.: Postoperative neurogenic bladder dysfunction is a major complication of radical hysterectomy for cervical cancer and is mainly caused by unavoidable damage to the bladder branch of the pelvic plexus (BBPP) associated with colateral blood vessels. Thus, we attempted to reconstitute disrupted BBPP and blood vessels using skeletal muscle-derived multipotent stem cells that show synchronized reconstitution capacity of vascular, muscular, and peripheral nervous systems. METHODS.: Under pentobarbital anesthesia, intravesical pressure by electrical stimulation of BBPP was measured as bladder function. The distal portion of BBPP with blood vessels was then cut unilaterally (experimental neurogenic bladder model). Measurements were performed before, immediately after, and at 4 weeks after transplantation as functional recovery. Stem cells were obtained from the right soleus and gastrocnemius muscles after enzymatic digestion and cell sorting as CD34/45 (Sk-34) and CD34/45 (Sk-DN). Suspended cells were autografted around the damaged region, whereas medium alone and CD45 cells were transplanted as control groups. To determine the morphological contribution of the transplanted cells, stem cells obtained from green fluorescent protein transgenic mouse muscles were transplanted into a nude rat model and were examined by immunohistochemistry and immunoelectron microscopy. RESULTS.: At 4 weeks after surgery, the transplantation group showed significantly higher functional recovery ( approximately 80%) than the two controls ( approximately 28% and 24%). The transplanted cells showed an incorporation into the damaged peripheral nerves and blood vessels after differentiation into Schwann cells, perineurial cells, vascular smooth muscle cells, pericytes, and fibroblasts around the bladder. CONCLUSION.: Transplantation of multipotent Sk-34 and Sk-DN cells is potentially useful for the reconstitution of damaged BBPP.

  13. Small Molecule Agonists of Cell Adhesion Molecule L1 Mimic L1 Functions In Vivo.

    Science.gov (United States)

    Kataria, Hardeep; Lutz, David; Chaudhary, Harshita; Schachner, Melitta; Loers, Gabriele

    2016-09-01

    Lack of permissive mechanisms and abundance of inhibitory molecules in the lesioned central nervous system of adult mammals contribute to the failure of functional recovery after injury, leading to severe disabilities in motor functions and pain. Peripheral nerve injury impairs motor, sensory, and autonomic functions, particularly in cases where nerve gaps are large and chronic nerve injury ensues. Previous studies have indicated that the neural cell adhesion molecule L1 constitutes a viable target to promote regeneration after acute injury. We screened libraries of known drugs for small molecule agonists of L1 and evaluated the effect of hit compounds in cell-based assays in vitro and in mice after femoral nerve and spinal cord injuries in vivo. We identified eight small molecule L1 agonists and showed in cell-based assays that they stimulate neuronal survival, neuronal migration, and neurite outgrowth and enhance Schwann cell proliferation and migration and myelination of neurons in an L1-dependent manner. In a femoral nerve injury mouse model, enhanced functional regeneration and remyelination after application of the L1 agonists were observed. In a spinal cord injury mouse model, L1 agonists improved recovery of motor functions, being paralleled by enhanced remyelination, neuronal survival, and monoaminergic innervation, reduced astrogliosis, and activation of microglia. Together, these findings suggest that application of small organic compounds that bind to L1 and stimulate the beneficial homophilic L1 functions may prove to be a valuable addition to treatments of nervous system injuries.

  14. Localization of the DMDL gene-encoded dystrophin-related protein using a panel of nineteen monoclonal antibodies: presence at neuromuscular junctions, in the sarcolemma of dystrophic skeletal muscle, in vascular and other smooth muscles, and in proliferating brain cell lines.

    Science.gov (United States)

    Nguyen, T M; Ellis, J M; Love, D R; Davies, K E; Gatter, K C; Dickson, G; Morris, G E

    1991-12-01

    mAbs have been raised against different epitopes on the protein product of the DMDL gene, which is an autosomal homologue of the X-linked DMD gene for dystrophin. These antibodies provide direct evidence that DMDL protein is localized near acetylcholine receptors at neuromuscular junctions in normal and mdx mouse intercostal muscle. The primary location in tissues other than skeletal muscle is smooth muscle, especially in the vascular system, which may account for the wide tissue distribution previously demonstrated by Western blotting. The DMDL protein was undetectable in the nonjunctional sarcolemma of normal human muscle, but was observed in nonjunctional sarcolemma of Duchenne muscular dystrophy patients, where dystrophin itself is absent or greatly reduced. The expression of DMDL protein is not restricted to smooth and skeletal muscle, however, since relatively large amounts are present in transformed brain cell lines of both glial and Schwann cell origin. This contrasts with the low levels of DMDL protein in adult brain tissue.

  15. Alterations in the Local Axonal Environment Influence Target Reinnervation and Neuronal Survival after Postnatal Axotomy

    National Research Council Canada - National Science Library

    Dainer, Hugh M

    2000-01-01

    Following peripheral nerve injury in adult animals, Schwann cells (SC) proliferate and provide guidance in the local axonal environment by generating the infrastructure along which regenerating nerves grow...

  16. Melanotic schwannoma of the lumbar spine: a case report and literature review

    National Research Council Canada - National Science Library

    Rodrigues, João Bernardo Sancio Rocha; Saleme, Nathália Ambrozim Santos; Jacob Junior, Charbel; Batista Junior, José Lucas; Cardoso, Igor Machado; Motta, Luciene Lage da; Lugão, Rodrigo dos Santos; Rezende, Rodrigo

    2015-01-01

    Schwannomas are benign tumors, usually solitary, encapsulated, slow-growing, which have their origin in differentiated neoplastic Schwann cells with extramedullary intradural usual development related to nerve roots...

  17. Brain-derived neurotrophic factor is increased in serum and skin levels of patients with chronic spontaneous urticaria.

    Science.gov (United States)

    Rössing, K; Novak, N; Mommert, S; Pfab, F; Gehring, M; Wedi, B; Kapp, A; Raap, U

    2011-10-01

    Chronic spontaneous urticaria is triggered by many direct and indirect aggravating factors including autoreactive/autoimmune mechanisms, infections, non-allergic and pseudoallergic intolerance reactions. However, the role of neuroimmune mechanisms in chronic spontaneous urticaria so far is unclear. Thus, we wanted to address the regulation of the neurotrophin brain-derived neurotrophic factor (BDNF) in serum and inflammatory skin of patients with chronic spontaneous urticaria in comparison to subjects with healthy skin. Fifty adult patients with chronic spontaneous urticaria and 23 skin-healthy subjects were studied. Chronic spontaneous urticaria was defined as recurrent weals for more than 6 weeks. Autologous serum skin test was performed in all patients with chronic spontaneous urticaria and BDNF serum levels were analysed by enzyme immunoassay in all subjects. Furthermore, skin biopsies were taken from weals of eight patients with chronic spontaneous urticaria as well as from healthy skin of eight controls to evaluate the expression of BDNF and its receptors including tyrosine kinase (trk) B and pan-neurotrophin receptor p75(NTR) by immunohistochemistry. BDNF serum levels were detectable in all subjects studied. However, BDNF levels were significantly higher in patients with chronic spontaneous urticaria compared to non-atopic skin-healthy controls (Pneurotrophins in the pathophysiology of this chronic inflammatory skin disease. Further studies are needed to address the functional role of BDNF on key target effector cells in chronic spontaneous urticaria to establish new therapeutic implications. © 2011 Blackwell Publishing Ltd.

  18. Predicted 3D Model of the Rabies Virus Glycoprotein Trimer

    Directory of Open Access Journals (Sweden)

    Bastida-González Fernando

    2016-01-01

    Full Text Available The RABVG ectodomain is a homotrimer, and trimers are often called spikes. They are responsible for the attachment of the virus through the interaction with nicotinic acetylcholine receptors, neural cell adhesion molecule (NCAM, and the p75 neurotrophin receptor (p75NTR. This makes them relevant in viral pathogenesis. The antigenic structure differs significantly between the trimers and monomers. Surfaces rich in hydrophobic amino acids are important for trimer stabilization in which the C-terminal of the ectodomain plays an important role; to understand these interactions between the G proteins, a mechanistic study of their functions was performed with a molecular model of G protein in its trimeric form. This verified its 3D conformation. The molecular modeling of G protein was performed by a I-TASSER server and was evaluated via a Rachamandran plot and ERRAT program obtained 84.64% and 89.9% of the residues in the favorable regions and overall quality factor, respectively. The molecular dynamics simulations were carried out on RABVG trimer at 310 K. From these theoretical studies, we retrieved the RMSD values from Cα atoms to assess stability. Preliminary model of G protein of rabies virus stable at 12 ns with molecular dynamics was obtained.

  19. Nerve growth factor regulates neurolymphatic remodeling during corneal inflammation and resolution.

    Science.gov (United States)

    Fink, Darci M; Connor, Alicia L; Kelley, Philip M; Steele, Maria M; Hollingsworth, Michael A; Tempero, Richard M

    2014-01-01

    The cellular and physiologic mechanisms that regulate the resolution of inflammation remain poorly defined despite their widespread importance in improving inflammatory disease outcomes. We studied the resolution of two cardinal signs of inflammation-pain and swelling-by investigating molecular mechanisms that regulate neural and lymphatic vessel remodeling during the resolution of corneal inflammation. A mouse model of corneal inflammation and wound recovery was developed to study this process in vivo. Administration of nerve growth factor (NGF) increased pain sensation and inhibited neural remodeling and lymphatic vessel regression processes during wound recovery. A complementary in vivo approach, the corneal micropocket assay, revealed that NGF-laden pellets stimulated lymphangiogenesis and increased protein levels of VEGF-C. Adult human dermal lymphatic endothelial cells did not express canonical NGF receptors TrkA and p75NTR or activate downstream MAPK- or Akt-pathway effectors in the presence of NGF, although NGF treatment increased their migratory and tubulogenesis capacities in vitro. Blockade of the VEGF-R2/R3 signaling pathway ablated NGF-mediated lymphangiogenesis in vivo. These findings suggest a hierarchical relationship with NGF functioning upstream of the VEGF family members, particularly VEGF-C, to stimulate lymphangiogenesis. Taken together, these studies show that NGF stimulates lymphangiogenesis and that NGF may act as a pathogenic factor that negatively regulates the normal neural and lymphatic vascular remodeling events that accompany wound recovery.

  20. Nerve growth factor regulates neurolymphatic remodeling during corneal inflammation and resolution.

    Directory of Open Access Journals (Sweden)

    Darci M Fink

    Full Text Available The cellular and physiologic mechanisms that regulate the resolution of inflammation remain poorly defined despite their widespread importance in improving inflammatory disease outcomes. We studied the resolution of two cardinal signs of inflammation-pain and swelling-by investigating molecular mechanisms that regulate neural and lymphatic vessel remodeling during the resolution of corneal inflammation. A mouse model of corneal inflammation and wound recovery was developed to study this process in vivo. Administration of nerve growth factor (NGF increased pain sensation and inhibited neural remodeling and lymphatic vessel regression processes during wound recovery. A complementary in vivo approach, the corneal micropocket assay, revealed that NGF-laden pellets stimulated lymphangiogenesis and increased protein levels of VEGF-C. Adult human dermal lymphatic endothelial cells did not express canonical NGF receptors TrkA and p75NTR or activate downstream MAPK- or Akt-pathway effectors in the presence of NGF, although NGF treatment increased their migratory and tubulogenesis capacities in vitro. Blockade of the VEGF-R2/R3 signaling pathway ablated NGF-mediated lymphangiogenesis in vivo. These findings suggest a hierarchical relationship with NGF functioning upstream of the VEGF family members, particularly VEGF-C, to stimulate lymphangiogenesis. Taken together, these studies show that NGF stimulates lymphangiogenesis and that NGF may act as a pathogenic factor that negatively regulates the normal neural and lymphatic vascular remodeling events that accompany wound recovery.

  1. Topical administration of adrenergic receptor pharmaceutics and nerve growth factor

    Directory of Open Access Journals (Sweden)

    Jena J Steinle

    2010-06-01

    Full Text Available Jena J SteinleDepartments of Ophthalmology and Anatomy and Neurobiology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN 38163, USAAbstract: Topical application of nerve growth factor (NGF and adrenergic receptor pharmaceutics are currently in use for corneal ulcers and glaucoma. A recent interest in the neuroprotective abilities of NGF has led to a renewed interest in NGF as a therapeutic for retinal and choroidal diseases. NGF can promote cell proliferation through actions of the TrkA receptor or promote apoptosis through receptor p75NTR. This understanding has led to novel interest in the role of NGF for diseases of the posterior eye. The role of β-adrenergic receptor agonists and antagonists for treatments of glaucoma, diabetic retinopathy, and their potential mechanisms of action, are still under investigation. This review discusses the current knowledge and applications of topical NGF and adrenergic receptor drugs for ocular disease.Keywords: NGF, β-adrenergic receptor agents, α-adrenergic receptor agents, retina, cornea, glaucoma

  2. TROY and LINGO-1 expression in astrocytes and macrophages/microglia in multiple sclerosis lesions.

    Science.gov (United States)

    Satoh, J; Tabunoki, H; Yamamura, T; Arima, K; Konno, H

    2007-02-01

    Nogo constitutes a family of neurite outgrowth inhibitors contributing to a failure of axonal regeneration in the adult central nervous system (CNS). Nogo-A is expressed exclusively on oligodendrocytes where Nogo-66 segment binds to Nogo receptor (NgR) expressed on neuronal axons. NgR signalling requires a coreceptor p75(NTR) or TROY in combination with an adaptor LINGO-1. To characterize the cell types expressing the NgR complex in the human CNS, we studied demyelinating lesions of multiple sclerosis (MS) brains by immunohistochemistry. TROY and LINGO-1 were identified in subpopulations of reactive astrocytes, macrophages/microglia and neurones but not in oligodendrocytes. TROY was up-regulated, whereas LINGO-1 was reduced in MS brains by Western blot. These results suggest that the ternary complex of NgR/TROY/LINGO-1 expressed on astrocytes, macrophages/microglia and neurones, by interacting with Nogo-A on oligodendrocytes, might modulate glial-neuronal interactions in demyelinating lesions of MS.

  3. Expression pattern of LINGO-1 in the developing nervous system of the chick embryo.

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    Okafuji, Tatsuya; Tanaka, Hideaki

    2005-12-01

    We isolated a chick homologue of LINGO-1 (cLINGO-1), a novel component of the Nogo-66 receptor (NgR)/p75 neurotrophin receptor (NTR) signaling complex, and examined the expression of cLINGO-1 in the developing brain and spinal cord of the chick embryo by in situ hybridization and immunohistochemistry. cLINGO-1 was expressed broadly in the spinal cord, including the ventral portion of the ventricular zone, and motor neurons. cLINGO-1 was also expressed in the dorsal root ganglion and boundary cap cells at dorsal and ventral roots. In the early embryonic brain, cLINGO-1 was first expressed in the prosencephalon and the ventral mesencephalon, and later in the telencephalon, the rostral part of the mesencephalon and some parts of the hindbrain. cLINGO-1 was also expressed in the ventral part of the neural retina and trigeminal and facial nerves. We also found that cLINGO-1, cNgR1 and p75NTR were expressed in overlapped patterns in the spinal cord and the dorsal root ganglion, but that these genes were expressed in distinct patterns in the early embryonic brain.

  4. An All-Recombinant Protein-Based Culture System Specifically Identifies Hematopoietic Stem Cell Maintenance Factors

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    Aki Ieyasu

    2017-03-01

    Full Text Available Hematopoietic stem cells (HSCs are considered one of the most promising therapeutic targets for the treatment of various blood disorders. However, due to difficulties in establishing stable maintenance and expansion of HSCs in vitro, their insufficient supply is a major constraint to transplantation studies. To solve these problems we have developed a fully defined, all-recombinant protein-based culture system. Through this system, we have identified hemopexin (HPX and interleukin-1α as responsible for HSC maintenance in vitro. Subsequent molecular analysis revealed that HPX reduces intracellular reactive oxygen species levels within cultured HSCs. Furthermore, bone marrow immunostaining and 3D immunohistochemistry revealed that HPX is expressed in non-myelinating Schwann cells, known HSC niche constituents. These results highlight the utility of this fully defined all-recombinant protein-based culture system for reproducible in vitro HSC culture and its potential to contribute to the identification of factors responsible for in vitro maintenance, expansion, and differentiation of stem cell populations.

  5. Investigation of cell adhesion in chitosan membranes for peripheral nerve regeneration.

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    Carvalho, Cristiana R; López-Cebral, Rita; Silva-Correia, Joana; Silva, Joana M; Mano, João F; Silva, Tiago H; Freier, Thomas; Reis, Rui L; Oliveira, Joaquim M

    2017-02-01

    Peripheral nerve injuries have produced major concerns in regenerative medicine for several years, as the recovery of normal nerve function continues to be a significant clinical challenge. Chitosan (CHT), because of its good biocompatibility, biodegradability and physicochemical properties, has been widely used as a biomaterial in tissue engineering scaffolding. In this study, CHT membranes were produced with three different Degrees of Acetylation (DA), envisioning its application in peripheral nerve regeneration. The three CHT membranes (DA I: 1%, DA II: 2%, DA III: 5%) were extensively characterized and were found to have a smooth and flat surface, with DA III membrane having slightly higher roughness and surface energy. All the membranes presented suitable mechanical properties and did not show any signs of calcification after SBF test. Biodegradability was similar for all samples, and adequate to physically support neurite outgrowth. The in vitro cell culture results indicate selective cell adhesion. The CHT membranes favoured Schwann cells invasion and proliferation, with a display of appropriate cytoskeletal morphology. At the same time they presented low fibroblast infiltration. This fact may be greatly beneficial for the prevention of fibrotic tissue formation, a common phenomenon impairing peripheral nerve regeneration. The great deal of results obtained during this work permitted to select the formulation with the greatest potential for further biological tests. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Nanofibrous scaffolds for the guidance of stem cell-derived neurons for auditory nerve regeneration.

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    Sandra Hackelberg

    Full Text Available Impairment of spiral ganglion neurons (SGNs of the auditory nerve is a major cause for hearing loss occurring independently or in addition to sensory hair cell damage. Unfortunately, mammalian SGNs lack the potential for autonomous regeneration. Stem cell based therapy is a promising approach for auditory nerve regeneration, but proper integration of exogenous cells into the auditory circuit remains a fundamental challenge. Here, we present novel nanofibrous scaffolds designed to guide the integration of human stem cell-derived neurons in the internal auditory meatus (IAM, the foramen allowing passage of the spiral ganglion to the auditory brainstem. Human embryonic stem cells (hESC were differentiated into neural precursor cells (NPCs and seeded onto aligned nanofiber mats. The NPCs terminally differentiated into glutamatergic neurons with high efficiency, and neurite projections aligned with nanofibers in vitro. Scaffolds were assembled by seeding GFP-labeled NPCs on nanofibers integrated in a polymer sheath. Biocompatibility and functionality of the NPC-seeded scaffolds were evaluated in vivo in deafened guinea pigs (Cavia porcellus. To this end, we established an ouabain-based deafening procedure that depleted an average 72% of SGNs from apex to base of the cochleae and caused profound hearing loss. Further, we developed a surgical procedure to implant seeded scaffolds directly into the guinea pig IAM. No evidence of an inflammatory response was observed, but post-surgery tissue repair appeared to be facilitated by infiltrating Schwann cells. While NPC survival was found to be poor, both subjects implanted with NPC-seeded and cell-free control scaffolds showed partial recovery of electrically-evoked auditory brainstem thresholds. Thus, while future studies must address cell survival, nanofibrous scaffolds pose a promising strategy for auditory nerve regeneration.

  7. Transplantation of dental pulp stem cells improves long-term diabetic polyneuropathy together with improvement of nerve morphometrical evaluation.

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    Omi, Maiko; Hata, Masaki; Nakamura, Nobuhisa; Miyabe, Megumi; Ozawa, Shogo; Nukada, Hitoshi; Tsukamoto, Masami; Sango, Kazunori; Himeno, Tatsuhito; Kamiya, Hideki; Nakamura, Jiro; Takebe, Jun; Matsubara, Tatsuaki; Naruse, Keiko

    2017-12-13

    Although previous reports have revealed the therapeutic potential of stem cell transplantation in diabetic polyneuropathy, the effects of cell transplantation on long-term diabetic polyneuropathy have not been investigated. In this study, we investigated whether the transplantation of dental pulp stem cells (DPSCs) ameliorated long-term diabetic polyneuropathy in streptozotocin (STZ)-induced diabetic rats. Forty-eight weeks after STZ injection, we transplanted DPSCs into the unilateral hindlimb skeletal muscles. Four weeks after DPSC transplantation (i.e., 52 weeks after STZ injection) the effects of DPSC transplantation on diabetic polyneuropathy were assessed. STZ-induced diabetic rats showed significant reductions in the sciatic motor/sensory nerve conduction velocity, increases in the current perception threshold, and decreases in capillary density in skeletal muscles and intra-epidermal nerve fiber density compared with normal rats, all of which were ameliorated by DPSC transplantation. Furthermore, sural nerve morphometrical analysis revealed that the transplantation of DPSCs significantly increased the myelin thickness and area. DPSC-conditioned media promoted the neurite outgrowth of dorsal root ganglion neurons and increased the viability and myelin-related protein expression of Schwann cells. These results indicated that the transplantation of DPSCs contributed to the neurophysiological and neuropathological recovery from a long duration of diabetic polyneuropathy.

  8. Isolation and characterization of two kinds of stem cells from the same human skin back sample with therapeutic potential in spinal cord injury.

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    Zhaowen Zong

    Full Text Available BACKGROUNDS AND OBJECTIVE: Spinal cord injury remains to be a challenge to clinicians and it is attractive to employ autologous adult stem cell transplantation in its treatment, however, how to harvest cells with therapeutic potential easily and how to get enough number of cells for transplantation are challenging issues. In the present study, we aimed to isolate skin-derived precursors (SKPs and dermal multipotent stem cells (dMSCs simultaneously from single human skin samples from patients with paraplegia. METHODS: Dissociated cells were initially generated from the dermal layer of skin samples from patients with paraplegia and cultured in SKPs proliferation medium. Four hours later, many cells adhered to the base of the flask. The suspended cells were then transferred to another flask for further culture as SKPs, while the adherent cells were cultured in dMSCs proliferation medium. Twenty-four hours later, the adherent cells were harvested and single-cell colonies were generated using serial dilution method. [(3H]thymidine incorporation assay, microchemotaxis Transwell chambers assay, RT-PCR and fluorescent immunocytochemistry were employed to examine the characterizations of the isolated cells. RESULTS: SKPs and dMSCs were isolated simultaneously from a single skin sample. SKPs and dMSCs differed in several respects, including in terms of intermediate protein expression, proliferation capacities, and differentiation tendencies towards mesodermal and neural progenies. However, both SKPs and dMSCs showed high rates of differentiation into neurons and Schwann cells under appropriate inducing conditions. dMSCs isolated by this method showed no overt differences from dMSCs isolated by routine methods. CONCLUSIONS: Two kinds of stem cells, namely SKPs and dMSCs, can be isolated simultaneously from individual human skin sample from paraplegia patients. Both of them show ability to differentiate into neural cells under proper inducing conditions

  9. The effect of lithium on hematopoietic, mesenchymal and neural stem cells.

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    Ferensztajn-Rochowiak, Ewa; Rybakowski, Janusz K

    2016-04-01

    Lithium has been used in modern psychiatry for more than 65 years, constituting a cornerstone for the long-term treatment of bipolar disorder. A number of biological properties of lithium have been discovered, including its hematological, antiviral and neuroprotective effects. In this article, a systematic review of the effect of lithium on hematopoietic, mesenchymal and neural stem cells is presented. The beneficial effects of lithium on the level of hematopoietic stem cells (HSC) and growth factors have been reported since 1970s. Lithium improves homing of stem cells, the ability to form colonies and HSC self-renewal. Lithium also exerts a favorable influence on the proliferation and maintenance of mesenchymal stem cells (MSC). Studies on the effect of lithium on neurogenesis have indicated an increased proliferation of progenitor cells in the dentate gyrus of the hippocampus and enhanced mitotic activity of Schwann cells. This may be connected with the neuroprotective and neurotrophic effects of lithium, reflected in an improvement in synaptic plasticity promoting cell survival and inhibiting apoptosis. In clinical studies, lithium treatment increases cerebral gray matter, mainly in the frontal lobes, hippocampus and amygdala. Recent findings also suggest that lithium may reduce the risk of dementia and exert a beneficial effect in neurodegenerative diseases. The most important mediators and signaling pathways of lithium action are the glycogen synthase kinase-3 and Wnt/β-catenin pathways. Recently, to study of bipolar disorder pathogenesis and the mechanism of lithium action, the induced pluripotent stem cells (iPSC) obtained from bipolar patients have been used. Copyright © 2015 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  10. Therapeutic isolation and expansion of human skeletal muscle-derived stem cells for the use of muscle-nerve-blood vessel reconstitution

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    Tetsuro eTamaki

    2015-06-01

    Full Text Available Skeletal muscle makes up 40-50% of body mass, and is thus considered to be a good adult stem cell source for autologous therapy. Although, several stem/progenitor cells have been fractionated from mouse skeletal muscle showing a high potential for therapeutic use, it is unclear whether this is the case in human. Differentiation and therapeutic potential of human skeletal muscle-derived cells (Sk-Cs was examined. Samples (5-10 g were obtained from the abdominal and leg muscles of 36 patients (age, 17-79 years undergoing prostate cancer treatment or leg amputation surgery. All patients gave informed consent. Sk-Cs were isolated using conditioned collagenase solution, and were then sorted as CD34-/CD45-/CD29+ (Sk-DN/29+ and CD34+/CD45- (Sk-34 cells, in a similar manner as for the previous mouse Sk-Cs. Both cell fractions were appropriately expanded using conditioned culture medium for about 2 weeks. Differentiation potentials were then examined during cell culture and in vivo transplantation into the severely damaged muscles of athymic nude mice and rats. Interestingly, these two cell fractions could be divided into highly myogenic (Sk-DN/29+ and multipotent stem cell (Sk-34 fractions, in contrast to mouse Sk-Cs, which showed comparable capacities in both cells. At 6 weeks after the separate transplantation of both cell fractions, the former showed an active contribution to muscle fiber regeneration, but the latter showed vigorous engraftment to the interstitium associated with differentiation into Schwann cells, perineurial/endoneurial cells, and vascular endothelial cells and pericytes, which corresponded to previous observations with mouse SK-Cs. Importantly, mixed cultures of both cells resulted the reduction of tissue reconstitution capacities in vivo, whereas co-transplantation after separate expansion showed favorable results. Therefore, human Sk-Cs are potentially applicable to therapeutic autografts and show multiple differentiation

  11. Evaluation of clinical experience using cell-based therapies in patients with spinal cord injury: a systematic review.

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    Harrop, James S; Hashimoto, Robin; Norvell, Dan; Raich, Annie; Aarabi, Bizhan; Grossman, Robert G; Guest, James D; Tator, Charles H; Chapman, Jens; Fehlings, Michael G

    2012-09-01

    Using a systematic approach, the authors evaluated the current utilization, safety, and effectiveness of cellular therapies for traumatic spinal cord injuries (SCIs) in humans. A systematic search and critical review of the literature published through mid-January 2012 was performed. Articles included in the search were restricted to the English language, studies with at least 10 patients, and those analyzing cellular therapies for traumatic SCI. Citations were evaluated for relevance using a priori criteria, and those that met the inclusion criteria were critically reviewed. Each article was then designated a level of evidence that was developed by the Oxford Centre for Evidence-Based Medicine. The initial literature search identified 651 relevant articles, which decreased to 350 after excluding case reports and reviews. Evaluation of articles at the title/abstract level, and later at the full-text level, limited the final