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Sample records for schwann cell p75ntr

  1. NADE, a p75NTR-associated cell death executor, is involved in signal transduction mediated by the common neurotrophin receptor p75NTR.

    Science.gov (United States)

    Mukai, J; Hachiya, T; Shoji-Hoshino, S; Kimura, M T; Nadano, D; Suvanto, P; Hanaoka, T; Li, Y; Irie, S; Greene, L A; Sato, T A

    2000-06-09

    The low affinity neurotrophin receptor p75NTR can mediate cell survival as well as cell death of neural cells by NGF and other neurotrophins. To elucidate p75NTR-mediated signal transduction, we screened p75NTR-associated proteins by a yeast two-hybrid system. We identified one positive clone and named NADE (p75NTR-associated cell death executor). Mouse NADE has marked homology to the human HGR74 protein. NADE specifically binds to the cell-death domain of p75NTR. Co-expression of NADE and p75NTR induced caspase-2 and caspase-3 activities and the fragmentation of nuclear DNA in 293T cells. However, in the absence of p75NTR, NADE failed to induce apoptosis, suggesting that NADE expression is necessary but insufficient for p75NTR-mediated apoptosis. Furthermore, p75NTR/NADE-induced cell death was dependent on NGF but not BDNF, NT-3, or NT-4/5, and the recruitment of NADE to p75NTR (intracellular domain) was dose-dependent. We obtained similar results from PC12 cells, nnr5 cells, and oligodendrocytes. Taken together, NADE is the first signaling adaptor molecule identified in the involvement of p75NTR-mediated apoptosis induced by NGF, and it may play an important role in the pathogenesis of neurogenetic diseases.

  2. Self-renewal and chemotherapy resistance of p75NTR positive cells in esophageal squamous cell carcinomas

    International Nuclear Information System (INIS)

    Huang, Sheng-Dong; Yuan, Yang; Liu, Xiao-Hong; Gong, De-Jun; Bai, Chen-Guang; Wang, Feng; Luo, Jun-Hui; Xu, Zhi-Yun

    2009-01-01

    p75 NTR has been used to isolate esophageal and corneal epithelial stem cells. In the present study, we investigated the expression of p75 NTR in esophageal squamous cell carcinoma (ESCC) and explored the biological properties of p75 NTR+ cells. p75 NTR expression in ESCC was assessed by immunohistochemistry. p75 NTR+ and p75 NTR- cells of 4 ESCC cell lines were separated by fluorescence-activated cell sorting. Differentially expressed genes between p75 NTR+ and p75 NTR- cells were determined by real-time quantitative reverse transcription-PCR. Sphere formation assay, DDP sensitivity assay, 64 copper accumulation assay and tumorigenicity analysis were performed to determine the capacity of self-renewal, chemotherapy resistance and tumorigenicity of p75 NTR+ cells. In ESCC specimens, p75 NTR was found mainly confined to immature cells and absent in cells undergoing terminal differentiation. The percentage of p75 NTR+ cells was 1.6%–3.7% in Eca109 and 3 newly established ESCC cell lines. The expression of Bmi-1, which is associated with self-renewal of stem cells, was significantly higher in p75 NTR+ cells. p63, a marker identified in keratinocyte stem cells, was confined mainly to p75 NTR+ cells. The expression of CTR1, which is associated with cisplatin (DDP)-resistance, was significantly decreased in p75 NTR+ cells. Expression levels of differentiation markers, such as involucrin, cytokeratin 13, β1-integrin and β4-integrin, were lower in p75 NTR+ cells. In addition, p75 NTR+ cells generated both p75 NTR+ and p75 NTR- cells, and formed nonadherent spherical clusters in serum-free medium supplemented with growth factors. Furthermore, p75 NTR+ cells were found to be more resistant to DDP and exhibited lower 64 copper accumulation than p75 NTR- cells. Our results demonstrated that p75 NTR+ cells possess some characteristics of CSCs, namely, self-renewal and chemotherapy resistance. Chemotherapy resistance of p75 NTR+ cells may probably be attributable to

  3. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Bandoła, Joanna; Richter, Cornelia; Ryser, Martin; Jamal, Arshad; Ashton, Michelle P; von Bonin, Malte; Kuhn, Matthias; Dorschner, Benjamin; Alexopoulou, Dimitra; Navratiel, Katrin; Roeder, Ingo; Dahl, Andreas; Hedrich, Christian M; Bonifacio, Ezio; Brenner, Sebastian; Thieme, Sebastian

    2017-01-01

    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.

  6. The p75NTR tumor suppressor induces cell cycle arrest facilitating caspase mediated apoptosis in prostate tumor cells

    International Nuclear Information System (INIS)

    Khwaja, Fatima; Tabassum, Arshia; Allen, Jeff; Djakiew, Daniel

    2006-01-01

    The p75 neurotrophin receptor (p75 NTR ) is a death receptor which belongs to the tumor necrosis factor receptor super-family of membrane proteins. This study shows that p75 NTR retarded cell cycle progression by induced accumulation of cells in G0/G1 and a reduction in the S phase of the cell cycle. The rescue of tumor cells from cell cycle progression by a death domain deleted (ΔDD) dominant-negative antagonist of p75 NTR showed that the death domain transduced anti-proliferative activity in a ligand-independent manner. Conversely, addition of NGF ligand rescued retardation of cell cycle progression with commensurate changes in components of the cyclin/cdk holoenzyme complex. In the absence of ligand, p75 NTR -dependent cell cycle arrest facilitated an increase in apoptotic nuclear fragmentation of the prostate cancer cells. Apoptosis of p75 NTR expressing cells occurred via the intrinsic mitochondrial pathway leading to a sequential caspase-9 and -7 cascade. Since the death domain deleted dominant-negative antagonist of p75 NTR rescued intrinsic caspase associated apoptosis in PC-3 cells, this shows p75 NTR was integral to ligand independent induction of apoptosis. Moreover, the ability of ligand to ameliorate the p75 NTR -dependent intrinsic apoptotic cascade indicates that NGF functioned as a survival factor for p75 NTR expressing prostate cancer cells

  7. Carprofen Induction of p75NTR Dependent Apoptosis via the p38 MAPK Pathway in Prostate Cancer Cells

    Science.gov (United States)

    Khwaja, Fatima S.; Quann, Emily J.; Pattabiraman, Nagarajan; Wynne, Shehla; Djakiew, Daniel

    2008-01-01

    The p75NTR functions as a tumor suppressor in prostate epithelial cells, where its expression declines with progression to malignant cancer. Previously, we demonstrated that treatment with R-flurbiprofen or ibuprofen induced p75NTR expression in several prostate cancer cell lines leading to p75NTR mediated decreased survival. Utilizing the 2-phenyl propionic acid moiety of these profens as a pharmacophore, we screened an in silico data base of 30 million compounds and identified carprofen as having an order of magnitude greater activity for induction of p75NTR levels and inhibition of cell survival. Prostate (PC-3, DU-145) and bladder (T24) cancer cells were more sensitive to carprofen induction of p75NTR associated loss of survival than breast (MCF7) and fibroblast (3T3) cells. Transfection of prostate cell lines with a dominant negative form of p75NTR prior to carprofen treatment partially rescued cell survival demonstrating a cause and effect relationship between carprofen induction of p75NTR levels and inhibition of survival. Carprofen induced apoptotic nuclear fragmentation in prostate but not in MCF7 and 3T3 cells. Furthermore, siRNA knockdown of the p38 MAPK protein prevented induction of p75NTR by carprofen in both prostate cell lines. Carprofen treatment induced phosphorylation of p38 MAPK as early as within 1 minute. Expression of a dominant negative form of MK2, the kinase downstream of p38 MAPK frequently associated with signaling cascades leading to apoptosis, prevented carprofen induction of the p75NTR protein. Collectively, we identify carprofen as a highly potent profen capable of inducing p75NTR dependent apoptosis via the p38 MAPK pathway in prostate cancer cells. PMID:18974393

  8. NADE (p75NTR-associated cell death executor) suppresses cellular growth in vivo.

    Science.gov (United States)

    Tong, Xiangjun; Xie, Dong; Roth, Wilfried; Reed, John; Koeffler, H Phillip

    2003-06-01

    NADE, a p75NTR (low-affinity neurotrophin receptor p75) -associated cell death executor, was initially cloned from a human ovarian granulosa cell cDNA library, as an unknown protein with the name, pHGR74. It was reported to mediate nerve growth factor-induced apoptosis. We independently isolated human NADE (pHGR74) from breast cancer cell lines. Expression of NADE in various human cancer cell lines, and human and murine tissues was examined. NADE was highly expressed in human endocrine-related organs and embryotic murine tissues. Forced expression of NADE in CHO (Chinese hamster ovary) cells and MDA-MB-231 human breast cancer cells had little effect on the growth of the cells in vitro, while it dramatically suppressed cellular growth in vivo. We used the yeast two-hybrid system to search for NADE binding protein. Dynactin was identified as a candidate. The p75NTR was not found in this assay and did not co-immunoprecipitate with human NADE. Furthermore, the cells stably transfected with NADE did not respond to NGF or TNF. Thus, human and murine NADE appear to have different functions.

  9. Silencing p75NTR prevents proNGF-induced endothelial cell death and development of acellular capillaries in rat retina

    Directory of Open Access Journals (Sweden)

    Ahmed Y Shanab

    Full Text Available Accumulation of the nerve growth factor precursor (proNGF and its receptor p75NTR have been associated with several neurodegenerative diseases in both brain and retina. However, whether proNGF contributes to microvascular degeneration remain unexplored. This study seeks to investigate the mechanism by which proNGF/p75NTR induce endothelial cell (EC death and development of acellular capillaries, a surrogate marker of retinal ischemia. Stable overexpression of the cleavage-resistant proNGF and molecular silencing of p75NTR were utilized in human retinal EC and rat retinas in vivo. Stable overexpression of proNGF decreased NGF levels and induced retinal vascular cell death evident by 1.9-fold increase in acellular capillaries and activation of JNK and cleaved-PARP that were mitigated by p75NTRshRNA. In vitro, overexpression of proNGF did not alter TNF-α level, reduced NGF, however induced EC apoptosis evident by activation of JNK and p38 MAPK, cleaved-PARP. Silencing p75NTR using siRNA restored expression of NGF and TrkA activation and prevented EC apoptosis. Treatment of EC with human-mutant proNGF induced apoptosis that coincided with marked protein interaction and nuclear translocation of p75NTR and the neurotrophin receptor interacting factor. These effects were abolished by a selective p75NTR antagonist. Therefore, targeting p75NTR represents a potential therapeutic strategy for diseases associated with aberrant expression of proNGF.

  10. p75NTR enhances PC12 cell tumor growth by a non-receptor mechanism involving downregulation of cyclin D2

    International Nuclear Information System (INIS)

    Fritz, Melinda D.; Mirnics, Zeljka K.; Nylander, Karen D.; Schor, Nina F.

    2006-01-01

    p75NTR is a member of the tumor necrosis superfamily of proteins which is variably associated with induction of apoptosis and proliferation. Cyclin D2 is one of the mediators of cellular progression through G1 phase of the cell cycle. The present study demonstrates the inverse relationship between expression of cyclin D2 and expression of p75NTR in PC12 cells. Induction of p75NTR expression in p75NTR-negative PC12 cells results in downregulation of cyclin D2; suppression of p75NTR expression with siRNA in native PC12 cells results in upregulation of cyclin D2. The effects of p75NTR on cyclin D2 expression are mimicked in p75NTR-negative cells by transfection with the intracellular domain of p75NTR. Cyclin-D2-positive PC12 cell cultures grow more slowly than cyclin-D2-negative cultures, and induction of expression of cyclin D2 slows the culture growth rate of cyclin-D2-negative cells. Finally, subcutaneous murine xenografts of cyclin-D2-negative, p75NTR-positive PC12 cells more frequently and more rapidly produce tumors than the analogous xenografts of cyclin-D2-positive, p75NTR-negative cells. These results suggest that p75NTR suppresses cyclin D2 expression in PC12 cells by a mechanism distinct from its function as a nerve growth factor receptor and that cyclin D2 expression decreases cell culture and xenografted tumor growth

  11. Carprofen induction of p75NTR-dependent apoptosis via the p38 mitogen-activated protein kinase pathway in prostate cancer cells.

    Science.gov (United States)

    Khwaja, Fatima S; Quann, Emily J; Pattabiraman, Nagarajan; Wynne, Shehla; Djakiew, Daniel

    2008-11-01

    The p75 neurotrophin receptor (p75(NTR)) functions as a tumor suppressor in prostate epithelial cells, where its expression declines with progression to malignant cancer. Previously, we showed that treatment with R-flurbiprofen or ibuprofen induced p75(NTR) expression in several prostate cancer cell lines leading to p75(NTR)-mediated decreased survival. Using the 2-phenyl propionic acid moiety of these profens as a pharmacophore, we screened an in silico database of 30 million compounds and identified carprofen as having an order of magnitude greater activity for induction of p75(NTR) levels and inhibition of cell survival. Prostate (PC-3 and DU-145) and bladder (T24) cancer cells were more sensitive to carprofen induction of p75(NTR)-associated loss of survival than breast (MCF-7) and fibroblast (3T3) cells. Transfection of prostate cell lines with a dominant-negative form of p75(NTR) before carprofen treatment partially rescued cell survival, showing a cause-and-effect relationship between carprofen induction of p75(NTR) levels and inhibition of survival. Carprofen induced apoptotic nuclear fragmentation in prostate but not in MCF-7 and 3T3 cells. Furthermore, small interfering RNA knockdown of the p38 mitogen-activated protein kinase (MAPK) protein prevented induction of p75(NTR) by carprofen in both prostate cell lines. Carprofen treatment induced phosphorylation of p38 MAPK as early as within 1 min. Expression of a dominant-negative form of MK2, the kinase downstream of p38 MAPK frequently associated with signaling cascades leading to apoptosis, prevented carprofen induction of the p75(NTR) protein. Collectively, we identify carprofen as a highly potent profen capable of inducing p75(NTR)-dependent apoptosis via the p38 MAPK pathway in prostate cancer cells.

  12. The p75NTR mediates a bifurcated signal transduction cascade through the NFκB and JNK pathways to inhibit cell survival

    International Nuclear Information System (INIS)

    Allen, Jeffrey; Khwaja, Fatima; Byers, Stephen; Djakiew, Daniel

    2005-01-01

    p75 NTR is most abundantly expressed in the nervous system, but is also widely expressed in many other organs and tissues where it primarily functions as a negative regulator of cell survival. In the prostate, p75 NTR functions as an inhibitory protein capable of slowing proliferation and inducing apoptosis. It has been shown that p75 NTR is expressed in the normal prostate, progressively lost from malignant tumor cells in vivo, and largely absent from prostate cancer cell lines derived from metastases. Although the role of p75 NTR in prostate cancer has been well established, the signal transduction pathway that mediates its inhibitory activity has only been partially elucidated. This study demonstrates that exogenous expression of p75 NTR down-regulates, in a dose-dependent manner, a bifurcated signaling cascade that results in reduced expression of potent transcription effectors. This two-arm signal transduction cascade was directly linked to the upstream receptor by using dominant-negative deletion constructs of p75 NTR that rescued tumor cells from p75 NTR -induced loss of survival and promotion of apoptosis. Furthermore, the dominant negatives rescued alterations in the levels of signal transduction intermediates. Conversely, the use of kinase-inactive intermediates that are downstream of the receptor further reduced expression of involved transcription effectors and reduced survival of the cells. These results provide a definitive link between the proximate p75 NTR and signal transduction intermediates leading to the transcription effectors NFκB and JNK, with associated growth suppression and induction of apoptosis

  13. 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

  14. Characterization of human dopamine responsive protein DRG-1 that binds to p75NTR-associated cell death executor NADE.

    Science.gov (United States)

    Yu, Yao; Wang, Jiadong; Yuan, Hanying; Qin, Feng; Wang, Jing; Zhang, Nailing; Li, Yu-Yang; Liu, Jianping; Lu, Hong

    2006-07-19

    Expression of human dopamine responsive gene-1 (DRG-1) is up-regulated in response to treatment of dopamine in the rat astrocytes. However, its functions are not clear up to now. In the presented studies, DRG-1 was identified to be a conserved gene in the vertebrate and expressed abundantly in human testis, brain and skeletal muscle. DRG-1 was shown to interact with human p75NTR-associated cell death executor (NADE) in vivo and in vitro, and the interaction occurred in cytoplasm. The regions required for the interaction were subsequently mapped to the N-terminal of DRG-1 and the C-terminal of NADE. Furthermore, MTT assay showed that stable expression of DRG-1 in 293 cells could promote cell proliferation, and this promotion was suppressed by overexpression of NADE. In flow cytometry cell cycle analysis, overexpression of DRG-1 in 293 or PC12 cells increased the population of cells in the S phase with a concomitant decrease in G0/G1 population. These findings suggest that DRG-1 may contribute to the dopamine-induced cell growth, which is negatively regulated by NADE.

  15. Organotypic culture of normal, dysplastic and squamous cell carcinoma-derived oral cell lines reveals loss of spatial regulation of CD44 and p75 NTR in malignancy.

    Science.gov (United States)

    Dalley, Andrew J; AbdulMajeed, Ahmad A; Upton, Zee; Farah, Camile S

    2013-01-01

    Oral squamous cell carcinomas (OSCC) often arise from dysplastic lesions. The role of cancer stem cells in tumour initiation is widely accepted, yet the potential existence of pre-cancerous stem cells in dysplastic tissue has received little attention. Cell lines from oral diseases ranging in severity from dysplasia to malignancy provide opportunity to investigate the involvement of stem cells in malignant progression from dysplasia. Stem cells are functionally defined by their ability to generate hierarchical tissue structures in consortium with spatial regulation. Organotypic cultures readily display tissue hierarchy in vitro; hence, in this study, we compared hierarchical expression of stem cell-associated markers in dermis-based organotypic cultures of oral epithelial cells from normal tissue (OKF6-TERT2), mild dysplasia (DOK), severe dysplasia (POE-9n) and OSCC (PE/CA P J15). Expression of CD44, p75(NTR), CD24 and ALDH was studied in monolayers by flow cytometry and in organotypic cultures by immunohistochemistry. Spatial regulation of CD44 and p75(NTR) was evident for organotypic cultures of normal (OKF6-TERT2) and dysplasia (DOK and POE-9n) but was lacking for OSCC (PE/CA PJ15)-derived cells. Spatial regulation of CD24 was not evident. All monolayer cultures exhibited CD44, p75(NTR), CD24 antigens and ALDH activity (ALDEFLUOR(®) assay), with a trend towards loss of population heterogeneity that mirrored disease severity. In monolayer, increased FOXA1 and decreased FOXA2 expression correlated with disease severity, but OCT3/4, Sox2 and NANOG did not. We conclude that dermis-based organotypic cultures give opportunity to investigate the mechanisms that underlie loss of spatial regulation of stem cell markers seen with OSCC-derived cells. © 2012 John Wiley & Sons A/S.

  16. [NRH2 induces cell apoptosis of cerebral tissues around hematomas after intracerebral hemorrhage through up-regulating proNGF, sortilin and p75NTR expressions].

    Science.gov (United States)

    Zeng, Zhiqing; Liu, Hong; Jiang, Di

    2015-04-01

    To observe the expressions of neurotrophin receptor homolog 2 (NRH2), nerve growth factor precursor (proNGF), sortilin and neurotrophin receptor p75 (p75NTR) in cerebral tissues around hematomas in the different periods after intracerebral hemorrhage, and explore their relationships to cell apoptosis. The specimens of cerebral tissues around hematomas were collected from the patients undergoing hematoma removal operation after intracerebral hemorrhage. These specimens were divided into four groups, namely ≤ 6 hours, 6-24 hours(including 24 hours), 24-72 hours (including 72 hours) and over 72 hours according to the time from intracerebral hemorrhage to specimen collection. At the same time, 10 brain tissues distant to hemorrhage that dropped in the operative process were collected as a control group. Apoptosis index (AI) was examined in brain cells by terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling (TUNEL). The expressions of NRH2, proNGF, sortilin and p75NTR mRNAs and proteins in brain tissues were detected through real-time quantitative PCR and Western blotting, respectively. Also, the expressions of Bcl-2 and Bax in brain tissues were analyzed using Western blotting. In vitro cultured astrocytes of rat cortex were transfected by NRH2 siRNA or scramble siRNA. The expressions of proNGF, sortilin and p75NTR proteins were detected using Western blotting. AI was higher in all groups of hemorrhage for 6 hours or longer than that in control and ≤ 6 hours groups, and AI in the group of 24-72 hours after intracerebral hemorrhage was the highest. However, there was no significant difference in AI between ≤ 6 hours group and control group. With the extension of intracerebral hemorrhage time, the expression levels of proNGF and p75NTR mRNAs and proteins were gradually elevated, reached the peak in 24-72 hours, and maintained a higher level after 72 hours, whereas there were no significant differences in the above indicators

  17. Expression and Significance of Stem Cell Markers CK19, Notch3, CD133, P75NTR, STRO-1 and ABCG2 in Pulmonary Squamous Carcinomas

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    Xuyong LIN, , , , ,

    2009-04-01

    Full Text Available Background and objective Increasing reports showed that some tumor stem cells were selfrenewal and multi-lineage differentiated in tumors, similar to the normal stem cells in human body. The aim of this study is to observe the expression of stem cell markers in lung squamous carcinoma tissues. Methods Fifty-four lung cancer specimens from surgery were analyzed for CK19, Notch3, CD133, P75NTR, STRO-1 and ABCG2 expression by using S-P immunohistochemistry. In addition, ten normal lung tissue samples were included as control. Results CK19, Notch3, CD133 and ABCG2 were expressed in 54 Lung cancer tissues, without expression of P75NTR and STRO-1. The expressionrate of CK19, Notch3, CD133 and ABCG2 was 66.67% (36/54, 87.04% (47/54, 50% (27/54, and 61.11% (33/54 respectively. The levels of expression of Notch3, CD133 and ABCG2 were significantly lower in high differentiation group than those in moderate and low differentiation group (P <0.05. The levels of expression of CK19, CD133 and ABCG2 were significantly higher in lymph node metastasis group than those in non-metastasis group (P <0.05. The percentage of total positive cells of four stem cell markers in serial tissue sections was lower than 2%. Conclusion There was expression ofsome stem cell markers in pulmonary squamous carcinomas, and there was relationship between expression degree withdifferentiation degree and lymph node metastasis.

  18. Reduced anxiety-like behavior and altered hippocampal morphology in female p75NTR exon IV-/- mice.

    Directory of Open Access Journals (Sweden)

    Zoe ePuschban

    2016-06-01

    Full Text Available The presence of the neurotrophin receptor p75NTR in adult basal forebrain cholinergic neurons, precursor cells in the subventricular cell layer and the subgranular cell layer of the hippocampus has been linked to alterations in learning as well as anxiety- and depression- related behaviors. In contrast to previous studies performed in a p75NTR exonIII-/- model still expressing the short isoform of the p75NTR, we focused on locomotor and anxiety–associated behavior in p75NTR exonIV-/- mice lacking both p75NTR isoforms. Comparing p75NTR exonIV-/- and wildtype mice for both male and female animals showed an anxiolytic-like behavior as evidenced by increased central activities in the open field paradigm and flex field activity system as well as higher numbers of open arm entries in the elevated plus maze test in female p75NTR knockout mice.Morphometrical analyses of dorsal and ventral hippocampus revealed a reduction of width of the dentate gyrus and the granular cell layer in the dorsal but not ventral hippocampus in male and female p75NTR exonIV -/- mice. We conclude that germ-line deletion of p75NTR seems to differentially affect morphometry of dorsal and ventral dentate gyrus and that p75NTR may play a role in anxiety-like behavior, specifically in female mice.

  19. Contribution of Schwann Cells to Remyelination in a Naturally Occurring Canine Model of CNS Neuroinflammation.

    Directory of Open Access Journals (Sweden)

    Kristel Kegler

    Full Text Available Gliogenesis under pathophysiological conditions is of particular clinical relevance since it may provide evidence for regeneration promoting cells recruitable for therapeutic purposes. There is evidence that neurotrophin receptor p75 (p75NTR-expressing cells emerge in the lesioned CNS. However, the phenotype and identity of these cells, and signals triggering their in situ generation under normal conditions and certain pathological situations has remained enigmatic. In the present study, we used a spontaneous, idiopathic and inflammatory CNS condition in dogs with prominent lympho-histiocytic infiltration as a model to study the phenotype of Schwann cells and their relation to Schwann cell remyelination within the CNS. Furthermore, the phenotype of p75NTR-expressing cells within the injured CNS was compared to their counter-part in control sciatic nerve and after peripheral nerve injury. In addition, organotypic slice cultures were used to further elucidate the origin of p75NTR-positive cells. In cerebral and cerebellar white and grey matter lesions as well as in the brain stem, p75NTR-positive cells co-expressed the transcription factor Sox2, but not GAP-43, GFAP, Egr2/Krox20, periaxin and PDGFR-α. Interestingly, and contrary to the findings in control sciatic nerves, p75NTR-expressing cells only co-localized with Sox2 in degenerative neuropathy, thus suggesting that such cells might represent dedifferentiated Schwann cells both in the injured CNS and PNS. Moreover, effective Schwann cell remyelination represented by periaxin- and P0-positive mature myelinating Schwann cells, was strikingly associated with the presence of p75NTR/Sox2-expressing Schwann cells. Intriguingly, the emergence of dedifferentiated Schwann cells was not affected by astrocytes, and a macrophage-dominated inflammatory response provided an adequate environment for Schwann cells plasticity within the injured CNS. Furthermore, axonal damage was reduced in brain stem areas

  20. Blocking p75 (NTR) receptors alters polyinnervationz of neuromuscular synapses during development.

    Science.gov (United States)

    Garcia, Neus; Tomàs, Marta; Santafe, Manel M; Lanuza, Maria A; Besalduch, Nuria; Tomàs, Josep

    2011-09-01

    High-resolution immunohistochemistry shows that the receptor protein p75(NTR) is present in the nerve terminal, muscle cell, and glial Schwann cell at the neuromuscular junction (NMJ) of postnatal rats (P4-P6) during the synapse elimination period. Blocking the receptor with the antibody anti-p75-192-IgG (1-5 μg/ml, 1 hr) results in reduced endplate potentials (EPPs) in mono- and polyinnervated synapses ex vivo, but the mean number of functional inputs per NMJ does not change for as long as 3 hr. Incubation with exogenous brain-derived neurotrophic factor (BDNF) for 1 hr (50 nM) resulted in a significant increase in the size of the EPPs in all nerve terminals, and preincubation with anti-p75-192-IgG prevented this potentiation. Long exposure (24 hr) in vivo of the NMJs to the antibody anti-p75-192-IgG (1-2 μg/ml) results in a delay of postnatal synapse elimination and even some regrowth of previously withdrawn axons, but also in some acceleration of the morphologic maturation of the postsynaptic nicotinic acetylcholine receptor (nAChR) clusters. The results indicate that p75(NTR) is involved in both ACh release and axonal retraction during postnatal axonal competition and synapse elimination. Copyright © 2011 Wiley-Liss, Inc.

  1. Localization of brain-derived neurotrophic factor, neurotrophin-4, tropomyosin-related kinase b receptor, and p75 NTR receptor by high-resolution immunohistochemistry on the adult mouse neuromuscular junction.

    Science.gov (United States)

    Garcia, Neus; Tomàs, Marta; Santafe, Manel M; Lanuza, M Angel; Besalduch, Nuria; Tomàs, Josep

    2010-03-01

    Neurotrophins and their receptors, the trk receptor tyrosine kinases (trks) and p75(NTR), are differentially expressed among the cell types that make up synapses. It is important to determine the precise location of these molecules involved in neurotransmission. Here we use immunostaining and Western blotting to study the localization and expression of neurotrophin brain-derived neurotrophic factor (BDNF) and neurotrophin-4 (NT-4) and the receptors tropomyosin-related kinase b (trkB) and p75(NTR) at the adult neuromuscular junction. Our confocal immunofluorescence results on the whole mounts of the mouse Levator auris longus muscle and on semithin cross-sections showed that BDNF, NT-4, trkB, and p75(NTR) were localized on the three cells in the neuromuscular synapse (motor axons, post-synaptic muscle and Schwann cells).

  2. Contribution of p75NTR to Schwannoma Growth and Therapeutic Responses

    Science.gov (United States)

    2017-05-01

    reducing schwannoma cell growth in culture and in animal models of human schwannoma disease. We find that the NF2 gene product, merlin, regulates p75NTR...treatment period. B. Waterfall plots of change in tumor volume for each tumor. Task 6- Define the ability of simultaneous inhibition of p75NTR and mTOR...mTOR inhibitors in culture, we have not used these compounds in animal models . Changes that had a significant impact on expenditures- None

  3. Co-induction of p75NTR and p75NTR-associated death executor in neurons after zinc exposure in cortical culture or transient ischemia in the rat.

    Science.gov (United States)

    Park, J A; Lee, J Y; Sato, T A; Koh, J Y

    2000-12-15

    Recently, a 22 kDa protein termed p75(NTR)-associated death executor (NADE) was discovered to be a necessary factor for p75(NTR)-mediated apoptosis in certain cells. However, the possible role for p75(NTR)/NADE in pathological neuronal death has yet been undetermined. In the present study, we have examined this possibility in vivo and in vitro. Exposure of cortical cultures to zinc induced both p75(NTR) and NADE in neurons, whereas exposure to NMDA, ionomycin, iron, or H(2)O(2) induced neither. In addition, zinc exposure increased neuronal NGF expression and its release into the medium. A function-blocking antibody of p75(NTR) (REX) inhibited association between p75(NTR) and NADE as well as neuronal death induced by zinc. Conversely, NGF augmented zinc-induced neuronal death. Caspase inhibitors reduced zinc-induced neuronal death, indicating that caspases were involved. Because reduction of NADE expression with cycloheximide or NADE antisense oligonucleotides attenuated zinc-induced neuronal death, NADE appears to contribute to p75(NTR)-induced cortical neuronal death as shown in other cells. Because zinc neurotoxicity may be a key mechanism of neuronal death after transient forebrain ischemia, we next examined this model. After ischemia, p75(NTR) and NADE were induced in degenerating rat hippocampal CA1 neurons. There was a close correlation between zinc accumulation and p75(NTR)/NADE induction. Suggesting the role of zinc here, injection of a metal chelator, CaEDTA, into the lateral ventricle completely blocked the induction of p75(NTR) and NADE. Our results suggest that co-induction of p75(NTR) and NADE plays a role in zinc-triggered neuronal death in vitro and in vivo.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Cabral, Katia M S; Raymundo, Diana P; Silva, Viviane S; Sampaio, Laura A G; Johanson, Laizes; Hill, Luis Fernando; Almeida, Fabio C L; Cordeiro, Yraima; Almeida, Marcius S

    2015-01-01

    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.

  7. Neurotrophin Receptors TrkA, p75NTR, and Sortilin Are Increased and Targetable in Thyroid Cancer.

    Science.gov (United States)

    Faulkner, Sam; Jobling, Philip; Rowe, Christopher W; Rodrigues Oliveira, S M; Roselli, Severine; Thorne, Rick F; Oldmeadow, Christopher; Attia, John; Jiang, Chen Chen; Zhang, Xu Dong; Walker, Marjorie M; Hondermarck, Hubert

    2018-01-01

    Neurotrophin receptors are emerging targets in oncology, but their clinicopathologic significance in thyroid cancer is unclear. In this study, the neurotrophin tyrosine receptor kinase TrkA (also called NTRK1), the common neurotrophin receptor p75 NTR , and the proneurotrophin receptor sortilin were analyzed with immunohistochemistry in a cohort of thyroid cancers (n = 128) and compared with adenomas and normal thyroid tissues (n = 62). TrkA was detected in 20% of thyroid cancers, compared with none of the benign samples (P = 0.0007). TrkA expression was independent of histologic subtypes but associated with lymph node metastasis (P = 0.0148), suggesting the involvement of TrkA in tumor invasiveness. Nerves in the tumor microenvironment were positive for TrkA. p75 NTR was overexpressed in anaplastic thyroid cancers compared with papillary and follicular subtypes (P Neurotrophin receptor expression was confirmed in a panel of thyroid cancer cell lines at the mRNA and protein levels. Functional investigations using the anaplastic thyroid cancer cell line CAL-62 found that siRNA against TrkA, p75 NTR , and sortilin decreased cell survival and cell migration through decreased SRC and ERK activation. Together, these data reveal TrkA, p75 NTR , and sortilin as potential therapeutic targets in thyroid cancer. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  8. Co-induction of p75(NTR) and the associated death executor NADE in degenerating hippocampal neurons after kainate-induced seizures in the rat.

    Science.gov (United States)

    Yi, Jung-Sun; Lee, Soon-Keum; Sato, Taka-Aki; Koh, Jae-Young

    2003-08-21

    Zinc induces in cultured cortical neurons both p75(NTR) and p75(NTR)-associated death executor (NADE), which together contribute to caspase-dependent neuronal apoptosis. Since zinc neurotoxicity may contribute to neuronal death following seizures, we examined whether p75(NTR) and NADE are co-induced also in rat hippocampal neurons degenerating after seizures. Staining of brain sections with a zinc-specific fluorescent dye (N-(6-methoxy-8-quinolyl)-p-carboxybenzoylsulphonamide) and acid fuchsin revealed zinc accumulation in degenerating neuronal cell bodies in CA1 and CA3 of hippocampus 24 h after kainate injection. Both anti-p75(NTR) and anti-NADE immunoreactivities appeared in zinc-accumulating/degenerating neurons in both areas. Intraventricular injection of CaEDTA, without altering the severity or time course of kainate-induced seizures, markedly attenuated the induction of p75(NTR)/NADE in hippocampus, which correlated with the decrease of caspase-3 activation and zinc accumulation/cell death. The present study has demonstrated that p75(NTR) and NADE are co-induced in neurons degenerating after kainate-induced seizures in rats, likely in a zinc-dependent manner.

  9. The Role of Neurotrophin Signaling in Gliomagenesis: A Focus on the p75 Neurotrophin Receptor (p75NTR/CD271).

    Science.gov (United States)

    Alshehri, M M; Robbins, S M; Senger, D L

    2017-01-01

    The p75 neurotrophin receptor (p75 NTR , a.k.a. CD271), a transmembrane glycoprotein and a member of the tumor necrosis family (TNF) of receptors, was originally identified as a nerve growth factor receptor in the mid-1980s. While p75 NTR is recognized to have important roles during neural development, its presence in both neural and nonneural tissues clearly supports the potential to mediate a broad range of functions depending on cellular context. Using an unbiased in vivo selection paradigm for genes underlying the invasive behavior of glioma, a critical characteristic that contributes to poor clinical outcome for glioma patients, we identified p75 NTR as a central regulator of glioma invasion. Herein we review the expanding role that p75 NTR plays in glioma progression with an emphasis on how p75 NTR may contribute to the treatment refractory nature of glioma. Based on the observation that p75 NTR is expressed and functional in two critical glioma disease reservoirs, namely, the highly infiltrative cells that evade surgical resection, and the radiation- and chemotherapy-resistant brain tumor-initiating cells (also referred to as brain tumor stem cells), we propose that p75 NTR and its myriad of downstream signaling effectors represent rationale therapeutic targets for this devastating disease. Lastly, we provide the provocative hypothesis that, in addition to the well-documented cell autonomous signaling functions, the neurotrophins, and their respective receptors, contribute in a cell nonautonomous manner to drive the complex cellular and molecular composition of the brain tumor microenvironment, an environment that fuels tumorigenesis. © 2017 Elsevier Inc. All rights reserved.

  10. 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

  11. 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

  12. 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.

  13. Cholinergic Degeneration and Alterations in the TrkA and p75NTR Balance as a Result of Pro-NGF Injection into Aged Rats

    Directory of Open Access Journals (Sweden)

    Ashley M. Fortress

    2011-01-01

    Full Text Available Learning and memory impairments occurring with Alzheimer's disease (AD are associated with degeneration of the basal forebrain cholinergic neurons (BFCNs. BFCNs extend their axons to the hippocampus where they bind nerve growth factor (NGF which is retrogradely transported to the cell body. While NGF is necessary for BFCN survival and function via binding to the high-affinity receptor TrkA, its uncleaved precursor, pro-NGF has been proposed to induce neurodegeneration via binding to the p75NTR and its coreceptor sortilin. Basal forebrain TrkA and NGF are downregulated with aging while pro-NGF is increased. Given these data, the focus of this paper was to determine a mechanism for how pro-NGF accumulation may induce BFCN degeneration. Twenty-four hours after a single injection of pro-NGF into hippocampus, we found increased hippocampal p75NTR levels, decreased hippocampal TrkA levels, and cholinergic degeneration. The data suggest that the increase in p75NTR with AD may be mediated by elevated pro-NGF levels as a result of decreased cleavage, and that pro-NGF may be partially responsible for age-related degenerative changes observed in the basal forebrain. This paper is the first in vivo evidence that pro-NGF can affect BFCNs and may do so by regulating expression of p75NTR neurotrophin receptors.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    R. Xu

    2015-08-01

    Full Text Available 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.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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

  17. 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.

  18. Essential role for zinc-triggered p75NTR activation in preconditioning neuroprotection.

    Science.gov (United States)

    Lee, Jin-Yeon; Kim, Yu-Jin; Kim, Tae-Youn; Koh, Jae-Young; Kim, Yang-Hee

    2008-10-22

    Ischemic preconditioning (PC) of the brain is a phenomenon by which mild ischemic insults render neurons resistant to subsequent strong insults. Key steps in ischemic PC of the brain include caspase-3 activation and poly(ADP-ribose) polymerase-1 (PARP-1) cleavage, but upstream events have not been clearly elucidated. We have tested whether endogenous zinc is required for ischemic PC of the brain in rats. Mild, transient zinc accumulation was observed in certain neurons after ischemic PC. Moreover, intraventricular administration of CaEDTA during ischemic PC abrogated both zinc accumulation and the protective effect against subsequent full ischemia. To elucidate the mechanism of the zinc-triggered PC (Zn PC) effect, cortical cultures were exposed to sublethal levels of zinc, and 18 h later to lethal levels of zinc or NMDA. Zn PC exhibited the characteristic features of ischemic PC, including caspase-3 activation, PARP-1 cleavage, and HSP70 induction, all of which are crucial for subsequent neuroprotection against NMDA or zinc toxicity. HSP70 induction was necessary for protection, as it halted caspase-3 activation before apoptosis. Interestingly, in both Zn PC in vitro and ischemic PC in vivo, p75(NTR) was necessary for neuroprotection. These results suggest that caspase-3 activation during ischemic PC, a necessary event for subsequent neuroprotection, may result from mild zinc accumulation and the consequent p75(NTR) activation in neurons.

  19. 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.

  20. Subclinical hypothyroidism in pregnant rats impaired learning and memory of their offspring by promoting the p75NTR signal pathway

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2018-05-01

    Full Text Available Objective: Maternal hypothyroidism during pregnancy can affect the neurodevelopment of their offspring. This study aimed to investigate the effects of maternal subclinical hypothyroidism (SCH on spatial learning and memory, and its relationship with the apoptotic factors in cerebral cortex of the offspring. Methods: Female adult Wistar rats were randomly divided into three groups (n = 15 per group: control (CON group, SCH group and overt hypothyroidism (OH group. Spatial learning and memory in the offspring were evaluated by long-term potentiation (LTP and Morris water-maze (MWM test. The protein expression of the p75 neurotrophin receptor (p75NTR, phospho-c-Jun N-terminal kinase (p-JNK, the pro-apoptotic protein p53 and Bax were detected by Western blotting. Results: The Pups in the SCH and OH groups showed longer escape latencies in the MWM and decreased field-excitatory post synaptic potentials in LTP tests compared with those in the CON group. p75NTR, p-JNK, p53 and Bax expression levels in the cerebral cortex increased in pups in the SCH and OH groups compared with those in the CON group. Conclusions: Maternal SCH during pregnancy may impair spatial learning and memory in the offspring and may be associated with the increased apoptosis in the cerebral cortex.

  1. 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

  2. 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...

  3. Contribution of p75NTR to Schwannoma Growth and Therapeutic Responses

    Science.gov (United States)

    2015-05-01

    in 0.125% typ- sin with EDTA (Life Technology) and 0.2% collagenase (Sigma) in Hank’s balanced salt solution without calcium and magnesium (Life...cells following deafness correlate with cell proliferation. Molecular and cellular neurosciences 47:306-315. Rong R, Surace EI , Haipek CA, Gutmann DH

  4. p75 neurotrophin receptor cleavage by α- and γ-secretases is required for neurotrophin-mediated proliferation of brain tumor-initiating cells.

    Science.gov (United States)

    Forsyth, Peter A; Krishna, Niveditha; Lawn, Samuel; Valadez, J Gerardo; Qu, Xiaotao; Fenstermacher, David A; Fournier, Michelle; Potthast, Lisa; Chinnaiyan, Prakash; Gibney, Geoffrey T; Zeinieh, Michele; Barker, Philip A; Carter, Bruce D; Cooper, Michael K; Kenchappa, Rajappa S

    2014-03-21

    Malignant gliomas are highly invasive, proliferative, and resistant to treatment. Previously, we have shown that p75 neurotrophin receptor (p75NTR) is a novel mediator of invasion of human glioma cells. However, the role of p75NTR in glioma proliferation is unknown. Here we used brain tumor-initiating cells (BTICs) and show that BTICs express neurotrophin receptors (p75NTR, TrkA, TrkB, and TrkC) and their ligands (NGF, brain-derived neurotrophic factor, and neurotrophin 3) and secrete NGF. Down-regulation of p75NTR significantly decreased proliferation of BTICs. Conversely, exogenouous NGF stimulated BTIC proliferation through α- and γ-secretase-mediated p75NTR cleavage and release of its intracellular domain (ICD). In contrast, overexpression of the p75NTR ICD induced proliferation. Interestingly, inhibition of Trk signaling blocked NGF-stimulated BTIC proliferation and p75NTR cleavage, indicating a role of Trk in p75NTR signaling. Further, blocking p75NTR cleavage attenuated Akt activation in BTICs, suggesting role of Akt in p75NTR-mediated proliferation. We also found that p75NTR, α-secretases, and the four subunits of the γ-secretase enzyme were elevated in glioblastoma multiformes patients. Importantly, the ICD of p75NTR was commonly found in malignant glioma patient specimens, suggesting that the receptor is activated and cleaved in patient tumors. These results suggest that p75NTR proteolysis is required for BTIC proliferation and is a novel potential clinical target.

  5. Involvement of TrkB- and p75NTR-signaling pathways in two contrasting forms of long-lasting synaptic plasticity

    Science.gov (United States)

    Sakuragi, Shigeo; Tominaga-Yoshino, Keiko; Ogura, Akihiko

    2013-11-01

    The repetition of experience is often necessary to establish long-lasting memory. However, the cellular mechanisms underlying this repetition-dependent consolidation of memory remain unclear. We previously observed in organotypic slice cultures of the rodent hippocampus that repeated inductions of long-term potentiation (LTP) led to a slowly developing long-lasting synaptic enhancement coupled with synaptogenesis. We also reported that repeated inductions of long-term depression (LTD) produced a long-lasting synaptic suppression coupled with synapse elimination. We proposed these phenomena as useful in vitro models for analyzing repetition-dependent consolidation. Here, we hypothesized that the enhancement and suppression are mediated by the brain-derived neurotrophic factor (BDNF)-TrkB signaling pathway and the proBDNF-p75NTR pathway, respectively. When we masked the respective pathways, reversals of the enhancement and suppression resulted. These results suggest the alternative activation of the p75NTR pathway by BDNF under TrkB-masking conditions and of the TrkB pathway by proBDNF under p75NTR-masking conditions, thus supporting the aforementioned hypothesis.

  6. Transdifferentiation of brain-derived neurotrophic factor (BDNF)-secreting mesenchymal stem cells significantly enhance BDNF secretion and Schwann cell marker proteins.

    Science.gov (United States)

    Bierlein De la Rosa, Metzere; Sharma, Anup D; Mallapragada, Surya K; Sakaguchi, Donald S

    2017-11-01

    The use of genetically modified mesenchymal stem cells (MSCs) is a rapidly growing area of research targeting delivery of therapeutic factors for neuro-repair. Cells can be programmed to hypersecrete various growth/trophic factors such as brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and nerve growth factor (NGF) to promote regenerative neurite outgrowth. In addition to genetic modifications, MSCs can be subjected to transdifferentiation protocols to generate neural cell types to physically and biologically support nerve regeneration. In this study, we have taken a novel approach by combining these two unique strategies and evaluated the impact of transdifferentiating genetically modified MSCs into a Schwann cell-like phenotype. After 8 days in transdifferentiation media, approximately 30-50% of transdifferentiated BDNF-secreting cells immunolabeled for Schwann cell markers such as S100β, S100, and p75 NTR . An enhancement was observed 20 days after inducing transdifferentiation with minimal decreases in expression levels. BDNF production was quantified by ELISA, and its biological activity tested via the PC12-TrkB cell assay. Importantly, the bioactivity of secreted BDNF was verified by the increased neurite outgrowth of PC12-TrkB cells. These findings demonstrate that not only is BDNF actively secreted by the transdifferentiated BDNF-MSCs, but also that it has the capacity to promote neurite sprouting and regeneration. Given the fact that BDNF production remained stable for over 20 days, we believe that these cells have the capacity to produce sustainable, effective, BDNF concentrations over prolonged time periods and should be tested within an in vivo system for future experiments. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. 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.

  8. La célula de Schwann The Schwann Cell

    OpenAIRE

    Spinel Clara; Perdomo Sandra

    2004-01-01

    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 ...

  9. 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.

  10. Schwann cell autophagy, myelinophagy, initiates myelin clearance from injured nerves

    NARCIS (Netherlands)

    Gomez-Sanchez, Jose A.; Carty, Lucy; Iruarrizaga-Lejarreta, Marta; Palomo-Irigoyen, Marta; Varela-Rey, Marta; Griffith, Megan; Hantke, Janina; Macias-Camara, Nuria; Azkargorta, Mikel; Aurrekoetxea, Igor; de Juan, Virginia Gutiérrez; Jefferies, Harold B. J.; Aspichueta, Patricia; Elortza, Félix; Aransay, Ana M.; Martínez-Chantar, María L.; Baas, Frank; Mato, José M.; Mirsky, Rhona; Woodhoo, Ashwin; Jessen, Kristján R.

    2015-01-01

    Although Schwann cell myelin breakdown is the universal outcome of a remarkably wide range of conditions that cause disease or injury to peripheral nerves, the cellular and molecular mechanisms that make Schwann cell-mediated myelin digestion possible have not been established. We report that

  11. Electrically induced release of acetylcholine from denervated Schwann cells.

    Science.gov (United States)

    Dennis, M J; Miledi, R

    1974-03-01

    1. Focal electrical stimulation of Schwann cells at the end-plates of denervated frog muscles elicited slow depolarizations of up to 30 mV in the muscle fibres. This response is referred to as a Schwann-cell end-plate potential (Schwann-e.p.p.).2. Repeated stimulation sometimes evoked further Schwann-e.p.p.s, but they were never sustained for more than 30 pulses. Successive e.p.p.s varied in amplitude and time course independently of the stimulus.3. The Schwann-e.p.p.s were reversibly blocked by curare, suggesting that they result from a release of acetylcholine (ACh) by the Schwann cells.4. ACh release by electrical stimulation did not seem to occur in quantal form and was not dependent on the presence of calcium ions in the external medium; nor was it blocked by tetrodotoxin.5. Stimulation which caused release of ACh also resulted in extensive morphological disruption of the Schwann cells, as seen with both light and electron microscopy.6. It is concluded that electrical stimulation of denervated Schwann cells causes break-down of the cell membrane and releases ACh, presumably in molecular form.

  12. 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

    Brain-derived neurotrophic factor (BDNF) is critically involved in modeling the developing nervous system and is an important regulator of a variety of crucial functions in the mature CNS. BDNF exerts its action through interactions with two transmembrane receptors, either separately or in concert....... BDNF has been implicated in several neurological disorders, and irregularities in BDNF function may have severe consequences. Administration of BDNF as a drug has thus far yielded few practicable results, and the potential side effects when using a multifunctional protein are substantial. In an effort...... 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...

  13. p75 Neurotrophin Receptor Suppresses the Proliferation of Human Gastric Cancer Cells

    Directory of Open Access Journals (Sweden)

    Haifeng Jin

    2007-06-01

    Full Text Available Identifying an effective therapeutic target is pivotal in the treatment of gastric cancer. In this study, we investigated the expression of p75 neurotrophin receptor (p75NTR in gastric cancer and the impact of its alteration on tumor growth. p75NTR expression was absent or significantly decreased in 212 cases of gastric cancers compared with the normal gastric mucosa (P < .05. Moreover, p75NTR expression was also lost or significantly decreased in various human gastric cancer cell lines. p75NTR inhibited in vitro growth activities and caused dramatic attenuation of tumor growth in animal models by induction of cell cycle arrest. Upregulation of p75NTR led to downregulation of cyclin A, cyclin D1, cyclin E, cyclin-dependent kinase 2, p-Rb, and PCNA, but to upregulation of Rb and p27 expressions. Conversely, downregulating p75NTR with specific siRNA yielded inverse results. The rescue of tumor cells from cell cycle progression by a death domain-deleted dominant-negative antagonist of p75NTRp75NTR showed that the death domain transduced antiproliferative activity in a ligandindependent manner and further demonstrated the inhibitive effect of p75NTR on growth in gastric cancer. Therefore, we provided evidence that p75NTR was a potential tumor suppressor and may be used as a therapeutic target for gastric cancer.

  14. Adhesion of axolemmal fragments to Schwann cells: a signal- and target-specific process closely linked to axolemmal induction of Schwann cell mitosis

    International Nuclear Information System (INIS)

    Sobue, G.; Pleasure, D.

    1985-01-01

    Radioiodinated rat CNS axolemmal fragments adhered to cultured rat Schwann cells by a time-, temperature-, and concentration-dependent process independent of extracellular ionized calcium. Adhesion showed target and signal specificity; axolemmal fragments adhered to endoneurial or dermal fibroblasts to a much lesser extent than to Schwann cells, and plasma membrane fragments from skeletal muscle, erythrocytes, or PNS myelin adhered to Schwann cells to a lesser extent than did axolemmal fragments. Brief trypsinization removed 94 to 97% of bound radioactivity from Schwann cells previously incubated with 125 I-axolemmal fragments for up to 24 hr, indicating that adhesion was largely a surface phenomenon rather than the result of rapid internalization of axolemmal fragments by the Schwann cells. When adhesion was compared to the axolemmal mitogenic response of Schwann cells, the concentration of axolemmal fragments yielding half-maximal adhesion was the same as the concentration producing half-maximal stimulation of Schwann cell mitosis. Trypsin digestion, homogenization, or heating of axolemmal fragments before application to cultured Schwann cells diminished adhesion and axolemmal fragment-induced stimulation of Schwann cell mitosis in a parallel fashion. Whereas adhesion of axolemmal fragments to the surfaces of the cultured Schwann cells reached completion within 4 hr in this assay system, induction of Schwann cell mitosis by the fragments required contact with Schwann cells for a minimum of 6 to 8 hr and reached a maximum when the axolemmal fragments had adhered to the Schwann cells for 24 hr or more

  15. 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

  16. p75 Neurotrophin Receptor Cleavage by α- and γ-Secretases Is Required for Neurotrophin-mediated Proliferation of Brain Tumor-initiating Cells*

    Science.gov (United States)

    Forsyth, Peter A.; Krishna, Niveditha; Lawn, Samuel; Valadez, J. Gerardo; Qu, Xiaotao; Fenstermacher, David A.; Fournier, Michelle; Potthast, Lisa; Chinnaiyan, Prakash; Gibney, Geoffrey T.; Zeinieh, Michele; Barker, Philip A.; Carter, Bruce D.; Cooper, Michael K.; Kenchappa, Rajappa S.

    2014-01-01

    Malignant gliomas are highly invasive, proliferative, and resistant to treatment. Previously, we have shown that p75 neurotrophin receptor (p75NTR) is a novel mediator of invasion of human glioma cells. However, the role of p75NTR in glioma proliferation is unknown. Here we used brain tumor-initiating cells (BTICs) and show that BTICs express neurotrophin receptors (p75NTR, TrkA, TrkB, and TrkC) and their ligands (NGF, brain-derived neurotrophic factor, and neurotrophin 3) and secrete NGF. Down-regulation of p75NTR significantly decreased proliferation of BTICs. Conversely, exogenouous NGF stimulated BTIC proliferation through α- and γ-secretase-mediated p75NTR cleavage and release of its intracellular domain (ICD). In contrast, overexpression of the p75NTR ICD induced proliferation. Interestingly, inhibition of Trk signaling blocked NGF-stimulated BTIC proliferation and p75NTR cleavage, indicating a role of Trk in p75NTR signaling. Further, blocking p75NTR cleavage attenuated Akt activation in BTICs, suggesting role of Akt in p75NTR-mediated proliferation. We also found that p75NTR, α-secretases, and the four subunits of the γ-secretase enzyme were elevated in glioblastoma multiformes patients. Importantly, the ICD of p75NTR was commonly found in malignant glioma patient specimens, suggesting that the receptor is activated and cleaved in patient tumors. These results suggest that p75NTR proteolysis is required for BTIC proliferation and is a novel potential clinical target. PMID:24519935

  17. Axon-Schwann cell interaction in the squid nerve fibre.

    Science.gov (United States)

    Villegas, J

    1972-09-01

    The electrical properties of Schwann cells and the effects of neuronal impulses on their membrane potential have been studied in the giant nerve fibre of the squid.1. The behaviour of the Schwann cell membrane to current injection into the cell was ohmic. No impulse-like responses were observed with displacements of 35 mV in the membrane potential. The resistance of the Schwann cell membrane was found to be approximately 10(3) Omega cm(2).2. A long-lasting hyperpolarization is observed in the Schwann cells following the conduction of impulse trains by the axon. Whereas the propagation of a single impulse had little effect, prolonged stimulation of the fibre at 250 impulses/sec was followed by a hyperpolarization of the Schwann cell that gradually declined over a period of several minutes.3. The prolonged effects of nerve impulse trains on the Schwann cell were similar to those produced by depolarizing current pulses applied to the axon by the voltage-clamp technique. Thus, a series of depolarizing pulses in the axon was followed by a long-lasting hyperpolarization of the Schwann cells. In contrast, the application of a series of hyperpolarizing 100 mV pulses at a frequency of 1/sec had no apparent effects.4. Changes in the external potassium concentration did not reproduce the long-lasting effects of nerve excitation.5. The hyperpolarizing effects of impulse trains were abolished by the incubation of the nerve fibre in a sea-water solution containing trypsin.6. These findings are discussed in relation to the possible mechanisms that might be responsible for the long-lasting hyperpolarizations of the Schwann cells.

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

    International Nuclear Information System (INIS)

    Shin, Youn Ho; Lee, Seo Jin; Jung, Junyang

    2013-01-01

    Highlights: ► ATP-treated sciatic explants shows the decreased expression of p75NGFR. ► Extracellular ATP inhibits the expression of phospho-ERK1/2. ► Lysosomal exocytosis is involved in Schwann cell dedifferentiation. ► 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.

  19. PAR1 activation affects the neurotrophic properties of Schwann cells.

    Science.gov (United States)

    Pompili, Elena; Fabrizi, Cinzia; Somma, Francesca; Correani, Virginia; Maras, Bruno; Schininà, Maria Eugenia; Ciraci, Viviana; Artico, Marco; Fornai, Francesco; Fumagalli, Lorenzo

    2017-03-01

    Protease-activated receptor-1 (PAR1) is the prototypic member of a family of four G-protein-coupled receptors that signal in response to extracellular proteases. In the peripheral nervous system, the expression and/or the role of PARs are still poorly investigated. High PAR1 mRNA expression was found in the rat dorsal root ganglia and the signal intensity of PAR1 mRNA increased in response to sciatic nerve transection. In the sciatic nerve, functional PAR1 receptor was reported at the level of non-compacted Schwann cell myelin microvilli of the nodes of Ranvier. Schwann cells are the principal population of glial cells of the peripheral nervous system which myelinate axons playing an important role during axonal regeneration and remyelination. The present study was undertaken in order to determine if the activation of PAR1 affects the neurotrophic properties of Schwann cells. Our results suggest that the stimulation of PAR1 could potentiate the Schwann cell ability to favour nerve regeneration. In fact, the conditioned medium obtained from Schwann cell cultures challenged with a specific PAR1 activating peptide (PAR1 AP) displays increased neuroprotective and neurotrophic properties with respect to the culture medium from untreated Schwann cells. The proteomic analysis of secreted proteins in untreated and PAR1 AP-treated Schwann cells allowed the identification of factors differentially expressed in the two samples. Some of them (such as macrophage migration inhibitory factor, matrix metalloproteinase-2, decorin, syndecan 4, complement C1r subcomponent, angiogenic factor with G patch and FHA domains 1) appear to be transcriptionally regulated after PAR1 AP treatment as shown by RT-PCR. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Metformin prevents methylglyoxal-induced apoptosis of mouse Schwann cells

    International Nuclear Information System (INIS)

    Ota, Kimiko; Nakamura, Jiro; Li, Weiguo; Kozakae, Mika; Watarai, Atsuko; Nakamura, Nobuhisa; Yasuda, Yutaka; Nakashima, Eirtaro; Naruse, Keiko; Watabe, Kazuhiko; Kato, Koichi; Oiso, Yutaka; Hamada, Yoji

    2007-01-01

    Methylglyoxal (MG) is involved in the pathogenesis of diabetic complications via the formation of advanced glycation end products (AGEs) and reactive oxygen species (ROS). To clarify whether the antidiabetic drug metformin prevents Schwann cell damage induced by MG, we cultured mouse Schwann cells in the presence of MG and metformin. Cell apoptosis was evaluated using Hoechst 33342 nuclear staining, caspase-3 activity, and c-Jun-N-terminal kinase (JNK) phosphorylation. Intracellular ROS formation was determined by flow cytometry, and AMP-activated kinase (AMPK) phosphorylation was also examined. MG treatment resulted in blunted cell proliferation, an increase in the number of apoptotic cells, and the activation of caspase-3 and JNK along with enhanced intracellular ROS formation. All of these changes were significantly inhibited by metformin. No significant activation of AMPK by MG or metformin was observed. Taken together, metformin likely prevents MG-induced apoptotic signals in mouse Schwann cells by inhibiting the formation of AGEs and ROS

  1. Proliferation of Schwann cells induced by axolemmal and myelin membranes

    International Nuclear Information System (INIS)

    Dinneen, M.

    1985-01-01

    Purified Schwann Cells were cultured from neonatal rat sciatic nerve using a modification of the method of Brockes. Schwann cells and contaminating fibroblasts were unambiguously identified using fluorescent antibodies of 2'3' cyclic nucleotide 3'-phosphodiesterase and the thy 1.1 antigen respectively. The Schwann cells were quiescent unless challenged with mitogens. They proliferated rapidly in response to the soluble mitogen, cholera toxin, or to membrane fractions from rat CNS or PNS, prepared by the method of DeVries. Mitogenic activity was present in both axolemmal and myelin enriched fractions and promoted a 10-15 fold increase in the rate of 3 H-thymidine uptake. The axolemmal mitogen was sensitive to heat (80 0 C for 10 minutes), trypsin digestion (0.05% x 30 mins) or to treatment with endoglycosidase D, suggesting that it could be a glycoprotein. Fifty percent of the axolemmal mitogenic activity was solubilized in 1% octyl-glucoside. The solubilized material, however, was very unstable and further purification was not possible. The myelin associated mitogenic activity was markedly different. It was resistant to freeze thaw cycles, trypsin digestion of endoglycosidase treatment and the activity was actually enhanced by heating at 100 0 C for two hours. It is proposed that the axolemmal activity is responsible for Schwann cell proliferation during development and that the myelin associated activity promotes Schwann cell proliferation during Wallerian degeneration

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

    African Journals Online (AJOL)

    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 differentiate into neuron-like cells when they are co-cultured with Schwann cells by Brdu pulse label technology.

  3. 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.

  4. Liposomes to target peripheral neurons and Schwann cells.

    Directory of Open Access Journals (Sweden)

    Sooyeon Lee

    Full Text Available While a wealth of literature for tissue-specific liposomes is emerging, optimal formulations to target the cells of the peripheral nervous system (PNS are lacking. In this study, we asked whether a novel formulation of phospholipid-based liposomes could be optimized for preferential uptake by microvascular endothelia, peripheral neurons and Schwann cells. Here, we report a unique formulation consisting of a phospholipid, a polymer surfactant and cholesterol that result in enhanced uptake by targeted cells. Using fluorescently labeled liposomes, we followed particle internalization and trafficking through a distinct route from dextran and escape from degradative compartments, such as lysosomes. In cultures of non-myelinating Schwann cells, liposomes associate with the lipid raft marker Cholera toxin, and their internalization is inhibited by disruption of lipid rafts or actin polymerization. In contrast, pharmacological inhibition of clathrin-mediated endocytosis does not significantly impact liposome entry. To evaluate the efficacy of liposome targeting in tissues, we utilized myelinating explant cultures of dorsal root ganglia and isolated diaphragm preparations, both of which contain peripheral neurons and myelinating Schwann cells. In these models, we detected preferential liposome uptake into neurons and glial cells in comparison to surrounding muscle tissue. Furthermore, in vivo liposome administration by intramuscular or intravenous injection confirmed that the particles were delivered to myelinated peripheral nerves. Within the CNS, we detected the liposomes in choroid epithelium, but not in myelinated white matter regions or in brain parenchyma. The described nanoparticles represent a novel neurophilic delivery vehicle for targeting small therapeutic compounds, biological molecules, or imaging reagents into peripheral neurons and Schwann cells, and provide a major advancement toward developing effective therapies for peripheral

  5. Subversion of Schwann Cell Glucose Metabolism by Mycobacterium leprae*

    Science.gov (United States)

    Medeiros, Rychelle Clayde Affonso; Girardi, Karina do Carmo de Vasconcelos; Cardoso, Fernanda Karlla Luz; Mietto, Bruno de Siqueira; Pinto, Thiago Gomes de Toledo; Gomez, Lilian Sales; Rodrigues, Luciana Silva; Gandini, Mariana; Amaral, Julio Jablonski; Antunes, Sérgio Luiz Gomes; Corte-Real, Suzana; Rosa, Patricia Sammarco; Pessolani, Maria Cristina Vidal; Nery, José Augusto da Costa; Sarno, Euzenir Nunes; Batista-Silva, Leonardo Ribeiro; Sola-Penna, Mauro; Oliveira, Marcus Fernandes; Moraes, Milton Ozório; Lara, Flavio Alves

    2016-01-01

    Mycobacterium leprae, the intracellular etiological agent of leprosy, infects Schwann promoting irreversible physical disabilities and deformities. These cells are responsible for myelination and maintenance of axonal energy metabolism through export of metabolites, such as lactate and pyruvate. In the present work, we observed that infected Schwann cells increase glucose uptake with a concomitant increase in glucose-6-phosphate dehydrogenase (G6PDH) activity, the key enzyme of the oxidative pentose pathway. We also observed a mitochondria shutdown in infected cells and mitochondrial swelling in pure neural leprosy nerves. The classic Warburg effect described in macrophages infected by Mycobacterium avium was not observed in our model, which presented a drastic reduction in lactate generation and release by infected Schwann cells. This effect was followed by a decrease in lactate dehydrogenase isoform M (LDH-M) activity and an increase in cellular protection against hydrogen peroxide insult in a pentose phosphate pathway and GSH-dependent manner. M. leprae infection success was also dependent of the glutathione antioxidant system and its main reducing power source, the pentose pathway, as demonstrated by a 50 and 70% drop in intracellular viability after treatment with the GSH synthesis inhibitor buthionine sulfoximine, and aminonicotinamide (6-ANAM), an inhibitor of G6PDH 6-ANAM, respectively. We concluded that M. leprae could modulate host cell glucose metabolism to increase the cellular reducing power generation, facilitating glutathione regeneration and consequently free-radical control. The impact of this regulation in leprosy neuropathy is discussed. PMID:27555322

  6. Nanoparticles carrying neurotrophin-3-modified Schwann cells promote repair of sciatic nerve defects.

    Science.gov (United States)

    Zong, Haibin; Zhao, Hongxing; Zhao, Yilei; Jia, Jingling; Yang, Libin; Ma, Chao; Zhang, Yang; Dong, Yuzhen

    2013-05-15

    Schwann cells and neurotrophin-3 play an important role in neural regeneration, but the secretion of neurotrophin-3 from Schwann cells is limited, and exogenous neurotrophin-3 is inactived easily in vivo. In this study, we have transfected neurotrophin-3 into Schwann cells cultured in vitro using nanoparticle liposomes. Results showed that neurotrophin-3 was successfully transfected into Schwann cells, where it was expressed effectively and steadily. A composite of Schwann cells transfected with neurotrophin-3 and poly(lactic-co-glycolic acid) biodegradable conduits was transplanted into rats to repair 10-mm sciatic nerve defects. Transplantation of the composite scaffold could restore the myoelectricity and wave amplitude of the sciatic nerve by electrophysiological examination, promote nerve axonal and myelin regeneration, and delay apoptosis of spinal motor neurons. Experimental findings indicate that neurotrophin-3 transfected Schwann cells combined with bridge grafting can promote neural regeneration and functional recovery after nerve injury.

  7. 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.

  8. Macrophage depletion and Schwann cell transplantation reduce cyst size after rat contusive spinal cord injury.

    Science.gov (United States)

    Lee, Yee-Shuan; Funk, Lucy H; Lee, Jae K; Bunge, Mary Bartlett

    2018-04-01

    Schwann cell transplantation is a promising therapy for the treatment of spinal cord injury (SCI) and is currently in clinical trials. In our continuing efforts to improve Schwann cell transplantation strategies, we sought to determine the combined effects of Schwann cell transplantation with macrophage depletion. Since macrophages are major inflammatory contributors to the acute spinal cord injury, and are the major phagocytic cells, we hypothesized that transplanting Schwann cells after macrophage depletion will improve cell survival and integration with host tissue after SCI. To test this hypothesis, rat models of contusive SCI at thoracic level 8 were randomly subjected to macrophage depletion or not. In rat subjected to macrophage depletion, liposomes filled with clodronate were intraperitoneally injected at 1, 3, 6, 11, and 18 days post injury. Rats not subjected to macrophage depletion were intraperitoneally injected with liposomes filled with phosphate buffered saline. Schwann cells were transplanted 1 week post injury in all rats. Biotinylated dextran amine (BDA) was injected at thoracic level 5 to evalute axon regeneration. The Basso, Beattie, and Bresnahan locomotor test, Gridwalk test, and sensory test using von Frey filaments were performed to assess functional recovery. Immunohistochemistry was used to detect glial fibrillary acidic protein, neurofilament, and green fluorescent protein (GFP), and also to visulize BDA-labelled axons. The GFP labeled Schwann cell and cyst and lesion volumes were quantified using stained slides. The numbers of BDA-positive axons were also quantified. At 8 weeks after Schwann cell transplantation, there was a significant reduction in cyst and lesion volumes in the combined treatment group compared to Schwann cell transplantation alone. These changes were not associated, however, with improved Schwann cell survival, axon growth, or locomotor recovery. Although combining Schwann cell transplantation with macrophage

  9. Macrophage depletion and Schwann cell transplantation reduce cyst size after rat contusive spinal cord injury

    Science.gov (United States)

    Lee, Yee-Shuan; Funk, Lucy H.; Lee, Jae K.; Bunge, Mary Bartlett

    2018-01-01

    Schwann cell transplantation is a promising therapy for the treatment of spinal cord injury (SCI) and is currently in clinical trials. In our continuing efforts to improve Schwann cell transplantation strategies, we sought to determine the combined effects of Schwann cell transplantation with macrophage depletion. Since macrophages are major inflammatory contributors to the acute spinal cord injury, and are the major phagocytic cells, we hypothesized that transplanting Schwann cells after macrophage depletion will improve cell survival and integration with host tissue after SCI. To test this hypothesis, rat models of contusive SCI at thoracic level 8 were randomly subjected to macrophage depletion or not. In rat subjected to macrophage depletion, liposomes filled with clodronate were intraperitoneally injected at 1, 3, 6, 11, and 18 days post injury. Rats not subjected to macrophage depletion were intraperitoneally injected with liposomes filled with phosphate buffered saline. Schwann cells were transplanted 1 week post injury in all rats. Biotinylated dextran amine (BDA) was injected at thoracic level 5 to evalute axon regeneration. The Basso, Beattie, and Bresnahan locomotor test, Gridwalk test, and sensory test using von Frey filaments were performed to assess functional recovery. Immunohistochemistry was used to detect glial fibrillary acidic protein, neurofilament, and green fluorescent protein (GFP), and also to visulize BDA-labelled axons. The GFP labeled Schwann cell and cyst and lesion volumes were quantified using stained slides. The numbers of BDA-positive axons were also quantified. At 8 weeks after Schwann cell transplantation, there was a significant reduction in cyst and lesion volumes in the combined treatment group compared to Schwann cell transplantation alone. These changes were not associated, however, with improved Schwann cell survival, axon growth, or locomotor recovery. Although combining Schwann cell transplantation with macrophage

  10. Macrophage depletion and Schwann cell transplantation reduce cyst size after rat contusive spinal cord injury

    Directory of Open Access Journals (Sweden)

    Yee-Shuan Lee

    2018-01-01

    Full Text Available Schwann cell transplantation is a promising therapy for the treatment of spinal cord injury (SCI and is currently in clinical trials. In our continuing efforts to improve Schwann cell transplantation strategies, we sought to determine the combined effects of Schwann cell transplantation with macrophage depletion. Since macrophages are major inflammatory contributors to the acute spinal cord injury, and are the major phagocytic cells, we hypothesized that transplanting Schwann cells after macrophage depletion will improve cell survival and integration with host tissue after SCI. To test this hypothesis, rat models of contusive SCI at thoracic level 8 were randomly subjected to macrophage depletion or not. In rat subjected to macrophage depletion, liposomes filled with clodronate were intraperitoneally injected at 1, 3, 6, 11, and 18 days post injury. Rats not subjected to macrophage depletion were intraperitoneally injected with liposomes filled with phosphate buffered saline. Schwann cells were transplanted 1 week post injury in all rats. Biotinylated dextran amine (BDA was injected at thoracic level 5 to evalute axon regeneration. The Basso, Beattie, and Bresnahan locomotor test, Gridwalk test, and sensory test using von Frey filaments were performed to assess functional recovery. Immunohistochemistry was used to detect glial fibrillary acidic protein, neurofilament, and green fluorescent protein (GFP, and also to visulize BDA-labelled axons. The GFP labeled Schwann cell and cyst and lesion volumes were quantified using stained slides. The numbers of BDA-positive axons were also quantified. At 8 weeks after Schwann cell transplantation, there was a significant reduction in cyst and lesion volumes in the combined treatment group compared to Schwann cell transplantation alone. These changes were not associated, however, with improved Schwann cell survival, axon growth, or locomotor recovery. Although combining Schwann cell transplantation with

  11. Schwann Cell Glycogen Selectively Supports Myelinated Axon Function

    Science.gov (United States)

    Brown, Angus M; Evans, Richard D; Black, Joel; Ransom, Bruce R

    2012-01-01

    Objectives Interruption of energy supply to peripheral axons is a cause of axon loss. We determined if glycogen was present in mammalian peripheral nerve, and if it supported axon conduction during aglycemia. Methods We used biochemical assay and electron microscopy to determine the presence of glycogen, and electrophysiology to monitor axon function. Results Glycogen was present in sciatic nerve, its concentration varying directly with ambient [glucose]. Electron microscopy detected glycogen granules primarily in myelinating Schwann cell cytoplasm and these diminished after exposure to aglycemia. During aglycemia, conduction failure in large myelinated axons (A fibers) mirrored the time-course of glycogen loss. Latency to CAP failure was directly related to nerve glycogen content at aglycemia onset. Glycogen did not benefit the function of slow-conducting, small diameter unmyelinated axons (C fibers) during aglycemia. Blocking glycogen breakdown pharmacologically accelerated CAP failure during aglycemia in A fibers, but not in C fibers. Lactate was as effective as glucose in supporting sciatic nerve function, and was continuously released into the extracellular space in the presence of glucose and fell rapidly during aglycemia. Interpretation Our findings indicated that glycogen is present in peripheral nerve, primarily in myelinating Schwann cells, and exclusively supports large diameter, myelinated axon conduction during aglycemia. Available evidence suggests that peripheral nerve glycogen breaks down during aglycemia and is passed, probably as lactate, to myelinated axons to support function. Unmyelinated axons are not protected by glycogen and are more vulnerable to dysfunction during periods of hypoglycemia. PMID:23034913

  12. After Nerve Injury, Lineage Tracing Shows That Myelin and Remak Schwann Cells Elongate Extensively and Branch to Form Repair Schwann Cells, Which Shorten Radically on Remyelination.

    Science.gov (United States)

    Gomez-Sanchez, Jose A; Pilch, Kjara S; van der Lans, Milou; Fazal, Shaline V; Benito, Cristina; Wagstaff, Laura J; Mirsky, Rhona; Jessen, Kristjan R

    2017-09-13

    There is consensus that, distal to peripheral nerve injury, myelin and Remak cells reorganize to form cellular columns, Bungner's bands, which are indispensable for regeneration. However, knowledge of the structure of these regeneration tracks has not advanced for decades and the structure of the cells that form them, denervated or repair Schwann cells, remains obscure. Furthermore, the origin of these cells from myelin and Remak cells and their ability to give rise to myelin cells after regeneration has not been demonstrated directly, although these conversions are believed to be central to nerve repair. Using genetic lineage-tracing and scanning-block face electron microscopy, we show that injury of sciatic nerves from mice of either sex triggers extensive and unexpected Schwann cell elongation and branching to form long, parallel processes. Repair cells are 2- to 3-fold longer than myelin and Remak cells and 7- to 10-fold longer than immature Schwann cells. Remarkably, when repair cells transit back to myelinating cells, they shorten ∼7-fold to generate the typically short internodes of regenerated nerves. The present experiments define novel morphological transitions in injured nerves and show that repair Schwann cells have a cell-type-specific structure that differentiates them from other cells in the Schwann cell lineage. They also provide the first direct evidence using genetic lineage tracing for two basic assumptions in Schwann cell biology: that myelin and Remak cells generate the elongated cells that build Bungner bands in injured nerves and that such cells can transform to myelin cells after regeneration. SIGNIFICANCE STATEMENT After injury to peripheral nerves, the myelin and Remak Schwann cells distal to the injury site reorganize and modify their properties to form cells that support the survival of injured neurons, promote axon growth, remove myelin-associated growth inhibitors, and guide regenerating axons to their targets. We show that the

  13. Effects of cholinergic compounds on the axon-Schwann cell relationship in the squid nerve fiber.

    Science.gov (United States)

    Villegas, J

    1975-04-01

    The effects of acetylcholine, carbamylcholine, D-tubocurarine, eserine, and alpha-bungarotoxin on the Schwann cell electrical potential of resting and stimulated squid nerve fibers were studied. Acetylcholine (10-7 M) and barbamylcholine (10-6 M) induce a prolonged hyper polarization in the Schwann cells of the unstimulated nerve fiber. In the presence of carbamylcholine (10-6 M) the behavior of the Schwann cell membrane to changes in the external potassium concentration approximates the behavior of an ideal potassium electrode. D-Tubocurarine (10-9 M) blocks the hyperpolarizing effects of nerve impulse trains and carbamylcholine (10-6 M), whereas at the same concentration eserine prolongs the Schwann cell hyperpolarizations induced by axon stimulation or by acetylcholine (10-7 M). alpha-Bungarotoxin (10-9M) also blocks the hyperpolarizing effect of nerve impulse trains and of carbamylcholine. D-Tubocurarine (10-5M) protects the Schwann cells against the irreversible action of alpha-bungarotoxin. These results show the existence of acetylcholine receptors in the Schwann cell membrane. Preliminary measurements of the binding of 125I-alpha bungarotoxin to the plasma membranes isolated from squid nerves also indicate the presence of acetylcholine receptors. These findings support the involvement of cholinergic mechanisms in the axon-Schwann cell relationship previously described.

  14. Trophic Effects of Dental Pulp Stem Cells on Schwann Cells in Peripheral Nerve Regeneration.

    Science.gov (United States)

    Yamamoto, Tsubasa; Osako, Yohei; Ito, Masataka; Murakami, Masashi; Hayashi, Yuki; Horibe, Hiroshi; Iohara, Koichiro; Takeuchi, Norio; Okui, Nobuyuki; Hirata, Hitoshi; Nakayama, Hidenori; Kurita, Kenichi; Nakashima, Misako

    2016-01-01

    Recently, mesenchymal stem cells have demonstrated a potential for neurotrophy and neurodifferentiation. We have recently isolated mobilized dental pulp stem cells (MDPSCs) using granulocyte-colony stimulating factor (G-CSF) gradient, which has high neurotrophic/angiogenic potential. The aim of this study is to investigate the effects of MDPSC transplantation on peripheral nerve regeneration. Effects of MDPSC transplantation were examined in a rat sciatic nerve defect model and compared with autografts and control conduits containing collagen scaffold. Effects of conditioned medium of MDPSCs were also evaluated in vitro. Transplantation of MDPSCs in the defect demonstrated regeneration of myelinated fibers, whose axons were significantly higher in density compared with those in autografts and control conduits only. Enhanced revascularization was also observed in the MDPSC transplants. The MDPSCs did not directly differentiate into Schwann cell phenotype; localization of these cells near Schwann cells induced several neurotrophic factors. Immunofluorescence labeling demonstrated reduced apoptosis and increased proliferation in resident Schwann cells in the MDPSC transplant compared with control conduits. These trophic effects of MDPSCs on proliferation, migration, and antiapoptosis in Schwann cells were further elucidated in vitro. The results demonstrate that MDPSCs promote axon regeneration through trophic functions, acting on Schwann cells, and promoting angiogenesis.

  15. Macrophage polarization in nerve injury: do Schwann cells play a role?

    Directory of Open Access Journals (Sweden)

    Jo Anne Stratton

    2016-01-01

    Full Text Available In response to peripheral nerve injury, the inflammatory response is almost entirely comprised of infiltrating macrophages. Macrophages are a highly plastic, heterogenic immune cell, playing an indispensable role in peripheral nerve injury, clearing debris and regulating the microenvironment to allow for efficient regeneration. There are several cells within the microenvironment that likely interact with macrophages to support their function - most notably the Schwann cell, the glial cell of the peripheral nervous system. Schwann cells express several ligands that are known to interact with receptors expressed by macrophages, yet the effects of Schwann cells in regulating macrophage phenotype remains largely unexplored. This review discusses macrophages in peripheral nerve injury and how Schwann cells may regulate their behavior.

  16. Schwann cells promote post-traumatic nerve inflammation and neuropathic pain through MHC class II.

    Science.gov (United States)

    Hartlehnert, Maike; Derksen, Angelika; Hagenacker, Tim; Kindermann, David; Schäfers, Maria; Pawlak, Mathias; Kieseier, Bernd C; Meyer Zu Horste, Gerd

    2017-10-02

    The activation of T helper cells requires antigens to be exposed on the surface of antigen presenting cells (APCs) via MHC class II (MHC-II) molecules. Expression of MHC-II is generally limited to professional APCs, but other cell types can express MHC-II under inflammatory conditions. However, the importance of these conditional APCs is unknown. We and others have previously shown that Schwann cells are potentially conditional APCs, but the functional relevance of MHC-II expression by Schwann cells has not been studied in vivo. Here, we conditionally deleted the MHC-II β-chain from myelinating Schwann cells in mice and investigated how this influenced post-traumatic intraneural inflammation and neuropathic pain using the chronic constriction injury (CCI) model. We demonstrate that deletion of MHC-II in myelinating Schwann cells reduces thermal hyperalgesia and, to a lesser extent, also diminishes mechanical allodynia in CCI in female mice. This was accompanied by a reduction of intraneural CD4+ T cells and greater preservation of preferentially large-caliber axons. Activation of T helper cells by MHC-II on Schwann cells thus promotes post-traumatic axonal loss and neuropathic pain. Hence, we provide experimental evidence that Schwann cells gain antigen-presenting function in vivo and modulate local immune responses and diseases in the peripheral nerves.

  17. The beneficial effect of genetically engineered Schwann cells with enhanced motility in peripheral nerve regeneration: review.

    Science.gov (United States)

    Gravvanis, A I; Lavdas, A A; Papalois, A; Tsoutsos, D A; Matsas, R

    2007-01-01

    The importance of Schwann cells in promoting nerve regeneration across a conduit has been extensively reported in the literature, and Schwann cell motility has been acknowledged as a prerequisite for myelination of the peripheral nervous system during regeneration after injury. Review of recent literature and retrospective analysis of our studies with genetically modified Schwann Cells with increased motility in order to identify the underlying mechanism of action and outline the future trends in peripheral nerve repair. Schwann cell transduction with the pREV-retrovirus, for expression of Sialyl-Transferase-X, resulting in conferring Polysialyl-residues (PSA) on NCAM, increases their motility in-vitro and ensures nerve regeneration through silicone tubes after end-to-side neurorraphy in the rat sciatic nerve model, thus significantly promoting fiber maturation and functional outcome. An artificial nerve graft consisting of a type I collagen tube lined with the genetically modified Schwann cells with increased motility, used to bridge a defect in end-to-end fashion in the rat sciatic nerve model, was shown to promote nerve regeneration to a level equal to that of a nerve autograft. The use of genetically engineered Schwann cells with enhanced motility for grafting endoneural tubes promotes axonal regeneration, by virtue of the interaction of the transplanted cells with regenerating axonal growth cones as well as via the recruitment of endogenous Schwann cells. It is envisaged that mixed populations of Schwann cells, expressing PSA and one or more trophic factors, might further enhance the regenerating and remyelinating potential of the lesioned nerves.

  18. 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

    in combination with BrdU immunocytochemistry showed that around 93% of the proliferating cells in the nerve segments were Schwann cells. Immunostaining for BrdU and GFAP (glial fibrillary acid protein) showed that IGF-II enhanced proliferation of Schwann cells surrounding unmyelinated nerve fibres. In contrast......, truncated IGF-I promoted proliferation of Schwann cells of myelinated nerve fibres while insulin increased proliferation of both cell types....

  19. Schwann cell seeded guidance tubes restore erectile function after ablation of cavernous nerves in rats.

    Science.gov (United States)

    May, F; Weidner, N; Matiasek, K; Caspers, C; Mrva, T; Vroemen, M; Henke, J; Lehmer, A; Schwaibold, H; Erhardt, W; Gänsbacher, B; Hartung, R

    2004-07-01

    Dissection of the cavernous nerves eliminates spontaneous erections. We evaluated the ability of Schwann cell seeded nerve guidance tubes to restore erections after bilateral cavernous nerve resection in rats. Sections (5 mm) of the cavernous nerve were excised bilaterally, followed by immediate bilateral microsurgical reconstruction. In 10 animals per group (20 study nerves) reconstruction was performed by genitofemoral nerve interposition, interposition of silicone tubes or interposition of silicone tubes seeded with homologous Schwann cells. As the control 10 animals (20 study nerves) underwent sham operation (positive control) and bilateral nerve ablation (without reconstruction) was performed in a further 10 (negative control). Erectile function was evaluated 3 months postoperatively by relaparotomy, electrical nerve stimulation and intracavernous pressure recording. After 3 months neurostimulation resulted in an intact erectile response in 90% (18 of 20) of Schwann cell grafts, while treatment with autologous nerves (30% or 6 of 20) or tubes only (50% or 10 of 20) was less successful (p Schwann cell grafts compared to results in the other treatment groups (p Schwann cell grafts. Schwann cell seeded guidance tubes restore erectile function after the ablation of cavernous nerves in rats and they are superior to autologous nerve grafts.

  20. Observations on the interactions of Schwann cells and astrocytes following x irradiation of neonatal rat spinal cord

    Energy Technology Data Exchange (ETDEWEB)

    Blakemore, W F; Patterson, R C

    1975-10-01

    Myelination was inhibited in the spinal cord of three day-old rats with 2000 rads of x irradiation. Myelination subsequently occurred as a result of caudal migration of oligodendrocytes and extensive invasion of the cord by Schwann cells. Although oligodendrocytes were present in areas containing Schwann cells, astrocytes were absent. The presence of Schwann cells in the neuropil of the spinal cord did not stimulate production of basement membrane by astrocytes, so no new glial limiting membrane was formed. Evidence is presented which suggests that if astrocytes do not form a glial limiting membrane when opposed by large numbers of Schwann cells they are destroyed by the invading cells. It is suggested that the glial limiting membrane normally inhibits entry of Schwann cells into the central nervous system; if this is destroyed and not reconstituted, Schwann cells can migrate freely into the neuropil.

  1. Schwann Cells in Neuromuscular Junction Formation and Maintenance.

    Science.gov (United States)

    Barik, Arnab; Li, Lei; Sathyamurthy, Anupama; Xiong, Wen-Cheng; Mei, Lin

    2016-09-21

    The neuromuscular junction (NMJ) is a tripartite synapse that is formed by motor nerve terminals, postjunctional muscle membranes, and terminal Schwann cells (TSCs) that cover the nerve-muscle contact. NMJ formation requires intimate communications among the three different components. Unlike nerve-muscle interaction, which has been well characterized, less is known about the role of SCs in NMJ formation and maintenance. We show that SCs in mice lead nerve terminals to prepatterned AChRs. Ablating SCs at E8.5 (i.e., prior nerve arrival at the clusters) had little effect on aneural AChR clusters at E13.5, suggesting that SCs may not be necessary for aneural clusters. SC ablation at E12.5, a time when phrenic nerves approach muscle fibers, resulted in smaller and fewer nerve-induced AChR clusters; however, SC ablation at E15.5 reduced AChR cluster size but had no effect on cluster density, suggesting that SCs are involved in AChR cluster maturation. Miniature endplate potential amplitude, but not frequency, was reduced when SCs were ablated at E15.5, suggesting that postsynaptic alterations may occur ahead of presynaptic deficits. Finally, ablation of SCs at P30, after NMJ maturation, led to NMJ fragmentation and neuromuscular transmission deficits. Miniature endplate potential amplitude was reduced 3 d after SC ablation, but both amplitude and frequency were reduced 6 d after. Together, these results indicate that SCs are not only required for NMJ formation, but also necessary for its maintenance; and postsynaptic function and structure appeared to be more sensitive to SC ablation. Neuromuscular junctions (NMJs) are critical for survival and daily functioning. Defects in NMJ formation during development or maintenance in adulthood result in debilitating neuromuscular disorders. The role of Schwann cells (SCs) in NMJ formation and maintenance was not well understood. We genetically ablated SCs during development and after NMJ formation to investigate the consequences

  2. The formation of lipid droplets favors intracellular Mycobacterium leprae survival in SW-10, non-myelinating Schwann cells

    OpenAIRE

    Jin, Song-Hyo; An, Sung-Kwan; Lee, Seong-Beom

    2017-01-01

    Leprosy is a chronic infectious disease that is caused by the obligate intracellular pathogen Mycobacterium leprae (M.leprae), which is the leading cause of all non-traumatic peripheral neuropathies worldwide. Although both myelinating and non-myelinating Schwann cells are infected by M.leprae in patients with lepromatous leprosy, M.leprae preferentially invades the non-myelinating Schwann cells. However, the effect of M.leprae infection on non-myelinating Schwann cells has not been elucidate...

  3. Cellular Scale Anisotropic Topography Guides Schwann Cell Motility

    Science.gov (United States)

    Mitchel, Jennifer A.; Hoffman-Kim, Diane

    2011-01-01

    Directed migration of Schwann cells (SC) is critical for development and repair of the peripheral nervous system. Understanding aspects of motility specific to SC, along with SC response to engineered biomaterials, may inform strategies to enhance nerve regeneration. Rat SC were cultured on laminin-coated microgrooved poly(dimethyl siloxane) platforms that were flat or presented repeating cellular scale anisotropic topographical cues, 30 or 60 µm in width, and observed with timelapse microscopy. SC motion was directed parallel to the long axis of the topography on both the groove floor and the plateau, with accompanying differences in velocity and directional persistence in comparison to SC motion on flat substrates. In addition, feature dimension affected SC morphology, alignment, and directional persistence. Plateaus and groove floors presented distinct cues which promoted differential motility and variable interaction with the topographical features. SC on the plateau surfaces tended to have persistent interactions with the edge topography, while SC on the groove floors tended to have infrequent contact with the corners and walls. Our observations suggest the capacity of SC to be guided without continuous contact with a topographical cue. SC exhibited a range of distinct motile morphologies, characterized by their symmetry and number of extensions. Across all conditions, SC with a single extension traveled significantly faster than cells with more or no extensions. We conclude that SC motility is complex, where persistent motion requires cellular asymmetry, and that anisotropic topography with cellular scale features can direct SC motility. PMID:21949703

  4. Schwann cell response on polypyrrole substrates upon electrical stimulation.

    Science.gov (United States)

    Forciniti, Leandro; Ybarra, Jose; Zaman, Muhammad H; Schmidt, Christine E

    2014-06-01

    Current injury models suggest that Schwann cell (SC) migration and guidance are necessary for successful regeneration and synaptic reconnection after peripheral nerve injury. The ability of conducting polymers such as polypyrrole (PPy) to exhibit chemical, contact and electrical stimuli for cells has led to much interest in their use for neural conduits. Despite this interest, there has been very little research on the effect that electrical stimulation (ES) using PPy has on SC behavior. Here we investigate the mechanism by which SCs interact with PPy in the presence of an electric field. Additionally, we explored the effect that the adsorption of different serum proteins on PPy upon the application of an electric field has on SC migration. The results indicate an increase in average displacement of the SC with ES, resulting in a net anodic migration. Moreover, indirect effects of protein adsorption due to the oxidation of the film upon the application of ES were shown to have a larger effect on migration speed than on migration directionality. These results suggest that SC migration speed is governed by an integrin- or receptor-mediated mechanism, whereas SC migration directionality is governed by electrically mediated phenomena. These data will prove invaluable in optimizing conducting polymers for their different biomedical applications such as nerve repair. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. Exploration of molecular pathways mediating electric field-directed Schwann cell migration by RNA-Seq

    Science.gov (United States)

    Yao, Li; Li, Yongchao; Knapp, Jennifer; Smith, Peter

    2015-01-01

    In peripheral nervous systems, Schwann cells wrap around axons of motor and sensory neurons to form the myelin sheath. Following spinal cord injury, Schwann cells regenerate and migrate to the lesion and are involved in the spinal cord regeneration process. Transplantation of Schwann cells into injured neural tissue results in enhanced spinal axonal regeneration. Effective directional migration of Schwann cells is critical in the neural regeneration process. In this study, we report that Schwann cells migrate anodally in an applied electric field (EF). The directedness and displacement of anodal migration increased significantly when the strength of the EF increased from 50 mV/mm to 200 mV/mm. The EF did not significantly affect the cell migration speed. To explore the genes and signaling pathways that regulate cell migration in EFs, we performed a comparative analysis of differential gene expression between cells stimulated with an EF (100 mV/mm) and those without using next-generation RNA sequencing, verified by RT-qPCR. Based on the cut-off criteria (FC > 1.2, q cells versus EF-stimulated cells. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis found that compared to the control group, 21 pathways are down-regulated, while 10 pathways are up-regulated. Differentially expressed genes participate in multiple cellular signaling pathways involved in the regulation of cell migration, including pathways of regulation of actin cytoskeleton, focal adhesion, and PI3K-Akt. PMID:25557037

  6. Biphasic electrical targeting plays a significant role in schwann cell activation.

    Science.gov (United States)

    Kim, In Sook; Song, Yun Mi; Cho, Tae Hyung; Pan, Hui; Lee, Tae Hyung; Kim, Sung June; Hwang, Soon Jung

    2011-05-01

    Electrical stimulation (ES) is a promising technique for axonal regeneration of peripheral nerve injuries. However, long-term, continuous ES in the form of biphasic electric current (BEC) to stimulate axonal regeneration has rarely been attempted and the effects of BEC on Schwann cells are unknown. We hypothesized that long-term, continuous ES would trigger the activation of Schwann cells, and we therefore investigated the effect of BEC on the functional differentiation of primary human mesenchymal stromal cells (hMSCs) into Schwann cells, as well as the activity of primary Schwann cells. Differentiation of hMSCs into Schwann cells was determined by coculture with rat pheochromocytoma cells (PC12 cell line). We also investigated the in vivo effects of long-term ES (4 weeks) on axonal outgrowth of a severed sciatic nerve with a 7-mm gap after retraction of the nerve ends in rats by implanting an electronic device to serve as a neural conduit. PC12 cells cocultured with hMSCs electrically stimulated during culture in Schwann cell differentiation medium (Group I) had longer neurites and a greater percentage of PC12 cells were neurite-sprouting than when cocultured with hMSCs cultured in growth medium (control group) or unstimulated hMSCs in the same culture conditions as used for Group I (Group II). Group I cells showed significant upregulation of Schwann cell-related neurotrophic factors such as nerve growth factor and glial-derived neurotrophic factor compared to Group II cells at both the mRNA and protein levels. Primary Schwann cells responded to continuous BEC with increased proliferation and the induction of nerve growth factor and glial-derived neurotrophic factor, similar to Group I cells, and in addition, induction of brain-derived neurotrophic factor was observed. Immunohistochemical investigation of sciatic nerve regenerates revealed that BEC increased axonal outgrowth significantly. These results demonstrate that BEC enhanced the functional activity of

  7. Neuron-glia signaling and the protection of axon function by Schwann cells.

    Science.gov (United States)

    Quintes, Susanne; Goebbels, Sandra; Saher, Gesine; Schwab, Markus H; Nave, Klaus-Armin

    2010-03-01

    The interaction between neurons and glial cells is a feature of all higher nervous systems. In the vertebrate peripheral nervous system, Schwann cells ensheath and myelinate axons thereby allowing rapid saltatory conduction and ensuring axonal integrity. Recently, some of the key molecules in neuron-Schwann cell signaling have been identified. Neuregulin-1 (NRG1) type III presented on the axonal surface determines the myelination fate of axons and controls myelin sheath thickness. Recent observations suggest that NRG1 regulates myelination via the control of Schwann cell cholesterol biosynthesis. This concept is supported by the finding that high cholesterol levels in Schwann cells are a rate-limiting factor for myelin protein production and transport of the major myelin protein P0 from the endoplasmic reticulum into the growing myelin sheath. NRG1 type III activates ErbB receptors on the Schwann cell, which leads to an increase in intracellular PIP3 levels via the PI3-kinase pathway. Surprisingly, enforced elevation of PIP3 levels by inactivation of the phosphatase PTEN in developing and mature Schwann cells does not entirely mimic NRG1 type III stimulated myelin growth, but predominantly causes focal hypermyelination starting at Schmidt-Lanterman incisures and nodes of Ranvier. This indicates that the glial transduction of pro-myelinating signals has to be under tight and life-long control to preserve integrity of the myelinated axon. Understanding the cross talk between neurons and Schwann cells will help to further define the role of glia in preserving axonal integrity and to develop therapeutic strategies for peripheral neuropathies such as CMT1A.

  8. Ribosomal trafficking is reduced in Schwann cells following induction of myelination

    Directory of Open Access Journals (Sweden)

    James M. Love

    2015-08-01

    Full Text Available Local synthesis of proteins within the Schwann cell periphery is extremely important for efficient process extension and myelination, when cells undergo dramatic changes in polarity and geometry. Still, it is unclear how ribosomal distributions are developed and maintained within Schwann cell projections to sustain local translation. In this multi-disciplinary study, we expressed a plasmid encoding a fluorescently labeled ribosomal subunit (L4-GFP in cultured primary rat Schwann cells. This enabled the generation of high-resolution, quantitative data on ribosomal distributions and trafficking dynamics within Schwann cells during early stages of myelination, induced by ascorbic acid treatment. Ribosomes were distributed throughout Schwann cell projections, with ~2-3 bright clusters along each projection. Clusters emerged within 1 day of culture and were maintained throughout early stages of myelination. Three days after induction of myelination, net ribosomal movement remained anterograde (directed away from the Schwann cell body, but ribosomal velocity decreased to about half the levels of the untreated group. Statistical and modeling analysis provided additional insight into key factors underlying ribosomal trafficking. Multiple regression analysis indicated that net transport at early time points was dependent on anterograde velocity, but shifted to dependence on anterograde duration at later time points. A simple, data-driven rate kinetics model suggested that the observed decrease in net ribosomal movement was primarily dictated by an increased conversion of anterograde particles to stationary particles, rather than changes in other directional parameters. These results reveal the strength of a combined experimental and theoretical approach in examining protein localization and transport, and provide evidence of an early establishment of ribosomal populations within Schwann cell projections with a reduction in trafficking following

  9. STAT3 Controls the Long-Term Survival and Phenotype of Repair Schwann Cells during Nerve Regeneration.

    Science.gov (United States)

    Benito, Cristina; Davis, Catherine M; Gomez-Sanchez, Jose A; Turmaine, Mark; Meijer, Dies; Poli, Valeria; Mirsky, Rhona; Jessen, Kristjan R

    2017-04-19

    After nerve injury, Schwann cells convert to a phenotype specialized to promote repair. But during the slow process of axonal regrowth, these repair Schwann cells gradually lose their regeneration-supportive features and eventually die. Although this is a key reason for the frequent regeneration failures in humans, the transcriptional mechanisms that control long-term survival and phenotype of repair cells have not been studied, and the molecular signaling underlying their decline is obscure. We show, in mice, that Schwann cell STAT3 has a dual role. It supports the long-term survival of repair Schwann cells and is required for the maintenance of repair Schwann cell properties. In contrast, STAT3 is less important for the initial generation of repair Schwann cells after injury. In repair Schwann cells, we find that Schwann cell STAT3 activation by Tyr705 phosphorylation is sustained during long-term denervation. STAT3 is required for maintaining autocrine Schwann cell survival signaling, and inactivation of Schwann cell STAT3 results in a striking loss of repair cells from chronically denervated distal stumps. STAT3 inactivation also results in abnormal morphology of repair cells and regeneration tracks, and failure to sustain expression of repair cell markers, including Shh, GDNF, and BDNF. Because Schwann cell development proceeds normally without STAT3, the function of this factor appears restricted to Schwann cells after injury. This identification of transcriptional mechanisms that support long-term survival and differentiation of repair cells will help identify, and eventually correct, the failures that lead to the deterioration of this important cell population. SIGNIFICANCE STATEMENT Although injured peripheral nerves contain repair Schwann cells that provide signals and spatial clues for promoting regeneration, the clinical outcome after nerve damage is frequently poor. A key reason for this is that, during the slow growth of axons through the proximal

  10. Electrical regulation of Schwann cells using conductive polypyrrole/chitosan polymers.

    Science.gov (United States)

    Huang, Jinghui; Hu, Xueyu; Lu, Lei; Ye, Zhengxu; Zhang, Quanyu; Luo, Zhuojing

    2010-04-01

    Electrical stimulation (ES) can dramatically enhance neurite outgrowth through conductive polymers and accelerate peripheral nerve regeneration in animal models of nerve injury. Therefore, conductive tissue engineering graft in combination with ES is a potential treatment for neural injuries. Conductive tissue engineering graft can be obtained by seeding Schwann cells on conductive scaffold. However, when ES is applied through the conductive scaffold, the impact of ES on Schwann cells has never been investigated. In this study, a biodegradable conductive composite made of conductive polypyrrole (PPy, 2.5%) and biodegradable chitosan (97.5%) was prepared in order to electrically stimulate Schwann cells. The tolerance of Schwann cells to ES was examined by a cell apoptosis assay. The growth of the cells was characterized using DAPI staining and a MTT assay. mRNA and protein levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in Schwann cells were assayed by RT-PCR and Western blotting, and the amount of NGF and BDNF secreted was determined by an ELISA assay. The results showed that the PPy/chitosan membranes supported cell adhesion, spreading, and proliferation with or without ES. Interestingly, ES applied through the PPy/chitosan composite dramatically enhanced the expression and secretion of NGF and BDNF when compared with control cells without ES. These findings highlight for the first time the possibility of enhancing nerve regeneration in conductive scaffolds through ES-increased neurotrophin secretion.

  11. p75 neurotrophin receptor is involved in proliferation of undifferentiated mouse embryonic stem cells

    International Nuclear Information System (INIS)

    Moscatelli, Ilana; Pierantozzi, Enrico; Camaioni, Antonella; Siracusa, Gregorio; Campagnolo, Luisa

    2009-01-01

    Neurotrophins and their receptors are known to play a role in the proliferation and survival of many different cell types of neuronal and non-neuronal lineages. In addition, there is much evidence in the literature showing that the p75 neurotrophin receptor (p75 NTR ), alone or in association with members of the family of Trk receptors, is expressed in a wide variety of stem cells, although its role in such cells has not been completely elucidated. In the present work we have investigated the expression of p75 NTR and Trks in totipotent and pluripotent cells, the mouse pre-implantation embryo and embryonic stem and germ cells (ES and EG cells). p75 NTR and TrkA can be first detected in the blastocyst from which ES cell lines are derived. Mouse ES cells retain p75 NTR /TrkA expression. Nerve growth factor is the only neurotrophin able to stimulate ES cell growth in culture, without affecting the expression of stem cell markers, alkaline phosphatase, Oct4 and Nanog. Such proliferation effect was blocked by antagonizing either p75 NTR or TrkA. Interestingly, immunoreactivity to anti-p75 NTR antibodies is lost upon ES cell differentiation. The expression pattern of neurotrophin receptors in murine ES cells differs from human ES cells, that only express TrkB and C, and do not respond to NGF. In this paper we also show that, while primordial germ cells (PGC) do not express p75 NTR , when they are made to revert to an ES-like phenotype, becoming EG cells, expression of p75 NTR is turned on.

  12. Cthrc1 is a negative regulator of myelination in Schwann cells.

    Science.gov (United States)

    Apra, Caroline; Richard, Laurence; Coulpier, Fanny; Blugeon, Corinne; Gilardi-Hebenstreit, Pascale; Vallat, Jean-michel; Lindner, Volkhard; Charnay, Patrick; Decker, Laurence

    2012-03-01

    The analysis of the molecular mechanisms involved in the initial interaction between neurons and Schwann cells is a key issue in understanding the myelination process. We recently identified Cthrc1 (Collagen triple helix repeat containing 1) as a gene upregulated in Schwann cells upon interaction with the axon. Cthrc1 encodes a secreted protein previously shown to be involved in migration and proliferation in different cell types. We performed a functional analysis of Cthrc1 in Schwann cells by loss-of- and gain-of-function approaches using RNA interference knockdown in cell culture and a transgenic mouse line that overexpresses the gene. This work establishes that Cthrc1 enhances Schwann cell proliferation but prevents myelination. In particular, time-course analysis of myelin formation intransgenic animals reveals that overexpression of Cthrc1 in Schwann cells leads to a delay in myelin formation with cells maintaining a proliferative state. Our data, therefore, demonstrate that Cthrc1 plays a negative regulatory role, fine-tuning the onset of peripheral myelination.

  13. Reconstitution of the NF1 GAP-related domain in NF1-deficient human Schwann cells

    International Nuclear Information System (INIS)

    Thomas, Stacey L.; Deadwyler, Gail D.; Tang, Jun; Stubbs, Evan B.; Muir, David; Hiatt, Kelly K.; Clapp, D. Wade; De Vries, George H.

    2006-01-01

    Schwann cells derived from peripheral nerve sheath tumors from individuals with Neurofibromatosis Type 1 (NF1) are deficient for the protein neurofibromin, which contains a GAP-related domain (NF1-GRD). Neurofibromin-deficient Schwann cells have increased Ras activation, increased proliferation in response to certain growth stimuli, increased angiogenic potential, and altered cell morphology. This study examined whether expression of functional NF1-GRD can reverse the transformed phenotype of neurofibromin-deficient Schwann cells from both benign and malignant peripheral nerve sheath tumors. We reconstituted the NF1-GRD using retroviral transduction and examined the effects on cell morphology, growth potential, and angiogenic potential. NF1-GRD reconstitution resulted in morphologic changes, a 16-33% reduction in Ras activation, and a 53% decrease in proliferation in neurofibromin-deficient Schwann cells. However, NF1-GRD reconstitution was not sufficient to decrease the in vitro angiogenic potential of the cells. This study demonstrates that reconstitution of the NF1-GRD can at least partially reverse the transformation of human NF1 tumor-derived Schwann cells

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Neurotrophin responsiveness of sympathetic neurons is regulated by rapid mobilization of the p75 receptor to the cell surface through TrkA activation of Arf6.

    Science.gov (United States)

    Edward Hickman, F; Stanley, Emily M; Carter, Bruce D

    2018-05-22

    availability, may provide insight into how and why neurodegenerative processes manifest and reveal new therapeutic targets. Results from this study indicate a novel mechanism by which p75NTR can be rapidly shuttled to the cell surface from existing intracellular pools and explores a unique pathway by which NGF regulates the sympathetic innervation of target tissues, which has profound consequences for the function of these organs. Copyright © 2018 the authors.

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

    Science.gov (United States)

    Jaegle, Martine; Ghazvini, Mehrnaz; Mandemakers, Wim; Piirsoo, Marko; Driegen, Siska; Levavasseur, Francoise; Raghoenath, Smiriti; Grosveld, Frank; Meijer, Dies

    2003-06-01

    The 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 development and tissue regeneration in adults following damage. In this report we demonstrate the involvement of a third transcription factor, the POU domain factor Brn-2. We show that Schwann cells express Brn-2 in a developmental profile similar to that of Oct-6 and that Brn-2 gene activation does not depend on Oct-6. Overexpression of Brn-2 in Oct-6-deficient Schwann cells, under control of the Oct-6 Schwann cell enhancer (SCE), results in partial rescue of the developmental delay phenotype, whereas compound disruption of both Brn-2 and Oct-6 results in a much more severe phenotype. Together these data strongly indicate that Brn-2 function largely overlaps with that of Oct-6 in driving the transition from promyelinating to myelinating Schwann cells.

  17. 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 ......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......), and myenteric plexi. In the sciatic nerve, N-cadherin decreases with age and progress of myelination. In adult animals, N-cadherin was found exclusively in nonmyelinating Schwann cells. The distribution of N-cadherin in developing E17 DRG primary cultures is similar to what was observed in vivo. Functional...

  18. Electrical stimulation of schwann cells promotes sustained increases in neurite outgrowth.

    Science.gov (United States)

    Koppes, Abigail N; Nordberg, Andrea L; Paolillo, Gina M; Goodsell, Nicole M; Darwish, Haley A; Zhang, Linxia; Thompson, Deanna M

    2014-02-01

    Endogenous electric fields are instructive during embryogenesis by acting to direct cell migration, and postnatally, they can promote axonal growth after injury (McCaig 1991, Al-Majed 2000). However, the mechanisms for these changes are not well understood. Application of an appropriate electrical stimulus may increase the rate and success of nerve repair by directly promoting axonal growth. Previously, DC electrical stimulation at 50 mV/mm (1 mA, 8 h duration) was shown to promote neurite outgrowth and a more pronounced effect was observed if both peripheral glia (Schwann cells) and neurons were co-stimulated. If electrical stimulation is delivered to an injury site, both the neurons and all resident non-neuronal cells [e.g., Schwann cells, endothelial cells, fibroblasts] will be treated and this biophysical stimuli can influence axonal growth directly or indirectly via changes to the resident, non-neuronal cells. In this work, non-neuronal cells were electrically stimulated, and changes in morphology and neuro-supportive cells were evaluated. Schwann cell response (morphology and orientation) was examined after an 8 h stimulation over a range of DC fields (0-200 mV/mm, DC 1 mA), and changes in orientation were observed. Electrically prestimulating Schwann cells (50 mV/mm) promoted 30% more neurite outgrowth relative to co-stimulating both Schwann cells with neurons, suggesting that electrical stimulation modifies Schwann cell phenotype. Conditioned medium from the electrically prestimulated Schwann cells promoted a 20% increase in total neurite outgrowth and was sustained for 72 h poststimulation. An 11-fold increase in nerve growth factor but not brain-derived neurotrophic factor or glial-derived growth factor was found in the electrically prestimulated Schwann cell-conditioned medium. No significant changes in fibroblast or endothelial morphology and neuro-supportive behavior were observed poststimulation. Electrical stimulation is widely used in

  19. Axon degeneration: make the Schwann cell great again

    Directory of Open Access Journals (Sweden)

    Keit Men Wong

    2017-01-01

    Full Text Available Axonal degeneration is a pivotal feature of many neurodegenerative conditions and substantially accounts for neurological morbidity. A widely used experimental model to study the mechanisms of axonal degeneration is Wallerian degeneration (WD, which occurs after acute axonal injury. In the peripheral nervous system (PNS, WD is characterized by swift dismantling and clearance of injured axons with their myelin sheaths. This is a prerequisite for successful axonal regeneration. In the central nervous system (CNS, WD is much slower, which significantly contributes to failed axonal regeneration. Although it is well-documented that Schwann cells (SCs have a critical role in the regenerative potential of the PNS, to date we have only scarce knowledge as to how SCs 'sense' axonal injury and immediately respond to it. In this regard, it remains unknown as to whether SCs play the role of a passive bystander or an active director during the execution of the highly orchestrated disintegration program of axons. Older reports, together with more recent studies, suggest that SCs mount dynamic injury responses minutes after axonal injury, long before axonal breakdown occurs. The swift SC response to axonal injury could play either a pro-degenerative role, or alternatively a supportive role, to the integrity of distressed axons that have not yet committed to degenerate. Indeed, supporting the latter concept, recent findings in a chronic PNS neurodegeneration model indicate that deactivation of a key molecule promoting SC injury responses exacerbates axonal loss. If this holds true in a broader spectrum of conditions, it may provide the grounds for the development of new glia-centric therapeutic approaches to counteract axonal loss.

  20. Mycolactone cytotoxicity in Schwann cells could explain nerve damage in Buruli ulcer.

    Directory of Open Access Journals (Sweden)

    Junichiro En

    2017-08-01

    Full Text Available Buruli ulcer is a chronic painless skin disease caused by Mycobacterium ulcerans. The local nerve damage induced by M. ulcerans invasion is similar to the nerve damage evoked by the injection of mycolactone in a Buruli ulcer mouse model. In order to elucidate the mechanism of this nerve damage, we tested and compared the cytotoxic effect of synthetic mycolactone A/B on cultured Schwann cells, fibroblasts and macrophages. Mycolactone induced much higher cell death and apoptosis in Schwann cell line SW10 than in fibroblast line L929. These results suggest that mycolactone is a key substance in the production of nerve damage of Buruli ulcer.

  1. ATP secretion from nerve trunks and Schwann cells mediated by glutamate.

    Science.gov (United States)

    Liu, Guo Jun; Bennett, Max R

    2003-11-14

    ATP release from rat sciatic nerves and from cultured Schwann cells isolated from the nerves was investigated using an online bioluminescence technique. ATP was released in relatively large amounts from rat sciatic nerve trunks during electrical stimulation. This release was blocked by the sodium channel inhibitor tetrodotoxin and the non-NMDA glutamate receptor blocker 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Schwann cells isolated from the nerve trunks did not release ATP when electrically stimulated but did in response to glutamate in a concentration-dependent manner. Glutamate-stimulated ATP release was inhibited by specific non-competitive AMPA receptor antagonist GYKI 52466 and competitive non-NMDA receptor antagonist CNQX. Glutamate-stimulated ATP release was decreased by inhibition of anion transporter inhibitors by furosemide, cystic fibrosis transmembrane conductance regulator by glibenclamide and exocytosis by botulinum toxin A, indicating that anion transporters and exocytosis provide the main secretion mechanisms for ATP release from the Schwann cells.

  2. GDNF-transduced Schwann cell grafts enhance regeneration of erectile nerves.

    Science.gov (United States)

    May, Florian; Matiasek, Kaspar; Vroemen, Maurice; Caspers, Christiane; Mrva, Thomas; Arndt, Christian; Schlenker, Boris; Gais, Peter; Brill, Thomas; Buchner, Alexander; Blesch, Armin; Hartung, Rudolf; Stief, Christian; Gansbacher, Bernd; Weidner, Norbert

    2008-11-01

    Schwann cell-seeded guidance tubes have been shown to promote cavernous nerve regeneration, and the local delivery of neurotrophic factors may additionally enhance nerve regenerative capacity. The present study evaluates whether the transplantation of GDNF-overexpressing Schwann cells may enhance regeneration of bilaterally transected erectile nerves in rats. Silicon tubes seeded with either GDNF-overexpressing or GFP-expressing Schwann cells were implanted into the gaps between transected cavernous nerve endings. Six (10 study nerves) or 12 wk (20 study nerves) postoperatively, erectile function was evaluated by relaparotomy, electrical nerve stimulation, and intracavernous pressure recording, followed by ultrastructural evaluation of reconstructed nerves employing bright-field and electron microscopy. Additional animals were either sham-operated (positive control; 20 study nerves) or received bilateral nerve transection without nerve reconstruction (negative control; 20 study nerves). The combination of GDNF delivery and Schwann cell application promoted an intact erectile response in 90% (9 of 10) of grafted nerves after 6 wk and in 95% (19 of 20) after 12 wk, versus 50% (5 of 10) and 80% (16 of 20) of GFP-expressing Schwann cell grafts (p=0.02). The functional recovery was paralleled by enhanced axonal regeneration in GDNF-overexpressing Schwann cell grafts, as indicated by larger cross-sectional areas and a significantly higher percentage of neural tissue compared with GFP-transduced controls. These findings demonstrate that the time required to elicit functional recovery of erectile nerves can be reduced by local delivery of GDNF. In terms of clinical application, this enhanced nerve repair might be critical for timely reinnervation of the corpus cavernosum as a prerequisite for functional recovery in men.

  3. The Wound Microenvironment Reprograms Schwann Cells to Invasive Mesenchymal-like Cells to Drive Peripheral Nerve Regeneration.

    Science.gov (United States)

    Clements, Melanie P; Byrne, Elizabeth; Camarillo Guerrero, Luis F; Cattin, Anne-Laure; Zakka, Leila; Ashraf, Azhaar; Burden, Jemima J; Khadayate, Sanjay; Lloyd, Alison C; Marguerat, Samuel; Parrinello, Simona

    2017-09-27

    Schwann cell dedifferentiation from a myelinating to a progenitor-like cell underlies the remarkable ability of peripheral nerves to regenerate following injury. However, the molecular identity of the differentiated and dedifferentiated states in vivo has been elusive. Here, we profiled Schwann cells acutely purified from intact nerves and from the wound and distal regions of severed nerves. Our analysis reveals novel facets of the dedifferentiation response, including acquisition of mesenchymal traits and a Myc module. Furthermore, wound and distal dedifferentiated Schwann cells constitute different populations, with wound cells displaying increased mesenchymal character induced by localized TGFβ signaling. TGFβ promotes invasion and crosstalks with Eph signaling via N-cadherin to drive collective migration of the Schwann cells across the wound. Consistently, Tgfbr2 deletion in Schwann cells resulted in misdirected and delayed reinnervation. Thus, the wound microenvironment is a key determinant of Schwann cell identity, and it promotes nerve repair through integration of multiple concerted signals. VIDEO ABSTRACT. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    José R Sotelo

    Full Text Available 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.

  6. 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.

  7. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  9. He-Ne laser irradiation affects proliferation of cultured rat Schwann cells in a dose-dependent manner

    International Nuclear Information System (INIS)

    Breugel, H.H.F.I. van; Bar, P.R.

    1993-01-01

    Schwann cell proliferation is considered an essential part of Wallerian degeneration after nerve damage. Laminin, an important component of the extracellular matrix and produced by Schwann cells, provides a preferred substrate for outgrowing axons. To study whether low energy (He-Ne) laser irradiation may exert a positive effect on nerve regeneration through an effect on Schwann cells, its effect was evaluated in vitro. Schwann cells were isolated from sciatic nerves of 4-5-day old Wistar rats and cultures on 96-multiwell plates. The cells were irradiated by a He-Ne laser beam. At three consecutive days, starting either at day 5 or day 8, cells were irradiated each day for 0.5, 1, 2, 5 or 10 min. Both cell number and laminin production were determined for each irradiation condition within one experiment. Schwann cells that were irradiated from day 8 on were hardly affected by laser irradiation. However, the proliferation of cells that were irradiated starting on day 5 was significantly increased after 1, 2 and 5 min of daily irradiation, compared to non-irradiated control cultures. The lamin production per cell of these Schwann cells was not significantly altered. From these results we conclude that He-Ne laser irradiation can modulate proliferation of rat Schwann cells in vitro in a dose-dependent manner. (Author)

  10. Pro-neurogenic effects of andrographolide on RSC96 Schwann cells in vitro

    Science.gov (United States)

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

    2016-01-01

    Nerve regeneration remains a challenge to the treatment of peripheral nerve injury. Andrographolide (Andro) is the main active constituent of Andrographis paniculata, which has been applied in the treatment of several diseases, including inflammation, in ancient China. Andro has been reported to facilitate the reduction of edema and to exert analgesic effects in the treatment of various diseases. These findings suggest that Andro may be considered a promising anti-inflammatory agent that may suppress destruction and accelerate proliferation of Schwann cells following peripheral nerve injury. In the present study, the effects of Andro on RSC96 cells were investigated in vitro. The RSC96 cell line is a spontaneously immortalized rat Schwann cell line, which was originally derived from a long-term culture of rat primary Schwann cells. RSC96 cells were treated with a range of 0 to 50 µM Andro prior to the MTT assay. Cell proliferation, morphology, synthesis and nerve-specific gene expression were performed to detect the effect of Andro on RSC96 cells. The results of the present study demonstrated that the recommended doses of Andro ranged between 0.78 and 12.5 µM, among which the most obvious response was observed when used at 3.125 µM (P<0.05). DNA content was improved in Andro groups compared with the control group (P<0.05). In addition, Andro was able to promote the gene expression of glial cell line-derived neurotrophic factor, brain-derived neurotrophic factor, ciliary neurotrophic factor, and the specific Schwann cell marker S100β (P<0.05). The results of a viability assay, hematoxylin-eosin staining, and immunohistochemistry were also improved in Andro groups. These results indicated that Andro may accelerate proliferation of RSC96 cells in vitro, whilst maintaining the Schwann cell phenotype; therefore, the present study may provide valuable evidence for the further exploration of the effects of Andro on peripheral nerves. PMID:27599453

  11. The formation of lipid droplets favors intracellular Mycobacterium leprae survival in SW-10, non-myelinating Schwann cells.

    Science.gov (United States)

    Jin, Song-Hyo; An, Sung-Kwan; Lee, Seong-Beom

    2017-06-01

    Leprosy is a chronic infectious disease that is caused by the obligate intracellular pathogen Mycobacterium leprae (M.leprae), which is the leading cause of all non-traumatic peripheral neuropathies worldwide. Although both myelinating and non-myelinating Schwann cells are infected by M.leprae in patients with lepromatous leprosy, M.leprae preferentially invades the non-myelinating Schwann cells. However, the effect of M.leprae infection on non-myelinating Schwann cells has not been elucidated. Lipid droplets (LDs) are found in M.leprae-infected Schwann cells in the nerve biopsies of lepromatous leprosy patients. M.leprae-induced LD formation favors intracellular M.leprae survival in primary Schwann cells and in a myelinating Schwann cell line referred to as ST88-14. In the current study, we initially characterized SW-10 cells and investigated the effects of LDs on M.leprae-infected SW-10 cells, which are non-myelinating Schwann cells. SW-10 cells express S100, a marker for cells from the neural crest, and NGFR p75, a marker for immature or non-myelinating Schwann cells. SW-10 cells, however, do not express myelin basic protein (MBP), a marker for myelinating Schwann cells, and myelin protein zero (MPZ), a marker for precursor, immature, or myelinating Schwann cells, all of which suggests that SW-10 cells are non-myelinating Schwann cells. In addition, SW-10 cells have phagocytic activity and can be infected with M. leprae. Infection with M. leprae induces the formation of LDs. Furthermore, inhibiting the formation of M. leprae-induced LD enhances the maturation of phagosomes containing live M.leprae and decreases the ATP content in the M. leprae found in SW-10 cells. These facts suggest that LD formation by M. leprae favors intracellular M. leprae survival in SW-10 cells, which leads to the logical conclusion that M.leprae-infected SW-10 cells can be a new model for investigating the interaction of M.leprae with non-myelinating Schwann cells.

  12. Mycobacterium leprae induces NF-κB-dependent transcription repression in human Schwann cells

    International Nuclear Information System (INIS)

    Pereira, Renata M.S.; Calegari-Silva, Teresa Cristina; Hernandez, Maristela O.; Saliba, Alessandra M.; Redner, Paulo; Pessolani, Maria Cristina V.; Sarno, Euzenir N.; Sampaio, Elizabeth P.; Lopes, Ulisses G.

    2005-01-01

    Mycobacterium leprae, the causative agent of leprosy, invades peripheral nerve Schwann cells, resulting in deformities associated with this disease. NF-κB is an important transcription factor involved in the regulation of host immune antimicrobial responses. We aimed in this work to investigate NF-κB signaling pathways in the human ST88-14 Schwannoma cell line infected with M. leprae. Gel shift and supershift assays indicate that two NF-κB dimers, p65/p50 and p50/p50, translocate to the nucleus in Schwann cells treated with lethally irradiated M. leprae. Consistent with p65/p50 and p50/p50 activation, we observed IκB-α degradation and reduction of p105 levels. The nuclear translocation of p50/p50 complex due to M. leprae treatment correlated with repression of NF-κB-driven transcription induced by TNF-α. Moreover, thalidomide inhibited p50 homodimer nuclear translocation induced by M. leprae and consequently rescues Schwann cells from NF-κB-dependent transcriptional repression. Here, we report for the first time that M. leprae induces NF-κB activation in Schwann cells and thalidomide is able to modulate this activation

  13. Neurite outgrowth is significantly increased by the simultaneous presentation of Schwann cells and moderate exogenous electric fields

    Science.gov (United States)

    Koppes, Abigail N.; Seggio, Angela M.; Thompson, Deanna M.

    2011-08-01

    Axonal extension is influenced by a variety of external guidance cues; therefore, the development and optimization of a multi-faceted approach is probably necessary to address the intricacy of functional regeneration following nerve injury. In this study, primary dissociated neonatal rat dorsal root ganglia neurons and Schwann cells were examined in response to an 8 h dc electrical stimulation (0-100 mV mm-1). Stimulated samples were then fixed immediately, immunostained, imaged and analyzed to determine Schwann cell orientation and characterize neurite outgrowth relative to electric field strength and direction. Results indicate that Schwann cells are viable following electrical stimulation with 10-100 mV mm-1, and retain a normal morphology relative to unstimulated cells; however, no directional bias is observed. Neurite outgrowth was significantly enhanced by twofold following exposure to either a 50 mV mm-1 electric field (EF) or co-culture with unstimulated Schwann cells by comparison to neurons cultured alone. Neurite outgrowth was further increased in the presence of simultaneously applied cues (Schwann cells + 50 mV mm-1 dc EF), exhibiting a 3.2-fold increase over unstimulated control neurons, and a 1.2-fold increase over either neurons cultured with unstimulated Schwann cells or the electrical stimulus alone. These results indicate that dc electric stimulation in combination with Schwann cells may provide synergistic guidance cues for improved axonal growth relevant to nerve injuries in the peripheral nervous system.

  14. 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

  15. Estrogen and progesterone stimulate Schwann cell proliferation in a sex- and age-dependent manner

    DEFF Research Database (Denmark)

    Svenningsen, Åsa Fex; Kanje, M

    1999-01-01

    The effects of estrogen and progesterone on Schwann cell proliferation were studied in cultured segments of the rat sciatic nerve from adult male, female, and newborn rats, by measurement of [3H thymidine incorporation or bromo-deoxy-uridine- (BrdU)-labelling and immunocytochemistry. Estrogen (10...

  16. 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

    Dicer is responsible for the generation of mature micro-RNAs (miRNAs) and loading them into RNA-induced silencing complex (RISC). RISC functions as a probe that targets mRNAs leading to translational suppression and mRNA degradation. Schwann cells (SCs) in the peripheral nervous system undergo re...

  17. 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

    Dicer is responsible for the generation of mature micro-RNAs (miRNAs) and loading them into RNA-induced silencing complex (RISC). RISC functions as a probe that targets mRNAs leading to translational suppression and mRNA degradation. Schwann cells (SCs) in the peripheral nervous system undergo...

  18. Effects of Schwann cell alignment along the oriented electrospun chitosan nanofibers on nerve regeneration.

    Science.gov (United States)

    Wang, Wei; Itoh, Soichiro; Konno, Katsumi; Kikkawa, Takeshi; Ichinose, Shizuko; Sakai, Katsuyoshi; Ohkuma, Tsuneo; Watabe, Kazuhiko

    2009-12-15

    We have constructed a chitosan nonwoven nanofiber mesh tube consisting of oriented fibers by the electrospinning method. The efficacy of oriented nanofibers on Schwann cell alignment and positive effect of this tube on peripheral nerve regeneration were confirmed. The physical properties of the chitosan nanofiber mesh sheets prepared by electrospinning with or without fiber orientation were characterized. Then, immortalized Schwann cells were cultured on these sheets. Furthermore, the chitosan nanofiber mesh tubes with or without orientation, and bilayered chitosan mesh tube with an inner layer of oriented nanofibers and an outer layer of randomized nanofibers were bridgegrafted into rat sciatic nerve defect. As a result of fiber orientation, the tensile strength along the axis of the sheet increased. Because Schwann cells aligned along the nanofibers, oriented fibrous sheets could exhibit a Schwann cell column. Functional recovery and electrophysiological recovery occurred in time in the oriented group as well as in the bilayered group, and approximately matched those in the isograft. Furthermore, histological analysis revealed that the sprouting of myelinated axons occurred vigorously followed by axonal maturation in the isograft, oriented, and bilayered group in the order. The oriented chitosan nanofiber mesh tube may be a promising substitute for autogenous nerve graft.

  19. Autophagy is involved in the reduction of myelinating Schwann cell cytoplasm during myelin maturation of the peripheral nerve.

    Directory of Open Access Journals (Sweden)

    So Young Jang

    Full Text Available Peripheral nerve myelination involves dynamic changes in Schwann cell morphology and membrane structure. Recent studies have demonstrated that autophagy regulates organelle biogenesis and plasma membrane dynamics. In the present study, we investigated the role of autophagy in the development and differentiation of myelinating Schwann cells during sciatic nerve myelination. Electron microscopy and biochemical assays have shown that Schwann cells remove excess cytoplasmic organelles during myelination through macroautophagy. Inhibition of autophagy via Schwann cell-specific removal of ATG7, an essential molecule for macroautophagy, using a conditional knockout strategy, resulted in abnormally enlarged abaxonal cytoplasm in myelinating Schwann cells that contained a large number of ribosomes and an atypically expanded endoplasmic reticulum. Small fiber hypermyelination and minor anomalous peripheral nerve functions are observed in this mutant. Rapamycin-induced suppression of mTOR activity during the early postnatal period enhanced not only autophagy but also developmental reduction of myelinating Schwann cells cytoplasm in vivo. Together, our findings suggest that autophagy is a regulatory mechanism of Schwann cells structural plasticity during myelination.

  20. 3-D Imaging Reveals Participation of Donor Islet Schwann Cells and Pericytes in Islet Transplantation and Graft Neurovascular Regeneration.

    Science.gov (United States)

    Juang, Jyuhn-Huarng; Kuo, Chien-Hung; Peng, Shih-Jung; Tang, Shiue-Cheng

    2015-02-01

    The primary cells that participate in islet transplantation are the endocrine cells. However, in the islet microenvironment, the endocrine cells are closely associated with the neurovascular tissues consisting of the Schwann cells and pericytes, which form sheaths/barriers at the islet exterior and interior borders. The two cell types have shown their plasticity in islet injury, but their roles in transplantation remain unclear. In this research, we applied 3-dimensional neurovascular histology with cell tracing to reveal the participation of Schwann cells and pericytes in mouse islet transplantation. Longitudinal studies of the grafts under the kidney capsule identify that the donor Schwann cells and pericytes re-associate with the engrafted islets at the peri-graft and perivascular domains, respectively, indicating their adaptability in transplantation. Based on the morphological proximity and cellular reactivity, we propose that the new islet microenvironment should include the peri-graft Schwann cell sheath and perivascular pericytes as an integral part of the new tissue.

  1. Adipose-Derived Stem Cells Promote Peripheral Nerve Regeneration In Vivo without Differentiation into Schwann-Like Lineage.

    Science.gov (United States)

    Sowa, Yoshihiro; Kishida, Tsunao; Imura, Tetsuya; Numajiri, Toshiaki; Nishino, Kenichi; Tabata, Yasuhiko; Mazda, Osam

    2016-02-01

    During recent decades, multipotent stem cells were found to reside in the adipose tissue, and these adipose-derived stem cells were shown to play beneficial roles, like those of Schwann cells, in peripheral nerve regeneration. However, it has not been well established whether adipose-derived stem cells offer beneficial effects to peripheral nerve injuries in vivo as Schwann cells do. Furthermore, the in situ survival and differentiation of adipose-derived stem cells after transplantation at the injured peripheral nerve tissue remain to be fully elucidated. Adipose-derived stem cells and Schwann cells were transplanted with gelatin hydrogel tubes at the artificially blunted sciatic nerve lesion in mice. Neuroregenerative abilities of them were comparably estimated. Cre-loxP-mediated fate tracking was performed to visualize survival in vivo of transplanted adipose-derived stem cells and to investigate whether they differentiated into Schwann linage cells at the peripheral nerve injury site. The transplantation of adipose-derived stem cells promoted regeneration of axons, formation of myelin, and restoration of denervation muscle atrophy to levels comparable to those achieved by Schwann cell transplantation. The adipose-derived stem cells survived for at least 4 weeks after transplantation without differentiating into Schwann cells. Transplanted adipose-derived stem cells did not differentiate into Schwann cells but promoted peripheral nerve regeneration at the injured site. The neuroregenerative ability was comparable to that of Schwann cells. Adipose-derived stem cells at an undifferentiated stage may be used as an alternative cell source for autologous cell therapy for patients with peripheral nerve injury.

  2. Evidence that glutamate mediates axon-to-Schwann cell signaling in the squid.

    Science.gov (United States)

    Lieberman, E M; Abbott, N J; Hassan, S

    1989-01-01

    High-frequency stimulation (100 Hz) of isolated giant axons of the small squid Alloteuthis subulata and the large squid Loligo forbesi caused the periaxonal Schwann cell resting potential (Em = -40 mV) to hyperpolarize up to 11 mV in direct proportion to train duration and action potential amplitude. In both species, the Schwann cell also hyperpolarized up to 17 mV with the application of L-glutamate (10(-9) to 10(-6) M), in a dose-dependent manner. By contrast, in the presence of 10(-8) M d-tubocurarine (d-TC) to block the cholinergic component of the Schwann cell response, Schwann cells depolarized 8-9 mV during electrical stimulation of the axon or application of L-glutamate. In the presence of 10(-5) M 2-amino-4-phosphonobutyrate (2-APB), the hyperpolarization to glutamate and to axon stimulation was blocked, whereas the cholinergic (carbachol-induced) hyperpolarization was unaffected. In experiments with Alloteuthis, L-aspartate (10(-7) M) also caused a Schwann cell hyperpolarization, but this was not blocked by 2-APB. In tests with glutamate receptor agonists and antagonists, quisqualate (10(-5) M) produced a hyperpolarization blocked by 10(-4) M L-glutamic acid diethylester (GDEE), which also blocked the response to axonal stimulation. Kainic acid (10(-4) M) also caused a hyperpolarization, but n-methyl-D-aspartate (NMDA; 10(-4) M), ibotenate (10(-5) M), alpha-amino-3-hydroxy-5-methyl-isoxazole proprionate (AMPA; (10(-4) M), and isethionate (10(-5) M) had no effect.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. 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

  4. 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.

  5. 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.

  6. Electric field stimulation through a substrate influences Schwann cell and extracellular matrix structure

    Science.gov (United States)

    Nguyen, Hieu T.; Wei, Claudia; Chow, Jacqueline K.; Nguy, Lindsey; Nguyen, Hieu K.; Schmidt, Christine E.

    2013-08-01

    Objective. Electric field (EF) stimulation has been used to cue cell growth for tissue engineering applications. In this study, we explore the electrical parameters and extracellular mechanisms that elicit changes in cell behavior when stimulated through the substrate. Approach. Rat Schwann cell morphology was compared when exposed to EF through the media or a conductive indium tin oxide substrate. Ionic and structural effects were then analyzed on Matrigel and collagen I, respectively. Main results. When stimulating through media, cells had greater alignment perpendicular to the EF with higher current densities (106 mA cm-2 at 245 mV mm-1), and reached maximum alignment within 8 h. Stimulation through the substrate with EF (up to 110 mV mm-1) did not affect Schwann cell orientation, however the EF caused extracellular matrix (ECM) coatings on substrates to peel away, suggesting EF can physically change the ECM. Applying alternating current (ac) 2-1000 Hz signals through the media or substrate both caused cells to flatten and protrude many processes, without preferential alignment. Matrigel exposed to a substrate EF of 10 mV mm-1 for 2 h had a greater calcium concentration near the cathode, but quickly dissipated when the EF was removed. Schwann cells seeded 7 d after gels were exposed to substrate EF still aligned perpendicular to the EF direction. Microscopy of collagen I exposed to substrate EF shows alignment and bundling of fibrils. Significance. These findings demonstrate EF exposure can control Schwann cell alignment and morphology, change ECM bulk/surface architecture, and align ECM structures.

  7. Dose-dependent effects of ouabain on spiral ganglion neurons and Schwann cells in mouse cochlea.

    Science.gov (United States)

    Zhang, Zhi-Jian; Guan, Hong-Xia; Yang, Kun; Xiao, Bo-Kui; Liao, Hua; Jiang, Yang; Zhou, Tao; Hua, Qing-Quan

    2017-10-01

    This study aimed in fully investigating the toxicities of ouabain to mouse cochlea and the related cellular environment, and providing an optimal animal model system for cell transplantation in the treatment of auditory neuropathy (AN) and sensorineural hearing loss (SNHL). Different dosages of ouabain were applied to mouse round window. The auditory brainstem responses and distortion product otoacoustic emissions were used to evaluate the cochlear function. The immunohistochemical staining and cochlea surface preparation were performed to detect the spiral ganglion neurons (SGNs), Schwann cells and hair cells. Ouabain at the dosages of 0.5 mM, 1 mM and 3 mM selectively and permanently destroyed SGNs and their functions, while leaving the hair cells relatively intact. Ouabain at 3 mM resulted in the most severe SGNs loss and induced significant loss of Schwann cells started as early as 7 days and with further damages at 14 and 30 days after ouabain exposure. The application of ouabain to mouse round window induces damages of SGNs and Schwann cells in a dose- and time-dependent manner, this study established a reliable and accurate animal model system of AN and SNHL.

  8. Schwann cell interactions with polymer films are affected by groove geometry and film hydrophilicity

    International Nuclear Information System (INIS)

    Mobasseri, S A; Downes, S; Terenghi, G

    2014-01-01

    We have developed a biodegradable polymer scaffold made of a polycaprolactone/polylactic acid (PCL/PLA) film. Surface properties such as topography and chemistry have a vital influence on cell–material interactions. Surface modifications of PCL/PLA films were performed using topographical cues and UV–ozone treatment to improve Schwann cell organisation and behaviour. Schwann cell attachment, alignment and proliferation were evaluated on the grooved UV–ozone treated and non-treated films. Solvent casting of the polymer solution on patterned silicon substrates resulted in films with different groove shapes: V (V), sloped (SL) and square (SQ) shapes. Pitted films, with no grooves, were prepared as a negative control. The UV–ozone treatment was performed to increase hydrophilicity. The process specifications for UV–ozone treatment were evaluated and 5 min radiation time and 6 cm distance to the UV source were suggested as the optimal practise. When cultured on grooved films, Schwann cells elongated on the V and SL shape grooves without crossing over, and grew in the direction of the grooves. However, there was less elongation with more crossing over on the SQ shape grooves. The maximum cell length (511 μm) was observed on the treated V-grooved films. The cells cultured on pitted UV–ozone treated surfaces showed random arrangements with no increase in length. We have demonstrated that the synergic effects of physical cues combined with UV–ozone treatment have the potential to enhance Schwann cell morphology and alignment. (paper)

  9. Toxicity to sensory neurons and Schwann cells in experimental linezolid-induced peripheral neuropathy.

    Science.gov (United States)

    Bobylev, Ilja; Maru, Helina; Joshi, Abhijeet R; Lehmann, Helmar C

    2016-03-01

    Peripheral neuropathy is a common side effect of prolonged treatment with linezolid. This study aimed to explore injurious effects of linezolid on cells of the peripheral nervous system and to establish in vivo and in vitro models of linezolid-induced peripheral neuropathy. C57BL/6 mice were treated with linezolid or vehicle over a total period of 4 weeks. Animals were monitored by weight, nerve conduction studies and behavioural tests. Neuropathic changes were assessed by morphometry on sciatic nerves and epidermal nerve fibre density in skin sections. Rodent sensory neuron and Schwann cell cultures were exposed to linezolid in vitro and assessed for mitochondrial dysfunction. Prolonged treatment with linezolid induced a mild, predominantly small sensory fibre neuropathy in vivo. Exposure of Schwann cells and sensory neurons to linezolid in vitro caused mitochondrial dysfunction primarily in neurons (and less prominently in Schwann cells). Sensory axonopathy could be partially prevented by co-administration of the Na(+)/Ca(2+) exchanger blocker KB-R7943. Clinical and pathological features of linezolid-induced peripheral neuropathy can be replicated in in vivo and in vitro models. Mitochondrial dysfunction may contribute to the axonal damage to sensory neurons that occurs after linezolid exposure. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  10. Neuronal Regulation of Schwann Cell Mitochondrial Ca2+ Signaling during Myelination

    OpenAIRE

    Daisuke Ino; Hiroshi Sagara; Junji Suzuki; Kazunori Kanemaru; Yohei Okubo; Masamitsu Iino

    2015-01-01

    Schwann cells (SCs) myelinate peripheral neurons to promote the rapid conduction of action potentials, and the process of myelination is known to be regulated by signals from axons to SCs. Given that SC mitochondria are one of the potential regulators of myelination, we investigated whether SC mitochondria are regulated by axonal signaling. Here, we show a purinergic mechanism that sends information from neurons to SC mitochondria during myelination. Our results show that electrical stimulati...

  11. Adenosine: an activity-dependent axonal signal regulating MAP kinase and proliferation in developing Schwann cells

    OpenAIRE

    Stevens, Beth; Ishibashi, Tomoko; Chen, Jiang-Fan; Fields, R. Douglas

    2004-01-01

    Nonsynaptic release of ATP from electrically stimulated dorsal root gangion (DRG) axons inhibits Schwann cell (SC) proliferation and arrests SC development at the premyelinating stage, but the specific types of purinergic receptor(s) and intracellular signaling pathways involved in this form of neuron–glia communication are not known. Recent research shows that adenosine is a neuron–glial transmitter between axons and myelinating glia of the CNS. The present study investigates the possibility...

  12. 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.

  13. Nerve Growth Factor in Cancer Cell Death and Survival

    International Nuclear Information System (INIS)

    Molloy, Niamh H.; Read, Danielle E.; Gorman, Adrienne M.

    2011-01-01

    One of the major challenges for cancer therapeutics is the resistance of many tumor cells to induction of cell death due to pro-survival signaling in the cancer cells. Here we review the growing literature which shows that neurotrophins contribute to pro-survival signaling in many different types of cancer. In particular, nerve growth factor, the archetypal neurotrophin, has been shown to play a role in tumorigenesis over the past decade. Nerve growth factor mediates its effects through its two cognate receptors, TrkA, a receptor tyrosine kinase and p75 NTR , a member of the death receptor superfamily. Depending on the tumor origin, pro-survival signaling can be mediated by TrkA receptors or by p75 NTR . For example, in breast cancer the aberrant expression of nerve growth factor stimulates proliferative signaling through TrkA and pro-survival signaling through p75 NTR . This latter signaling through p75 NTR promotes increased resistance to the induction of cell death by chemotherapeutic treatments. In contrast, in prostate cells the p75 NTR mediates cell death and prevents metastasis. In prostate cancer, expression of this receptor is lost, which contributes to tumor progression by allowing cells to survive, proliferate and metastasize. This review focuses on our current knowledge of neurotrophin signaling in cancer, with a particular emphasis on nerve growth factor regulation of cell death and survival in cancer

  14. 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

  15. Neural differentiation of adipose-derived stem cells by indirect co-culture with Schwann cells

    Directory of Open Access Journals (Sweden)

    Li Xiaojie

    2009-01-01

    Full Text Available To investigate whether adipose-derived stem cells (ADSCs could be subject to neural differentiation induced only by Schwann cell (SC factors, we co-cultured ADSCs and SCs in transwell culture dishes. Immunoassaying, Western blot analysis, and RT-PCR were performed (1, 3, 7, 14 d and the co-cultured ADSCs showed gene and protein expression of S-100, Nestin, and GFAP. Further, qRT-PCR disclosed relative quantitative differences in the above three gene expressions. We think ADSCs can undergo induced neural differentiation by being co-cultured with SCs, and such differentia­tions begin 1 day after co-culture, become apparent after 7 days, and thereafter remain stable till the 14th day.

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

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    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).

  17. Conduction of impulses by axons regenerated in a Schwann cell graft in the transected adult rat thoracic spinal cord.

    Science.gov (United States)

    Pinzon, A; Calancie, B; Oudega, M; Noga, B R

    2001-06-01

    Central nervous system axons regenerate into a Schwann cell implant placed in the transected thoracic spinal cord of an adult rat. The present study was designed to test whether these regenerated axons are capable of conducting action potentials. Following the transection and removal of a 4- to 5-mm segment of the thoracic spinal cord (T8-T9), a polymer guidance channel filled with a mixture of adult rat Schwann cells and Matrigel was grafted into a 4- to 5-mm-long gap in the transected thoracic spinal cord. The two cut ends of the spinal cord were eased into the guidance channel openings. Transected control animals received a channel containing Matrigel only. Three months after implantation, electrophysiological studies were performed. Tungsten microelectrodes were used for monopolar stimulation of regenerated axons within the Schwann cell graft. Glass microelectrodes were used to record responses in the spinal cord rostral to the stimulation site. Evoked responses to electrical stimulation of the axon cable were found in two out of nine Schwann cell-grafted animals. These responses had approximate latencies in the range of those of myelinated axons. No responses were seen in any of the Matrigel-grafted animals. Histological analysis revealed that the two cases that showed evoked potentials had the largest number of myelinated axons present in the cable. This study demonstrates that axons regenerating through Schwann cell grafts in the complete transected spinal cord can produce measurable evoked responses following electrical stimulation. Copyright 2001 Wiley-Liss, Inc.

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

    African Journals Online (AJOL)

    Administrator

    2011-04-25

    Apr 25, 2011 ... Bone marrow stromal cells (BMSCs), a type of multipotent stem cell, can differentiate into various types ... induced to differentiate into neuron-like cells when they are ... axonal regeneration and functional reconstruction do not.

  19. Allotransplanted DRG neurons or Schwann cells affect functional recovery in a rodent model of sciatic nerve injury.

    Science.gov (United States)

    Dayawansa, Samantha; Wang, Ernest W; Liu, Weimin; Markman, John D; Gelbard, Harris A; Huang, Jason H

    2014-11-01

    In this study, the functional recoveries of Sprague-Dawley rats following repair of a complete sciatic nerve transection using allotransplanted dorsal root ganglion (DRG) neurons or Schwann cells were examined using a number of outcome measures. Four groups were compared: (1) repair with a nerve guide conduit seeded with allotransplanted Schwann cells harvested from Wistar rats, (2) repair with a nerve guide conduit seeded with DRG neurons, (3) repair with solely a nerve guide conduit, and (4) sham-surgery animals where the sciatic nerve was left intact. The results corroborated our previous reported histology findings and measures of immunogenicity. The Wistar-DRG-treated group achieved the best recovery, significantly outperforming both the Wistar-Schwann group and the nerve guide conduit group in the Von Frey assay of touch response (P DRG and Wistar-Schwann seeded repairs showed lower frequency and severity in an autotomy measure of the self-mutilation of the injured leg because of neuralgia. These results suggest that in complete peripheral nerve transections, surgical repair using nerve guide conduits with allotransplanted DRG and Schwann cells may improve recovery, especially DRG neurons, which elicit less of an immune response.

  20. Schwann cell-mediated delivery of glial cell line-derived neurotrophic factor restores erectile function after cavernous nerve injury.

    Science.gov (United States)

    May, Florian; Buchner, Alexander; Schlenker, Boris; Gratzke, Christian; Arndt, Christian; Stief, Christian; Weidner, Norbert; Matiasek, Kaspar

    2013-03-01

    To evaluate the time-course of functional recovery after cavernous nerve injury using glial cell line-derived neurotrophic factor-transduced Schwann cell-seeded silicon tubes. Sections of the cavernous nerves were excised bilaterally (5 mm), followed by immediate bilateral surgical repair. A total of 20 study nerves per group were reconstructed by interposition of empty silicon tubes and silicon tubes seeded with either glial cell line-derived neurotrophic factor-overexpressing or green fluorescent protein-expressing Schwann cells. Control groups were either sham-operated or received bilateral nerve transection without nerve reconstruction. Erectile function was evaluated by relaparotomy, electrical nerve stimulation and intracavernous pressure recording after 2, 4, 6, 8 and 10 weeks. The animals underwent re-exploration only once, and were killed afterwards. The nerve grafts were investigated for the maturation state of regenerating nerve fibers and the fascular composition. Recovery of erectile function took at least 4 weeks in the current model. Glial cell line-derived neurotrophic factor-transduced Schwann cell grafts restored erectile function better than green fluorescent protein-transduced controls and unseeded conduits. Glial cell line-derived neurotrophic factor-transduced grafts promoted an intact erectile response (4/4) at 4, 6, 8 and 10 weeks that was overall significantly superior to negative controls (P cell line-derived neurotrophic factor-transduced grafts compared with negative controls (P = 0.018) and unseeded tubes (P = 0.034). Return of function was associated with the electron microscopic evidence of preganglionic myelinated nerve fibers and postganglionic unmyelinated axons. Schwann cell-mediated delivery of glial cell line-derived neurotrophic factor presents a viable approach for the treatment of erectile dysfunction after cavernous nerve injury. © 2013 The Japanese Urological Association.

  1. Implanted hair follicle stem cells form Schwann cells that support repair of severed peripheral nerves.

    Science.gov (United States)

    Amoh, Yasuyuki; Li, Lingna; Campillo, Raul; Kawahara, Katsumasa; Katsuoka, Kensei; Penman, Sheldon; Hoffman, Robert M

    2005-12-06

    The hair follicle bulge area is an abundant, easily accessible source of actively growing, pluripotent adult stem cells. Nestin, a protein marker for neural stem cells, also is expressed in follicle stem cells and their immediate, differentiated progeny. The fluorescent protein GFP, whose expression is driven by the nestin regulatory element in transgenic mice, served to mark the follicle cell fate. The pluripotent nestin-driven GFP stem cells are positive for the stem cell marker CD34 but negative for keratinocyte marker keratin 15, suggesting their relatively undifferentiated state. These cells can differentiate into neurons, glia, keratinocytes, smooth muscle cells, and melanocytes in vitro. In vivo studies show the nestin-driven GFP hair follicle stem cells can differentiate into blood vessels and neural tissue after transplantation to the subcutis of nude mice. Equivalent hair follicle stem cells derived from transgenic mice with beta-actin-driven GFP implanted into the gap region of a severed sciatic nerve greatly enhance the rate of nerve regeneration and the restoration of nerve function. The follicle cells transdifferentiate largely into Schwann cells, which are known to support neuron regrowth. Function of the rejoined sciatic nerve was measured by contraction of the gastrocnemius muscle upon electrical stimulation. After severing the tibial nerve and subsequent transplantation of hair follicle stem cells, walking print length and intermediate toe spread significantly recovered, indicating that the transplanted mice recovered the ability to walk normally. These results suggest that hair follicle stem cells provide an important, accessible, autologous source of adult stem cells for regenerative medicine.

  2. Proneurotrophin-3 promotes cell cycle withdrawal of developing cerebellar granule cell progenitors via the p75 neurotrophin receptor.

    Science.gov (United States)

    Zanin, Juan Pablo; Abercrombie, Elizabeth; Friedman, Wilma J

    2016-07-19

    Cerebellar granule cell progenitors (GCP) proliferate extensively in the external granule layer (EGL) of the developing cerebellum prior to differentiating and migrating. Mechanisms that regulate the appropriate timing of cell cycle withdrawal of these neuronal progenitors during brain development are not well defined. The p75 neurotrophin receptor (p75(NTR)) is highly expressed in the proliferating GCPs, but is downregulated once the cells leave the cell cycle. This receptor has primarily been characterized as a death receptor for its ability to induce neuronal apoptosis following injury. Here we demonstrate a novel function for p75(NTR) in regulating proper cell cycle exit of neuronal progenitors in the developing rat and mouse EGL, which is stimulated by proNT3. In the absence of p75(NTR), GCPs continue to proliferate beyond their normal period, resulting in a larger cerebellum that persists into adulthood, with consequent motor deficits.

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

    Science.gov (United States)

    Shakhbazau, Antos; Kawasoe, Jean; Hoyng, Stefan A; Kumar, Ranjan; van Minnen, Jan; Verhaagen, Joost; Midha, Rajiv

    2012-05-01

    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 lentiviral vector encoding NGF (NGF-SCs). Transplantation of NGF-SCs in a rat sciatic nerve transection/repair model led to significant increase of NGF levels 2weeks after injury and correspondingly to substantial improvement in axonal regeneration. Numbers of NF200, ChAT and CGRP-positive axon profiles, as well as the gastrocnemius muscle weights, were significantly higher in the NGF-Schwann cell group compared to the animals that received control SCs transduced with a lentiviral vector encoding GFP (GFP-SCs). Comparison with other models of NGF application signifies the important role of this neurotrophin during the early stages of regeneration, and supports the importance of developing combined gene and cell therapy for peripheral nerve repair. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. 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.

  5. 3-D Imaging Reveals Participation of Donor Islet Schwann Cells and Pericytes in Islet Transplantation and Graft Neurovascular Regeneration

    Directory of Open Access Journals (Sweden)

    Jyuhn-Huarng Juang

    2015-02-01

    Full Text Available The primary cells that participate in islet transplantation are the endocrine cells. However, in the islet microenvironment, the endocrine cells are closely associated with the neurovascular tissues consisting of the Schwann cells and pericytes, which form sheaths/barriers at the islet exterior and interior borders. The two cell types have shown their plasticity in islet injury, but their roles in transplantation remain unclear. In this research, we applied 3-dimensional neurovascular histology with cell tracing to reveal the participation of Schwann cells and pericytes in mouse islet transplantation. Longitudinal studies of the grafts under the kidney capsule identify that the donor Schwann cells and pericytes re-associate with the engrafted islets at the peri-graft and perivascular domains, respectively, indicating their adaptability in transplantation. Based on the morphological proximity and cellular reactivity, we propose that the new islet microenvironment should include the peri-graft Schwann cell sheath and perivascular pericytes as an integral part of the new tissue.

  6. A polymer foam conduit seeded with Schwann cells promotes guided peripheral nerve regeneration.

    Science.gov (United States)

    Hadlock, T; Sundback, C; Hunter, D; Cheney, M; Vacanti, J P

    2000-04-01

    Alternatives to autografts have long been sought for use in bridging neural gaps. Many entubulation materials have been studied, although with generally disappointing results in comparison with autografts. The purpose of this study was to design a more effective neural guidance conduit, to introduce Schwann cells into the conduit, and to determine regenerative capability through it in an in vivo model. A novel, fully biodegradable polymer conduit was designed and fabricated for use in peripheral nerve repair, which approximates the macro- and microarchitecture of native peripheral nerves. It comprised a series of longitudinally aligned channels, with diameters ranging from 60 to 550 microns. The lumenal surfaces promoted the adherence of Schwann cells, whose presence is known to play a key role in nerve regeneration. This unique channel architecture increased the surface area available for Schwann cell adherence up to five-fold over that available through a simple hollow conduit. The conduit was composed of a high-molecular-weight copolymer of lactic and glycolic acids (PLGA) (MW 130,000) in an 85:15 monomer ratio. A novel foam-processing technique, employing low-pressure injection molding, was used to create highly porous conduits (approximately 90% pore volume) with continuous longitudinal channels. Using this technique, conduits were constructed containing 1, 5, 16, 45, or more longitudinally aligned channels. Prior to cellular seeding of these conduits, the foams were prewet with 50% ethanol, flushed with physiologic saline, and coated with laminin solution (10 microg/mL). A Schwann cell suspension was dynamically introduced into these processed foams at a concentration of 5 X 10(5) cells/mL, using a simple bioreactor flow loop. In vivo regeneration studies were carried out in which cell-laden five-channel polymer conduits (individual channel ID 500 microm, total conduit OD 2.3 mm) were implanted across a 7-mm gap in the rat sciatic nerve (n = 4), and midgraft

  7. Glucose-induced metabolic memory in Schwann cells: prevention by PPAR agonists.

    Science.gov (United States)

    Kim, Esther S; Isoda, Fumiko; Kurland, Irwin; Mobbs, Charles V

    2013-09-01

    A major barrier in reversing diabetic complications is that molecular and pathologic effects of elevated glucose persist despite normalization of glucose, a phenomenon referred to as metabolic memory. In the present studies we have investigated the effects of elevated glucose on Schwann cells, which are implicated in diabetic neuropathy. Using quantitative PCR arrays for glucose and fatty acid metabolism, we have found that chronic (>8 wk) 25 mM high glucose induces a persistent increase in genes that promote glycolysis, while inhibiting those that oppose glycolysis and alternate metabolic pathways such as fatty acid metabolism, the pentose phosphate pathway, and trichloroacetic acid cycle. These sustained effects were associated with decreased peroxisome proliferator-activated receptor (PPAR)γ binding and persistently increased reactive oxygen species, cellular NADH, and altered DNA methylation. Agonists of PPARγ and PPARα prevented select effects of glucose-induced gene expression. These observations suggest that Schwann cells exhibit features of metabolic memory that may be regulated at the transcriptional level. Furthermore, targeting PPAR may prevent metabolic memory and the development of diabetic complications.

  8. Adenosine: an activity-dependent axonal signal regulating MAP kinase and proliferation in developing Schwann cells.

    Science.gov (United States)

    Stevens, Beth; Ishibashi, Tomoko; Chen, Jiang-Fan; Fields, R Douglas

    2004-02-01

    Nonsynaptic release of ATP from electrically stimulated dorsal root gangion (DRG) axons inhibits Schwann cell (SC) proliferation and arrests SC development at the premyelinating stage, but the specific types of purinergic receptor(s) and intracellular signaling pathways involved in this form of neuron-glia communication are not known. Recent research shows that adenosine is a neuron-glial transmitter between axons and myelinating glia of the CNS. The present study investigates the possibility that adenosine might have a similar function in communicating between axons and premyelinating SCs. Using a combination of pharmacological and molecular approaches, we found that mouse SCs in culture express functional adenosine receptors and ATP receptors, a far more complex array of purinergic receptors than thought previously. Adenosine, but not ATP, activates ERK/MAPK through stimulation of cAMP-linked A2(A) adenosine receptors. Both ATP and adenosine inhibit proliferation of SCs induced by platelet-derived growth factor (PDGF), via mechanisms that are partly independent. In contrast to ATP, adenosine failed to inhibit the differentiation of SCs to the O4+ stage. This indicates that, in addition to ATP, adenosine is an activity-dependent signaling molecule between axons and premyelinating Schwann cells, but that electrical activity, acting through adenosine, has opposite effects on the differentiation of myelinating glia in the PNS and CNS.

  9. 17β-Estradiol Promotes Schwann Cell Proliferation and Differentiation, Accelerating Early Remyelination in a Mouse Peripheral Nerve Injury Model

    Directory of Open Access Journals (Sweden)

    Yan Chen

    2016-01-01

    Full Text Available Estrogen induces oligodendrocyte remyelination in response to demyelination in the central nervous system. Our objective was to determine the effects of 17β-estradiol (E2 on Schwann cell function and peripheral nerve remyelination after injury. Adult male C57BL/6J mice were used to prepare the sciatic nerve transection injury model and were randomly categorized into control and E2 groups. To study myelination in vitro, dorsal root ganglion (DRG explant culture was prepared using 13.5-day-old mouse embryos. Primary Schwann cells were isolated from the sciatic nerves of 1- to 3-day-old Sprague–Dawley rats. Immunostaining for myelin basic protein (MBP expression and toluidine blue staining for myelin sheaths demonstrated that E2 treatment accelerates early remyelination in the “nerve bridge” region between the proximal and distal stumps of the transection injury site in the mouse sciatic nerve. The 5-bromo-2′-deoxyuridine incorporation assay revealed that E2 promotes Schwann cell proliferation in the bridge region and in the primary culture, which is blocked using AKT inhibitor MK2206. The in vitro myelination in the DRG explant culture determined showed that the MBP expression in the E2-treated group is higher than that in the control group. These results show that E2 promotes Schwann cell proliferation and myelination depending on AKT activation.

  10. 17β-Estradiol Promotes Schwann Cell Proliferation and Differentiation, Accelerating Early Remyelination in a Mouse Peripheral Nerve Injury Model

    Science.gov (United States)

    Chen, Yan; Guo, Wenjie; Li, Wenjuan; Cheng, Meng; Hu, Ying; Xu, Wenming

    2016-01-01

    Estrogen induces oligodendrocyte remyelination in response to demyelination in the central nervous system. Our objective was to determine the effects of 17β-estradiol (E2) on Schwann cell function and peripheral nerve remyelination after injury. Adult male C57BL/6J mice were used to prepare the sciatic nerve transection injury model and were randomly categorized into control and E2 groups. To study myelination in vitro, dorsal root ganglion (DRG) explant culture was prepared using 13.5-day-old mouse embryos. Primary Schwann cells were isolated from the sciatic nerves of 1- to 3-day-old Sprague–Dawley rats. Immunostaining for myelin basic protein (MBP) expression and toluidine blue staining for myelin sheaths demonstrated that E2 treatment accelerates early remyelination in the “nerve bridge” region between the proximal and distal stumps of the transection injury site in the mouse sciatic nerve. The 5-bromo-2′-deoxyuridine incorporation assay revealed that E2 promotes Schwann cell proliferation in the bridge region and in the primary culture, which is blocked using AKT inhibitor MK2206. The in vitro myelination in the DRG explant culture determined showed that the MBP expression in the E2-treated group is higher than that in the control group. These results show that E2 promotes Schwann cell proliferation and myelination depending on AKT activation. PMID:27872858

  11. 3-D Imaging Reveals Participation of Donor Islet Schwann Cells and Pericytes in Islet Transplantation and Graft Neurovascular Regeneration

    OpenAIRE

    Juang, Jyuhn-Huarng; Kuo, Chien-Hung; Peng, Shih-Jung; Tang, Shiue-Cheng

    2015-01-01

    The primary cells that participate in islet transplantation are the endocrine cells. However, in the islet microenvironment, the endocrine cells are closely associated with the neurovascular tissues consisting of the Schwann cells and pericytes, which form sheaths/barriers at the islet exterior and interior borders. The two cell types have shown their plasticity in islet injury, but their roles in transplantation remain unclear. In this research, we applied 3-dimensional neurovascular histolo...

  12. Interactions between intraspinal Schwann cells and the cellular constituents normally occurring in the spinal cord: an ultrastructural study in the irradiated rat

    International Nuclear Information System (INIS)

    Sims, T.J.; Gilmore, S.A.

    1983-01-01

    Relationships between intraspinal Schwann cells and neuroglia, particularly astrocytes, were studied following X-irradiation of the spinal cord in 3-day old rats. Initially, this exposure results in a depletion of the neuroglial population. By 10 days post-irradiation (P-I), gaps occur in the glia limitans, although the overlying basal lamina remains intact. Development of and myelination by intraspinal Schwann cells is well underway by 15 days P-I. These Schwann cell-occupied regions have a paucity of astrocyte processes, a finding which persists throughout the study (60 days P-I), and several types of Schwann cell-neuroglial interfaces are observed. The gaps in the glia limitans widen as the P-I interval increases. At 45 and 60 days P-I, the basal lamina no longer forms a singular, continuous covering over the spinal cord surface, but follows instead a rather tortuous course over the disrupted glia limitans and the intraspinal Schwann cells. Although the mode of initial occurrence of Schwann cells within the spinal cord is not yet understood, the data indicate that the astrocyte population is involved in that process, as well as in limiting the further development of Schwann cells within the substance of the spinal cord. (Auth.)

  13. Primary culture of human Schwann and schwannoma cells: improved and simplified protocol.

    Science.gov (United States)

    Dilwali, Sonam; Patel, Pratik B; Roberts, Daniel S; Basinsky, Gina M; Harris, Gordon J; Emerick, Kevin S; Stankovic, Konstantina M

    2014-09-01

    Primary culture of human Schwann cells (SCs) and vestibular schwannoma (VS) cells are invaluable tools to investigate SC physiology and VS pathobiology, and to devise effective pharmacotherapies against VS, which are sorely needed. However, existing culture protocols, in aiming to create robust, pure cultures, employ methods that can lead to loss of biological characteristics of the original cells, potentially resulting in misleading biological findings. We have developed a minimally manipulative method to culture primary human SC and VS cells, without the use of selective mitogens, toxins, or time-consuming and potentially transformative laboratory techniques. Schwann cell purity was quantified longitudinally using S100 staining in SC cultures derived from the great auricular nerve and VS cultures followed for 7 and 12 weeks, respectively. SC cultures retained approximately ≥85% purity for 2 weeks. VS cultures retained approximately ≥80% purity for the majority of the span of 12 weeks, with maximal purity of 87% at 2 weeks. The VS cultures showed high level of biological similarity (68% on average) to their respective parent tumors, as assessed using a protein array featuring 41 growth factors and receptors. Apoptosis rate in vitro negatively correlated with tumor volume. Our results, obtained using a faster, simplified culturing method than previously utilized, indicate that highly pure, primary human SC and VS cultures can be established with minimal manipulation, reaching maximal purity at 2 weeks of culture. The VS cultures recapitulate the parent tumors' biology to a great degree, making them relevant models to investigate VS pathobiology. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Chrysanthi eSamara

    2013-11-01

    Full Text Available 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.

  15. Low-frequency electrical stimulation induces the proliferation and differentiation of peripheral blood stem cells into Schwann cells.

    Science.gov (United States)

    Gu, Xudong; Fu, Jianming; Bai, Jing; Zhang, Chengwen; Wang, Jing; Pan, Wenping

    2015-02-01

    Functional recovery after peripheral nerve injury remains a tough problem at present. Specifically, a type of glial cell exists in peripheral nerves that promotes axonal growth and myelin formation and secretes various active substances, such as neurotrophic factors, extracellular matrix and adherence factors. These substances have important significance for the survival, growth and regeneration of nerve fibers. Numerous recent studies have shown that electrical stimulation can increase the number of myelinated nerve fibers. However, whether electrical stimulation acts on neurons or Schwann cells has not been verified in vivo. This study investigates low-frequency electrical stimulation-induced proliferation and differentiation of peripheral blood stem cells into Schwann cells and explores possible mechanisms. Peripheral blood stem cells from Sprague-Dawley rats were primarily cultured. Cells in passage 3 were divided into 4 groups: a low-frequency electrical stimulation group (20 Hz, 100 μs, 3 V), a low-frequency electrical stimulation+PD98059 (blocking the extracellular signal-regulated kinase [ERK] signaling pathway) group, a PD98059 group and a control group (no treatment). After induction, the cells were characterized. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazoliumbromide assay was employed to measure the absorbance values at 570 nm in the 4 groups. A Western blot assay was used to detect the expression of cyclin D1 and cyclin-dependent kinase 4 (CDK4) in each group. No significant difference in cell viability was detected before induction. Peripheral blood stem cells from the 4 groups differentiated into Schwann cells. Phosphorylated ERK 1/2, cyclin D1 and CDK4 protein levels were highest in the low-frequency electrical stimulation group and lowest in the ERK blockage group. Phosphorylated ERK 1/2, cyclin D1 and CDK4 protein levels in the low-frequency electrical stimulation+ERK blockage group were lower than those in the low-frequency electrical

  16. Dynamic Quantification of Host Schwann Cell Migration into Peripheral Nerve Allografts

    Science.gov (United States)

    Whitlock, Elizabeth L.; Myckatyn, Terence M.; Tong, Alice Y.; Yee, Andrew; Yan, Ying; Magill, Christina K.; Johnson, Philip J.; Mackinnon, Susan E.

    2010-01-01

    Host Schwann cell (SC) migration into nerve allografts is the limiting factor in the duration of immunosuppression following peripheral nerve allotransplantation, and may be affected by different immunosuppressive regimens. Our objective was to compare SC migration patterns between clinical and experimental immunosuppression regimens both over time and at the harvest endpoint. Eighty mice that express GFP under the control of the Schwann cell specific S100 promoter were engrafted with allogeneic, nonfluorescent sciatic nerve grafts. Mice received immunosuppression with either tacrolimus (FK506), or experimental T-cell triple costimulation blockade (CSB), consisting of CTLA4-immunoglobulin fusion protein, anti-CD40 monoclonal antibody, and anti-inducible costimulator monoclonal antibody. Migration of GFP-expressing host SCs into wild-type allografts was assessed in vivo every 3 weeks until 15 weeks postoperatively, and explanted allografts were evaluated for immunohistochemical staining patterns to differentiate graft from host SCs. Immunosuppression with tacrolimus exhibited a plateau of SC migration, characterized by significant early migration (< 3 weeks) followed by a constant level of host SCs in the graft (15 weeks). At the endpoint, graft fluorescence was decreased relative to surrounding host nerve, and donor SCs persisted within the graft. CSB-treated mice displayed gradually increasing migration of host SCs into the graft, without the plateau noted in tacrolimus-treated mice, and also maintained a population of donor SCs at the 15-week endpoint. SC migration patterns are affected by immunosuppressant choice, particularly in the immediate postoperative period, and the use of a single treatment of CSB may allow for gradual population of nerve allografts with host SCs. PMID:20633557

  17. 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

  18. Neuronal Regulation of Schwann Cell Mitochondrial Ca2+ Signaling during Myelination

    Directory of Open Access Journals (Sweden)

    Daisuke Ino

    2015-09-01

    Full Text Available Schwann cells (SCs myelinate peripheral neurons to promote the rapid conduction of action potentials, and the process of myelination is known to be regulated by signals from axons to SCs. Given that SC mitochondria are one of the potential regulators of myelination, we investigated whether SC mitochondria are regulated by axonal signaling. Here, we show a purinergic mechanism that sends information from neurons to SC mitochondria during myelination. Our results show that electrical stimulation of rat sciatic nerve increases extracellular ATP levels enough to activate purinergic receptors. Indeed, electrical stimulation of sciatic nerves induces Ca2+ increases in the cytosol and the mitochondrial matrix of surrounding SCs via purinergic receptor activation. Chronic suppression of this pathway during active myelination suppressed the longitudinal and radial development of myelinating SCs and caused hypomyelination. These results demonstrate a neuron-to-SC mitochondria signaling, which is likely to have an important role in proper myelination.

  19. Study of the Peripheral Nerve Fibers Myelin Structure Changes during Activation of Schwann Cell Acetylcholine Receptors.

    Directory of Open Access Journals (Sweden)

    Ekaterina E Verdiyan

    Full Text Available In the present paper we consider a new type of mechanism by which neurotransmitter acetylcholine (ACh regulates the properties of peripheral nerve fibers myelin. Our data show the importance of the relationship between the changes in the number of Schwann cell (SC acetylcholine receptors (AChRs and the axon excitation (different intervals between action potentials (APs. Using Raman spectroscopy, an effect of activation of SC AChRs on the myelin membrane fluidity was investigated. It was found, that ACh stimulates an increase in lipid ordering degree of the myelin lipids, thus providing evidence for specific role of the "axon-SC" interactions at the axon excitation. It was proposed, that during the axon excitation, the SC membrane K+- depolarization and the Ca2+-influx led to phospholipase activation or exocytosis of intracellular membrane vesicles and myelin structure reorganization.

  20. Impact of scaffold micro and macro architecture on Schwann cell proliferation under dynamic conditions in a rotating wall vessel bioreactor

    International Nuclear Information System (INIS)

    Valmikinathan, Chandra M.; Hoffman, John; Yu, Xiaojun

    2011-01-01

    Over the last decade tissue engineering has emerged as a powerful alternative to regenerate lost tissues owing to trauma or tumor. Evidence shows that Schwann cell containing scaffolds have improved performance in vivo as compared to scaffolds that depend on cellularization post implantation. However, owing to limited supply of cells from the patients themselves, several approaches have been taken to enhance cell proliferation rates to produce complete and uniform cellularization of scaffolds. The most common approach is the application of a bioreactor to enhance cell proliferation rate and therefore reduce the time needed to obtain sufficiently significant number of glial cells, prior to implantation. In this study, we show the application of a rotating wall bioreactor system for studying Schwann cell proliferation on nanofibrous spiral shaped scaffolds, prepared by solvent casting and salt leaching techniques. The scaffolds were fabricated from polycaprolactone (PCL), which has ideal mechanical properties and upon degradation does not produce acidic byproducts. The spiral scaffolds were coated with aligned or random nanofibers, produced by electrospinning, to provide a substrate that mimics the native extracellular matrix and the essential contact guidance cues. At the 4 day time point, an enhanced rate of cell proliferation was observed on the open structured nanofibrous spiral scaffolds in a rotating wall bioreactor, as compared to static culture conditions. However, the cell proliferation rate on the other contemporary scaffolds architectures such as the tubular and cylindrical scaffolds show reduced cell proliferation in the bioreactor as compared to static conditions, at the same time point. Moreover, the rotating wall bioreactor does not alter the orientation or the phenotype of the Schwann cells on the aligned nanofiber containing scaffolds, wherein, the cells remain aligned along the length of the scaffolds. Therefore, these open structured spiral

  1. Patterns of x-radiation-induced Schwann cell development in spinal cords of immature rats

    International Nuclear Information System (INIS)

    Gilmore, S.A.; Heard, J.K.; Leiting, J.E.

    1983-01-01

    Schwann cells, Schwann cell myelin, and connective tissue components develop in the spinal cord of the immature rat following exposure to x-rays. For the purposes of this paper, these intraspinal peripheral nervous tissue constituents are referred to as IPNT. A series of investigations are in progress to elucidate factors related to the development of IPNT, and the present study is a light microscopic evaluation of the relationship between the amount of radiation administered (1,000-3,000R) to the lumbosacral spinal cord in 3-day-old rats and the incidence and distribution of IPNT at intervals up to 60 days postirradiation (P-I). The results showed that IPNT was present in only 33% of the rats exposed to 1,000R, whereas its presence was observed in 86% or more of those in the 2,000-, 2,500-, and 3,000R groups. The distribution of IPNT was quite limited in the 1,000R group, where it was restricted to the spinal cord-dorsal root junction and was found in only a few sections within the irradiated area. The distribution was more widespread with increasing amounts of radiation, and IPNT occupied substantial portions of the dorsal funiculi and extended into the dorsal gray matter in the 3,000R group. In all aR mals developing IPNT in the groups receiving 2,000R or more, the IPNT was present in essentially all sections from the irradiated area. Further studies will compare in detail spinal cords exposed to 1,000R in which IPNT is an infrequent, limited occurrence with those exposed to higher doses where IPNT occurs in a more widespread fashion in essentially all animals

  2. The Pseudopod System for Axon-Glia Interactions: Stimulation and Isolation of Schwann Cell Protrusions that Form in Response to Axonal Membranes.

    Science.gov (United States)

    Poitelon, Yannick; Feltri, M Laura

    2018-01-01

    In the peripheral nervous system, axons dictate the differentiation state of Schwann cells. Most of this axonal influence on Schwann cells is due to juxtacrine interactions between axonal transmembrane molecules (e.g., the neuregulin growth factor) and receptors on the Schwann cell (e.g., the ErbB2/ErbB3 receptor). The fleeting nature of this interaction together with the lack of synchronicity in the development of the Schwann cell population limits our capability to study this phenomenon in vivo. Here we present a simple Boyden Chamber-based method to study this important cell-cell interaction event. We isolate the early protrusions of Schwann cells that are generated in response to juxtacrine stimulation by sensory neuronal membranes. This method is compatible with a large array of current biochemical analyses and provides an effective approach to study biomolecules that are differentially localized in Schwann cell protrusions and cell bodies in response to axonal signals. A similar approach can be extended to different kinds of cell-cell interactions.

  3. Cellulose/soy protein isolate composite membranes: evaluations of in vitro cytocompatibility with Schwann cells and in vivo toxicity to animals.

    Science.gov (United States)

    Luo, Lihua; Gong, Wenrong; Zhou, Yi; Yang, Lin; Li, Daokun; Huselstein, Celine; Wang, Xiong; He, Xiaohua; Li, Yinping; Chen, Yun

    2015-01-01

    To evaluate the in vitro cytocompatibility of cellulose/soy protein isolate composite membranes (CSM) with Schwann cells and in vivo toxicity to animals. A series of cellulose/soy protein isolate composite membranes (CSM) were prepared by blending, solution casting and coagulation process. The cytocompatibility of the CSM to Schwann cells were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and by direct cells culture of Schwann cells on the surfaces of the CSM, respectively. The in vivo toxicity of the CSM to animals were also evaluated by acute toxicity testing, skin sensitization testing, pyrogen testing and intracutaneous stimulation testing, respectively, according to the ISO 10993 standard. The MTT assay showed that the cell viability of Schwann cells cultured in extracts from the CSM was higher than that from the neat cellulose membrane without containing SPI component. The direct cells culture indicated that the Schwann cells could attach and grow well on the surface of the CSM and the incorporation of SPI into cellulose contributed to improvement of cell adhesion and proliferation. The evaluations of in vivo biological safety suggested that the CSM showed no acute toxicity, no skin sensitization and no intracutaneous stimulation to the experimental animals. The CSM had in vitro cytocompatibility with Schwann cells and biological safety to animals, suggesting potential for the applications as nerve conduit for the repair of nerve defect.

  4. Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation.

    Science.gov (United States)

    Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

    2015-07-10

    Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Hyperglycemia Promotes Schwann Cell De-differentiation and De-myelination via Sorbitol Accumulation and Igf1 Protein Down-regulation*

    Science.gov (United States)

    Hao, Wu; Tashiro, Syoichi; Hasegawa, Tomoka; Sato, Yuiko; Kobayashi, Tami; Tando, Toshimi; Katsuyama, Eri; Fujie, Atsuhiro; Watanabe, Ryuichi; Morita, Mayu; Miyamoto, Kana; Morioka, Hideo; Nakamura, Masaya; Matsumoto, Morio; Amizuka, Norio; Toyama, Yoshiaki; Miyamoto, Takeshi

    2015-01-01

    Diabetes mellitus (DM) is frequently accompanied by complications, such as peripheral nerve neuropathy. Schwann cells play a pivotal role in regulating peripheral nerve function and conduction velocity; however, changes in Schwann cell differentiation status in DM are not fully understood. Here, we report that Schwann cells de-differentiate into immature cells under hyperglycemic conditions as a result of sorbitol accumulation and decreased Igf1 expression in those cells. We found that de-differentiated Schwann cells could be re-differentiated in vitro into mature cells by treatment with an aldose reductase inhibitor, to reduce sorbitol levels, or with vitamin D3, to elevate Igf1 expression. In vivo DM models exhibited significantly reduced nerve function and conduction, Schwann cell de-differentiation, peripheral nerve de-myelination, and all conditions were significantly rescued by aldose reductase inhibitor or vitamin D3 administration. These findings reveal mechanisms underlying pathological changes in Schwann cells seen in DM and suggest ways to treat neurological conditions associated with this condition. PMID:25998127

  6. Hyperglycemia Alters the Schwann Cell Mitochondrial Proteome and Decreases Coupled Respiration in the Absence of Superoxide Production

    OpenAIRE

    Zhang, Liang; Yu, Cuijuan; Vasquez, Francisco E.; Galeva, Nadya; Onyango, Isaac; Swerdlow, Russell H.; Dobrowsky, Rick T.

    2010-01-01

    Hyperglycemia-induced mitochondrial dysfunction contributes to sensory neuron pathology in diabetic neuropathy. Although Schwann cells (SCs) also undergo substantial degeneration in diabetic neuropathy, the effect of hyperglycemia on SC mitochondrial proteome and mitochondrial function has not been examined. Stable isotope labeling with amino acids in cell culture (SILAC) was used to quantify the temporal effect of hyperglycemia on the mitochondrial proteome of primary SCs isolated from neona...

  7. Grafting of ARPE-19 and Schwann cells to the subretinal space in RCS rats.

    Science.gov (United States)

    Wang, Shaomei; Lu, Bin; Wood, Patrick; Lund, Raymond D

    2005-07-01

    To study the distribution of the human retinal pigment epithelium (hRPE) cell line ARPE-19 and human Schwann (hSC) cells grafted to the subretinal space of the Royal College of Surgeon (RCS) rat and the relation of graft cell distribution to photoreceptor rescue. Cell suspensions of both donor types were injected into the subretinal space of 3-week-old dystrophic RCS rats through a transscleral approach, human fibroblast and medium were used as control grafts. All animals were maintained on oral cyclosporine. At 1, 2, 4, 6, 15, 28, and 36 weeks after grafting, animals were killed. Human cell-specific markers were used to localize donor cells. Both donor cell types, as revealed by antibodies survived for a substantial time. Their distribution was very different: hRPE cells formed a large clump early on and, with time, spread along the host RPE in a layer one to two cells deep, whereas hSCs formed many smaller clumps, mainly in the subretinal space. Both cells rescued photoreceptors beyond the area of donor cell distribution. The number of surviving cells declined with time. Both hRPE and hSC grafts can survive and rescue photoreceptors for a substantial time after grafting. The number of both donor cell types declined with time, which could be an immune-related problem and/or due to other factors intrinsic to the host RCS retina. The fact that rescue occurred beyond the area of donor cell distribution suggests that diffusible factors are involved, raising the possibility that the two cell types function in a similar manner to rescue photoreceptors.

  8. 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......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...

  9. Schwann Cell-Mediated Preservation of Vision in Retinal Degenerative Diseases via the Reduction of Oxidative Stress: A Possible Mechanism.

    Science.gov (United States)

    Mahmoudzadeh, Raziyeh; Heidari-Keshel, Saeed; Lashay, Alireza

    2016-01-01

    After injury to the central nervous system (CNS), regeneration is often inadequate, except in the case of remyelination. This remyelination capacity of the CNS is a good example of a stem/precursor cell-mediated renewal process. Schwann cells have been found to act as remyelinating agents in the peripheral nervous system (PNS), but several studies have highlighted their potential role in remyelination in the CNS too. Schwann cells are able to protect and support retinal cells by secreting growth factors such as brain-derived neurotrophic factor, glial cell line-derived neurotrophic factor, and basic fibroblast growth factor. Retinal degenerative diseases can be highly debilitating, and they are a major concern in countries with an ageing populations. One of the leading causes of permanent loss of vision in the West is a retinal degenerative disease known as age-related macular degeneration (AMD). In the United States, nearly 1.75 million people over the age of 40 have advanced AMD, and it is estimated that this number will increase to approximately 3 million people by 2020. One of the most common pathways involved in the initiation and development of retinal diseases is the oxidative stress pathway. In patients with diabetes, Schwann cells have been shown to be able to secrete large amounts of antioxidant enzymes that protect the PNS from the oxidative stress that results from fluctuations in blood glucose levels. This antioxidant ability may be involved in the mechanism by which Schwann cells are able to promote reconstruction in the CNS, especially in individuals with retinal injuries and degenerative diseases.

  10. 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.

  11. 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.

  12. 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.

  13. Graded Elevation of c-Jun in Schwann Cells In Vivo: Gene Dosage Determines Effects on Development, Remyelination, Tumorigenesis, and Hypomyelination.

    Science.gov (United States)

    Fazal, Shaline V; Gomez-Sanchez, Jose A; Wagstaff, Laura J; Musner, Nicolo; Otto, Georg; Janz, Martin; Mirsky, Rhona; Jessen, Kristján R

    2017-12-13

    Schwann cell c-Jun is implicated in adaptive and maladaptive functions in peripheral nerves. In injured nerves, this transcription factor promotes the repair Schwann cell phenotype and regeneration and promotes Schwann-cell-mediated neurotrophic support in models of peripheral neuropathies. However, c-Jun is associated with tumor formation in some systems, potentially suppresses myelin genes, and has been implicated in demyelinating neuropathies. To clarify these issues and to determine how c-Jun levels determine its function, we have generated c-Jun OE/+ and c-Jun OE/OE mice with graded expression of c-Jun in Schwann cells and examined these lines during development, in adulthood, and after injury using RNA sequencing analysis, quantitative electron microscopic morphometry, Western blotting, and functional tests. Schwann cells are remarkably tolerant of elevated c-Jun because the nerves of c-Jun OE/+ mice, in which c-Jun is elevated ∼6-fold, are normal with the exception of modestly reduced myelin thickness. The stronger elevation of c-Jun in c-Jun OE/OE mice is, however, sufficient to induce significant hypomyelination pathology, implicating c-Jun as a potential player in demyelinating neuropathies. The tumor suppressor P19 ARF is strongly activated in the nerves of these mice and, even in aged c-Jun OE/OE mice, there is no evidence of tumors. This is consistent with the fact that tumors do not form in injured nerves, although they contain proliferating Schwann cells with strikingly elevated c-Jun. Furthermore, in crushed nerves of c-Jun OE/+ mice, where c-Jun levels are overexpressed sufficiently to accelerate axonal regeneration, myelination and function are restored after injury. SIGNIFICANCE STATEMENT In injured and diseased nerves, the transcription factor c-Jun in Schwann cells is elevated and variously implicated in controlling beneficial or adverse functions, including trophic Schwann cell support for neurons, promotion of regeneration, tumorigenesis

  14. 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.

  15. Role of Schwann cells in the regeneration of penile and peripheral nerves

    Directory of Open Access Journals (Sweden)

    Lin Wang

    2015-01-01

    Full Text Available Schwann cells (SCs are the principal glia of the peripheral nervous system. The end point of SC development is the formation of myelinating and nonmyelinating cells which ensheath large and small diameter axons, respectively. They play an important role in axon regeneration after injury, including cavernous nerve injury that leads to erectile dysfunction (ED. Despite improvement in radical prostatectomy surgical techniques, many patients still suffer from ED postoperatively as surgical trauma causes traction injuries and local inflammatory changes in the neuronal microenvironment of the autonomic fibers innervating the penis resulting in pathophysiological alterations in the end organ. The aim of this review is to summarize contemporary evidence regarding: (1 the origin and development of SCs in the peripheral and penile nerve system; (2 Wallerian degeneration and SC plastic change following peripheral and penile nerve injury; (3 how SCs promote peripheral and penile nerve regeneration by secreting neurotrophic factors; (4 and strategies targeting SCs to accelerate peripheral nerve regeneration. We searched PubMed for articles related to these topics in both animal models and human research and found numerous studies suggesting that SCs could be a novel target for treatment of nerve injury-induced ED.

  16. 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.

  17. Non-viral genetic transfection of rat Schwann cells with FuGENE HD© lipofection and AMAXA© nucleofection is feasible but impairs cell viability.

    Science.gov (United States)

    Kraus, Armin; Täger, Joachim; Kohler, Konrad; Haerle, Max; Werdin, Frank; Schaller, Hans-Eberhard; Sinis, Nektarios

    2010-11-01

    To determine transfection efficiency of FuGENE HD© lipofection and AMAXA© nucleofection on rat Schwann cells (SC). The ischiadic and median nerves of 6-8 week old Lewis rats were cultured in modified melanocyte-growth medium. SCs were genetically transfected with green fluorescent protein (GFP) as reporter gene using FuGENE HD© lipofection and AMAXA© nucleofection. Transfection rates were determined by visualization of GFP fluorescence under fluorescence microscopy and cell counting. Transfected cell to non-transfected cell relation was determined. Purity of Schwann cell culture was 88% as determined by immunohistologic staining. Transfection rate of FuGENE HD© lipofection was 2%, transfection rate of AMAXA© nucleofection was 10%. With both methods, Schwann cells showed pronounced aggregation behavior which made them unfeasible for further cultivation. Settling of Schwann cells on laminin and poly-L-ornithine coated plates was compromised by either method. Non-viral transfection of rat SC with FuGENE HD© lipofection and AMAXA© nucleofection is basically possible with a higher transfection rate for nucleofection than for lipofection. As cell viability is compromised by either method however, viral transfection is to be considered if higher efficiency is required.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Neuronal Regulation of Schwann Cell Mitochondrial Ca(2+) Signaling during Myelination.

    Science.gov (United States)

    Ino, Daisuke; Sagara, Hiroshi; Suzuki, Junji; Kanemaru, Kazunori; Okubo, Yohei; Iino, Masamitsu

    2015-09-29

    Schwann cells (SCs) myelinate peripheral neurons to promote the rapid conduction of action potentials, and the process of myelination is known to be regulated by signals from axons to SCs. Given that SC mitochondria are one of the potential regulators of myelination, we investigated whether SC mitochondria are regulated by axonal signaling. Here, we show a purinergic mechanism that sends information from neurons to SC mitochondria during myelination. Our results show that electrical stimulation of rat sciatic nerve increases extracellular ATP levels enough to activate purinergic receptors. Indeed, electrical stimulation of sciatic nerves induces Ca(2+) increases in the cytosol and the mitochondrial matrix of surrounding SCs via purinergic receptor activation. Chronic suppression of this pathway during active myelination suppressed the longitudinal and radial development of myelinating SCs and caused hypomyelination. These results demonstrate a neuron-to-SC mitochondria signaling, which is likely to have an important role in proper myelination. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Electrical stimulation induces calcium-dependent release of NGF from cultured Schwann cells.

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    Huang, Jinghui; Ye, Zhengxu; Hu, Xueyu; Lu, Lei; Luo, Zhuojing

    2010-04-01

    Production of nerve growth factor (NGF) from Schwann cells (SCs) progressively declines in the distal stump, if axonal regeneration is staggered across the suture site after peripheral nerve injuries. This may be an important factor limiting the outcome of nerve injury repair. Thus far, extensive efforts are devoted to modulating NGF production in cultured SCs, but little has been achieved. In the present in vitro study, electrical stimulation (ES) was attempted to stimulate cultured SCs to release NGF. Our data showed that ES was capable of enhancing NGF release from cultured SCs. An electrical field (1 Hz, 5 V/cm) caused a 4.1-fold increase in NGF release from cultured SCs. The ES-induced NGF release is calcium dependent. Depletion of extracellular or/and intracellular calcium partially/ completely abolished the ES-induced NGF release. Further pharmacological interventions showed that ES induces calcium influx through T-type voltage-gated calcium channels and mobilizes calcium from 1, 4, 5-trisphosphate-sensitive stores and caffeine/ryanodine-sensitive stores, both of which contributed to the enhanced NGF release induced by ES. In addition, a calcium-triggered exocytosis mechanism was involved in the ES-induced NGF release from cultured SCs. These findings show the feasibility of using ES in stimulating SCs to release NGF, which holds great potential in promoting nerve regeneration by enhancing survival and outgrowth of damaged nerves, and is of great significance in nerve injury repair and neuronal tissue engineering.

  1. 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.

  2. Rac1 controls Schwann cell myelination through cAMP and NF2/merlin

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

    2013-01-01

    During peripheral nervous system development, Schwann cells (SCs) surrounding single large axons differentiate into myelinating SCs. Previous studies implicate RhoGTPases in SC myelination, but the mechanisms involved in RhoGTPase regulation of SC myelination are unknown. Here, we show that SC myelination is arrested in Rac1 conditional knockout (Rac1-CKO) mice. Rac1 knockout abrogated phosphorylation of the effector p21-activated kinase (PAK) and decreased NF2/merlin phosphorylation. Mutation of NF2/merlin rescued the myelin deficit in Rac1-CKO mice in vivo, and the shortened processes in cultured Rac1-CKO SCs in vitro. Mechanistically, cyclic adenosine monophosphate (cAMP) levels and E-cadherin expression were decreased in the absence of Rac1, and both were restored by mutation of NF2/merlin. Reduced cAMP is a cause of the myelin deficiency in Rac1-CKO mice, as elevation of cAMP by rolipram in Rac1-CKO mice in vivo allowed myelin formation. Thus NF2/merlin and cAMP function downstream of Rac1 signaling in SC myelination, and cAMP levels control Rac1-regulated SC myelination. PMID:23197717

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

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    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.

  4. 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.

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

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    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.

  6. Schwann cell transplantation improves reticulospinal axon growth and forelimb strength after severe cervical spinal cord contusion.

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    Schaal, S M; Kitay, B M; Cho, K S; Lo, T P; Barakat, D J; Marcillo, A E; Sanchez, A R; Andrade, C M; Pearse, D D

    2007-01-01

    Schwann cell (SC) implantation alone has been shown to promote the growth of propriospinal and sensory axons, but not long-tract descending axons, after thoracic spinal cord injury (SCI). In the current study, we examined if an axotomy close to the cell body of origin (so as to enhance the intrinsic growth response) could permit supraspinal axons to grow onto SC grafts. Adult female Fischer rats received a severe (C5) cervical contusion (1.1 mm displacement, 3 KDyn). At 1 week postinjury, 2 million SCs ex vivo transduced with lentiviral vector encoding enhanced green fluorescent protein (EGFP) were implanted within media into the injury epicenter; injury-only animals served as controls. Animals were tested weekly using the BBB score for 7 weeks postimplantation and received at end point tests for upper body strength: self-supported forelimb hanging, forearm grip force, and the incline plane. Following behavioral assessment, animals were anterogradely traced bilaterally from the reticular formation using BDA-Texas Red. Stereological quantification revealed a twofold increase in the numbers of preserved NeuN+ neurons rostral and caudal to the injury/graft site in SC implanted animals, corroborating previous reports of their neuroprotective efficacy. Examination of labeled reticulospinal axon growth revealed that while rarely an axon was present within the lesion site of injury-only controls, numerous reticulospinal axons had penetrated the SC implant/lesion milieu. This has not been observed following implantation of SCs alone into the injured thoracic spinal cord. Significant behavioral improvements over injury-only controls in upper limb strength, including an enhanced grip strength (a 296% increase) and an increased self-supported forelimb hanging, accompanied SC-mediated neuroprotection and reticulospinal axon growth. The current study further supports the neuroprotective efficacy of SC implants after SCI and demonstrates that SCs alone are capable of supporting

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

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    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.

  8. Electrically induced brain-derived neurotrophic factor release from Schwann cells.

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    Luo, Beier; Huang, Jinghui; Lu, Lei; Hu, Xueyu; Luo, Zhuojing; Li, Ming

    2014-07-01

    Regulating the production of brain-derived neurotrophic factor (BDNF) in Schwann cells (SCs) is critical for their application in traumatic nerve injury, neurodegenerative disorders, and demyelination disease in both central and peripheral nervous systems. The present study investigated the possibility of using electrical stimulation (ES) to activate SCs to release BDNF. We found that short-term ES was capable of promoting BDNF production from SCs, and the maximal BDNF release was achieved by ES at 6 V (3 Hz, 30 min). We further examined the involvement of intracellular calcium ions ([Ca2+]i) in the ES-induced BDNF production in SCs by pharmacological studies. We found that the ES-induced BDNF release required calcium influx through T-type voltage-gated calcium channel (VGCC) and calcium mobilization from internal calcium stores, including inositol triphosphate-sensitive stores and caffeine/ryanodine-sensitive stores. In addition, calcium-calmodulin dependent protein kinase IV (CaMK IV), mitogen-activated protein kinase (MAPK), and cAMP response element-binding protein (CREB) were found to play important roles in the ES-induced BDNF release from SCs. In conclusion, ES is capable of activating SCs to secrete BDNF, which requires the involvement of calcium influx through T-type VGCC and calcium mobilization from internal calcium stores. In addition, activation of CaMK IV, MAPK, and CREB were also involved in the ES-induced BDNF release. The findings indicate that ES can improve the neurotrophic ability in SCs and raise the possibility of developing electrically stimulated SCs as a source of cell therapy for nerve injury in both peripheral and central nervous systems. Copyright © 2014 Wiley Periodicals, Inc.

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

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    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.

  10. Wnt1 from cochlear schwann cells enhances neuronal differentiation of transplanted neural stem cells in a rat spiral ganglion neuron degeneration model.

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    He, Ya; Zhang, Peng-Zhi; Sun, Dong; Mi, Wen-Juan; Zhang, Xin-Yi; Cui, Yong; Jiang, Xing-Wang; Mao, Xiao-Bo; Qiu, Jian-Hua

    2014-04-01

    Although neural stem cell (NSC) transplantation is widely expected to become a therapy for nervous system degenerative diseases and injuries, the low neuronal differentiation rate of NSCs transplanted into the inner ear is a major obstacle for the successful treatment of spiral ganglion neuron (SGN) degeneration. In this study, we validated whether the local microenvironment influences the neuronal differentiation of transplanted NSCs in the inner ear. Using a rat SGN degeneration model, we demonstrated that transplanted NSCs were more likely to differentiate into microtubule-associated protein 2 (MAP2)-positive neurons in SGN-degenerated cochleae than in control cochleae. Using real-time quantitative PCR and an immunofluorescence assay, we also proved that the expression of Wnt1 (a ligand of Wnt signaling) increases significantly in Schwann cells in the SGN-degenerated cochlea. We further verified that NSC cultures express receptors and signaling components for Wnts. Based on these expression patterns, we hypothesized that Schwann cell-derived Wnt1 and Wnt signaling might be involved in the regulation of the neuronal differentiation of transplanted NSCs. We verified our hypothesis in vitro using a coculture system. We transduced a lentiviral vector expressing Wnt1 into cochlear Schwann cell cultures and cocultured them with NSC cultures. The coculture with Wnt1-expressing Schwann cells resulted in a significant increase in the percentage of NSCs that differentiated into MAP2-positive neurons, whereas this differentiation-enhancing effect was prevented by Dkk1 (an inhibitor of the Wnt signaling pathway). These results suggested that Wnt1 derived from cochlear Schwann cells enhanced the neuronal differentiation of transplanted NSCs through Wnt signaling pathway activation. Alterations of the microenvironment deserve detailed investigation because they may help us to conceive effective strategies to overcome the barrier of the low differentiation rate of transplanted

  11. Direct Conversion of Human Fibroblasts into Schwann Cells that Facilitate Regeneration of Injured Peripheral Nerve In Vivo.

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    Sowa, Yoshihiro; Kishida, Tsunao; Tomita, Koichi; Yamamoto, Kenta; Numajiri, Toshiaki; Mazda, Osam

    2017-04-01

    Schwann cells (SCs) play pivotal roles in the maintenance and regeneration of the peripheral nervous system. Although transplantation of SCs enhances repair of experimentally damaged peripheral and central nerve tissues, it is difficult to prepare a sufficient number of functional SCs for transplantation therapy without causing adverse events for the donor. Here, we generated functional SCs by somatic cell reprogramming procedures and demonstrated their capability to promote peripheral nerve regeneration. Normal human fibroblasts were phenotypically converted into SCs by transducing SOX10 and Krox20 genes followed by culturing for 10 days resulting in approximately 43% directly converted Schwann cells (dSCs). The dSCs expressed SC-specific proteins, secreted neurotrophic factors, and induced neuronal cells to extend neurites. The dSCs also displayed myelin-forming capability both in vitro and in vivo. Moreover, transplantation of the dSCs into the transected sciatic nerve in mice resulted in significantly accelerated regeneration of the nerve and in improved motor function at a level comparable to that with transplantation of the SCs obtained from a peripheral nerve. The dSCs induced by our procedure may be applicable for novel regeneration therapy for not only peripheral nerve injury but also for central nerve damage and for neurodegenerative disorders related to SC dysfunction. Stem Cells Translational Medicine 2017;6:1207-1216. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  12. Navigating neurites utilize cellular topography of Schwann cell somas and processes for optimal guidance

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    Lopez-Fagundo, Cristina; Mitchel, Jennifer A.; Ramchal, Talisha D.; Dingle, Yu-Ting L.; Hoffman-Kim, Diane

    2013-01-01

    The path created by aligned Schwann cells (SCs) after nerve injury underlies peripheral nerve regeneration. We developed geometric bioinspired substrates to extract key information needed for axon guidance by deconstructing the topographical cues presented by SCs. We have previously reported materials that directly replicate SC topography with micro- and nanoscale resolution, but a detailed explanation of the means of directed axon extension on SC topography has not yet been described. Here, using neurite tracing and time-lapse microscopy, we analyzed the SC features that influence axon guidance. Novel poly(dimethylsiloxane) materials, fabricated via photolithography, incorporated bioinspired topographical components with the shapes and sizes of aligned SCs, namely somas and processes, where the length of the processes were varied but the soma geometry and dimensions were kept constant. Rat dorsal root ganglia neurites aligned to all materials presenting bioinspired topography after a 5 days in culture and to bioinspired materials presenting soma and process features after only 17 hours in culture. Key findings of this study were: Neurite response to underlying bioinspired topographical features was time dependent, where at 5 days, neurites aligned most strongly to materials presenting combinations of soma and process features, with higher than average density of either process or soma features; but at 17 hours they aligned more strongly to materials presenting average densities of soma and process features and to materials presenting process features only. These studies elucidate the influence of SC topography on axon guidance in a time-dependent setting and have implications for the optimization of nerve regeneration strategies. PMID:23557939

  13. A guidance channel seeded with autologous Schwann cells for repair of cauda equina injury in a primate model.

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    Calancie, Blair; Madsen, Parley W; Wood, Patrick; Marcillo, Alexander E; Levi, Allan D; Bunge, Richard P

    2009-01-01

    To evaluate an implantable guidance channel (GC) seeded with autologous Schwann cells to promote regeneration of transected spinal nerve root axons in a primate model. Schwann cells were obtained from sural nerve segments of monkeys (Macaca fascicularis; cynomolgus). Cells were cultured, purified, and seeded into a PAN/PVC GC. Approximately 3 weeks later, monkeys underwent laminectomy and dural opening. Nerve roots of the L4 through L7 segments were identified visually. The threshold voltage needed to elicit hindlimb muscle electromyography (EMG) after stimulation of intact nerve roots was determined. Segments of 2 or 3 nerve roots (each approximately 8-15 mm in length) were excised. The GC containing Schwann cells was implanted between the proximal and distal stumps of these nerve roots and attached to the stumps with suture. Follow-up evaluation was conducted on 3 animals, with survival times of 9 to 14 months. Upon reexposure of the implant site, subdural nerve root adhesions were noted in all 3 animals. Several of the implanted GC had collapsed and were characterized by thin strands of connective tissue attached to either end. In contrast, 3 of the 8 implanted GC were intact and had white, glossy cables entering and exiting the conduits. Electrical stimulation of the tissue cable in each of these 3 cases led to low-threshold evoked EMG responses, suggesting that muscles had been reinnervated by axons regenerating through the repair site and into the distal nerve stump. During harvesting of the GC implant, sharp transection led to spontaneous EMG in the same 3 roots showing a low threshold to electrical stimulation, whereas no EMG was seen when harvesting nerve roots with high thresholds to elicit EMG. Histology confirmed large numbers of myelinated axons at the midpoint of 2 GC judged to have reinnervated target muscles. We found a modest rate of successful regeneration and muscle reinnervation after treatment of nerve root transection with a Schwann cell

  14. 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.

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

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    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

  16. G-CSF prevents caspase 3 activation in Schwann cells after sciatic nerve transection, but does not improve nerve regeneration.

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    Frost, Hanna K; Kodama, Akira; Ekström, Per; Dahlin, Lars B

    2016-10-15

    Exogenous granulocyte-colony stimulating factor (G-CSF) has emerged as a drug candidate for improving the outcome after peripheral nerve injuries. We raised the question if exogenous G-CSF can improve nerve regeneration following a clinically relevant model - nerve transection and repair - in healthy and diabetic rats. In short-term experiments, distance of axonal regeneration and extent of injury-induced Schwann cell death was quantified by staining for neurofilaments and cleaved caspase 3, respectively, seven days after repair. There was no difference in axonal outgrowth between G-CSF-treated and non-treated rats, regardless if healthy Wistar or diabetic Goto-Kakizaki (GK) rats were examined. However, G-CSF treatment caused a significant 13% decrease of cleaved caspase 3-positive Schwann cells at the lesion site in healthy rats, but only a trend in diabetic rats. In the distal nerve segments of healthy rats a similar trend was observed. In long-term experiments of healthy rats, regeneration outcome was evaluated at 90days after repair by presence of neurofilaments, wet weight of gastrocnemius muscle, and perception of touch (von Frey monofilament testing weekly). The presence of neurofilaments distal to the suture line was similar in G-CSF-treated and non-treated rats. The weight ratio of ipsi-over contralateral gastrocnemius muscles, and perception of touch at any time point, were likewise not affected by G-CSF treatment. In addition, the inflammatory response in short- and long-term experiments was studied by analyzing ED1 stainable macrophages in healthy rats, but in neither case was any attenuation seen at the injury site or distal to it. G-CSF can prevent caspase 3 activation in Schwann cells in the short-term, but does not detectably affect the inflammatory response, nor improve early or late axonal outgrowth or functional recovery. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

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

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    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.

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

    Directory of Open Access Journals (Sweden)

    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

  19. Sustained Expression of Negative Regulators of Myelination Protects Schwann Cells from Dysmyelination in a Charcot-Marie-Tooth 1B Mouse Model.

    Science.gov (United States)

    Florio, Francesca; Ferri, Cinzia; Scapin, Cristina; Feltri, M Laura; Wrabetz, Lawrence; D'Antonio, Maurizio

    2018-05-02

    Schwann cell differentiation and myelination in the PNS are the result of fine-tuning of positive and negative transcriptional regulators. As myelination starts, negative regulators are downregulated, whereas positive ones are upregulated. Fully differentiated Schwann cells maintain an extraordinary plasticity and can transdifferentiate into "repair" Schwann cells after nerve injury. Reactivation of negative regulators of myelination is essential to generate repair Schwann cells. Negative regulators have also been implicated in demyelinating neuropathies, although their role in disease remains elusive. Here, we used a mouse model of Charcot-Marie-Tooth neuropathy type 1B (CMT1B), the P0S63del mouse characterized by ER stress and the activation of the unfolded protein response, to show that adult Schwann cells are in a partial differentiation state because they overexpress transcription factors that are normally expressed only before myelination. We provide evidence that two of these factors, Sox2 and Id2, act as negative regulators of myelination in vivo However, their sustained expression in neuropathy is protective because ablation of Sox2 or/and Id2 from S63del mice of both sexes results in worsening of the dysmyelinating phenotype. This is accompanied by increased levels of mutant P0 expression and exacerbation of ER stress, suggesting that limited differentiation may represent a novel adaptive mechanism through which Schwann cells counter the toxic effect of a mutant terminal differentiation protein. SIGNIFICANCE STATEMENT In many neuropathies, Schwann cells express high levels of early differentiation genes, but the significance of these altered expression remained unclear. Because many of these factors may act as negative regulators of myelination, it was suggested that their misexpression could contribute to dysmyelination. Here, we show that the transcription factors Sox2 and Id2 act as negative regulators of myelination in vivo , but that their sustained

  20. Electrical Differentiation of Mesenchymal Stem Cells into Schwann-Cell-Like Phenotypes Using Inkjet-Printed Graphene Circuits.

    Science.gov (United States)

    Das, Suprem R; Uz, Metin; Ding, Shaowei; Lentner, Matthew T; Hondred, John A; Cargill, Allison A; Sakaguchi, Donald S; Mallapragada, Surya; Claussen, Jonathan C

    2017-04-01

    Graphene-based materials (GBMs) have displayed tremendous promise for use as neurointerfacial substrates as they enable favorable adhesion, growth, proliferation, spreading, and migration of immobilized cells. This study reports the first case of the differentiation of mesenchymal stem cells (MSCs) into Schwann cell (SC)-like phenotypes through the application of electrical stimuli from a graphene-based electrode. Electrical differentiation of MSCs into SC-like phenotypes is carried out on a flexible, inkjet-printed graphene interdigitated electrode (IDE) circuit that is made highly conductive (sheet resistance electrically stimulated/treated (etMSCs) display significant enhanced cellular differentiation and paracrine activity above conventional chemical treatment strategies [≈85% of the etMSCs differentiated into SC-like phenotypes with ≈80 ng mL -1 of nerve growth factor (NGF) secretion vs. 75% and ≈55 ng mL -1 for chemically treated MSCs (ctMSCs)]. These results help pave the way for in vivo peripheral nerve regeneration where the flexible graphene electrodes could conform to the injury site and provide intimate electrical simulation for nerve cell regrowth. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. 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.

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

    International Nuclear Information System (INIS)

    Wu, Weijie; Liu, Yuxi; Wang, Youhua

    2016-01-01

    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.

  3. Proliferación y expresión de marcadores por células de Schwann de rata adulta en cultivo Schwann cells proliferation and marker expression on adult rat in culture

    Directory of Open Access Journals (Sweden)

    Martínez Constanza

    1999-06-01

    Full Text Available En este trabajo se evalúan diferentes técnicas para obten-ción y cultivo de células de Schwann provenientes del nervio periférico de rata adulta, de las cuales la que evi-dencia mejor respuesta es la que combina una degenera-ción walleriana durante 14 días in vitro, seguida de una disociación enzimática. La adición de mitógenos como la forskolina y extracto de pituitaria no muestra un efecto sobre estas células. Los niveles de enriquecimiento en células de Schwann, defi-nidos de acuerdo con patrones morfológicos y de expre-sión de marcadores tales como la proteína S-100 o la pro-teína acida fíbrilar glial (GFAP, son buenos (del orden de 80-88% hasta los ocho días de cultivo. La detección de bromodeoxiouridina (BrdU incorporada por células en fase S del ciclo celular, demuestra que en términos ge-nerales la tasa de incorporación de BrdU de las células guales del sistema nervioso periférico no cambia.This study evaluated some techniques for culture and growth of Schwann Cells from adult rats peripheral nerves. The best of these methods is a combination of in vitro Wallerian degeneration during 14 days, followed by an enzimatic dissociation with collagenase and dispase Mitogens like forskolin and pituitary extract do not have any effects on these cells. Enrichement of the culture (measure by morphological and inmunocitochemical criteria was about 80-88% until 8 days in culture. Stable Level of BrdU incorporation suggested that the population of cells entering S phase does not change.

  4. Side-To-Side Nerve Bridges Support Donor Axon Regeneration Into Chronically Denervated Nerves and Are Associated With Characteristic Changes in Schwann Cell Phenotype.

    Science.gov (United States)

    Hendry, J Michael; Alvarez-Veronesi, M Cecilia; Snyder-Warwick, Alison; Gordon, Tessa; Borschel, Gregory H

    2015-11-01

    Chronic denervation resulting from long nerve regeneration times and distances contributes greatly to suboptimal outcomes following nerve injuries. Recent studies showed that multiple nerve grafts inserted between an intact donor nerve and a denervated distal recipient nerve stump (termed "side-to-side nerve bridges") enhanced regeneration after delayed nerve repair. To examine the cellular aspects of axon growth across these bridges to explore the "protective" mechanism of donor axons on chronically denervated Schwann cells. In Sprague Dawley rats, 3 side-to-side nerve bridges were placed over a 10-mm distance between an intact donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) distal nerve stump. Green fluorescent protein-expressing TIB axons grew across the bridges and were counted in cross section after 4 weeks. Immunofluorescent axons and Schwann cells were imaged over a 4-month period. Denervated Schwann cells dedifferentiated to a proliferative, nonmyelinating phenotype within the bridges and the recipient denervated CP nerve stump. As donor TIB axons grew across the 3 side-to-side nerve bridges and into the denervated CP nerve, the Schwann cells redifferentiated to the myelinating phenotype. Bridge placement led to an increased mass of hind limb anterior compartment muscles after 4 months of denervation compared with muscles whose CP nerve was not "protected" by bridges. This study describes patterns of donor axon regeneration and myelination in the denervated recipient nerve stump and supports a mechanism where these donor axons sustain a proregenerative state to prevent deterioration in the face of chronic denervation.

  5. Lysophospholipid Receptors Are Differentially Expressed in Rat Terminal Schwann Cells, As Revealed by a Single Cell RT-PCR and In Situ Hybridization

    International Nuclear Information System (INIS)

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

    2006-01-01

    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 (LPA 1 , LPA 2 , LPA 3 , S1P 1 , S1P 2 , S1P 3 , S1P 4 , and S1P 5 ) 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 LPA 3 was expressed only in TSCs, whereas S1P 1 was expressed in TSCs and skeletal muscle, but not in MSCs. Other types of LPL receptor genes, including LPA 1 , S1P 2 , S1P 3 , S1P 4 , were expressed in both types of Schwann cells. None of the LPL receptor gene family showed MSCs-specific expression

  6. 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.

  7. A magnetically responsive nanocomposite scaffold combined with Schwann cells promotes sciatic nerve regeneration upon exposure to magnetic field

    Directory of Open Access Journals (Sweden)

    Liu ZY

    2017-10-01

    Full Text Available Zhongyang Liu,1,* Shu Zhu,1,* Liang Liu,2,* Jun Ge,3,4,* Liangliang Huang,1 Zhen Sun,1 Wen Zeng,5 Jinghui Huang,1 Zhuojing Luo1 1Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, 2Department of Orthopedics, No 161 Hospital of PLA, Wuhan, Hubei, 3Department of Orthopedics, No 323 Hospital of PLA, Xi’an, Shaanxi, 4Department of Anatomy, Fourth Military Medical University, Xi’an, Shaanxi, 5Department of Neurosurgery, Tangdu Hospital, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China *These authors contributed equally to this work Abstract: Peripheral nerve repair is still challenging for surgeons. Autologous nerve transplantation is the acknowledged therapy; however, its application is limited by the scarcity of available donor nerves, donor area morbidity, and neuroma formation. Biomaterials for engineering artificial nerves, particularly materials combined with supportive cells, display remarkable promising prospects. Schwann cells (SCs are the absorbing seeding cells in peripheral nerve engineering repair; however, the attenuated biologic activity restricts their application. In this study, a magnetic nanocomposite scaffold fabricated from magnetic nanoparticles and a biodegradable chitosan–glycerophosphate polymer was made. Its structure was evaluated and characterized. The combined effects of magnetic scaffold (MG with an applied magnetic field (MF on the viability of SCs and peripheral nerve injury repair were investigated. The magnetic nanocomposite scaffold showed tunable magnetization and degradation rate. The MGs synergized with the applied MF to enhance the viability of SCs after transplantation. Furthermore, nerve regeneration and functional recovery were promoted by the synergism of SCs-loaded MGs and MF. Based on the current findings, the combined application of MGs and SCs with applied MF is a promising therapy for the engineering of peripheral

  8. Implanted hair follicle stem cells form Schwann cells that support repair of severed peripheral nerves

    OpenAIRE

    Amoh, Yasuyuki; Li, Lingna; Campillo, Raul; Kawahara, Katsumasa; Katsuoka, Kensei; Penman, Sheldon; Hoffman, Robert M.

    2005-01-01

    The hair follicle bulge area is an abundant, easily accessible source of actively growing, pluripotent adult stem cells. Nestin, a protein marker for neural stem cells, also is expressed in follicle stem cells and their immediate, differentiated progeny. The fluorescent protein GFP, whose expression is driven by the nestin regulatory element in transgenic mice, served to mark the follicle cell fate. The pluripotent nestin-driven GFP stem cells are positive for the stem cell marker CD34 but ne...

  9. 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.

  10. Manipulation of Schwann cell migration across the astrocyte boundary by polysialyltransferase-loaded superparamagnetic nanoparticles under magnetic field

    Directory of Open Access Journals (Sweden)

    Xia B

    2016-12-01

    Full Text Available Bing Xia,* Liangliang Huang,* Lei Zhu, Zhongyang Liu, Teng Ma, Shu Zhu, Jinghui Huang, Zhuojing Luo Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China *These authors contributed equally to this work Abstract: Schwann cell (SC transplantation is an attractive strategy for spinal cord injury (SCI. However, the efficacy of SC transplantation has been limited by the poor migratory ability of SCs in the astrocyte-rich central nervous system (CNS environment and the inability to intermingle with the host astrocyte. In this study, we first magnetofected SCs by polysialyltransferase-functionalized superparamagnetic iron oxide nanoparticles (PST/SPIONs to induce overexpression of polysialylation of neural cell adhesion molecule (PSA-NCAM to enhance SC migration ability, before manipulating the direction of SC migration with the assistance of an applied magnetic field (MF. It was found that magnetofection with PST/SPIONs significantly upregulated the expression of PSA-NCAM in SCs, which significantly enhanced the migration ability of SCs, but without preferential direction in the absence of MF. The number and averaged maximum distance of SCs with PST/SPIONs migrating into the astrocyte domain were significantly enhanced by an applied MF. In a 300 µm row along the astrocyte boundary, the number of SCs with PST/SPIONs migrating into the astrocyte domain under an MF was 2.95 and 6.71 times higher than that in the absence of MF and the intact control SCs, respectively. More interestingly, a confrontation assay demonstrated that SCs with PST/SPIONs were in close contact with astrocytes and no longer formed boundaries in the presence of MF. In conclusion, SCs with PST/SPIONs showed enhanced preferential migration along the axis of a magnetic force, which might be beneficial for the formation of Büngner bands in the CNS. These findings raise the possibilities of enhancing the

  11. 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

  12. Combined effects of rat Schwann cells and 17β-estradiol in a spinal cord injury model.

    Science.gov (United States)

    Namjoo, Zeinab; Moradi, Fateme; Aryanpour, Roya; Piryaei, Abbas; Joghataei, Mohammad Taghi; Abbasi, Yusef; Hosseini, Amir; Hassanzadeh, Sajad; Taklimie, Fatemeh Ranjbar; Beyer, Cordian; Zendedel, Adib

    2018-04-15

    Spinal cord injury (SCI) is a devastating traumatic event which burdens the affected individuals and the health system. Schwann cell (SC) transplantation is a promising repair strategy after SCI. However, a large number of SCs do not survive following transplantation. Previous studies demonstrated that 17β-estradiol (E2) protects different cell types and reduces tissue damage in SCI experimental animal model. In the current study, we evaluated the protective potential of E2 on SCs in vitro and investigated whether the combination of hormonal and SC therapeutic strategy has a better effect on the outcome after SCI. Primary SC cultures were incubated with E2 for 72 h. In a subsequent experiment, thoracic contusion SCI was induced in male rats followed by sustained administration of E2 or vehicle. Eight days after SCI, DiI-labeled SCs were transplanted into the injury epicenter in vehicle and E2-treated animals. The combinatory regimen decreased neurological and behavioral deficits and protected neurons and oligodendrocytes in comparison to vehicle rats. Moreover, E2 and SC significantly decreased the number of Iba-1+ (microglia) and GFAP + cells (astrocyte) in the SCI group. In addition, we found a significant reduction of mitochondrial fission-markers (Fis1) and an increase of fusion-markers (Mfn1 and Mfn2) in the injured spinal cord after E2 and SC treatment. These data demonstrated that E2 protects SCs against hypoxia-induced SCI and improves the survival of transplanted SCs.

  13. In Vitro Analysis of the Role of Schwann Cells on Axonal Degeneration and Regeneration Using Sensory Neurons from Dorsal Root Ganglia.

    Science.gov (United States)

    López-Leal, Rodrigo; Diaz, Paula; Court, Felipe A

    2018-01-01

    Sensory neurons from dorsal root ganglion efficiently regenerate after peripheral nerve injuries. These neurons are widely used as a model system to study degenerative mechanisms of the soma and axons, as well as regenerative axonal growth in the peripheral nervous system. This chapter describes techniques associated to the study of axonal degeneration and regeneration using explant cultures of dorsal root ganglion sensory neurons in vitro in the presence or absence of Schwann cells. Schwann cells are extremely important due to their involvement in tissue clearance during axonal degeneration as well as their known pro-regenerative effect during regeneration in the peripheral nervous system. We describe methods to induce and study axonal degeneration triggered by axotomy (mechanical separation of the axon from its soma) and treatment with vinblastine (which blocks axonal transport), which constitute clinically relevant mechanical and toxic models of axonal degeneration. In addition, we describe three different methods to evaluate axonal regeneration using quantitative methods. These protocols constitute a valuable tool to analyze in vitro mechanisms associated to axonal degeneration and regeneration of sensory neurons and the role of Schwann cells in these processes.

  14. Electroactive biodegradable polyurethane significantly enhanced Schwann cells myelin gene expression and neurotrophin secretion for peripheral nerve tissue engineering.

    Science.gov (United States)

    Wu, Yaobin; Wang, Ling; Guo, Baolin; Shao, Yongpin; Ma, Peter X

    2016-05-01

    Myelination of Schwann cells (SCs) is critical for the success of peripheral nerve regeneration, and biomaterials that can promote SCs' neurotrophin secretion as scaffolds are beneficial for nerve repair. Here we present a biomaterials-approach, specifically, a highly tunable conductive biodegradable flexible polyurethane by polycondensation of poly(glycerol sebacate) and aniline pentamer, to significantly enhance SCs' myelin gene expression and neurotrophin secretion for peripheral nerve tissue engineering. SCs are cultured on these conductive polymer films, and the biocompatibility of these films and their ability to enhance myelin gene expressions and sustained neurotrophin secretion are successfully demonstrated. The mechanism of SCs' neurotrophin secretion on conductive films is demonstrated by investigating the relationship between intracellular Ca(2+) level and SCs' myelination. Furthermore, the neurite growth and elongation of PC12 cells are induced by adding the neurotrophin medium suspension produced from SCs-laden conductive films. These data suggest that these conductive degradable polyurethanes that enhance SCs' myelin gene expressions and sustained neurotrophin secretion perform great potential for nerve regeneration applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Skin derived precursor Schwann cell-generated acellular matrix modified chitosan/silk scaffolds for bridging rat sciatic nerve gap.

    Science.gov (United States)

    Zhu, Changlai; Huang, Jing; Xue, Chengbin; Wang, Yaxian; Wang, Shengran; Bao, Shuangxi; Chen, Ruyue; Li, Yuan; Gu, Yun

    2017-12-27

    Extracellular/acellular matrix has been attracted much research interests for its unique biological characteristics, and ACM modified neural scaffolds shows the remarkable role of promoting peripheral nerve regeneration. In this study, skin-derived precursors pre-differentiated into Schwann cells (SKP-SCs) were used as parent cells to generate acellular(ACM) for constructing a ACM-modified neural scaffold. SKP-SCs were co-cultured with chitosan nerve guidance conduits (NGC) and silk fibroin filamentous fillers, followed by decellularization to stimulate ACM deposition. This NGC-based, SKP-SC-derived ACM-modified neural scaffold was used for bridging a 10 mm long rat sciatic nerve gap. Histological and functional evaluation after grafting demonstrated that regenerative outcomes achieved by this engineered neural scaffold were better than those achieved by a plain chitosan-silk fibroin scaffold, and suggested the benefits of SKP-SC-derived ACM for peripheral nerve repair. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

  16. Effect of platelet-rich plasma (PRP) concentration on proliferation, neurotrophic function and migration of Schwann cells in vitro.

    Science.gov (United States)

    Zheng, Canbin; Zhu, Qingtang; Liu, Xiaolin; Huang, Xijun; He, Caifeng; Jiang, Li; Quan, Daping; Zhou, Xiang; Zhu, Zhaowei

    2016-05-01

    Platelet-rich plasma (PRP) contains various growth factors and appears to have the potential to promote peripheral nerve regeneration, but evidence is lacking regarding its biological effect on Schwann cells (SCs). The present study was designed to investigate the effect of PRP concentration on SCs in order to determine the plausibility of using this plasma-derived therapy for peripheral nerve injury. PRP was obtained from rats by double-step centrifugation and was characterized by determining platelet numbers and growth factor concentrations. Primary cultures of rat SCs were exposed to various concentrations of PRP (40%, 20%, 10%, 5% and 2.5%). Cell proliferation assays and flow cytometry were performed to study to assess SC proliferation. Quantitative real-time PCR and ELISA analysis were performed to determine the ability of PRP to induce SCs to produce nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF). Microchemotaxis assay was used to analyse the cell migration capacity. The results obtained indicated that the platelet concentration and growth factors in our PRP preparations were significantly higher than in whole blood. Cell culture experiments showed that 2.5-20% PRP significantly stimulated SC proliferation and migration compared to untreated controls in a dose-dependent manner. In addition, the expression and secretion of NGF and GDNF were significantly increased. However, the above effects of SCs were suppressed by high PRP concentrations (40%). In conclusion, the appropriate concentration of PRP had the potency to stimulate cell proliferation, induced the synthesis of neurotrophic factors and significantly increased migration of SCs dose-dependently. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.

  17. Curcumin accelerates the repair of sciatic nerve injury in rats through reducing Schwann cells apoptosis and promoting myelinization.

    Science.gov (United States)

    Zhao, Zhiwei; Li, Xiaoling; Li, Qing

    2017-08-01

    Schwann cells (SCs) play an indispensable role in the repair and regeneration of injured peripheral nerve. Curcumin can reduce SCs apoptosis, and promote the regeneration and functional recovery of injured peripheral nerves. However, the corresponding mechanisms are not clear. The article was aimed to explore the effect and corresponding mechanisms of curcumin on the repair of sciatic nerve injury in rats. After surgery induced sciatic nerve injury, the model rats were divided into three groups and treated with curcumin, curcumin+PD98059 and curcumin+IGF-1 respectively for 4days. The phosphorylation of Erk1/2 and Akt, and the expression of LC3-II, Beclin 1 and p62 were measured using western blotting. After treatment for 60days, myelination of the injured sciatic nerve was evaluated by MBP immunohistochemical staining and the expression of PMP22, Fibrin and S100 were determined using qRT-PCR and western blotting. In vitro, RSC96 cells were starved for 12h to induce autophagy, and received DMSO, curcumin, PD98059+curcumin, IGF-1+curcumin and BFA1 respectively. The phosphorylation of Erk1/2、Akt and the expression of LC3-II, Beclin 1, p62, PMP22, Fibrin and S100 were measured using western blotting, and the cell apoptosis was detected by flow cytometry. Curcumin could promote injury-induced cell autophagy, remyelination and axon regeneration in sciatic nerve of rats. In vitro, curcumin could accelerate cell autophagy through regulating autophagy related Erk1/2 and Akt pathway, prevent cell apoptosis and promote expression of PMP22 and S100, and reduced deposition of Fibrin in cultured RSC96 SCs. Curcumin could accelerate injured sciatic nerve repair in rats through reducing SCs apoptosis and promoting myelinization. Copyright © 2017. Published by Elsevier Masson SAS.

  18. Single-walled carbon nanotubes alter Schwann cell behavior differentially within 2D and 3D environments.

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    Behan, Brenda L; DeWitt, Daniel G; Bogdanowicz, Danielle R; Koppes, Abigail N; Bale, Shyam S; Thompson, Deanna M

    2011-01-01

    Both spinal cord injury (SCI) and large-gap peripheral nerve defects can be debilitating affecting a patient's long-term quality of life and presently, there is no suitable treatment for functional regeneration of these injured tissues. A number of works have suggested the benefits of electrical stimulation to promote both glial migration and neuronal extension. In this work, an electrically conductive hydrogel containing single-walled carbon nanotubes (SWCNT) for neural engineering applications is presented and the Schwann cell (SC) response to SWCNT is examined in both 2D and 3D microenvironments. Results from clonogenic and alamarBlue® assays in 2D indicate that SWCNT (10-50 μg mL(-1)) inhibit SC proliferation but do not affect cell viability. Following SWCNT exposure in 2D, changes in SC morphology can be observed with the nanomaterial attached to the cell membrane at concentrations as low as 10 μg mL(-1). In contrast to the results gathered in 2D, SC embedded within the 3D hydrogel loaded with 10-50 μg mL(-1) of SWCNT exhibited little or no measurable change in cell proliferation, viability, or morphology as assessed using a digestion assay, alamarBlue, and confocal microscopy. Collectively, this highlights that an electrically-conductive SWCNT collagen I-Matrigel™ biomaterial may be suitable for neural tissue engineering and is able to sustain populations of SC. Findings suggest that 2D nanoparticle toxicity assays may not be accurate predictors of the 3D response, further motivating the examination of these materials in a more physiologically relevant environment. Copyright © 2010 Wiley Periodicals, Inc.

  19. 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

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    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

  20. Expression analysis of the N-Myc downstream-regulated gene 1 indicates that myelinating Schwann cells are the primary disease target in hereditary motor and sensory neuropathy-Lom.

    Science.gov (United States)

    Berger, Philipp; Sirkowski, Erich E; Scherer, Steven S; Suter, Ueli

    2004-11-01

    Mutations in the gene encoding N-myc downstream-regulated gene-1 (NDRG1) lead to truncations of the encoded protein and are associated with an autosomal recessive demyelinating neuropathy--hereditary motor and sensory neuropathy-Lom. NDRG1 protein is highly expressed in peripheral nerve and is localized in the cytoplasm of myelinating Schwann cells, including the paranodes and Schmidt-Lanterman incisures. In contrast, sensory and motor neurons as well as their axons lack NDRG1. NDRG1 mRNA levels in developing and injured adult sciatic nerves parallel those of myelin-related genes, indicating that the expression of NDRG1 in myelinating Schwann cells is regulated by axonal interactions. Oligodendrocytes also express NDRG1, and the subtle CNS deficits of affected patients may result from a lack of NDRG1 in these cells. Our data predict that the loss of NDRG1 leads to a Schwann cell autonomous phenotype resulting in demyelination, with secondary axonal loss.

  1. Transplantation of bone-marrow-derived cells into a nerve guide resulted in transdifferentiation into Schwann cells and effective regeneration of transected mouse sciatic nerve.

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    Pereira Lopes, Fátima Rosalina; Frattini, Flávia; Marques, Suelen Adriani; Almeida, Fernanda Martins de; de Moura Campos, Lenira Camargo; Langone, Francesco; Lora, Silvano; Borojevic, Radovan; Martinez, Ana Maria Blanco

    2010-10-01

    Peripheral nerves possess the capacity of self-regeneration after traumatic injury. Nevertheless, the functional outcome after peripheral-nerve regeneration is often poor, especially if the nerve injuries occur far from their targets. Aiming to optimize axon regeneration, we grafted bone-marrow-derived cells (BMDCs) into a collagen-tube nerve guide after transection of the mouse sciatic nerve. The control group received only the culture medium. Motor function was tested at 2, 4, and 6 weeks after surgery, using the sciatic functional index (SFI), and showed that functional recovery was significantly improved in animals that received the cell grafts. After 6 weeks, the mice were anesthetized, perfused transcardially, and the sciatic nerves were dissected and processed for transmission electron microscopy and light microscopy. The proximal and distal segments of the nerves were compared, to address the question of improvement in growth rate; the results revealed a maintenance and increase of nerve regeneration for both myelinated and non-myelinated fibers in distal segments of the experimental group. Also, quantitative analysis of the distal region of the regenerating nerves showed that the numbers of myelinated fibers, Schwann cells (SCs) and g-ratio were significantly increased in the experimental group compared to the control group. The transdifferentiation of BMDCs into Schwann cells was confirmed by double labeling with S100/and Hoechst staining. Our data suggest that BMDCs transplanted into a nerve guide can differentiate into SCs, and improve the growth rate of nerve fibers and motor function in a transected sciatic-nerve model.

  2. p75 neurotrophin receptor positive dental pulp stem cells: new hope for patients with neurodegenerative disease and neural injury.

    Science.gov (United States)

    Dai, Jie-wen; Yuan, Hao; Shen, Shun-yao; Lu, Jing-ting; Zhu, Xiao-fang; Yang, Tong; Zhang, Jiang-fei; Shen, Guo-fang

    2013-08-01

    Neurodegenerative diseases and neural injury are 2 of the most feared disorders that afflict humankind by leading to permanent paralysis and loss of sensation. Cell based treatment for these diseases had gained special interest in recent years. Previous studies showed that dental pulp stem cells (DPSCs) could differentiate toward functionally active neurons both in vitro and in vivo, and could promote neuranagenesis through both cell-autonomous and paracrine neuroregenerative activities. Some of these neuroregenerative activities were unique to tooth-derived stem cells and superior to bone marrow stromal cells. However, DPSCs used in most of these studies were mixed and unfractionated dental pulp cells that contain several types of cells, and most were fibroblast cells while just contain a small portion of DPSCs. Thus, there might be weaker ability of neuranagenesis and more side effects from the fibroblast cells that cannot differentiate into neural cells. p75 neurotrophin receptor (p75NTR) positive DPSCs subpopulation was derived from migrating cranial neural crest cells and had been isolated from DPSCs, which had capacity of differentiation into neurons and repairing neural system. In this article, we hypothesize that p75NTR positive DPSCs simultaneously have greater propensity for neuronal differentiation and fewer side effects from fibroblast, and in vivo transptantation of autologous p75NTR positive DPSCs is a novel method for neuranagenesis. This will bring great hope to patients with neurodegenerative disease and neural injury.

  3. Combining neurotrophin-transduced schwann cells and rolipram to promote functional recovery from subacute spinal cord injury.

    Science.gov (United States)

    Flora, Govinder; Joseph, Gravil; Patel, Samik; Singh, Amanpreet; Bleicher, Drew; Barakat, David J; Louro, Jack; Fenton, Stephanie; Garg, Maneesh; Bunge, Mary Bartlett; Pearse, Damien D

    2013-01-01

    Following spinal cord injury (SCI), both an inhibitory environment and lack of intrinsic growth capacity impede axonal regeneration. In a previous study, prevention of cyclic adenosine monophosphate (AMP) hydrolysis by the phosphodiesterase-4 inhibitor rolipram, in combination with Schwann cell (SC) grafts, promoted significant supraspinal and proprioceptive fiber growth and/or sparing and improved locomotion. In another study, transplanted SCs transduced to generate a bifunctional neurotrophin (D15A) led to significant increases in graft SCs and axons, including supraspinal and myelinated axons. Here we studied the growth and myelination of local and supraspinal axons and functional outcome following the combination of rolipram administration and neurotrophin-transduced SC implantation after SCI. Rolipram was administered subcutaneously for 4 weeks immediately after contusion at vertebral T8 (25.0-mm weight drop, MASCIS impactor). GFP or GFP-D15A-transduced SCs were injected into the injury epicenter 1 week after SCI. GFP-D15A SC grafts and GFP SC grafts with rolipram contained significantly more serotonergic fibers compared to GFP SCs. SC myelinated axons were increased significantly in GFP SC with rolipram-treated animals compared to animals receiving SCI alone. Rolipram administered with either GFP or GFP-D15A SCs significantly increased numbers of brain stem-derived axons below the lesion/implant area and improved hindlimb function. Compared to the single treatments, the combination led to the largest SC grafts, the highest numbers of serotonergic fibers in the grafts, and increased numbers of axons from the reticular formation below the lesion/implant area and provided the greatest improvement in hindlimb function. These findings demonstrate the therapeutic potential for a combination therapy involving the maintenance of cyclic AMP levels and neurotrophin-transduced SCs to repair the subacutely injured spinal cord.

  4. Polyurethane/Gelatin Nanofibrils Neural Guidance Conduit Containing Platelet-Rich Plasma and Melatonin for Transplantation of Schwann Cells.

    Science.gov (United States)

    Salehi, Majid; Naseri-Nosar, Mahdi; Ebrahimi-Barough, Somayeh; Nourani, Mohammdreza; Khojasteh, Arash; Farzamfar, Saeed; Mansouri, Korosh; Ai, Jafar

    2018-04-01

    The current study aimed to enhance the efficacy of peripheral nerve regeneration using a biodegradable porous neural guidance conduit as a carrier to transplant allogeneic Schwann cells (SCs). The conduit was prepared from polyurethane (PU) and gelatin nanofibrils (GNFs) using thermally induced phase separation technique and filled with melatonin (MLT) and platelet-rich plasma (PRP). The prepared conduit had the porosity of 87.17 ± 1.89%, the contact angle of 78.17 ± 5.30° and the ultimate tensile strength and Young's modulus of 5.40 ± 0.98 MPa and 3.13 ± 0.65 GPa, respectively. The conduit lost about 14% of its weight after 60 days in distilled water. The produced conduit enhanced the proliferation of SCs demonstrated by a tetrazolium salt-based assay. For functional analysis, the conduit was seeded with 1.50 × 10 4 SCs (PU/GNFs/PRP/MLT/SCs) and implanted into a 10-mm sciatic nerve defect of Wistar rat. Three control groups were used: (1) PU/GNFs/SCs, (2) PU/GNFs/PRP/SCs, and (3) Autograft. The results of sciatic functional index, hot plate latency, compound muscle action potential amplitude and latency, weight-loss percentage of wet gastrocnemius muscle and histopathological examination using hematoxylin-eosin and Luxol fast blue staining, demonstrated that using the PU/GNFs/PRP/MLT conduit to transplant SCs to the sciatic nerve defect resulted in a higher regenerative outcome than the PU/GNFs and PU/GNFs/PRP conduits.

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

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    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.

  6. Electrical Stimulation of Schwann Cells Promotes Sustained Increases in Neurite Outgrowth

    OpenAIRE

    Koppes, Abigail N.; Nordberg, Andrea L.; Paolillo, Gina M.; Goodsell, Nicole M.; Darwish, Haley A.; Zhang, Linxia; Thompson, Deanna M.

    2013-01-01

    Endogenous electric fields are instructive during embryogenesis by acting to direct cell migration, and postnatally, they can promote axonal growth after injury (McCaig 1991, Al-Majed 2000). However, the mechanisms for these changes are not well understood. Application of an appropriate electrical stimulus may increase the rate and success of nerve repair by directly promoting axonal growth. Previously, DC electrical stimulation at 50 mV/mm (1 mA, 8 h duration) was shown to promote neurite ou...

  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. Adult DRG Stem/Progenitor Cells Generate Pericytes in the Presence of Central Nervous System (CNS) Developmental Cues, and Schwann Cells in Response to CNS Demyelination.

    Science.gov (United States)

    Vidal, Marie; Maniglier, Madlyne; Deboux, Cyrille; Bachelin, Corinne; Zujovic, Violetta; Baron-Van Evercooren, Anne

    2015-06-01

    It has been proposed that the adult dorsal root ganglia (DRG) harbor neural stem/progenitor cells (NPCs) derived from the neural crest. However, the thorough characterization of their stemness and differentiation plasticity was not addressed. In this study, we investigated adult DRG-NPC stem cell properties overtime, and their fate when ectopically grafted in the central nervous system. We compared them in vitro and in vivo to the well-characterized adult spinal cord-NPCs derived from the same donors. Using micro-dissection and neurosphere cultures, we demonstrate that adult DRG-NPCs have quasi unlimited self-expansion capacities without compromising their tissue specific molecular signature. Moreover, they differentiate into multiple peripheral lineages in vitro. After transplantation, adult DRG-NPCs generate pericytes in the developing forebrain but remyelinating Schwann cells in response to spinal cord demyelination. In addition, we show that axonal and endothelial/astrocytic factors as well astrocytes regulate the fate of adult DRG-NPCs in culture. Although the adult DRG-NPC multipotency is restricted to the neural crest lineage, their dual responsiveness to developmental and lesion cues highlights their impressive adaptive and repair potentials making them valuable targets for regenerative medicine. © 2015 AlphaMed Press.

  9. 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

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

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    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.

  11. Formation and function of synapses with respect to Schwann cells at the end of motor nerve terminal branches on mature amphibian (Bufo marinus) muscle.

    Science.gov (United States)

    Macleod, G T; Dickens, P A; Bennett, M R

    2001-04-01

    A study has been made of the formation and regression of synapses with respect to Schwann cells at the ends of motor nerve terminal branches in mature toad (Bufo marinus) muscle. Synapse formation and regression, as inferred from the appearance and loss of N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide (FM1-43)-stained vesicle clusters, occurred at the ends of terminal branches over a 16 hr period. Multiple microelectrodes placed in an array about FM1-43 blobs at the ends of terminal branches detected the electrical signs of neurotransmitter being released onto receptors. Injection of a calcium indicator (Oregon Green 488 BAPTA-1) into the motor nerve with subsequent imaging of the calcium transients, in response to stimulation, often showed a reduced calcium influx in the ends of terminal branches. Injection of a fluorescent dye into motor nerves revealed the full extent of their terminal branches and growing processes. Injection of the terminal Schwann cells (TSCs) often revealed pseudopodial TSC processes up to 10-microm-long. Imaging of these TSC processes over minutes or hours showed that they were highly labile and capable of extending several micrometers in a few minutes. Injection of motor nerve terminals with a different dye to that injected into their TSCs revealed that terminal processes sometimes followed the TSC processes over a few hours. It is suggested that the ends of motor nerve terminals in vivo are in a constant state of remodeling through the formation and regression of processes, that TSC processes guide the remodeling, and that it can occur over a relatively short period of time.

  12. 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

  13. S100ß and fibroblast growth factor-2 are present in cultured Schwann cells and may exert paracrine actions on the peripheral nerve injury S100ß e fator de crescimento de fibroblasto-2 estão presentes nas células de Schwann cultivadas e exercem ações parácrinas na lesão do nervo

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    Tatiana Duobles

    2008-12-01

    Full Text Available 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 treatment of central nervous system lesions, in special the spinal cord injury, a procedure that triggers an enhanced sensorymotor function. Those cells have been proposed to repair long gap nerve injury. METHODS: Here we used double labeling immunohistochemistry and Western blot to better characterize in vitro and in vivo the presence of the proteins in the Schwann cells and in the satellite cells of the DRG as well as their regulation in those cells after a crush of the rat sciatic nerve. RESULTS: FGF-2 and S100ß are present in the Schwann cells of the sciatic nerve and in the satellite cells of the DRG. S100ß positive satellite cells showed increased size of the axotomized DRG and possessed elevated amount of FGF-2 immunoreactivity. Reactive satellite cells with increased FGF-2 labeling formed a ring-like structure surrounding DRG neuronal cell bodies.Reactive S100ß positive Schwann cells of proximal stump of axotomized sciatic nerve also expressed higher amounts of FGF-2. CONCLUSION: Reactive peripheral glial cells synthesizing FGF-2 and S100ß may be important in wound repair and restorative events in the lesioned peripheral nerves.OBJETIVO: O fator neurotrófico fator de crescimento de fibroblastos-2 (FGF-2, bFGF e a proteína ligante de Ca++ S100ß são expressos pelas células de Schwann dos nervos e por células satélites do gânglio da raiz dorsal (GRD. Estudos recentes indicam a importância das moléculas nos mecanismos parácrinos relacionados

  14. 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.

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

    Science.gov (United States)

    Mesentier-Louro, Louise A; De Nicolò, Sara; Rosso, Pamela; De Vitis, Luigi A; Castoldi, Valerio; Leocani, Letizia; Mendez-Otero, Rosalia; Santiago, Marcelo F; Tirassa, Paola; Rama, Paolo; Lambiase, Alessandro

    2017-01-05

    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, p75 NTR , 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 p75 NTR enhancement. In contrast, ONC-induced reduction of TrkA, and increased proNGF were observed only at 7 and 14 dac. We propose that proNGF and p75 NTR 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.

  16. 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

  17. Short-term low-frequency electrical stimulation enhanced remyelination of injured peripheral nerves by inducing the promyelination effect of brain-derived neurotrophic factor on Schwann cell polarization.

    Science.gov (United States)

    Wan, Lidan; Xia, Rong; Ding, Wenlong

    2010-09-01

    Electrical stimulation (ES) has been found to aid repair of nerve injuries and have been shown to increase and direct neurite outgrowth during stimulation. However, the effect of ES on peripheral remyelination after nerve damage has been investigated less well, and the mechanism underlying its action remains unclear. In the present study, the crush-injured sciatic nerves in rats were subjected to 1 hr of continuous ES (20 Hz, 100 microsec, 3 V). Electron microscopy and nerve morphometry were performed to investigate the extent of regenerated nerve myelination. The expression profiles of P0, Par-3, and brain-derived neurotrophic factor (BDNF) in the injuried sciatic nerves and in the dorsal root ganglion neuron/Schwann cell cocultures were examined by Western blotting. Par-3 localization in the sciatic nerves was determined by immunohistochemistry to demonstrate Schwann cell polarization during myelination. We reported that 20-Hz ES increased the number of myelinated fibers and the thickness myelin sheath at 4 and 8 weeks postinjury. P0 level in the ES-treated groups, both in vitro and in vivo, was enhanced compared with the controls. The earlier peak of Par-3 in the ES-treated groups indicated an earlier initiation of Schwann cell myelination. Additionally, ES significantly elevated BDNF expression in nerve tissues and in cocultures. ES on the site of nerve injury potentiates axonal regrowth and myelin maturation during peripheral nerve regeneration. Furthermore, the therapeutic actions of ES on myelination are mediated via enhanced BDNF signals, which drive the promyelination effect on Schwann cells at the onset of myelination.

  18. Loss-of-Function Mutations in LGI4, a Secreted Ligand Involved in Schwann Cell Myelination, Are Responsible for Arthrogryposis Multiplex Congenita.

    Science.gov (United States)

    Xue, Shifeng; Maluenda, Jérôme; Marguet, Florent; Shboul, Mohammad; Quevarec, Loïc; Bonnard, Carine; Ng, Alvin Yu Jin; Tohari, Sumanty; Tan, Thong Teck; Kong, Mung Kei; Monaghan, Kristin G; Cho, Megan T; Siskind, Carly E; Sampson, Jacinda B; Rocha, Carolina Tesi; Alkazaleh, Fawaz; Gonzales, Marie; Rigonnot, Luc; Whalen, Sandra; Gut, Marta; Gut, Ivo; Bucourt, Martine; Venkatesh, Byrappa; Laquerrière, Annie; Reversade, Bruno; Melki, Judith

    2017-04-06

    Arthrogryposis multiplex congenita (AMC) is a developmental condition characterized by multiple joint contractures resulting from reduced or absent fetal movements. Through genetic mapping of disease loci and whole-exome sequencing in four unrelated multiplex families presenting with severe AMC, we identified biallelic loss-of-function mutations in LGI4 (leucine-rich glioma-inactivated 4). LGI4 is a ligand secreted by Schwann cells that regulates peripheral nerve myelination via its cognate receptor ADAM22 expressed by neurons. Immunolabeling experiments and transmission electron microscopy of the sciatic nerve from one of the affected individuals revealed a lack of myelin. Functional tests using affected individual-derived iPSCs showed that these germline mutations caused aberrant splicing of the endogenous LGI4 transcript and in a cell-based assay impaired the secretion of truncated LGI4 protein. This is consistent with previous studies reporting arthrogryposis in Lgi4-deficient mice due to peripheral hypomyelination. This study adds to the recent reports implicating defective axoglial function as a key cause of AMC. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  19. SorCS2 Regulates Dopaminergic Wiring and Is Processed into an Apoptotic Two-Chain Receptor in Peripheral Glia

    DEFF Research Database (Denmark)

    Glerup, Simon; Olsen, Ditte; Vægter, Christian Bjerggaard

    2014-01-01

    Balancing trophic and apoptotic cues is critical for development and regeneration of neuronal circuits. Here we identify SorCS2 as a proneurotrophin (proNT) receptor, mediating both trophic and apoptotic signals in conjunction with p75NTR. CNS neurons, but not glia, express SorCS2 as a single-chain...... behavioral response to amphetamine reminiscent of ADHD. Contrary, in PNS glia, but not in neurons, proteolytic processing produced a two-chain SorCS2 isoform that mediated proNT-dependent Schwann cell apoptosis. Sciatic nerve injury triggered generation of two-chain SorCS2 in p75NTR-positive dying Schwann...... cells, with apoptosis being profoundly attenuated in Sorcs2−/− mice. In conclusion, we have demonstrated that two-chain processing of SorCS2 enables neurons and glia to respond differently to proneurotrophins....

  20. Sugar Composition Analysis of Fuzi Polysaccharides by HPLC-MSn and Their Protective Effects on Schwann Cells Exposed to High Glucose

    Directory of Open Access Journals (Sweden)

    Bei-Bei Wang

    2016-11-01

    Full Text Available Fuzi has been used to treat diabetic complications for many years in china. In a previous study, we have shown that Fuzi aqueous extract can attenuate Diabetic peripheral neuropathy (DPN in rats and protect Schwann cells from injury. Thus, the protective effect of Fuzi polysaccharides (FPS on high glucose-induced SCs and the preliminary mechanism were investigated. Firstly, the FPS were obtained and their monose composition was analyzed by the combination of pre-column derivatization and high performance liquid chromatography coupled with electrospray ionization multi-tandem mass spectrometry (HPLC/ESI-MSn. The results witnessed the efficiency of this method and seven monosaccharides were tentatively identified, among which fucose was first reported. Simultaneously, m/z 215 can be considered as diagnostic ions to confirm the number of monosaccharides. Next, high glucose-induced SC model was applied and divided into model group, treated group of FPS, normal and osmotic control group. After treatment for 48 h, the data showed FPS could significantly decrease the intracellular ROS and apoptosis, which were determined by the corresponding fluorescent probes. Then, the expression of oxidative stress-related proteins in SCs were measured by Western blot. Furthermore, the protein tests found that FPS markedly up-regulated superoxide dismutase (SOD, catalase (CAT and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α protein level, but down-regulated NADPH oxidase-1 (Nox1 protein level. Moreover, FPS could also increase AMP-activated protein kinase (AMPK activation significantly. Hence, we preliminary deduced that AMPK-PGC-1α pathway may play an important role in the protective effect of FPS against high glucose-induced cell damage.

  1. 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.

    Science.gov (United States)

    Luo, Lihua; Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan; Wang, Xiong; Huselstein, Celine; Chen, Yun

    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

  2. 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.

  3. Characterization of p75+ ectomesenchymal stem cells from rat embryonic facial process tissue

    International Nuclear Information System (INIS)

    Wen, Xiujie; Liu, Luchuan; Deng, Manjing; Zhang, Li; Liu, Rui; Xing, Yongjun; Zhou, Xia; Nie, Xin

    2012-01-01

    Highlights: ► Ectomesenchymal stem cells (EMSCs) were found to migrate to rat facial processes at E11.5. ► We successfully sorted p75NTR positive EMSCs (p75 + EMSCs). ► p75 + EMSCs up to nine passages showed relative stable proliferative activity. ► We examined the in vitro multilineage potential of p75 + EMSCs. ► p75 + 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 + 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 + 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.

  4. 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

    2018-05-01

    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, 106B: 1463-1476, 2018. © 2017 Wiley Periodicals, Inc.

  5. 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.

  6. Involvement of brain-derived neurotrophic factor (BDNF) in the functional elimination of synaptic contacts at polyinnervated neuromuscular synapses during development.

    Science.gov (United States)

    Garcia, N; Santafe, M M; Tomàs, M; Lanuza, M A; Besalduch, N; Tomàs, J

    2010-05-15

    We use immunohistochemistry to describe the localization of brain-derived neurotrophic factor (BDNF) and its receptors trkB and p75(NTR) in the neuromuscular synapses of postnatal rats (P6-P7) during the synapse elimination period. The receptor protein p75(NTR) is present in the nerve terminal, muscle cell and glial Schwann cell whereas BDNF and trkB proteins can be detected mainly in the pre- and postsynaptic elements. Exogenously applied BDNF (10 nM for 3 hr or 50 nM for 1 hr) increases ACh release from singly and dually innervated synapses. This effect may be specific for BDNF because the neurotrophin NT-4 (2-8 nM) does not modulate release at P6-P7. Blocking the receptors trkB and p75(NTR) (with K-252a and anti-p75-192-IgG, respectively) completely abolishes the potentiating effect of exogenous BDNF. In addition, exogenous BDNF transiently recruits functionally depressed silent terminals, and this effect seems to be mediated by trkB. Calcium ions, the L-type voltage-dependent calcium channels and protein kinase C are involved in BDNF-mediated nerve ending recruitment. Blocking experiments suggest that endogenous BDNF could operate through p75(NTR) receptors coupled to potentiate ACh release in all nerve terminals because the anti-p75-192-IgG reduces release. However, blocking the trkB receptor (K-252a) or neutralizing endogenous BDNF with the trkB-IgG fusion protein reveals a trkB-mediated release inhibition on almost mature strong endings in dual junctions. Taken together these results suggest that a BDNF-induced p75(NTR)-mediated ACh release potentiating mechanism and a BDNF-induced trkB-mediated release inhibitory mechanism may contribute to developmental synapse disconnection. (c) 2009 Wiley-Liss, Inc.

  7. p75 Neurotrophin Receptor Signaling Activates Sterol Regulatory Element-binding Protein-2 in Hepatocyte Cells via p38 Mitogen-activated Protein Kinase and Caspase-3.

    Science.gov (United States)

    Pham, Dan Duc; Do, Hai Thi; Bruelle, Céline; Kukkonen, Jyrki P; Eriksson, Ove; Mogollón, Isabel; Korhonen, Laura T; Arumäe, Urmas; Lindholm, Dan

    2016-05-13

    Nerve growth factor (NGF) influences the survival and differentiation of a specific population of neurons during development, but its role in non-neuronal cells has been less studied. We observed here that NGF and its pro-form, pro-NGF, are elevated in fatty livers from leptin-deficient mice compared with controls, concomitant with an increase in low density lipoprotein receptors (LDLRs). Stimulation of mouse primary hepatocytes with NGF or pro-NGF increased LDLR expression through the p75 neurotrophin receptor (p75NTR). Studies using Huh7 human hepatocyte cells showed that the neurotrophins activate the sterol regulatory element-binding protein-2 (SREBP2) that regulates genes involved in lipid metabolism. The mechanisms for this were related to stimulation of p38 mitogen-activated protein kinase (p38 MAPK) and activation of caspase-3 and SREBP2 cleavage following NGF and pro-NGF stimulations. Cell fractionation experiments showed that caspase-3 activity was increased particularly in the membrane fraction that harbors SREBP2 and caspase-2. Experiments showed further that caspase-2 interacts with pro-caspase-3 and that p38 MAPK reduced this interaction and caused caspase-3 activation. Because of the increased caspase-3 activity, the cells did not undergo cell death following p75NTR stimulation, possibly due to concomitant activation of nuclear factor-κB (NF-κB) pathway by the neurotrophins. These results identify a novel signaling pathway triggered by ligand-activated p75NTR that via p38 MAPK and caspase-3 mediate the activation of SREBP2. This pathway may regulate LDLRs and lipid uptake particularly after injury or during tissue inflammation accompanied by an increased production of growth factors, including NGF and pro-NGF. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. 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

  9. A new sodium channel {alpha}-subunit gene (Scn9a) from Schwann cells maps to the Scn1a, Scn2a, Scn3a cluster of mouse chromosome 2

    Energy Technology Data Exchange (ETDEWEB)

    Beckers, M.C.; Ernst, E.; Gros, P. [McGill Univ., Montreal (Canada)

    1996-08-15

    We have used a total of 27 AXB/BXA recombinant inbred mouse strains to determine the chromosomal location of a newly identified gene encoding an {alpha}-subunit isoform of the sodium channel from Schwann cells, Scn9a. Linkage analysis established that Scn9a mapped to the proximal segment of mouse chromosome 2. The segregation of restriction fragment length polymorphisms in 145 progeny from a Mus spretus x C57BL/6J backcross indicates that Scn9a is very tightly linked to Scn1a (gene encoding the type I sodium channel {alpha}-subunit of the brain) and forms part of a cluster of four Scna genes located on mouse chromosome 2. 17 refs., 1 fig., 3 tabs.

  10. 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...... 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....

  11. The p75 neurotrophin receptor: at the crossroad of neural repair and death

    Science.gov (United States)

    Meeker, Rick B.; Williams, Kimberly S.

    2015-01-01

    The strong repair and pro-survival functions of neurotrophins at their primary receptors, TrkA, TrkB and TrkC, have made them attractive candidates for treatment of nervous system injury and disease. However, difficulties with the clinical implementation of neurotrophin therapies have prompted the search for treatments that are stable, easier to deliver and allow more precise regulation of neurotrophin actions. Recently, the p75 neurotrophin receptor (p75NTR) has emerged as a potential target for pharmacological control of neurotrophin activity, supported in part by studies demonstrating 1) regulation of neural plasticity in the mature nervous system, 2) promotion of adult neurogenesis and 3) increased expression in neurons, macrophages, microglia, astrocytes and/or Schwann cells in response to injury and neurodegenerative diseases. Although the receptor has no intrinsic catalytic activity it interacts with and modulates the function of TrkA, TrkB, and TrkC, as well as sortilin and the Nogo receptor. This provides substantial cellular and molecular diversity for regulation of neuron survival, neurogenesis, immune responses and processes that support neural function. Upregulation of the p75NTR under pathological conditions places the receptor in a key position to control numerous processes necessary for nervous system recovery. Support for this possibility has come from recent studies showing that small, non-peptide p75NTR ligands can selectively modify pro-survival and repair functions. While a great deal remains to be discovered about the wide ranging functions of the p75NTR, studies summarized in this review highlight the immense potential for development of novel neuroprotective and neurorestorative therapies. PMID:26109945

  12. The p75 neurotrophin receptor: at the crossroad of neural repair and death

    Directory of Open Access Journals (Sweden)

    Rick B Meeker

    2015-01-01

    Full Text Available The strong repair and pro-survival functions of neurotrophins at their primary receptors, TrkA, TrkB and TrkC, have made them attractive candidates for treatment of nervous system injury and disease. However, difficulties with the clinical implementation of neurotrophin therapies have prompted the search for treatments that are stable, easier to deliver and allow more precise regulation of neurotrophin actions. Recently, the p75 neurotrophin receptor (p75 NTR has emerged as a potential target for pharmacological control of neurotrophin activity, supported in part by studies demonstrating 1 regulation of neural plasticity in the mature nervous system, 2 promotion of adult neurogenesis and 3 increased expression in neurons, macrophages, microglia, astrocytes and/or Schwann cells in response to injury and neurodegenerative diseases. Although the receptor has no intrinsic catalytic activity it interacts with and modulates the function of TrkA, TrkB, and TrkC, as well as sortilin and the Nogo receptor. This provides substantial cellular and molecular diversity for regulation of neuron survival, neurogenesis, immune responses and processes that support neural function. Upregulation of the p75 NTR under pathological conditions places the receptor in a key position to control numerous processes necessary for nervous system recovery. Support for this possibility has come from recent studies showing that small, non-peptide p75 NTR ligands can selectively modify pro-survival and repair functions. While a great deal remains to be discovered about the wide ranging functions of the p75 NTR , studies summarized in this review highlight the immense potential for development of novel neuroprotective and neurorestorative therapies.

  13. 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

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

    International Nuclear Information System (INIS)

    Wen, Xiujie; Liu, Luchuan; Deng, Manjing; Liu, Rui; Zhang, Li; Nie, Xin

    2015-01-01

    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 + ) CNCCs, isolated using fluorescence activated cell sorter, exhibited fibroblast-like morphology and characteristics of mesenchymal stem cells. Incubation of p75 + 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 + cells, suggesting their differentiation along cementoblast-like lineage. p75 + 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 + ) CNCCs are fibroblast-like and resemble mesenchymal stem cells. • p75 + CNCCs in dental follicle cell medium (DFCCM/dNCP) appear like cementoblasts. • DFCCM/dNCP-treated p75 + cells express cementoblast specific mineralization markers. • p75 + cells are pure stem

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

    Indian Academy of Sciences (India)

    pounded the cell theory with M Schleiden, had diverse interests. ... (Courtesy: Dr. Vanaja Shetty, The Foundation for Medical Research, Mumbai) ... Role of Schwann Cells in Myelination ... arrangement of microvilli extending from the Schwann cell embedded in the gap matrix ... Schwann cells Regulate Nerve Development.

  16. Kidins220/ARMS depletion is associated with the neural-to Schwann-like transition in a human neuroblastoma cell line model.

    Science.gov (United States)

    Rogers, Danny A; Schor, Nina F

    2013-03-10

    Peripheral neuroblastic tumors exist as a heterogeneous mixture of neuroblastic (N-type) cells and Schwannian stromal (S-type) cells. These stromal cells not only represent a differentiated and less aggressive fraction of the tumor, but also have properties that can influence the further differentiation of nearby malignant cells. In vitro neuroblastoma cultures exhibit similar heterogeneity with N-type and S-type cells representing the neuroblastic and stromal portions of the tumor, respectively, in behavior, morphology, and molecular expression patterns. In this study, we deplete kinase D-interacting substrate of 220kD (Kidins220) with an shRNA construct and thereby cause morphologic transition of the human SH-SY5Y neuroblastoma cell line from N-type to S-type. The resulting cells have similar morphology and expression profile to SH-EP1 cells, a native S-type cell line from the same parent cell line, and to SH-SY5Y cells treated with BrdU, a treatment that induces S-type morphology. Specifically, both Kidins220-deficient SH-SY5Y cells and native SH-EP1 cells demonstrate down-regulation of the genes DCX and STMN2, markers for the neuronal lineage. We further show that Kidins220, DCX and STMN2 are co-down-regulated in cells of S-type morphology generated by methods other than Kidins220 depletion. Finally, we report that the association of low Kidins220 expression with S-type morphology and low DCX and STMN2 expression is demonstrated in spontaneously occurring human peripheral neuroblastic tumors. We propose that Kidins220 is critical in N- to S-type transition of neural crest tumor cells. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Activation of MAPK overrides the termination of myelin growth and replaces Nrg1/ErbB3 signals during Schwann cell development and myelination

    NARCIS (Netherlands)

    M.E. Sheean (Maria); E. McShane (Erik); C. Cheret (Cyril); J. Walcher (Jan); T. Müller (Thomas); A. Wulf-Goldenberg (Annika); S. Hoelper (Soraya); A.N. Garratt (Alistair); M. Krüger (Markus); K. Rajewsky (Klaus); D.N. Meijer (Dies); W. Birchmeier (Walter); G.R. Lewin (Gary); M. Selbach (Matthias); C. Birchmeier (Carmen)

    2014-01-01

    textabstractMyelination depends on the synthesis of large amounts of myelin transcripts and proteins and is controlled by Nrg1/ErbB/Shp2 signaling. We developed a novel pulse labeling strategy based on stable isotope labeling with amino acids in cell culture (SILAC) to measure the dynamics of myelin

  18. 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.

  19. La célula de schwann

    OpenAIRE

    Perdomo, Sandra; Spinel, Clara

    2011-01-01

    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 ...

  20. Quantifying Spiral Ganglion Neurite and Schwann Behavior on Micropatterned Polymer Substrates.

    Science.gov (United States)

    Cheng, Elise L; Leigh, Braden; Guymon, C Allan; Hansen, Marlan R

    2016-01-01

    The first successful in vitro experiments on the cochlea were conducted in 1928 by Honor Fell (Fell, Arch Exp Zellforsch 7(1):69-81, 1928). Since then, techniques for culture of this tissue have been refined, and dissociated primary culture of the spiral ganglion has become a widely accepted in vitro model for studying nerve damage and regeneration in the cochlea. Additionally, patterned substrates have been developed that facilitate and direct neural outgrowth. A number of automated and semi-automated methods for quantifying this neurite outgrowth have been utilized in recent years (Zhang et al., J Neurosci Methods 160(1):149-162, 2007; Tapias et al., Neurobiol Dis 54:158-168, 2013). Here, we describe a method to study the effect of topographical cues on spiral ganglion neurite and Schwann cell alignment. We discuss our microfabrication process, characterization of pattern features, cell culture techniques for both spiral ganglion neurons and spiral ganglion Schwann cells. In addition, we describe protocols for reducing fibroblast count, immunocytochemistry, and methods for quantifying neurite and Schwann cell alignment.

  1. 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.

  2. Myelination competent conditionally immortalized mouse Schwann cells

    NARCIS (Netherlands)

    Saavedra, José T.; Wolterman, Ruud A.; Baas, Frank; ten Asbroek, Anneloor L. M. A.

    2008-01-01

    Numerous mouse myelin mutants are available to analyze the biology of the peripheral nervous system related to health and disease in vivo. However, robust in vitro biochemical characterizations of players in peripheral nerve processes are still not possible due to the limited growth capacities of

  3. p75 Neurotrophin Receptor in the Skin: Beyond Its Neurotrophic Function.

    Science.gov (United States)

    Pincelli, Carlo

    2017-01-01

    p75 neurotrophin receptor (p75 NTR ), also known as CD271, is the low-affinity receptor that, together with the tyrosine kinase receptor tropomyosin-receptor kinase (Trk), mediate neurotrophin (NT) functions. Beside their classic role in skin innervation, NT and their receptors constitute a complex cutaneous network associated with a number of autocrine and paracrine activities. In this context, the role of p75 NTR is becoming more and more important. This review will focus on the intriguing functions of p75 NTR in healthy and diseased skin. First, p75 NTR counterbalances the proliferative and survival activities of its cognate receptor Trk by inducing keratinocyte apoptosis. In addition, p75 NTR identifies an early transit-amplifying (TA) keratinocyte population and plays a critical role in keratinocyte stem cell transition to its progeny as well as in epidermal differentiation. p75 NTR is absent in psoriatic TA cells, thus rendering these cells resistant to apoptosis. On the other hand, p75 NTR infection restores NT-induced apoptosis in psoriatic keratinocytes. Taken together, these results provide evidence for a critical role of p75 NTR in epidermal homeostasis, while its lack may account for the TA defect in psoriasis. While the issue of p75 NTR as a marker of melanoma initiating cells is still to be solved, there is strong evidence that downregulation of this receptor is a precondition to melanoma invasion and metastasis in vitro and in vivo . All in all, this review points to p75 NTR as a major actor in both physiologic and pathologic conditions at the skin level.

  4. BNN27, a 17-Spiroepoxy Steroid Derivative, Interacts With and Activates p75 Neurotrophin Receptor, Rescuing Cerebellar Granule Neurons from Apoptosis.

    Science.gov (United States)

    Pediaditakis, Iosif; Kourgiantaki, Alexandra; Prousis, Kyriakos C; Potamitis, Constantinos; Xanthopoulos, Kleanthis P; Zervou, Maria; Calogeropoulou, Theodora; Charalampopoulos, Ioannis; Gravanis, Achille

    2016-01-01

    Neurotrophin receptors mediate a plethora of signals affecting neuronal survival. The p75 pan-neurotrophin receptor controls neuronal cell fate after its selective activation by immature and mature isoforms of all neurotrophins. It also exerts pleiotropic effects interacting with a variety of ligands in different neuronal or non-neuronal cells. In the present study, we explored the biophysical and functional interactions of a blood-brain-barrier (BBB) permeable, C17-spiroepoxy steroid derivative, BNN27, with p75 NTR receptor. BNN27 was recently shown to bind to NGF high-affinity receptor, TrkA. We now tested the p75 NTR -mediated effects of BNN27 in mouse Cerebellar Granule Neurons (CGNs), expressing p75 NTR , but not TrkA receptors. Our findings show that BNN27 physically interacts with p75 NTR receptors in specific amino-residues of its extracellular domain, inducing the recruitment of p75 NTR receptor to its effector protein RIP2 and the simultaneous release of RhoGDI in primary neuronal cells. Activation of the p75 NTR receptor by BNN27 reverses serum deprivation-induced apoptosis of CGNs resulting in the decrease of the phosphorylation of pro-apoptotic JNK kinase and of the cleavage of Caspase-3, effects completely abolished in CGNs, isolated from p75 NTR null mice. In conclusion, BNN27 represents a lead molecule for the development of novel p75 NTR ligands, controlling specific p75 NTR -mediated signaling of neuronal cell fate, with potential applications in therapeutics of neurodegenerative diseases and brain trauma.

  5. 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

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

    Indian Academy of Sciences (India)

    Theodor Schwann, the German physiologist who first pro- pounded the cell theory with M Schleiden, had diverse interests. He was not only the first to isolate the enzyme pepsin, but also investigated muscle contraction and nerve structure. In the mid nineteenth century Schwann discovered that a sheath made up of myelin ...

  7. p53 is important for the anti-proliferative effect of ibuprofen in colon carcinoma cells

    International Nuclear Information System (INIS)

    Janssen, Astrid; Schiffmann, Susanne; Birod, Kerstin; Maier, Thorsten J.; Wobst, Ivonne; Geisslinger, Gerd; Groesch, Sabine

    2008-01-01

    S-ibuprofen which inhibits the cyclooxygenase-1/-2 and R-ibuprofen which shows no COX-inhibition at therapeutic concentrations have anti-carcinogenic effects in human colon cancer cells; however, the molecular mechanisms for these effects are still unknown. Using HCT-116 colon carcinoma cell lines, expressing either the wild-type form of p53 (HCT-116 p53 wt ) or being p(HCT-116 p53 -/- ), we demonstrated that both induction of a cell cycle block and apoptosis after S- and R-ibuprofen treatment is in part dependent on p53. Also in the in vivo nude mice model HCT-116 p53 -/- xenografts were less sensitive for S- and R-ibuprofen treatment than HCT-116 p53 wt cells. Furthermore, results indicate that induction of apoptosis in HCT-116 p53 wt cells after ibuprofen treatment is in part dependent on a signalling pathway including the neutrophin receptor p75 NTR , p53 and Bax

  8. Combination of exogenous cell transplantation and 5-HT4 receptor agonism induce endogenous enteric neural crest-derived cells in a rat hypoganglionosis model.

    Science.gov (United States)

    Yu, Hui; Zheng, Bai-Jun; Pan, Wei-Kang; Wang, Huai-Jie; Xie, Chong; Zhao, Yu-Ying; Chen, Xin-Lin; Liu, Yong; Gao, Ya

    2017-02-01

    Enteric neural crest-derived cells (ENCCs) can migrate into endogenous ganglia and differentiate into progeny cells, and have even partially rescued bowel function; however, poor reliability and limited functional recovery after ENCC transplantation have yet to be addressed. Here, we investigated the induction of endogenous ENCCs by combining exogenous ENCC transplantation with a 5-HT 4 receptor agonist mosapride in a rat model of hypoganglionosis, established by benzalkonium chloride treatment. ENCCs, isolated from the gut of newborn rats, were labeled with a lentiviral eGFP reporter. ENCCs and rats were treated with the 5-HT 4 receptor agonist/antagonist. The labeled ENCCs were then transplanted into the muscular layer of benzalkonium chloride-treated colons. At given days post-intervention, colonic tissue samples were removed for histological analysis. ENCCs and neurons were detected by eGFP expression and immunoreactivity to p75 NTR and peripherin, respectively. eGFP-positive ENCCs and neurons could survive and maintain levels of fluorescence after transplantation. With longer times post-intervention, the number of peripherin-positive cells gradually increased in all groups. Significantly more peripherin-positive cells were found following ENCCs plus mosapride treatment, compared with the other groups. These results show that exogenous ENCCs combined with the 5-HT 4 receptor agonist effectively induced endogenous ENCCs proliferation and differentiation in a rat hypoganglionosis model. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Circadian control of p75 neurotrophin receptor leads to alternate activation of Nrf2 and c-Rel to reset energy metabolism in astrocytes via brain-derived neurotrophic factor.

    Science.gov (United States)

    Ishii, Tetsuro; Warabi, Eiji; Mann, Giovanni E

    2018-05-01

    Circadian clock genes regulate energy metabolism partly through neurotrophins in the body. The low affinity neurotrophin receptor p75 NTR is a clock component directly regulated by the transcriptional factor Clock:Bmal1 complex. Brain-derived neurotrophic factor (BDNF) is expressed in the brain and plays a key role in coordinating metabolic interactions between neurons and astrocytes. BDNF transduces signals through TrkB and p75 NTR receptors. This review highlights a novel molecular mechanism by which BDNF via circadian control of p75 NTR leads to daily resetting of glucose and glycogen metabolism in brain astrocytes to accommodate their functional interaction with neurons. Astrocytes store glycogen as an energy reservoir to provide active neurons with the glycolytic metabolite lactate. Astrocytes predominantly express the truncated receptor TrkB.T1 which lacks an intracellular receptor tyrosine kinase domain. TrkB.T1 retains the capacity to regulate cell morphology through regulation of Rho GTPases. In contrast, p75 NTR mediates generation of the bioactive lipid ceramide upon stimulation with BDNF and inhibits PKA activation. As ceramide directly activates PKCζ, we discuss the importance of the TrkB.T1-p75 NTR -ceramide-PKCζ signaling axis in the stimulation of glycogen and lipid synthesis and activation of RhoA. Ceramide-PKCζ-casein kinase 2 signaling activates Nrf2 to support oxidative phosphorylation via upregulation of antioxidant enzymes. In the absence of p75 NTR , TrkB.T1 functionally interacts with adenosine A 2A R and dopamine D1R receptors to enhance cAMP-PKA signaling and activate Rac1 and NF-κB c-Rel, favoring glycogen hydrolysis, gluconeogenesis and aerobic glycolysis. Thus, diurnal changes in p75 NTR levels in astrocytes resets energy metabolism via BDNF to accommodate their metabolic interaction with neurons. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. 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.

  11. Combination of exogenous cell transplantation and 5-HT4 receptor agonism induce endogenous enteric neural crest-derived cells in a rat hypoganglionosis model

    International Nuclear Information System (INIS)

    Yu, Hui; Zheng, Bai-Jun; Pan, Wei-Kang; Wang, Huai-Jie; Xie, Chong; Zhao, Yu-Ying; Chen, Xin-Lin; Liu, Yong; Gao, Ya

    2017-01-01

    Enteric neural crest-derived cells (ENCCs) can migrate into endogenous ganglia and differentiate into progeny cells, and have even partially rescued bowel function; however, poor reliability and limited functional recovery after ENCC transplantation have yet to be addressed. Here, we investigated the induction of endogenous ENCCs by combining exogenous ENCC transplantation with a 5-HT 4 receptor agonist mosapride in a rat model of hypoganglionosis, established by benzalkonium chloride treatment. ENCCs, isolated from the gut of newborn rats, were labeled with a lentiviral eGFP reporter. ENCCs and rats were treated with the 5-HT 4 receptor agonist/antagonist. The labeled ENCCs were then transplanted into the muscular layer of benzalkonium chloride-treated colons. At given days post-intervention, colonic tissue samples were removed for histological analysis. ENCCs and neurons were detected by eGFP expression and immunoreactivity to p75 NTR and peripherin, respectively. eGFP-positive ENCCs and neurons could survive and maintain levels of fluorescence after transplantation. With longer times post-intervention, the number of peripherin-positive cells gradually increased in all groups. Significantly more peripherin-positive cells were found following ENCCs plus mosapride treatment, compared with the other groups. These results show that exogenous ENCCs combined with the 5-HT 4 receptor agonist effectively induced endogenous ENCCs proliferation and differentiation in a rat hypoganglionosis model. - Highlights: • Survival and differentiation of exogenous ENCCs in treated colons. • With longer times post-intervention, the number of ENCCs and their progeny cells gradually increased. • Exogenous ENCCs combined with the 5-HT4 receptor agonist ffectively induced ENCCs proliferation and differentiation.

  12. 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.

  13. 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

  14. Deficient p75 low-affinity neurotrophin receptor expression does alter the composition of cellular infiltrate in experimental autoimmune encephalomyelitis in C57BL/6 mice

    NARCIS (Netherlands)

    Kust, B; Mantingh-Otter, [No Value; Boddeke, E; Copray, S

    We have shown earlier that induction of experimental autoimmune encephalomyelitis (EAE)-a model for the human disease multiple sclerosis-in C5713L/6 wild-type mice resulted in the expression of the p75 low-affinity neurotrophin receptor (p75(NTR)) in endothelial cells in the CNS. In comparison to

  15. 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.

  16. 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.

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

    Science.gov (United States)

    2015-10-01

    manifests itself in the denser bone in tennis players ’ racket-holding arms or bone loss in astronauts. After the discovery of piezoresponse in dry...57 (2001) 477–484. [51] H.T. Nguyen, C. Wei, J.K. Chow, L. Nguy, H.K. Nguyen, C.E. Schmidt, Electric field stimulation through a substrate influences ...deformation in dry conditions. The range of electrical output and electric fields are shown in Table 1. The results show that at 1 Hz, 10% deformation

  18. 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.

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

    Science.gov (United States)

    2016-10-01

    and Biopharmaceutics, 2005. 61(3): p. 171-180. 6. Sellers, D.L., et al., Poly (lactic-co-glycolic) acid microspheres encapsulated in Pluronic F- 127...described (Greiner and Wendorff, 2007; Lee et al., 2011; Weber et al., 2010). 15% (w/v) of poly (vinylidene fluoride trifluoroethylene) (65/35) (PVDF...UK) was administrated twice a day for 3 days immediately after surgery to reduce pain . Gentamycin (APP Pharmaceuticals, LLC, Schaumburg, IL, 40 mg

  20. A role of peripheral myelin protein 2 in lipid homeostasis of myelinating Schwann cells

    NARCIS (Netherlands)

    Zenker, J.; Stettner, M.; Ruskamo, S.; Domenech-Estevez, E.; Baloui, H.; Medard, J.J.; Verheijen, M.H.G.; Brouwers, J.F.; Kursula, P.; Kieseier, B.C.; Chrast, R.

    2014-01-01

    Peripheral myelin protein 2 (Pmp2, P2 or Fabp8), a member of the fatty acid binding protein family, was originally described together with myelin basic protein (Mbp or P1) and myelin protein zero (Mpz or P0) as one of the most abundant myelin proteins in the peripheral nervous system (PNS). Although

  1. A role of peripheral myelin protein 2 in lipid homeostasis of myelinating Schwann cells.

    NARCIS (Netherlands)

    Zenker, Jennifer; ruskamo, salla; domenech-estevez, Enric; medard, jean-jacques; Verheijen, M.H.; Brouwers, Jos|info:eu-repo/dai/nl/173812694; Kursula, Petri; kieseier, bernd; Chrast, Roman

    Peripheral myelin protein 2 (Pmp2, P2 or Fabp8), a member of the fatty acid binding protein family, was originally described together with myelin basic protein (Mbp or P1) and myelin protein zero (Mpz or P0) as one of the most abundant myelin proteins in the peripheral nervous system (PNS). Although

  2. 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

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

    International Nuclear Information System (INIS)

    Assimakopoulou, Martha; Kondyli, Maria; Gatzounis, George; Maraziotis, Theodore; Varakis, John

    2007-01-01

    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 p75 NTR neurotrophin receptor. Trk receptors promote cell survival and differentiation while p75 NTR induces, in most cases, the activity of JNK-p53-Bax apoptosis pathway or suppresses intracellular survival signaling cascades. Robust Trk activation blocks p75 NTR -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 p75 NTR , and the activation of JNK pathway in human astrocytomas and in adjacent non-neoplastic brain tissue. 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 p75 NTR 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. 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, p75 NTR 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 significantly co-expressed in a tumor

  4. 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

  5. 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.

  6. Expression of polysialylated neural cell adhesion molecules on adult stem cells after neuronal differentiation of inner ear spiral ganglion neurons

    International Nuclear Information System (INIS)

    Park, Kyoung Ho; Yeo, Sang Won; Troy, Frederic A.

    2014-01-01

    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

  7. New aspects of the pathogenesis of canine distemper leukoencephalitis.

    Science.gov (United States)

    Lempp, Charlotte; Spitzbarth, Ingo; Puff, Christina; Cana, Armend; Kegler, Kristel; Techangamsuwan, Somporn; Baumgärtner, Wolfgang; Seehusen, Frauke

    2014-07-02

    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 astrocytes

  8. New Aspects of the Pathogenesis of Canine Distemper Leukoencephalitis

    Science.gov (United States)

    Lempp, Charlotte; Spitzbarth, Ingo; Puff, Christina; Cana, Armend; Kegler, Kristel; Techangamsuwan, Somporn; Baumgärtner, Wolfgang; Seehusen, Frauke

    2014-01-01

    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 astrocytes

  9. Non-Invasive Cell-Based Therapy for Traumatic Optic Neuropathy

    Science.gov (United States)

    2013-10-01

    2004. 18(11): p. 1122-5. 4. Castillo, B., Jr., et al., Retinal ganglion cell survival is promoted by genetically modified astrocytes designed to...growth factors such as peripheral nerve ensheathing cells (Schwann cells) or cells genetically modified to release growth factors and (iv) cells with...Book: Retinal Degenerations, editors: Tombran-Tink and Barnstable. 620-2; Humana Press; Chapter 17: 317-342. Gamm DM, Wang S, Lu B, Girman S, Holmes T

  10. Development of cardiac parasympathetic neurons, glial cells, and regional cholinergic innervation of the mouse heart.

    Science.gov (United States)

    Fregoso, S P; Hoover, D B

    2012-09-27

    Very little is known about the development of cardiac parasympathetic ganglia and cholinergic innervation of the mouse heart. Accordingly, we evaluated the growth of cholinergic neurons and nerve fibers in mouse hearts from embryonic day 18.5 (E18.5) through postnatal day 21(P21). Cholinergic perikarya and varicose nerve fibers were identified in paraffin sections immunostained for the vesicular acetylcholine transporter (VAChT). Satellite cells and Schwann cells in adjacent sections were identified by immunostaining for S100β calcium binding protein (S100) and brain-fatty acid binding protein (B-FABP). We found that cardiac ganglia had formed in close association to the atria and cholinergic innervation of the atrioventricular junction had already begun by E18.5. However, most cholinergic innervation of the heart, including the sinoatrial node, developed postnatally (P0.5-P21) along with a doubling of the cross-sectional area of cholinergic perikarya. Satellite cells were present throughout neonatal cardiac ganglia and expressed primarily B-FABP. As they became more mature at P21, satellite cells stained strongly for both B-FABP and S100. Satellite cells appeared to surround most cardiac parasympathetic neurons, even in neonatal hearts. Mature Schwann cells, identified by morphology and strong staining for S100, were already present at E18.5 in atrial regions that receive cholinergic innervation at later developmental times. The abundance and distribution of S100-positive Schwann cells increased postnatally along with nerve density. While S100 staining of cardiac Schwann cells was maintained in P21 and older mice, Schwann cells did not show B-FABP staining at these times. Parallel development of satellite cells and cholinergic perikarya in the cardiac ganglia and the increase in abundance of Schwann cells and varicose cholinergic nerve fibers in the atria suggest that neuronal-glial interactions could be important for development of the parasympathetic nervous

  11. Clinical Evaluation of Decellularized Nerve Allograft with Autologous Bone Marrow Stem Cells to Improve Peripheral Nerve Repair and Functional Outcomes

    Science.gov (United States)

    2017-07-01

    with autologous mesenchymal stem cells . Exp Neurol. 2007 Apr; 204(2):658-66. 19. Dezawa M., et al., Sciatic nerve regeneration in rats induced by...36 23. Mimura T., et al., Peripheral nerve regeneration by transplantation of bone marrow stromal cell -derived Schwann cells in adult rats. J...AWARD NUMBER: W81XWH-15-2-0026 TITLE: Clinical Evaluation of Decellularized Nerve Allograft with Autologous Bone Marrow Stem Cells to Improve

  12. In vitro evaluation of cell-seeded chitosan films for peripheral nerve tissue engineering

    OpenAIRE

    Wrobel, Sandra; Serra, Sofia Cristina; Samy, S. M.; Sousa, Nuno; Heimann, Claudia; Barwig, Christina; Grothe, Claudia; Salgado, A. J.; Talini, Kirsten Haastert

    2014-01-01

    Natural biomaterials have attracted an increasing interest in the field of tissue-engineered nerve grafts, representing a possible alternative to autologous nerve transplantation. With the prospect of developing a novel entubulation strategy for transected nerves with cell-seeded chitosan films, we examined the biocompatibility of such films in vitro. Different types of rat Schwann cells (SCs)-immortalized, neonatal, and adult-as well as rat bone-marrow-derived mesenchymal stromal cells (BMSC...

  13. S100A16 promotes differentiation and contributes to a less aggressive tumor phenotype in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Sapkota, Dipak; Bruland, Ove; Parajuli, Himalaya; Osman, Tarig A.; Teh, Muy-Teck; Johannessen, Anne C.; Costea, Daniela Elena

    2015-01-01

    Altered expression of S100A16 has been reported in human cancers, but its biological role in tumorigenesis is not fully understood. This study aimed to investigate the clinical significance and functional role of S100A16 in oral squamous cell carcinoma (OSCC) suppression. S100A16 mRNA and/or protein levels were examined by quantitative RT-PCR and immunohistochemistry in whole- and laser microdissected-specimens of normal human oral mucosa (NHOM, n = 65), oral dysplastic lesions (ODL, n = 21), OSCCs (n = 132) and positive cervical nodes (n = 17). S100A16 protein expression in OSCC was examined for correlations with clinicopathological variables and patient survival. S100A16 was over-expressed and knocked-down in OSCC-derived (CaLH3 and H357) cells by employing retroviral constructs to investigate its effects on cell proliferation, sphere formation and three dimensional (3D)-organotypic invasive abilities in vitro and tumorigenesis in a mouse xenograft model. Both S100A16 mRNA and protein levels were found to be progressively down-regulated from NHOM to ODL and OSCC. Low S100A16 protein levels in OSCC significantly correlated with reduced 10-year overall survival and poor tumor differentiation. Analysis of two external OSCC microarray datasets showed a positive correlation between the mRNA expression levels of S100A16 and keratinocyte differentiation markers. CaLH3 and H357 cell fractions enriched for differentiated cells either by lack of adherence to collagen IV or FACS sorting for low p75NTR expression expressed significantly higher S100A16 mRNA levels than the subpopulations enriched for less differentiated cells. Corroborating these findings, retroviral mediated S100A16 over-expression and knock-down in CaLH3 and H357 cells led to respective up- and down-regulation of differentiation markers. In vitro functional studies showed significant reduction in cell proliferation, sphere formation and 3D-invasive abilities of CaLH3 and H357 cells upon S100A16 over

  14. The GAD-given Right of Dentate Gyrus Granule Cells to Become GABAergic

    Science.gov (United States)

    Mody, Istvan

    2002-01-01

    low-affinity neurotrophin receptor p75NTR, perhaps as part of a programmed developmental switch, can convert the phenotype of the sympathetic neuron from noradrenergic to cholinergic 4. Other examples of two fast neurotransmitters released from the same neuron include GABA and glycine in interneurons of the spinal cord 5 and glutamate and dopamine in ventral midbrain dopamine neurons 6. Of all CNS neurons, the granule cells of the dentate gyrus appear to be the champions of neurotransmitter colocalization: glutamate, enkephalin, dynorphin, zinc, and finally GABA 2, 7, 8, 9. With this many transmitters in a single neuron, there are probably different ways in which they can be released. Dynorphin and other opioid peptides can be released directly from the dendrites to inhibit excitatory transmission 8. A similar mechanism may take place for GABA, as described in cortical GABAergic neurons 10. PMID:15309121

  15. Uptake of 3H-thymidine by the receptor cell populations after injury of the sensory nerve fibres

    International Nuclear Information System (INIS)

    Chuchkov, Ch.N.

    1978-01-01

    The material of the study was the skin from the beak of two-day ducklings. The investigation was carried out on the 2nd, 5th, 20th and 45th day after the crushing of the sensory nerve fibres entering the capsulated Herbst receptors. Twenty four hours before the biopsy, the ducklings were injected at 6 hours intervals with 3 H-thymidine. The number of labelled index in the three cell pupulations, participating in the receptor development was determined. The cells of the subcapsular space of all control animals (with intacted suborbital nerves) have shown the highest labelled index. The index of the capsular perineural cells is about 12 times lower, while the labelled index of the Schwann receptor cells is about 10 times lower. Following the denervation, the labelled index in increasing and reaches its maximum on the 5th postoperative day. The Schwann receptor cells in comparison to the two other cell populations show the most significant deviation during the regeneration (45th day after the intervention). The investigations show that all three cell populations pass through a miotic cycle of innovation. The low labelled index of the Schwann receptors (1-2 labelled cells in 1000) is an indication of a high differentiation. One can assume that their regeneration takes place at the expense of the proper proliferation activity as well as of the differentiation of the Schwann cells from the distal section of the regenerating sensory nerve fibres. Taking into consideration the high labelled index of the other populations, it seems most probable that their regeneration takes place for the expense of their own cell populations. (A.B.)

  16. 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

  17. Entropy measures of collective cell migration

    Science.gov (United States)

    Whitby, Ariadne; Parrinello, Simona; Faisal, Aldo

    2015-03-01

    Collective cell migration is a critical process during tissue formation and repair. To this end there is a need to develop tools to quantitatively measure the dynamics of collective cell migration obtained from microscopy data. Drawing on statistical physics we use entropy of velocity fields derived from dense optic flow to quantitatively measure collective migration. Using peripheral nerve repair after injury as experimental system, we study how Schwann cells, guided by fibroblasts, migrate in cord-like structures across the cut, paving a highway for neurons. This process of emergence of organised behaviour is key for successful repair, yet the emergence of leader cells and transition from a random to ordered state is not understood. We find fibroblasts induce correlated directionality in migrating Schwann cells as measured by a decrease in the entropy of motion vector. We show our method is robust with respect to image resolution in time and space, giving a principled assessment of how various molecular mechanisms affect macroscopic features of collective cell migration. Finally, the generality of our method allows us to process both simulated cell movement and microscopic data, enabling principled fitting and comparison of in silico to in vitro. ICCS, Imperial College London & MRC Clinical Sciences Centre.

  18. 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.

  19. Escalated regeneration in sciatic nerve crush injury by the combined therapy of human amniotic fluid mesenchymal stem cells and fermented soybean extracts, Natto.

    Science.gov (United States)

    Pan, Hung-Chuan; Yang, Dar-Yu; Ho, Shu-Peng; Sheu, Meei-Ling; Chen, Chung-Jung; Hwang, Shiaw-Min; Chang, Ming-Hong; Cheng, Fu-Chou

    2009-08-23

    Attenuation of inflammatory cell deposits and associated cytokines prevented the apoptosis of transplanted stem cells in a sciatic nerve crush injury model. Suppression of inflammatory cytokines by fermented soybean extracts (Natto) was also beneficial to nerve regeneration. In this study, the effect of Natto on transplanted human amniotic fluid mesenchymal stem cells (AFS) was evaluated. Peripheral nerve injury was induced in SD rats by crushing a sciatic nerve using a vessel clamp. Animals were categorized into four groups: Group I: no treatment; Group II: fed with Natto (16 mg/day for 7 consecutive days); Group III: AFS embedded in fibrin glue; Group IV: Combination of group II and III therapy. Transplanted AFS and Schwann cell apoptosis, inflammatory cell deposits and associated cytokines, motor function, and nerve regeneration were evaluated 7 or 28 days after injury. The deterioration of neurological function was attenuated by AFS, Natto, or the combined therapy. The combined therapy caused the most significantly beneficial effects. Administration of Natto suppressed the inflammatory responses and correlated with decreased AFS and Schwann cell apoptosis. The decreased AFS apoptosis was in line with neurological improvement such as expression of early regeneration marker of neurofilament and late markers of S-100 and decreased vacuole formation. Administration of either AFS, or Natto, or combined therapy augmented the nerve regeneration. In conclusion, administration of Natto may rescue the AFS and Schwann cells from apoptosis by suppressing the macrophage deposits, associated inflammatory cytokines, and fibrin deposits.

  20. Escalated regeneration in sciatic nerve crush injury by the combined therapy of human amniotic fluid mesenchymal stem cells and fermented soybean extracts, Natto

    Directory of Open Access Journals (Sweden)

    Pan Hung-Chuan

    2009-08-01

    Full Text Available Abstract Attenuation of inflammatory cell deposits and associated cytokines prevented the apoptosis of transplanted stem cells in a sciatic nerve crush injury model. Suppression of inflammatory cytokines by fermented soybean extracts (Natto was also beneficial to nerve regeneration. In this study, the effect of Natto on transplanted human amniotic fluid mesenchymal stem cells (AFS was evaluated. Peripheral nerve injury was induced in SD rats by crushing a sciatic nerve using a vessel clamp. Animals were categorized into four groups: Group I: no treatment; Group II: fed with Natto (16 mg/day for 7 consecutive days; Group III: AFS embedded in fibrin glue; Group IV: Combination of group II and III therapy. Transplanted AFS and Schwann cell apoptosis, inflammatory cell deposits and associated cytokines, motor function, and nerve regeneration were evaluated 7 or 28 days after injury. The deterioration of neurological function was attenuated by AFS, Natto, or the combined therapy. The combined therapy caused the most significantly beneficial effects. Administration of Natto suppressed the inflammatory responses and correlated with decreased AFS and Schwann cell apoptosis. The decreased AFS apoptosis was in line with neurological improvement such as expression of early regeneration marker of neurofilament and late markers of S-100 and decreased vacuole formation. Administration of either AFS, or Natto, or combined therapy augmented the nerve regeneration. In conclusion, administration of Natto may rescue the AFS and Schwann cells from apoptosis by suppressing the macrophage deposits, associated inflammatory cytokines, and fibrin deposits.

  1. The neural crest is a source of mesenchymal stem cells with specialized hematopoietic stem cell niche function.

    Science.gov (United States)

    Isern, Joan; García-García, Andrés; Martín, Ana M; Arranz, Lorena; Martín-Pérez, Daniel; Torroja, Carlos; Sánchez-Cabo, Fátima; Méndez-Ferrer, Simón

    2014-09-25

    Mesenchymal stem cells (MSCs) and osteolineage cells contribute to the hematopoietic stem cell (HSC) niche in the bone marrow of long bones. However, their developmental relationships remain unclear. In this study, we demonstrate that different MSC populations in the developing marrow of long bones have distinct functions. Proliferative mesoderm-derived nestin(-) MSCs participate in fetal skeletogenesis and lose MSC activity soon after birth. In contrast, quiescent neural crest-derived nestin(+) cells preserve MSC activity, but do not generate fetal chondrocytes. Instead, they differentiate into HSC niche-forming MSCs, helping to establish the HSC niche by secreting Cxcl12. Perineural migration of these cells to the bone marrow requires the ErbB3 receptor. The neonatal Nestin-GFP(+) Pdgfrα(-) cell population also contains Schwann cell precursors, but does not comprise mature Schwann cells. Thus, in the developing bone marrow HSC niche-forming MSCs share a common origin with sympathetic peripheral neurons and glial cells, and ontogenically distinct MSCs have non-overlapping functions in endochondrogenesis and HSC niche formation.

  2. Morphological, molecular and functional differences of adult bone marrow- and adipose-derived stem cells isolated from rats of different ages

    Energy Technology Data Exchange (ETDEWEB)

    Mantovani, Cristina [Blond McIndoe Laboratories, School of Biomedicine, The University of Manchester, Room 3,106 Stopford Building, Oxford Road, Manchester M13 9PT, Academic Health Science Centre, Faculty of Medicine and Human Sciences (United Kingdom); Department of Integrative Medical Biology and Surgical and Perioperative Science, Umea University, Umea (Sweden); Department of Surgical and Perioperative Science, Umea University, Umea (Sweden); Raimondo, Stefania [Dipartimento di Scienze Cliniche e Biologiche, University of Turin (Italy); Haneef, Maryam S. [Blond McIndoe Laboratories, School of Biomedicine, The University of Manchester, Room 3,106 Stopford Building, Oxford Road, Manchester M13 9PT, Academic Health Science Centre, Faculty of Medicine and Human Sciences (United Kingdom); Geuna, Stefano [Dipartimento di Scienze Cliniche e Biologiche, University of Turin (Italy); Terenghi, Giorgio [Blond McIndoe Laboratories, School of Biomedicine, The University of Manchester, Room 3,106 Stopford Building, Oxford Road, Manchester M13 9PT, Academic Health Science Centre, Faculty of Medicine and Human Sciences (United Kingdom); Shawcross, Susan G., E-mail: sue.shawcross@manchester.ac.uk [Blond McIndoe Laboratories, School of Biomedicine, The University of Manchester, Room 3,106 Stopford Building, Oxford Road, Manchester M13 9PT, Academic Health Science Centre, Faculty of Medicine and Human Sciences (United Kingdom); Wiberg, Mikael [Department of Integrative Medical Biology and Surgical and Perioperative Science, Umea University, Umea (Sweden); Department of Surgical and Perioperative Science, Umea University, Umea (Sweden)

    2012-10-01

    Adult mesenchymal stem cells have self-renewal and multiple differentiation potentials, and play important roles in regenerative medicine. However, their use may be limited by senescence or age of the donor, leading to changes in stem cell functionality. We investigated morphological, molecular and functional differences between bone marrow-derived (MSC) and adipose-derived (ASC) stem cells isolated from neonatal, young and old rats compared to Schwann cells from the same animals. Immunocytochemistry, RT-PCR, proliferation assays, western blotting and transmission electron microscopy were used to investigate expression of senescence markers. Undifferentiated and differentiated ASC and MSC from animals of different ages expressed Notch-2 at similar levels; protein-38 and protein-53 were present in all groups of cells with a trend towards increased levels in cells from older animals compared to those from neonatal and young rats. Following co-culture with adult neuronal cells, dMSC and dASC from animals of all ages elicited robust neurite outgrowth. Mitotracker{sup Registered-Sign} staining was consistent with ultrastructural changes seen in the mitochondria of cells from old rats, indicative of senescence. In conclusion, this study showed that although the cells from aged animals expressed markers of senescence, aged MSC and ASC differentiated into SC-like cells still retain potential to support axon regeneration. -- Highlights: Black-Right-Pointing-Pointer Aged MSC and ASC differentiated into Schwann-like cells support axon regeneration. Black-Right-Pointing-Pointer p53 expression does not appreciably influence the biology of Schwann or stem cells. Black-Right-Pointing-Pointer Notch 2 expression was similar in cells derived from animals of different ages. Black-Right-Pointing-Pointer Proliferation rates of dMSC varied little over time or with animal age.

  3. Morphological, molecular and functional differences of adult bone marrow- and adipose-derived stem cells isolated from rats of different ages

    International Nuclear Information System (INIS)

    Mantovani, Cristina; Raimondo, Stefania; Haneef, Maryam S.; Geuna, Stefano; Terenghi, Giorgio; Shawcross, Susan G.; Wiberg, Mikael

    2012-01-01

    Adult mesenchymal stem cells have self-renewal and multiple differentiation potentials, and play important roles in regenerative medicine. However, their use may be limited by senescence or age of the donor, leading to changes in stem cell functionality. We investigated morphological, molecular and functional differences between bone marrow-derived (MSC) and adipose-derived (ASC) stem cells isolated from neonatal, young and old rats compared to Schwann cells from the same animals. Immunocytochemistry, RT-PCR, proliferation assays, western blotting and transmission electron microscopy were used to investigate expression of senescence markers. Undifferentiated and differentiated ASC and MSC from animals of different ages expressed Notch-2 at similar levels; protein-38 and protein-53 were present in all groups of cells with a trend towards increased levels in cells from older animals compared to those from neonatal and young rats. Following co-culture with adult neuronal cells, dMSC and dASC from animals of all ages elicited robust neurite outgrowth. Mitotracker ® staining was consistent with ultrastructural changes seen in the mitochondria of cells from old rats, indicative of senescence. In conclusion, this study showed that although the cells from aged animals expressed markers of senescence, aged MSC and ASC differentiated into SC-like cells still retain potential to support axon regeneration. -- Highlights: ► Aged MSC and ASC differentiated into Schwann-like cells support axon regeneration. ► p53 expression does not appreciably influence the biology of Schwann or stem cells. ► Notch 2 expression was similar in cells derived from animals of different ages. ► Proliferation rates of dMSC varied little over time or with animal age.

  4. In vivo transformation of neural stem cells following transplantation in the injured nervous system.

    Science.gov (United States)

    Radtke, Christine; Redeker, Joern; Jokuszies, Andreas; Vogt, Peter M

    2010-04-01

    Johnson et al report tumor formation following murine neural precursor cell transplantation in a rat peripheral nerve injury model, emphasizing the importance of full in vitro characterization of cells prior to transplantation. Cell lines can change during expansion and subclones which may become tumerogenic may be selected in the process of expansion. Cell transplantation studies with committed cells that have been minimally manipulated and expanded in culture such as olfactory ensheathing cells and Schwann cells may pose less risk of tumerogenicity, but have the disadvantage of limited cell harvest yields. The balance between in vitro transformation of expanded cell lines and the limitation of cell harvest yields from preparation of more stable committed cells must be considered in selection of cells for therapeutic intervention for nerve repair. Copyright Thieme Medical Publishers.

  5. The role of undifferentiated adipose-derived stem cells in peripheral nerve repair.

    Science.gov (United States)

    Zhang, Rui; Rosen, Joseph M

    2018-05-01

    Peripheral nerve injuries impose significant health and economic consequences, yet no surgical repair can deliver a complete recovery of sensory or motor function. Traditional methods of repair are less than ideal: direct coaptation can only be performed when tension-free repair is possible, and transplantation of nerve autograft can cause donor-site morbidity and neuroma formation. Cell-based therapy delivered via nerve conduits has thus been explored as an alternative method of nerve repair in recent years. Stem cells are promising sources of the regenerative core material in a nerve conduit because stem cells are multipotent in function, abundant in supply, and more accessible than the myelinating Schwann cells. Among different types of stem cells, undifferentiated adipose-derived stem cell (uASC), which can be processed from adipose tissue in less than two hours, is a promising yet underexplored cell type. Studies of uASC have emerged in the past decade and have shown that autologous uASCs are non-immunogenic, easy to access, abundant in supply, and efficacious at promoting nerve regeneration. Two theories have been proposed as the primary regenerative mechanisms of uASC: in situ trans-differentiation towards Schwann cells, and secretion of trophic and anti-inflammatory factors. Future studies need to fully elucidate the mechanisms, side effects, and efficacy of uASC-based nerve regeneration so that uASCs can be utilized in clinical settings.

  6. Loss-of-Function Mutations in LGI4, a Secreted Ligand Involved in Schwann Cell Myelination, Are Responsible for Arthrogryposis Multiplex Congenita

    NARCIS (Netherlands)

    Xue, Shifeng; Maluenda, Jérôme; Marguet, Florent; Shboul, Mohammad; Quevarec, Loïc; Bonnard, Carine; Ng, Alvin Yu Jin; Tohari, Sumanty; Tan, Thong Teck; Kong, Mung Kei; Monaghan, Kristin G.; Cho, Megan T.; Siskind, Carly E.; Sampson, Jacinda B.; Rocha, Carolina Tesi; Alkazaleh, Fawaz; Gonzales, Marie; Rigonnot, Luc; Whalen, Sandra; Gut, Marta; Gut, Ivo; Bucourt, Martine; Venkatesh, Byrappa; Laquerrière, Annie; Reversade, Bruno; Melki, Judith

    2017-01-01

    Arthrogryposis multiplex congenita (AMC) is a developmental condition characterized by multiple joint contractures resulting from reduced or absent fetal movements. Through genetic mapping of disease loci and whole-exome sequencing in four unrelated multiplex families presenting with severe AMC, we

  7. Dendrimer-driven neurotrophin expression differs in temporal patterns between rodent and human stem cells.

    Science.gov (United States)

    Shakhbazau, Antos; Shcharbin, Dzmitry; Seviaryn, Ihar; Goncharova, Natalya; Kosmacheva, Svetlana; Potapnev, Mihail; Bryszewska, Maria; Kumar, Ranjan; Biernaskie, Jeffrey; Midha, Rajiv

    2012-05-07

    This study reports the use of a nonviral expression system based on polyamidoamine dendrimers for time-restricted neurotrophin overproduction in mesenchymal stem cells and skin precursor-derived Schwann cells. The dendrimers were used to deliver plasmids for brain-derived neurotrophic factor (BDNF) or neurotrophin-3 (NT-3) expression in both rodent and human stem cells, and the timelines of expression were studied. We have found that, despite the fact that transfection efficiencies and protein expression levels were comparable, dendrimer-driven expression in human mesenchymal stem cells was characterized by a more rapid decline compared to rodent cells. Transient expression systems can be beneficial for some neurotrophins, which were earlier reported to cause unwanted side effects in virus-based long-term expression models. Nonviral neurotrophin expression is a biologically safe and accessible alternative to increase the therapeutic potential of autologous adult stem cells and stem cell-derived functional differentiated cells.

  8. 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...

  9. Human umbilical cord mesenchymal stem cells promote peripheral nerve repair via paracrine mechanisms

    Directory of Open Access Journals (Sweden)

    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.

  10. Mesenchymal Stem Cell-Like Cells Derived from Mouse Induced Pluripotent Stem Cells Ameliorate Diabetic Polyneuropathy in Mice

    Directory of Open Access Journals (Sweden)

    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.

  11. Systemic administration of erythropoietin inhibits retinopathy in RCS rats.

    Directory of Open Access Journals (Sweden)

    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

  12. Diabetes and overexpression of proNGF cause retinal neurodegeneration via activation of RhoA pathway.

    Directory of Open Access Journals (Sweden)

    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.

  13. 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...

  14. The pluripotency of hair follicle stem cells.

    Science.gov (United States)

    Hoffman, Robert M

    2006-02-01

    The hair follicle bulge area is an abundant, easily accessible source of actively growing, pluripotent adult stem cells. Nestin, a protein marker for neural stem cells, is also expressed in follicle stem cells as well as their immediate differentiated progeny. The nestin-expressing hair follicle stem cells differentiated into neurons, glial cells, keratinocytes and smooth muscle cells in vitro. Hair-follicle stem cells were implanted into the gap region of a severed sciatic nerve. The hair follicle stem cells greatly enhanced the rate of nerve regeneration and the restoration of nerve function. The follicle stem cells transdifferentiated largely into Schwann cells which are known to support neuron regrowth. Function of the rejoined sciatic nerve was measured by contraction of the gastrocnemius muscle upon electrical stimulation. After severing the tibial nerve and subsequent transplantation of hair-follicle stem cells, the transplanted mice recovered the ability to walk normally. These results suggest that hair-follicle stem cells provide an important accessible, autologous source of adult stem cells for regenerative medicine.

  15. Effects of sciatic-conditioned medium on neonatal rat retinal cells in vitro

    Directory of Open Access Journals (Sweden)

    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. Demonstration of S-100 protein in sustentacular cells of phaeochromocytomas and paragangliomas

    DEFF Research Database (Denmark)

    Schroder, H D; Johannsen, L

    1986-01-01

    to the sustentacular cells of normal paraganglia and adrenal medulla were found in all paragangliomas and in the benign and aggressively growing phaeochromocytomas. In the two malignant tumours no positive reaction was demonstrated. In one tumour the sustentacular cells were shown to contain glial fibrillary acidic......Eighteen phaeochromocytomas, including both sporadic and familial cases, four cervical paragangliomas, two jugular paragangliomas, and one abdominal paraganglioma were examined immunohistochemically for the presence of S-100 protein. Positive staining in cells morphologically similar...... protein further supporting their Schwann cell relationship. The number of S-100 positive cells varied considerably. They demonstrated a spindle celled or elongated configuration with long slender processes. The nature of the sustentacular cell proliferation, neoplastic versus reactive, is discussed....

  17. The Urodele Limb Regeneration Blastema: The Cell Potential

    Directory of Open Access Journals (Sweden)

    Kenyon S. Tweedell

    2010-01-01

    Full Text Available The developmental potential of the limb regeneration blastema, a mass of mesenchymal cells of mixed origins, was once considered as being pluripotent, capable of forming all cell types. Now evidence asserts that the blastema is a heterogeneous mixture of progenitor cells derived from tissues of the amputation site, with limited developmental potential, plus various stem cells with multipotent abilities. Many specialized cells, bone, cartilage, muscle, and Schwann cells, at the injury site undergo dedifferentiation to a progenitor state and maintain their cell lineage as they redifferentiate in the regenerate. Muscle satellite reserve stem cells that are active in repair of injured muscle may also dedifferentiate and contribute new muscle cells to the limb blastema. Other cells from the dermis act as multipotent stem cells that replenish dermal fibroblasts and differentiate into cartilage. The blastema primordium is a self-organized, equipotential system, but at the cellular level can compensate for specific cell loss. It is able to induce dedifferentiation of introduced exogenous cells and such cells may be transformed into new cell types. Indigenous cells of the blastema associated with amputated tissues may also transform or possibly transdifferentiate into new cell types. The blastema is a microenvironment that enables dedifferentiation, redifferentiation, transdifferentiation, and stem cell activation, leading to progenitor cells of the limb regenerate.

  18. A genetic screen for anchorage-independent proliferation in mammalian cells identifies a membrane-bound neuregulin.

    Directory of Open Access Journals (Sweden)

    Davide Danovi

    2010-07-01

    Full Text Available Anchorage-independent proliferation is a hallmark of oncogenic transformation and is thought to be conducive to proliferation of cancer cells away from their site of origin. We have previously reported that primary Schwann cells expressing the SV40 Large T antigen (LT are not fully transformed in that they maintain a strict requirement for attachment, requiring a further genetic change, such as oncogenic Ras, to gain anchorage-independence. Using the LT-expressing cells, we performed a genetic screen for anchorage-independent proliferation and identified Sensory and Motor Neuron Derived Factor (SMDF, a transmembrane class III isoform of Neuregulin 1. In contrast to oncogenic Ras, SMDF induced enhanced proliferation in normal primary Schwann cells but did not trigger cellular senescence. In cooperation with LT, SMDF drove anchorage-independent proliferation, loss of contact inhibition and tumourigenicity. This transforming ability was shared with membrane-bound class III but not secreted class I isoforms of Neuregulin, indicating a distinct mechanism of action. Importantly, we show that despite being membrane-bound signalling molecules, class III neuregulins transform via a cell intrinsic mechanism, as a result of constitutive, elevated levels of ErbB signalling at high cell density and in anchorage-free conditions. This novel transforming mechanism may provide new targets for cancer therapy.

  19. Malignant granular cell tumor of the abdominal wall mimicking desmoid tumor: A case report with CT imaging findings and literature review

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Je Hong; Ahn, Sung Eun; Lee, Dong Ho; Park, Seong Jin; Moon, Sung Kyoung; Lim, Joo Won [Dept. Radiology, Kyung Hee University Hospital, Kyung Hee University School of Medicine, Seoul (Korea, Republic of)

    2016-08-15

    Granular cell tumors (GCTs) are extremely rare mesenchymal neoplasms of Schwann cell origin. Malignant GCTs (MGCTs) comprise 0.5-2% of all GCTs. In the present report, we describe a case of a 66-year-old man with MGCT of the abdominal wall. The patient visited our hospital due to a recently growing palpable soft tissue mass in the abdominal wall. Computed tomography scan revealed a 4.3 × 4.1 × 2.9 cm sized mass arising from the left abdominal wall, which was contemplated as a desmoid tumor before surgical excision. Histopathological examination confirmed MGCT.

  20. Distribution of elements in rat peripheral axons and nerve cell bodies determined by x-ray microprobe analysis

    Energy Technology Data Exchange (ETDEWEB)

    LoPachin, R.M. Jr.; Lowery, J.; Eichberg, J.; Kirkpatrick, J.B.; Cartwright, J. Jr.; Saubermann, A.J.

    1988-09-01

    X-ray microprobe analysis was used to determine concentrations (millimoles of element per kilogram dry weight) of Na, P, Cl, K, and Ca in cellular compartments of frozen, unfixed sections of rat sciatic and tibial nerves and dorsal root ganglion (DRG). Five compartments were examined in peripheral nerve (axoplasm, mitochondria, myelin, extraaxonal space, and Schwann cell cytoplasm), and four were analyzed in DRG nerve cell bodies (cytoplasm, mitochondria, nucleus, and nucleolus). Each morphological compartment exhibited characteristic concentrations of elements. The extraaxonal space contained high concentrations of Na, Cl, and Ca, whereas intraaxonal compartments exhibited lower concentrations of these elements but relatively high K contents. Nerve axoplasm and axonal mitochondria had similar elemental profiles, and both compartments displayed proximodistal gradients of decreasing levels of K, Cl, and, to some extent, Na. Myelin had a selectively high P concentration with low levels of other elements. The elemental concentrations of Schwann cell cytoplasm and DRG were similar, but both were different from that of axoplasm, in that K and Cl were markedly lower whereas P was higher. DRG cell nuclei contained substantially higher K levels than cytoplasm. The subcellular distribution of elements was clearly shown by color-coded images generated by computer-directed digital x-ray imaging. The results of this study demonstrate characteristic elemental distributions for each anatomical compartment, which doubtless reflect nerve cell structure and function.

  1. Regulated expression of the neural cell adhesion molecule L1 by specific patterns of neural impulses.

    Science.gov (United States)

    Itoh, K; Stevens, B; Schachner, M; Fields, R D

    1995-11-24

    Development of the mammalian nervous system is regulated by neural impulse activity, but the molecular mechanisms are not well understood. If cell recognition molecules [for example, L1 and the neural cell adhesion molecule (NCAM)] were influenced by specific patterns of impulse activity, cell-cell interactions controlling nervous system structure could be regulated by nervous system function at critical stages of development. Low-frequency electrical pulses delivered to mouse sensory neurons in culture (0.1 hertz for 5 days) down-regulated expression of L1 messenger RNA and protein (but not NCAM). Fasciculation of neurites, adhesion of neuroblastoma cells, and the number of Schwann cells on neurites was reduced after 0.1-hertz stimulation, but higher frequencies or stimulation after synaptogenesis were without effect.

  2. Visualization of phosphatidic acid fluctuations in the plasma membrane of living cells.

    Directory of Open Access Journals (Sweden)

    José P Ferraz-Nogueira

    Full Text Available We developed genetically-encoded fluorescent sensors based on Förster Resonance Energy Transfer to monitor phosphatidic acid (PA fluctuations in the plasma membrane using Spo20 as PA-binding motif. Basal PA levels and phospholipase D activity varied in different cell types. In addition, stimuli that activate PA phosphatases, leading to lower PA levels, increased lamellipodia and filopodia formation. Lower PA levels were observed in the leading edge than in the trailing edge of migrating HeLa cells. In MSC80 and OLN93 cells, which are stable cell lines derived from Schwann cells and oligodendrocytes, respectively, a higher ratio of diacylglycerol to PA levels was demonstrated in the membrane processes involved in myelination, compared to the cell body. We propose that the PA sensors reported here are valuable tools to unveil the role of PA in a variety of intracellular signaling pathways.

  3. 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.

  4. Reduction of the immunostainable length of the hippocampal dentate granule cells’ primary cilia in 3xAD-transgenic mice producing human Aβ1-42 and tau

    International Nuclear Information System (INIS)

    Chakravarthy, Balu; Gaudet, Chantal; Ménard, Michel; Brown, Leslie; Atkinson, Trevor; LaFerla, Frank M.; Ito, Shingo; Armato, Ubaldo; Dal Prà, Ilaria; Whitfield, James

    2012-01-01

    Highlights: ► Aβ and tau-induced neurofibrillary tangles play a key role in Alzheimer’s disease. ► Aβ 1-42 and mutant tau protein together reduce the primary cilium length. ► This shortening likely reduces cilium-dependent neurogenesis and memory function. ► This provides a model of an Aβ/tau targeting of a neuronal signaling organelle. -- Abstract: The hippocampal dentate gyrus is one of the two sites of continuous neurogenesis in adult rodents and humans. Virtually all dentate granule cells have a single immobile cilium with a microtubule spine or axoneme covered with a specialized cell membrane loaded with receptors such as the somatostatin receptor 3 (SSTR3), and the p75 neurotrophin receptor (p75 NTR ). The signals from these receptors have been reported to stimulate neuroprogenitor proliferation and the post-mitotic maturation of newborn granule cells into functioning granule cells. We have found that in 6–24-months-old triple transgenic Alzheimer’s disease model mice (3xTg-AD) producing both Aβ 1-42 and the mutant human tau protein tau P301L, the dentate granule cells still had immunostainable SSTR3- and p75 NTR -bearing cilia but they were only half the length of the immunostained cilia in the corresponding wild-type mice. However, the immunostainable length of the granule cell cilia was not reduced either in 2xTg-AD mice accumulating large amounts of Aβ 1-42 or in mice accumulating only a mutant human tau protein. Thus it appears that a combination of Aβ 1-42 and tau protein accumulation affects the levels of functionally important receptors in 3xTg-AD mice. These observations raise the important possibility that structural and functional changes in granule cell cilia might have a role in AD.

  5. 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.

  6. Transplantation of olfactory ensheathing cells as adjunct cell therapy for peripheral nerve injury.

    Science.gov (United States)

    Radtke, Christine; Wewetzer, Konstantin; Reimers, Kerstin; Vogt, Peter M

    2011-01-01

    Traumatic events, such as work place trauma or motor vehicle accident violence, result in a significant number of severe peripheral nerve lesions, including nerve crush and nerve disruption defects. Transplantation of myelin-forming cells, such as Schwann cells (SCs) or olfactory ensheathing cells (OECs), may be beneficial to the regenerative process because the applied cells could mediate neurotrophic and neuroprotective effects by secretion of chemokines. Moreover, myelin-forming cells are capable of bridging the repair site by establishing an environment permissive to axonal regeneration. The cell types that are subject to intense investigation include SCs and OECs either derived from the olfactory bulb or the olfactory mucosa, stromal cells from bone marrow (mesenchymal stem cells, MSCs), and adipose tissue-derived cells. OECs reside in the peripheral and central nervous system and have been suggested to display unique regenerative properties. However, so far OECs were mainly used in experimental studies to foster central regeneration and it was not until recently that their regeneration-promoting activity for the peripheral nervous system was recognized. In the present review, we summarize recent experimental evidence regarding the regenerative effects of OECs applied to the peripheral nervous system that may be relevant to design novel autologous cell transplantation therapies. © 2011 Cognizant Comm. Corp.

  7. Inhibitory effects of brain-derived neurotrophic factor precursor on viability and neurite growth of murine hippocampal neurons

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    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

  8. Suppression of asparaginyl endopeptidase attenuates breast cancer-induced bone pain through inhibition of neurotrophin receptors.

    Science.gov (United States)

    Yao, Peng; Ding, Yuanyuan; Han, Zhenkai; Mu, Ying; Hong, Tao; Zhu, Yongqiang; Li, Hongxi

    2017-01-01

    Objective Cancer-induced bone pain is a common clinical problem in breast cancer patients with bone metastasis. However, the mechanisms driving cancer-induced bone pain are poorly known. Recent studies show that a novel protease, asparaginyl endopeptidase (AEP) plays crucial roles in breast cancer metastasis and progression. We aim to determine the functions and targeted suppress of AEP in a mouse model of breast cancer-induced bone pain. Methods Breast cancer cells with AEP knocked-down or overexpression were constructed and implanted into the intramedullary space of the femur to induce pain-like behavior in mice. AEP-specific inhibitors or purified AEP proteins were further used in animal model. The histological characters of femur and pain ethological changes were measured. The expressions of AEP and neurotrophin receptors (p75NTR and TrkA) in dorsal root ganglion and spinal cord were examined. Results Femur radiographs and histological analysis revealed that cells with AEP knocked-down reduced bone destruction and pain behaviors. However, cells with AEP overexpression elevated bone damage and pain behaviors. Further, Western blot results found that the expressions of p75NTR and TrkA in dorsal root ganglions and spinal cords were reduced in mice inoculated with AEP knocked-down cells. Targeted suppression of AEP with specific small compounds significantly reduced the bone pain while purified recombinant AEP proteins increased bone pain. Conclusions AEP aggravate the development of breast cancer bone metastasis and bone pain by increasing the expression of neurotrophin receptors. AEP might be an effective target for treatment of breast cancerinduced bone pain.

  9. 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

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    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.

  10. 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. PMID:25788929

  11. 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.

  12. 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.

  13. 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.

  14. The Role of Rab Proteins in Neuronal Cells and in the Trafficking of Neurotrophin Receptors

    Science.gov (United States)

    Bucci, Cecilia; Alifano, Pietro; Cogli, Laura

    2014-01-01

    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. PMID:25295627

  15. Germline Transgenic Methods for Tracking Cells and Testing Gene Function during Regeneration in the Axolotl

    Science.gov (United States)

    Khattak, Shahryar; Schuez, Maritta; Richter, Tobias; Knapp, Dunja; Haigo, Saori L.; Sandoval-Guzmán, Tatiana; Hradlikova, Kristyna; Duemmler, Annett; Kerney, Ryan; Tanaka, Elly M.

    2013-01-01

    The salamander is the only tetrapod that regenerates complex body structures throughout life. Deciphering the underlying molecular processes of regeneration is fundamental for regenerative medicine and developmental biology, but the model organism had limited tools for molecular analysis. We describe a comprehensive set of germline transgenic strains in the laboratory-bred salamander Ambystoma mexicanum (axolotl) that open up the cellular and molecular genetic dissection of regeneration. We demonstrate tissue-dependent control of gene expression in nerve, Schwann cells, oligodendrocytes, muscle, epidermis, and cartilage. Furthermore, we demonstrate the use of tamoxifen-induced Cre/loxP-mediated recombination to indelibly mark different cell types. Finally, we inducibly overexpress the cell-cycle inhibitor p16INK4a, which negatively regulates spinal cord regeneration. These tissue-specific germline axolotl lines and tightly inducible Cre drivers and LoxP reporter lines render this classical regeneration model molecularly accessible. PMID:24052945

  16. A forgotten facial nerve tumour: granular cell tumour of the parotid and its implications for treatment.

    Science.gov (United States)

    Lerut, B; Vosbeck, J; Linder, T E

    2011-04-01

    We present a rare case of a facial nerve granular cell tumour in the right parotid gland, in a 10-year-old boy. A parotid or neurogenic tumour was suspected, based on magnetic resonance imaging. Intra-operatively, strong adhesions to surrounding structures were found, and a midfacial nerve branch had to be sacrificed for complete tumour removal. Recent reports verify that granular cell tumours arise from Schwann cells of peripheral nerve branches. The rarity of this tumour within the parotid gland, its origin from peripheral nerves, its sometimes misleading imaging characteristics, and its rare presentation with facial weakness and pain all have considerable implications on the surgical strategy and pre-operative counselling. Fine needle aspiration cytology may confirm the neurogenic origin of this lesion. When resecting the tumour, the surgeon must anticipate strong adherence to the facial nerve and be prepared to graft, or sacrifice, certain branches of this nerve.

  17. 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

  18. 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

    2017-06-27

    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.

  19. 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.

  20. 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.

  1. Delayed nerve stimulation promotes axon-protective neurofilament phosphorylation, accelerates immune cell clearance and enhances remyelination in vivo in focally demyelinated nerves.

    Science.gov (United States)

    McLean, Nikki A; Popescu, Bogdan F; Gordon, Tessa; Zochodne, Douglas W; Verge, Valerie M K

    2014-01-01

    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.

  2. 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.

  3. Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

    Science.gov (United States)

    Coste, Cécile; Neirinckx, Virginie; Gothot, André; Wislet, Sabine; Rogister, Bernard

    2015-01-01

    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 (CXCL) 12-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-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.

  4. Peripheral Glial Cells in the Development of Diabetic Neuropathy

    Science.gov (United States)

    Gonçalves, Nádia Pereira; Vægter, Christian Bjerggaard; Pallesen, Lone Tjener

    2018-01-01

    The global prevalence of diabetes is rapidly increasing, affecting more than half a billion individuals within the next few years. As diabetes negatively affects several physiological systems, this dramatic increase represents not only impaired quality of life on the individual level but also a huge socioeconomic challenge. One of the physiological consequences affecting up to half of diabetic patients is the progressive deterioration of the peripheral nervous system, resulting in spontaneous pain and eventually loss of sensory function, motor weakness, and organ dysfunctions. Despite intense research on the consequences of hyperglycemia on nerve functions, the biological mechanisms underlying diabetic neuropathy are still largely unknown, and treatment options lacking. Research has mainly focused directly on the neuronal component, presumably from the perspective that this is the functional signal-transmitting unit of the nerve. However, it is noteworthy that each single peripheral sensory neuron is intimately associated with numerous glial cells; the neuronal soma is completely enclosed by satellite glial cells and the length of the longest axons covered by at least 1,000 Schwann cells. The glial cells are vital for the neuron, but very little is still known about these cells in general and especially how they respond to diabetes in terms of altered neuronal support. We will discuss current knowledge of peripheral glial cells and argue that increased research in these cells is imperative for a better understanding of the mechanisms underlying diabetic neuropathy. PMID:29770116

  5. Cell Therapy in Spinal Cord Injury: a Mini- Reivew

    Directory of Open Access Journals (Sweden)

    Soraya Mehrabi

    2013-04-01

    Full Text Available 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.

  6. Induction of Skin-Derived Precursor Cells from Human Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Sugiyama-Nakagiri, Yoriko; Fujimura, Tsutomu; Moriwaki, Shigeru

    2016-01-01

    The generation of full thickness human skin from dissociated cells is an attractive approach not only for treating skin diseases, but also for treating many systemic disorders. However, it is currently not possible to obtain an unlimited number of skin dermal cells. The goal of this study was to develop a procedure to produce skin dermal stem cells from induced pluripotent stem cells (iPSCs). Skin-derived precursor cells (SKPs) were isolated as adult dermal precursors that could differentiate into both neural and mesodermal progenies and could reconstitute the dermis. Thus, we attempted to generate SKPs from iPSCs that could reconstitute the skin dermis. Human iPSCs were initially cultured with recombinant noggin and SB431542, an inhibitor of activin/nodal and TGFβ signaling, to induce neural crest progenitor cells. Those cells were then treated with SKP medium that included CHIR99021, a WNT signal activator. The induction efficacy from neural crest progenitor cells to SKPs was more than 97%. No other modifiers tested were able to induce those cells. Those human iPSC-derived SKPs (hiPSC-SKPs) showed a similar gene expression signature to SKPs isolated from human skin dermis. Human iPSC-SKPs differentiated into neural and mesodermal progenies, including adipocytes, skeletogenic cell types and Schwann cells. Moreover, they could be induced to follicular type keratinization when co-cultured with human epidermal keratinocytes. We here provide a new efficient protocol to create human skin dermal stem cells from hiPSCs that could contribute to the treatment of various skin disorders.

  7. 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.

  8. 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

    2013-01-01

    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

  9. Effects of age and insulin-like growth factor-1 on rat neurotrophin receptor expression after nerve injury.

    Science.gov (United States)

    Luo, T David; Alton, Timothy B; Apel, Peter J; Cai, Jiaozhong; Barnwell, Jonathan C; Sonntag, William E; Smith, Thomas L; Li, Zhongyu

    2016-10-01

    Neurotrophin receptors, such as p75(NTR) , direct neuronal response to injury. Insulin-like growth factor-1 receptor (IGF-1R) mediates the increase in p75(NTR) during aging. The aim of this study was to examine the effect of aging and insulin-like growth factor-1 (IGF-1) treatment on recovery after peripheral nerve injury. Young and aged rats underwent tibial nerve transection with either local saline or IGF-1 treatment. Neurotrophin receptor mRNA and protein expression were quantified. Aged rats expressed elevated baseline IGF-1R (34% higher, P = 0.01) and p75(NTR) (68% higher, P < 0.01) compared with young rats. Post-injury, aged animals expressed significantly higher p75(NTR) levels (68.5% above baseline at 4 weeks). IGF-1 treatment suppressed p75(NTR) gene expression at 4 weeks (17.2% above baseline, P = 0.002) post-injury. Local IGF-1 treatment reverses age-related declines in recovery after peripheral nerve injuries by suppressing p75(NTR) upregulation and pro-apoptotic complexes. IGF-1 may be considered a viable adjuvant therapy to current treatment modalities. Muscle Nerve 54: 769-775, 2016. © 2016 Wiley Periodicals, Inc.

  10. Towards the PET radiotracer for p75 neurotrophin receptor: [(11)C]LM11A-24 shows biological activity in vitro, but unfavorable ex vivo and in vivo profile.

    Science.gov (United States)

    Gibon, Julien; Kang, Min Su; Aliaga, Arturo; Sharif, Behrang; Rosa-Neto, Pedro; Séguéla, Philippe; Barker, Philip A; Kostikov, Alexey

    2016-10-01

    Mature neurotrophins as well as their pro forms are critically involved in the regulation of neuronal functions. They are signaling through three distinct types of receptors: tropomyosin receptor kinase family (TrkA/B/C), p75 neurotrophin receptor (p75(NTR)) and sortilin. Aberrant expression of p75(NTR) in the CNS is implicated in a variety of neurodegenerative diseases, including Alzheimer's disease. The goal of this work was to evaluate one of the very few reported p75(NTR) small molecule ligands as a lead compound for development of novel PET radiotracers for in vivo p75(NTR) imaging. Here we report that previously described ligand LM11A-24 shows significant inhibition of carbachol-induced persistent firing (PF) of entorhinal cortex (EC) pyramidal neurons in wild-type mice via selective interaction with p75(NTR). Based on this electrophysiological assay, the compound has very high potency with an EC50<10nM. We optimized the radiosynthesis of [(11)C]LM11A-24 as the first attempt to develop PET radioligand for in vivo imaging of p75(NTR). Despite some weak interaction with CNS tissues, the radiolabeled compound showed unfavorable in vivo profile presumably due to high hydrophilicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Human hair follicle pluripotent stem (hfPS) cells promote regeneration of peripheral-nerve injury: an advantageous alternative to ES and iPS cells.

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    Amoh, Yasuyuki; Kanoh, Maho; Niiyama, Shiro; Hamada, Yuko; Kawahara, Katsumasa; Sato, Yuichi; Hoffman, Robert M; Katsuoka, Kensei

    2009-08-01

    The optimal source of stem cells for regenerative medicine is a major question. Embryonic stem (ES) cells have shown promise for pluripotency but have ethical issues and potential to form teratomas. Pluripotent stem cells have been produced from skin cells by either viral-, plasmid- or transposon-mediated gene transfer. These stem cells have been termed induced pluripotent stem cells or iPS cells. iPS cells may also have malignant potential and are inefficiently produced. Embryonic stem cells may not be suited for individualized therapy, since they can undergo immunologic rejection. To address these fundamental problems, our group is developing hair follicle pluripotent stem (hfPS) cells. Our previous studies have shown that mouse hfPS cells can differentiate to neurons, glial cells in vitro, and other cell types, and can promote nerve and spinal cord regeneration in vivo. hfPS cells are located above the hair follicle bulge in what we have termed the hfPS cell area (hfPSA) and are nestin positive and keratin 15 (K-15) negative. Human hfPS cells can also differentiate into neurons, glia, keratinocytes, smooth muscle cells, and melanocytes in vitro. In the present study, human hfPS cells were transplanted in the severed sciatic nerve of the mouse where they differentiated into glial fibrillary-acidic-protein (GFAP)-positive Schwann cells and promoted the recovery of pre-existing axons, leading to nerve generation. The regenerated nerve recovered function and, upon electrical stimulation, contracted the gastrocnemius muscle. The hfPS cells can be readily isolated from the human scalp, thereby providing an accessible, autologous and safe source of stem cells for regenerative medicine that have important advantages over ES or iPS cells. (c) 2009 Wiley-Liss, Inc.

  12. Roles of neural stem cells in the repair of peripheral nerve injury.

    Science.gov (United States)

    Wang, Chong; Lu, Chang-Feng; Peng, Jiang; Hu, Cheng-Dong; Wang, Yu

    2017-12-01

    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.

  13. The Palmitoylation State of PMP22 Modulates Epithelial Cell Morphology and Migration

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    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.

  14. The Effect of Plasma Treated PLGA/MWCNTs-COOH Composite Nanofibers on Nerve Cell Behavior

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    Jing Wang

    2017-12-01

    Full Text Available Electrospun nanofibrous scaffolds which can mimic the architecture of the natural extracellular matrix (ECM are potential candidates for peripheral nerve repair application. Multi-walled carbon nanotubes (MWCNTs are used in peripheral nerve repair due to their ability to promote neurite extension and support neural network formation. In this study, surface-modified nanofibrous scaffolds composed of poly(lactic-co-glycolic acid (PLGA and various ratios of carboxyl-modified MWCNTs (MWCNTs-COOH (PC0, PC2, PC4 and PC8 were fabricated by electrospinning. The effects of MWCNTs-COOH on the fibers’ morphology, diameter distribution, mechanical properties and surface hydrophilicity were characterized by Scanning Electron Microscopy (SEM, ImageJ software, tensile testing and water contact angle. Furthermore, air plasma treatment was applied to improve the surface hydrophilicity of the scaffolds, and the optimal treatment condition was determined in terms of surface morphology, water contact angle and PC12 cell adhesion. Plasma treated nanofibers (p-PC0, p-PC2, p-PC4 and p-PC8 under optimal treatment conditions were used for further study. PC12 cell proliferation and differentiation were both improved by the addition of MWCNTs-COOH in scaffolds. Additionally, the proliferation and maturation of Schwann cells were enhanced on scaffolds containing MWCNTs-COOH. The neurite outgrowth of rat dorsal root ganglia (DRG neurons was promoted on MWCNTs-COOH-containing scaffolds, and those cultured on p-PC8 scaffolds showed elongated neurites with a length up to 78.27 μm after 3 days culture. Our results suggested that plasma treated nanofibers under appropriate conditions were able to improve cell attachment. They also demonstrated that plasma treated scaffolds containing MWCNTs-COOH, especially the p-PC8 nanofibrous scaffold could support the proliferation, differentiation, maturation and neurite extension of PC12 cells, Schwann cells and DRG neurons. Therefore

  15. Promoting peripheral myelin repair

    OpenAIRE

    Zhou, Ye; Notterpek, Lucia

    2016-01-01

    Compared to the central nervous system (CNS), peripheral nerves have a remarkable ability to regenerate and remyelinate. This regenerative capacity to a large extent is dependent on and supported by Schwann cells, the myelin-forming glial cells of the peripheral nervous system (PNS). In a variety of paradigms, Schwann cells are critical in the removal of the degenerated tissue, which is followed by remyelination of newly-regenerated axons. This unique plasticity of Schwann cells has been the ...

  16. Contribution of Underlying Connective Tissue Cells to Taste Buds in Mouse Tongue and Soft Palate

    Science.gov (United States)

    Mederacke, Ingmar; Komatsu, Yoshihiro; Stice, Steve; Schwabe, Robert F.; Mistretta, Charlotte M.; Mishina, Yuji; Liu, Hong-Xiang

    2016-01-01

    Taste buds, the sensory organs for taste, have been described as arising solely from the surrounding epithelium, which is in distinction from other sensory receptors that are known to originate from neural precursors, i.e., neural ectoderm that includes neural crest (NC). Our previous study suggested a potential contribution of NC derived cells to early immature fungiform taste buds in late embryonic (E18.5) and young postnatal (P1-10) mice. In the present study we demonstrated the contribution of the underlying connective tissue (CT) to mature taste buds in mouse tongue and soft palate. Three independent mouse models were used for fate mapping of NC and NC derived connective tissue cells: (1) P0-Cre/R26-tdTomato (RFP) to label NC, NC derived Schwann cells and derivatives; (2) Dermo1-Cre/RFP to label mesenchymal cells and derivatives; and (3) Vimentin-CreER/mGFP to label Vimentin-expressing CT cells and derivatives upon tamoxifen treatment. Both P0-Cre/RFP and Dermo1-Cre/RFP labeled cells were abundant in mature taste buds in lingual taste papillae and soft palate, but not in the surrounding epithelial cells. Concurrently, labeled cells were extensively distributed in the underlying CT. RFP signals were seen in the majority of taste buds and all three types (I, II, III) of differentiated taste bud cells, with the neuronal-like type III cells labeled at a greater proportion. Further, Vimentin-CreER labeled cells were found in the taste buds of 3-month-old mice whereas Vimentin immunoreactivity was only seen in the CT. Taken together, our data demonstrate a previously unrecognized origin of taste bud cells from the underlying CT, a conceptually new finding in our knowledge of taste bud cell derivation, i.e., from both the surrounding epithelium and the underlying CT that is primarily derived from NC. PMID:26741369

  17. Contribution of Underlying Connective Tissue Cells to Taste Buds in Mouse Tongue and Soft Palate.

    Directory of Open Access Journals (Sweden)

    Kristin Boggs

    Full Text Available Taste buds, the sensory organs for taste, have been described as arising solely from the surrounding epithelium, which is in distinction from other sensory receptors that are known to originate from neural precursors, i.e., neural ectoderm that includes neural crest (NC. Our previous study suggested a potential contribution of NC derived cells to early immature fungiform taste buds in late embryonic (E18.5 and young postnatal (P1-10 mice. In the present study we demonstrated the contribution of the underlying connective tissue (CT to mature taste buds in mouse tongue and soft palate. Three independent mouse models were used for fate mapping of NC and NC derived connective tissue cells: (1 P0-Cre/R26-tdTomato (RFP to label NC, NC derived Schwann cells and derivatives; (2 Dermo1-Cre/RFP to label mesenchymal cells and derivatives; and (3 Vimentin-CreER/mGFP to label Vimentin-expressing CT cells and derivatives upon tamoxifen treatment. Both P0-Cre/RFP and Dermo1-Cre/RFP labeled cells were abundant in mature taste buds in lingual taste papillae and soft palate, but not in the surrounding epithelial cells. Concurrently, labeled cells were extensively distributed in the underlying CT. RFP signals were seen in the majority of taste buds and all three types (I, II, III of differentiated taste bud cells, with the neuronal-like type III cells labeled at a greater proportion. Further, Vimentin-CreER labeled cells were found in the taste buds of 3-month-old mice whereas Vimentin immunoreactivity was only seen in the CT. Taken together, our data demonstrate a previously unrecognized origin of taste bud cells from the underlying CT, a conceptually new finding in our knowledge of taste bud cell derivation, i.e., from both the surrounding epithelium and the underlying CT that is primarily derived from NC.

  18. Contribution of Underlying Connective Tissue Cells to Taste Buds in Mouse Tongue and Soft Palate.

    Science.gov (United States)

    Boggs, Kristin; Venkatesan, Nandakumar; Mederacke, Ingmar; Komatsu, Yoshihiro; Stice, Steve; Schwabe, Robert F; Mistretta, Charlotte M; Mishina, Yuji; Liu, Hong-Xiang

    2016-01-01

    Taste buds, the sensory organs for taste, have been described as arising solely from the surrounding epithelium, which is in distinction from other sensory receptors that are known to originate from neural precursors, i.e., neural ectoderm that includes neural crest (NC). Our previous study suggested a potential contribution of NC derived cells to early immature fungiform taste buds in late embryonic (E18.5) and young postnatal (P1-10) mice. In the present study we demonstrated the contribution of the underlying connective tissue (CT) to mature taste buds in mouse tongue and soft palate. Three independent mouse models were used for fate mapping of NC and NC derived connective tissue cells: (1) P0-Cre/R26-tdTomato (RFP) to label NC, NC derived Schwann cells and derivatives; (2) Dermo1-Cre/RFP to label mesenchymal cells and derivatives; and (3) Vimentin-CreER/mGFP to label Vimentin-expressing CT cells and derivatives upon tamoxifen treatment. Both P0-Cre/RFP and Dermo1-Cre/RFP labeled cells were abundant in mature taste buds in lingual taste papillae and soft palate, but not in the surrounding epithelial cells. Concurrently, labeled cells were extensively distributed in the underlying CT. RFP signals were seen in the majority of taste buds and all three types (I, II, III) of differentiated taste bud cells, with the neuronal-like type III cells labeled at a greater proportion. Further, Vimentin-CreER labeled cells were found in the taste buds of 3-month-old mice whereas Vimentin immunoreactivity was only seen in the CT. Taken together, our data demonstrate a previously unrecognized origin of taste bud cells from the underlying CT, a conceptually new finding in our knowledge of taste bud cell derivation, i.e., from both the surrounding epithelium and the underlying CT that is primarily derived from NC.

  19. 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.

  20. Ex Vivo Assay of Electrical Stimulation to Rat Sciatic Nerves: Cell Behaviors and Growth Factor Expression.

    Science.gov (United States)

    Du, Zhiyong; Bondarenko, Olexandr; Wang, Dingkun; Rouabhia, Mahmoud; Zhang, Ze

    2016-06-01

    Neurite outgrowth and axon regeneration are known to benefit from electrical stimulation. However, how neuritis and their surroundings react to electrical field is difficult to replicate by monolayer cell culture. In this work freshly harvested rat sciatic nerves were cultured and exposed to two types of electrical field, after which time the nerve tissues were immunohistologically stained and the expression of neurotrophic factors and cytokines were evaluated. ELISA assay was used to confirm the production of specific proteins. All cell populations survived the 48 h culture with little necrosis. Electrical stimulation was found to accelerate Wallerian degeneration and help Schwann cells to switch into migratory phenotype. Inductive electrical stimulation was shown to upregulate the secretion of multiple neurotrophic factors. Cellular distribution in nerve tissue was altered upon the application of an electrical field. This work thus presents an ex vivo model to study denervated axon in well controlled electrical field, bridging monolayer cell culture and animal experiment. It also demonstrated the critical role of electrical field distribution in regulating cellular activities. © 2015 Wiley Periodicals, Inc.

  1. Direct visualization of membrane architecture of myelinating cells in transgenic mice expressing membrane-anchored EGFP.

    Science.gov (United States)

    Deng, Yaqi; Kim, BongWoo; He, Xuelian; Kim, Sunja; Lu, Changqing; Wang, Haibo; Cho, Ssang-Goo; Hou, Yiping; Li, Jianrong; Zhao, Xianghui; Lu, Q Richard

    2014-04-01

    Myelinogenesis is a complex process that involves substantial and dynamic changes in plasma membrane architecture and myelin interaction with axons. Highly ramified processes of oligodendrocytes in the central nervous system (CNS) make axonal contact and then extrapolate to wrap around axons and form multilayer compact myelin sheathes. Currently, the mechanisms governing myelin sheath assembly and axon selection by myelinating cells are not fully understood. Here, we generated a transgenic mouse line expressing the membrane-anchored green fluorescent protein (mEGFP) in myelinating cells, which allow live imaging of details of myelinogenesis and cellular behaviors in the nervous systems. mEGFP expression is driven by the promoter of 2'-3'-cyclic nucleotide 3'-phosphodiesterase (CNP) that is expressed in the myelinating cell lineage. Robust mEGFP signals appear in the membrane processes of oligodendrocytes in the CNS and Schwann cells in the peripheral nervous system (PNS), wherein mEGFP expression defines the inner layers of myelin sheaths and Schmidt-Lanterman incisures in adult sciatic nerves. In addition, mEGFP expression can be used to track the extent of remyelination after demyelinating injury in a toxin-induced demyelination animal model. Taken together, the membrane-anchored mEGFP expression in the new transgenic line would facilitate direct visualization of dynamic myelin membrane formation and assembly during development and process remodeling during remyelination after various demyelinating injuries.

  2. 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.

  3. The oligodendroglial precursor cell line Oli-neu represents a cell culture system to examine functional expression of the mouse gap junction gene connexin29 (Cx29

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    Goran Christoph Söhl

    2013-06-01

    Full Text Available The potential gap junction forming mouse connexin29 (Cx29 protein is concomitantly expressed with connexin32 (Cx32 in peripheral myelin forming Schwann cells and together with both Cx32 and connexin47 (Cx47 in oligodendrocytes of the CNS. To study the genomic structure and functional expression of Cx29, either primary cells or cell culture systems might be selected, from which the latter are easier to cultivate. Both structure and expression of Cx29 is still not fully understood. In the mouse sciatic nerve, brain and the oligodendroglial precursor cell line Oli-neu the Cx29 gene is processed in two transcript isoforms both harbouring a unique reading frame. In contrast to Cx32 and Cx47, only Cx29 protein is abundantly expressed in undifferentiated as well as differentiated Oli-neu cells but the absence of Etbr dye transfer after microinjection concealed the function of Cx29 mediated gap junction communication between those cells. Although HeLa cells stably transfected with Cx29 or Cx29-eGFP neither demonstrated any permeability for Lucifer yellow nor for neurobiotin, blocking of Etbr uptake from the media by gap junction blockers does suppose a role of Cx29 in hemi-channel function. Thus, we conclude that, due to its high abundance of Cx29 expression and its reproducible culture conditions, the oligodendroglial precursor cell line Oli-neu might constitute an appropriate cell culture system to study molecular mechanisms or putative extracellular stimuli to functionally open Cx29 channels or hemi-channels.

  4. Late calcium EDTA rescues hippocampal CA1 neurons from global ischemia-induced death.

    Science.gov (United States)

    Calderone, Agata; Jover, Teresa; Mashiko, Toshihiro; Noh, Kyung-min; Tanaka, Hidenobu; Bennett, Michael V L; Zukin, R Suzanne

    2004-11-03

    Transient global ischemia induces a delayed rise in intracellular Zn2+, which may be mediated via glutamate receptor 2 (GluR2)-lacking AMPA receptors (AMPARs), and selective, delayed death of hippocampal CA1 neurons. The molecular mechanisms underlying Zn2+ toxicity in vivo are not well delineated. Here we show the striking finding that intraventricular injection of the high-affinity Zn2+ chelator calcium EDTA (CaEDTA) at 30 min before ischemia (early CaEDTA) or at 48-60 hr (late CaEDTA), but not 3-6 hr, after ischemia, afforded robust protection of CA1 neurons in approximately 50% (late CaEDTA) to 75% (early CaEDTA) of animals. We also show that Zn2+ acts via temporally distinct mechanisms to promote neuronal death. Early CaEDTA attenuated ischemia-induced GluR2 mRNA and protein downregulation (and, by inference, formation of Zn2+-permeable AMPARs), the delayed rise in Zn2+, and neuronal death. These findings suggest that Zn2+ acts at step(s) upstream from GluR2 gene downregulation and implicate Zn2+ in transcriptional regulation and/or GluR2 mRNA stability. Early CaEDTA also blocked mitochondrial release of cytochrome c and Smac/DIABLO (second mitochondria-derived activator of caspases/direct inhibitor of apoptosis protein-binding protein with low pI), caspase-3 activity (but not procaspase-3 cleavage), p75NTR induction, and DNA fragmentation. These findings indicate that CaEDTA preserves the functional integrity of the mitochondrial outer membrane and arrests the caspase death cascade. Late injection of CaEDTA at a time when GluR2 is downregulated and caspase is activated inhibited the delayed rise in Zn2+, p75NTR induction, DNA fragmentation, and cell death. The finding of neuroprotection by late CaEDTA administration has striking implications for intervention in the delayed neuronal death associated with global ischemia.

  5. An All-Recombinant Protein-Based Culture System Specifically Identifies Hematopoietic Stem Cell Maintenance Factors

    Directory of Open Access Journals (Sweden)

    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.

  6. In vitro formation of the Merkel cell-neurite complex in embryonic mouse whiskers using organotypic co-cultures.

    Science.gov (United States)

    Ishida, Kentaro; Saito, Tetsuichiro; Mitsui, Toshiyuki

    2018-06-01

    A Merkel cell-neurite complex is a touch receptor composed of specialized epithelial cells named Merkel cells and peripheral sensory nerves in the skin. Merkel cells are found in touch-sensitive skin components including whisker follicles. The nerve fibers that innervate Merkel cells of a whisker follicle extend from the maxillary branch of the trigeminal ganglion. Whiskers as a sensory organ attribute to the complicated architecture of the Merkel cell-neurite complex, and therefore it is intriguing how the structure is formed. However, observing the dynamic process of the formation of a Merkel cell-neurite complex in whiskers during embryonic development is still difficult. In this study, we tried to develop an organotypic co-culture method of a whisker pad and a trigeminal ganglion explant to form the Merkel cell-neurite complex in vitro. We initially developed two distinct culture methods of a single whisker row and a trigeminal ganglion explant, and then combined them. By dissecting and cultivating a single row from a whisker pad, the morphogenesis of whisker follicles could be observed under a microscope. After the co-cultivation of the whisker row with a trigeminal ganglion explant, a Merkel cell-neurite complex composed of Merkel cells, which were positive for both cytokeratin 8 and SOX2, Neurofilament-H-positive trigeminal nerve fibers and Schwann cells expressing Nestin, SOX2 and SOX10 was observed via immunohistochemical analyses. These results suggest that the process for the formation of a Merkel cell-neurite complex can be observed under a microscope using our organotypic co-culture method. © 2018 Japanese Society of Developmental Biologists.

  7. Unique in vivo properties of olfactory ensheathing cells that may contribute to neural repair and protection following spinal cord injury

    Science.gov (United States)

    Kocsis, Jeffery D.; Lankford, Karen L.; Sasaki, Masanori; Radtke, Christine

    2009-01-01

    Olfactory ensheathing cells (OECs) are specialized glial cells that guide olfactory receptor axons from the nasal mucosa into the brain where they make synaptic contacts in the olfactory bulb. While a number of studies have demonstrated that in vivo transplantation of OECs into injured spinal cord results in improved functional outcome, precise cellular mechanisms underlying this improvement are not fully understood. Current thinking is that OECs can encourage axonal regeneration, provide trophic support for injured neurons and for angiogenesis, and remyelinate axons. However, Schwann cell (SC) transplantation also results in significant functional improvement in animal models of spinal cord injury. In culture SCs and OECs share a number of phenotypic properties such as expression of the low affinity NGF receptor (p75). An important area of research has been to distinguish potential differences in the in vivo behavior of OECs and SCs to determine if one cell type may offer greater advantage as a cellular therapeutic candidate. In this review we focus on several unique features of OECs when they are transplanted into the spinal cord. PMID:19429149

  8. Integration of donor mesenchymal stem cell-derived neuron-like cells into host neural network after rat spinal cord transection.

    Science.gov (United States)

    Zeng, Xiang; Qiu, Xue-Cheng; Ma, Yuan-Huan; Duan, Jing-Jing; Chen, Yuan-Feng; Gu, Huai-Yu; Wang, Jun-Mei; Ling, Eng-Ang; Wu, Jin-Lang; Wu, Wutian; Zeng, Yuan-Shan

    2015-06-01

    Functional deficits following spinal cord injury (SCI) primarily attribute to loss of neural connectivity. We therefore tested if novel tissue engineering approaches could enable neural network repair that facilitates functional recovery after spinal cord transection (SCT). Rat bone marrow-derived mesenchymal stem cells (MSCs), genetically engineered to overexpress TrkC, receptor of neurotrophin-3 (NT-3), were pre-differentiated into cells carrying neuronal features via co-culture with NT-3 overproducing Schwann cells in 3-dimensional gelatin sponge (GS) scaffold for 14 days in vitro. Intra-GS formation of MSC assemblies emulating neural network (MSC-GS) were verified morphologically via electron microscopy (EM) and functionally by whole-cell patch clamp recording of spontaneous post-synaptic currents. The differentiated MSCs still partially maintained prototypic property with the expression of some mesodermal cytokines. MSC-GS or GS was then grafted acutely into a 2 mm-wide transection gap in the T9-T10 spinal cord segments of adult rats. Eight weeks later, hindlimb function of the MSC-GS-treated SCT rats was significantly improved relative to controls receiving the GS or lesion only as indicated by BBB score. The MSC-GS transplantation also significantly recovered cortical motor evoked potential (CMEP). Histologically, MSC-derived neuron-like cells maintained their synapse-like structures in vivo; they additionally formed similar connections with host neurites (i.e., mostly serotonergic fibers plus a few corticospinal axons; validated by double-labeled immuno-EM). Moreover, motor cortex electrical stimulation triggered c-fos expression in the grafted and lumbar spinal cord cells of the treated rats only. Our data suggest that MSC-derived neuron-like cells resulting from NT-3-TrkC-induced differentiation can partially integrate into transected spinal cord and this strategy should be further investigated for reconstructing disrupted neural circuits. Copyright

  9. Isolation and characterization of two kinds of stem cells from the same human skin back sample with therapeutic potential in spinal cord injury.

    Directory of Open Access Journals (Sweden)

    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

  10. Reconstruction of radical prostatectomy-induced urethral damage using skeletal muscle-derived multipotent stem cells.

    Science.gov (United States)

    Hoshi, Akio; Tamaki, Tetsuro; Tono, Kayoko; Okada, Yoshinori; Akatsuka, Akira; Usui, Yukio; Terachi, Toshiro

    2008-06-15

    Postoperative damage of the urethral rhabdosphincter (URS) and neurovascular bundle (NVB) is a major operative complication of radical prostatectomy. It is generally recognized to be caused by unavoidable surgical damage to the muscle-nerve-blood vessel units around the urethra. We attempted to treat this damage using skeletal muscle-derived stem cells, which are able to reconstitute muscle-nerve-blood vessel units. Cells were enzymatically extracted and sorted by flow cytometry as CD34/45 (Sk-34) and CD34/45 (Sk-DN) cells from green fluorescent protein transgenic mice and rats. URS-NVB damage was induced by manually removing one-third of the total URS and unilateral invasion of NVB in wild-type Sprague-Dawley and node rats. Freshly isolated Sk-34, Sk-34+Sk-DN cells, and cultured Sk-DN cells were directly transplanted into the damaged portion. At 4 and 12 weeks after transplantation, urethral pressure profile by electrical stimulation through the sacral surface (L6-S1) was evaluated as functional recovery. The recovery ratio in the control and transplanted groups was 37.6% and 72.9%, at 4 weeks, and 41.6% and 78.4% at 12 weeks, respectively (Pcells differentiated into numerous skeletal muscle fibers having neuromuscular junctions (innervation) and nerve bundle-related Schwann cells and perineurium, and blood vessel-related endothelial cells and pericyte around the urethra. Thus, we conclude that transplantation of skeletal muscle-derived multipotent Sk-34 and Sk-DN cells is potentially useful for the reconstitution of postoperative damage of URS and NVB after radical prostatectomy.

  11. Neurotrophins, their receptors and KI-67 in human GH-secreting pituitary adenomas: an immunohistochemical analysis.

    Science.gov (United States)

    Artico, M; Bianchi, E; Magliulo, G; De Vincentiis, M; De Santis, E; Orlandi, A; Santoro, A; Pastore, F S; Giangaspero, F; Caruso, R; Re, M; Fumagalli, L

    2012-01-01

    Pituitary adenomas are a diverse group of tumors arising from the pituitary gland. Typically, they are small, slow-growing, hormonally inactive lesions that come to light as incidental findings on radiologic or postmortem examinations, although some small, slow-growing lesions with excessive hormonal activity may manifest with a clinical syndrome. The family of neurotrophins plays a key role in the development and maintenance of the pituitary endocrine cell function and in the regulation of hypothalamo-pituitary-adrenocortical axis activity. The objective of our experimental study is to investigate the localization of the neurotrophins, their relative receptors and to detect the expression level of Ki-67 to determine whether all these factors participate in the transformation and development of human pituitary adenomas. A very strong expression of Neurotrophin-3 (NT-3) and its receptor TrKC was observed in the extracellular matrix (ECM) and vessel endothelium, together with a clear/marked presence of Brain-derived neurotrophic factor (BDNF), and its receptor TrKB, thus confirming their direct involvement in the progression of pituitary adenomas. On the contrary, NGF (Nerve growth factor) and its receptor TrKA and p75NTR were weakly expressed in the epithelial gland cells and the ECM.

  12. NRAGE induces β-catenin/Arm O-GlcNAcylation and negatively regulates Wnt signaling

    International Nuclear Information System (INIS)

    Chen, Yuxin; Jin, Lei; Xue, Bin; Jin, Dong; Sun, Fenyong; Wen, Chuanjun

    2017-01-01

    The Wnt pathway is crucial for animal development, as well as tumor formation. Understanding the regulation of Wnt signaling will help to elucidate the mechanism of the cell cycle, cell differentiation and tumorigenesis. It is generally accepted that in response to Wnt signals, β-catenin accumulates in the cytoplasm and is imported into the nucleus where it recruits LEF/TCF transcription factors to activate the expression of target genes. In this study, we report that human NRAGE, a neurotrophin receptor p75 (p75NTR) binding protein, markedly suppresses the expression of genes activated by the Wnt pathway. Consistent with this finding, loss of function of NRAGE by RNA interference (RNAi) activates the Wnt pathway. Moreover, NRAGE suppresses the induction of axis duplication by microinjected β-catenin in Xenopus embryos. To our surprise, NRAGE induces nuclear localization of β-catenin and increases its DNA binding ability. Further studies reveal that NRAGE leads to the modification of β-catenin/Arm with O-linked beta-N-acetylglucosamine (O-GlcNAc), and failure of the association between β-catenin/Arm and pygopus(pygo) protein, which is required for transcriptional activation of Wnt target genes. Therefore, our findings suggest a novel mechanism for regulating Wnt signaling. - Highlights: • NRAGE suppresses the expressions of Wnt pathway downstream genes. • NRAGE induces nuclear localization of β-catenin and increases its DNA binding ability. • NRAGE activity leads to the O-GlcNAcylation of β-catenin.

  13. 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

  14. Neurotrophin-4 in the brain of adult Nothobranchius furzeri.

    Science.gov (United States)

    D'Angelo, L; Avallone, L; Cellerino, A; de Girolamo, P; Paolucci, M; Varricchio, E; Lucini, C

    2016-09-01

    Neurotrophin-4 (NT-4) is a member of the well-known family of neurotrophins that regulate the development of neuronal networks by participating in neuronal survival and differentiation, the growth of neuronal processes, synaptic development and plasticity, as well as myelination. NT-4 interacts with two distinct receptors: TrkB, high affinity receptor and p75 low-affinity neurotrophin receptor (p75(NTR)). In the present survey, we identified the gene encoding NT-4 in the teleost Nothobranchius furzeri, a model species for aging research. The identified gene shows a similarity of about 72% with medaka, the closest related species. The neuroanatomical localization of NT-4 mRNA is obtained by using an LNA probe. NT-4 mRNA expression is observed in neurons and glial cells of the forebrain and hindbrain, with very low signal found in the midbrain. This survey confirms that NT-4 is expressed in the brain of N. furzeri during adulthood, suggesting that it could also be implicated in the maintenance and regulation of neuronal functions. Copyright © 2016 Elsevier GmbH. All rights reserved.

  15. 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.

  16. Purified Human Skeletal Muscle-Derived Stem Cells Enhance the Repair and Regeneration in the Damaged Urethra.

    Science.gov (United States)

    Nakajima, Nobuyuki; Tamaki, Tetsuro; Hirata, Maki; Soeda, Shuichi; Nitta, Masahiro; Hoshi, Akio; Terachi, Toshiro

    2017-10-01

    Postoperative damage of the urethral rhabdosphincter and nerve-vascular networks is a major complication of radical prostatectomy and generally causes incontinence and/or erectile dysfunction. The human skeletal muscle-derived stem cells, which have a synchronized reconstitution capacity of muscle-nerve-blood vessel units, were applied to this damage. Cells were enzymatically extracted from the human skeletal muscle, sorted using flow cytometry as CD34/45 (Sk-34) and CD29/34/45 (Sk-DN/29) fractions, and separately cultured/expanded in appropriate conditions within 2 weeks. Urethral damage was induced by manually removing one third of the wall of the muscle layer in nude rats. A mixture of expanded Sk-34 and Sk-DN/29 cells was applied on the damaged portion for the cell transplantation (CT) group. The same amount of media was used for the non-CT (NT) group. Urethral pressure profile was evaluated via electrical stimulation to assess functional recovery. Cell engraftments and differentiations were detected using immunohistochemistry and immunoelectron microscopy. Expression of angiogenic cytokines was also analyzed using reverse transcriptase-polymerase chain reaction and protein array. At 6 weeks after transplantation, the CT group showed a significantly higher functional recovery than the NT group (70.2% and 39.1%, respectively; P cells differentiated into skeletal muscle fibers, nerve-related Schwann cells, perineuriums, and vascular pericytes. Active paracrine angiogenic cytokines in the mixed cells were also detected with enhanced vascular formation in vivo. The transplantation of Sk-34 and Sk-DN/29 cells is potentially useful for the reconstitution of postoperative damage of the urethral rhabdosphincter and nerve-vascular networks.

  17. Adult-Brain-Derived Neural Stem Cells Grafting into a Vein Bridge Increases Postlesional Recovery and Regeneration in a Peripheral Nerve of Adult Pig

    Directory of Open Access Journals (Sweden)

    Olivier Liard

    2012-01-01

    Full Text Available We attempted transplantation of adult neural stem cells (ANSCs inside an autologous venous graft following surgical transsection of nervis cruralis with 30 mm long gap in adult pig. The transplanted cell suspension was a primary culture of neurospheres from adult pig subventricular zone (SVZ which had been labeled in vitro with BrdU or lentivirally transferred fluorescent protein. Lesion-induced loss of leg extension on the thigh became definitive in controls but was reversed by 45–90 days after neurosphere-filled vein grafting. Electromyography showed stimulodetection recovery in neurosphere-transplanted pigs but not in controls. Postmortem immunohistochemistry revealed neurosphere-derived cells that survived inside the venous graft from 10 to 240 post-lesion days and all displayed a neuronal phenotype. Newly formed neurons were distributed inside the venous graft along the severed nerve longitudinal axis. Moreover, ANSC transplantation increased CNPase expression, indicating activation of intrinsic Schwann cells. Thus ANSC transplantation inside an autologous venous graft provides an efficient repair strategy.

  18. Adipose-derived mesenchymal stem cells accelerate nerve regeneration and functional recovery in a rat model of recurrent laryngeal nerve injury

    Directory of Open Access Journals (Sweden)

    Yun Li

    2017-01-01

    Full Text Available Medialization thyroplasty or injection laryngoplasty for unilateral vocal fold paralysis cannot restore mobility of the vocal fold. Recent studies have shown that transplantation of mesenchymal stem cells is effective in the repair of nerve injuries. This study investigated whether adipose-derived stem cell transplantation could repair recurrent laryngeal nerve injury. Rat models of recurrent laryngeal nerve injury were established by crushing with micro forceps. Adipose-derived mesenchymal stem cells (ADSCs; 8 × 105 or differentiated Schwann-like adipose-derived mesenchymal stem cells (dADSCs; 8 × 105 or extracellular matrix were injected at the site of injury. At 2, 4 and 6 weeks post-surgery, a higher density of myelinated nerve fiber, thicker myelin sheath, improved vocal fold movement, better recovery of nerve conduction capacity and reduced thyroarytenoid muscle atrophy were found in ADSCs and dADSCs groups compared with the extracellular matrix group. The effects were more pronounced in the ADSCs group than in the dADSCs group. These experimental results indicated that ADSCs transplantation could be an early interventional strategy to promote regeneration after recurrent laryngeal nerve injury.

  19. Peripheral Nerve Regeneration by Secretomes of Stem Cells from Human Exfoliated Deciduous Teeth.

    Science.gov (United States)

    Sugimura-Wakayama, Yukiko; Katagiri, Wataru; Osugi, Masashi; Kawai, Takamasa; Ogata, Kenichi; Sakaguchi, Kohei; Hibi, Hideharu

    2015-11-15

    Peripheral nerve regeneration across nerve gaps is often suboptimal, with poor functional recovery. Stem cell transplantation-based regenerative therapy is a promising approach for axon regeneration and functional recovery of peripheral nerve injury; however, the mechanisms remain controversial and unclear. Recent studies suggest that transplanted stem cells promote tissue regeneration through a paracrine mechanism. We investigated the effects of conditioned media derived from stem cells from human exfoliated deciduous teeth (SHED-CM) on peripheral nerve regeneration. In vitro, SHED-CM-treated Schwann cells exhibited significantly increased proliferation, migration, and the expression of neuron-, extracellular matrix (ECM)-, and angiogenesis-related genes. SHED-CM stimulated neuritogenesis of dorsal root ganglia and increased cell viability. Similarly, SHED-CM enhanced tube formation in an angiogenesis assay. In vivo, a 10-mm rat sciatic nerve gap model was bridged by silicon conduits containing SHED-CM or serum-free Dulbecco's modified Eagle's medium. Light and electron microscopy confirmed that the number of myelinated axons and axon-to-fiber ratio (G-ratio) were significantly higher in the SHED-CM group at 12 weeks after nerve transection surgery. The sciatic functional index (SFI) and gastrocnemius (target muscle) wet weight ratio demonstrated functional recovery. Increased compound muscle action potentials and increased SFI in the SHED-CM group suggested sciatic nerve reinnervation of the target muscle and improved functional recovery. We also observed reduced muscle atrophy in the SHED-CM group. Thus, SHEDs may secrete various trophic factors that enhance peripheral nerve regeneration through multiple mechanisms. SHED-CM may therefore provide a novel therapy that creates a more desirable extracellular microenvironment for peripheral nerve regeneration.

  20. Gold nanoparticles functionalized with a fragment of the neural cell adhesion molecule L1 stimulate L1-mediated functions

    Science.gov (United States)

    Schulz, Florian; Lutz, David; Rusche, Norman; Bastús, Neus G.; Stieben, Martin; Höltig, Michael; Grüner, Florian; Weller, Horst; Schachner, Melitta; Vossmeyer, Tobias; Loers, Gabriele

    2013-10-01

    The neural cell adhesion molecule L1 is involved in nervous system development and promotes regeneration in animal models of acute and chronic injury of the adult nervous system. To translate these conducive functions into therapeutic approaches, a 22-mer peptide that encompasses a minimal and functional L1 sequence of the third fibronectin type III domain of murine L1 was identified and conjugated to gold nanoparticles (AuNPs) to obtain constructs that interact homophilically with the extracellular domain of L1 and trigger the cognate beneficial L1-mediated functions. Covalent conjugation was achieved by reacting mixtures of two cysteine-terminated forms of this L1 peptide and thiolated poly(ethylene) glycol (PEG) ligands (~2.1 kDa) with citrate stabilized AuNPs of two different sizes (~14 and 40 nm in diameter). By varying the ratio of the L1 peptide-PEG mixtures, an optimized layer composition was achieved that resulted in the expected homophilic interaction of the AuNPs. These AuNPs were stable as tested over a time period of 30 days in artificial cerebrospinal fluid and interacted with the extracellular domain of L1 on neurons and Schwann cells, as could be shown by using cells from wild-type and L1-deficient mice. In vitro, the L1-derivatized particles promoted neurite outgrowth and survival of neurons from the central and peripheral nervous system and stimulated Schwann cell process formation and proliferation. These observations raise the hope that, in combination with other therapeutic approaches, L1 peptide-functionalized AuNPs may become a useful tool to ameliorate the deficits resulting from acute and chronic injuries of the mammalian nervous system.The neural cell adhesion molecule L1 is involved in nervous system development and promotes regeneration in animal models of acute and chronic injury of the adult nervous system. To translate these conducive functions into therapeutic approaches, a 22-mer peptide that encompasses a minimal and functional L1

  1. Bone marrow-derived fibroblast growth factor-2 induces glial cell proliferation in the regenerating peripheral nervous system

    Directory of Open Access Journals (Sweden)

    Ribeiro-Resende Victor

    2012-07-01

    Full Text Available Abstract Background Among the essential biological roles of bone marrow-derived cells, secretion of many soluble factors is included and these small molecules can act upon specific receptors present in many tissues including the nervous system. Some of the released molecules can induce proliferation of Schwann cells (SC, satellite cells and lumbar spinal cord astrocytes during early steps of regeneration in a rat model of sciatic nerve transection. These are the major glial cell types that support neuronal survival and axonal growth following peripheral nerve injury. Fibroblast growth factor-2 (FGF-2 is the main mitogenic factor for SCs and is released in large amounts by bone marrow-derived cells, as well as by growing axons and endoneurial fibroblasts during development and regeneration of the peripheral nervous system (PNS. Results Here we show that bone marrow-derived cell treatment induce an increase in the expression of FGF-2 in the sciatic nerve, dorsal root ganglia and the dorsolateral (DL region of the lumbar spinal cord (LSC in a model of sciatic nerve transection and connection into a hollow tube. SCs in culture in the presence of bone marrow derived conditioned media (CM resulted in increased proliferation and migration. This effect was reduced when FGF-2 was neutralized by pretreating BMMC or CM with a specific antibody. The increased expression of FGF-2 was validated by RT-PCR and immunocytochemistry in co-cultures of bone marrow derived cells with sciatic nerve explants and regenerating nerve tissue respectivelly. Conclusion We conclude that FGF-2 secreted by BMMC strongly increases early glial proliferation, which can potentially improve PNS regeneration.

  2. Combined use of decellularized allogeneic artery conduits with autologous transdifferentiated adipose-derived stem cells for facial nerve regeneration in rats.

    Science.gov (United States)

    Sun, Fei; Zhou, Ke; Mi, Wen-juan; Qiu, Jian-hua

    2011-11-01

    Natural biological conduits containing seed cells have been widely used as an alternative strategy for nerve gap reconstruction to replace traditional nerve autograft techniques. The purpose of this study was to investigate the effects of a decellularized allogeneic artery conduit containing autologous transdifferentiated adipose-derived stem cells (dADSCs) on an 8-mm facial nerve branch lesion in a rat model. After 8 weeks, functional evaluation of vibrissae movements and electrophysiological assessment, retrograde labeling of facial motoneurons and morphological analysis of regenerated nerves were performed to assess nerve regeneration. The transected nerves reconstructed with dADSC-seeded artery conduits achieved satisfying regenerative outcomes associated with morphological and functional improvements which approached those achieved with Schwann cell (SC)-seeded artery conduits, and superior to those achieved with artery conduits alone or ADSC-seeded artery conduits, but inferior to those achieved with nerve autografts. Besides, numerous transplanted PKH26-labeled dADSCs maintained their acquired SC-phenotype and myelin sheath-forming capacity inside decellularized artery conduits and were involved in the process of axonal regeneration and remyelination. Collectively, our combined use of decellularized allogeneic artery conduits with autologous dADSCs certainly showed beneficial effects on nerve regeneration and functional restoration, and thus represents an alternative approach for the reconstruction of peripheral facial nerve defects. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Giant Panda (Ailuropoda melanoleuca) Buccal Mucosa Tissue as a Source of Multipotent Progenitor Cells.

    Science.gov (United States)

    Prescott, Hilary M A; Manning, Craig; Gardner, Aaron; Ritchie, William A; Pizzi, Romain; Girling, Simon; Valentine, Iain; Wang, Chengdong; Jahoda, Colin A B

    2015-01-01

    Since the first mammal was cloned, the idea of using this technique to help endangered species has aroused considerable interest. However, several issues limit this possibility, including the relatively low success rate at every stage of the cloning process, and the dearth of usable tissues from these rare animals. iPS cells have been produced from cells from a number of rare mammalian species and this is the method of choice for strategies to improve cloning efficiency and create new gametes by directed differentiation. Nevertheless information about other stem cell/progenitor capabilities of cells from endangered species could prove important for future conservation approaches and adds to the knowledge base about cellular material that can be extremely limited. Multipotent progenitor cells, termed skin-derived precursor (SKP) cells, can be isolated directly from mammalian skin dermis, and human cheek tissue has also been shown to be a good source of SKP-like cells. Recently we showed that structures identical to SKPs termed m-SKPs could be obtained from monolayer/ two dimensional (2D) skin fibroblast cultures. Here we aimed to isolate m-SKPs from cultured cells of three endangered species; giant panda (Ailuropoda melanoleuca); red panda (Ailurus fulgens); and Asiatic lion (Panthera leo persica). m-SKP-like spheres were formed from the giant panda buccal mucosa fibroblasts; whereas dermal fibroblast (DF) cells cultured from abdominal skin of the other two species were unable to generate spheres. Under specific differentiation culture conditions giant panda spheres expressed neural, Schwann, adipogenic and osteogenic cell markers. Furthermore, these buccal mucosa derived spheres were shown to maintain expression of SKP markers: nestin, versican, fibronectin, and P75 and switch on expression of the stem cell marker ABCG2. These results demonstrate that giant panda cheek skin can be a useful source of m-SKP multipotent progenitors. At present lack of sample numbers

  4. Giant Panda (Ailuropoda melanoleuca Buccal Mucosa Tissue as a Source of Multipotent Progenitor Cells.

    Directory of Open Access Journals (Sweden)

    Hilary M A Prescott

    Full Text Available Since the first mammal was cloned, the idea of using this technique to help endangered species has aroused considerable interest. However, several issues limit this possibility, including the relatively low success rate at every stage of the cloning process, and the dearth of usable tissues from these rare animals. iPS cells have been produced from cells from a number of rare mammalian species and this is the method of choice for strategies to improve cloning efficiency and create new gametes by directed differentiation. Nevertheless information about other stem cell/progenitor capabilities of cells from endangered species could prove important for future conservation approaches and adds to the knowledge base about cellular material that can be extremely limited. Multipotent progenitor cells, termed skin-derived precursor (SKP cells, can be isolated directly from mammalian skin dermis, and human cheek tissue has also been shown to be a good source of SKP-like cells. Recently we showed that structures identical to SKPs termed m-SKPs could be obtained from monolayer/ two dimensional (2D skin fibroblast cultures. Here we aimed to isolate m-SKPs from cultured cells of three endangered species; giant panda (Ailuropoda melanoleuca; red panda (Ailurus fulgens; and Asiatic lion (Panthera leo persica. m-SKP-like spheres were formed from the giant panda buccal mucosa fibroblasts; whereas dermal fibroblast (DF cells cultured from abdominal skin of the other two species were unable to generate spheres. Under specific differentiation culture conditions giant panda spheres expressed neural, Schwann, adipogenic and osteogenic cell markers. Furthermore, these buccal mucosa derived spheres were shown to maintain expression of SKP markers: nestin, versican, fibronectin, and P75 and switch on expression of the stem cell marker ABCG2. These results demonstrate that giant panda cheek skin can be a useful source of m-SKP multipotent progenitors. At present lack of

  5. Sortilin Associates with Trk Receptors to Enhance Anterograde Transport and Signaling by Neurotrophins

    DEFF Research Database (Denmark)

    Vægter, Christian Bjerggaard

      Neurotrophins (NT) are neuronal growth factors essential for development and maintenance of the nervous system. They are released in two forms with opposing biological functions. The proforms induce apoptosis by engaging a death signaling complex comprising the p75NTR neurotrophin receptor...

  6. Conformational characterization of nerve growth factor-β reveals that its regulatory pro-part domain stabilizes three loop regions in its mature part

    DEFF Research Database (Denmark)

    Trabjerg, Esben; Kartberg, Fredrik; Christensen, Søren

    2017-01-01

    of the common neurotrophin receptor (p75NTR) and sortilin. The overexpression of both proNGF and sortilin has been associated with several neurodegenerative diseases. Insights into the conformational differences between proNGF and NGF are central to a better understanding of the opposing mechanisms of action...

  7. Early-postnatal iron deficiency impacts plasticity in the dorsal and ventral hippocampus in piglets

    NARCIS (Netherlands)

    Nelissen, Ellis; De Vry, Jochen; Antonides, Alexandra; Paes, Dean; Schepers, Melissa; van der Staay, Franz Josef|info:eu-repo/dai/nl/074262653; Prickaerts, Jos; Vanmierlo, Tim

    2017-01-01

    In this study, we investigated whether alterations in plasticity markers such as brain-derived neurotrophic factor (BDNF), p75 neurotrophin receptor (p75(NTR)) and tyrosine receptor kinase B (TrkB) are underlying iron deficiency (ID)-induced cognitive impairments in iron depleted piglets. Newborn

  8. Use of Synthetic Nerve Grafts to Restore Cavernous Nerve Function Following Prostate Cancer Surgery: In Vitro and In Vivo Studies

    National Research Council Canada - National Science Library

    Konety, Badrinath R

    2006-01-01

    .... Schwann cell and neurona stem cells en neurite growth are being investigated. Tubulized sheets of the polymer with and without those factors/cells have been used to microsurgically replace resected cavernous nerve...

  9. Stem Cells

    Science.gov (United States)

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  10. Reconstruction of Multiple Facial Nerve Branches Using Skeletal Muscle-Derived Multipotent Stem Cell Sheet-Pellet Transplantation.

    Science.gov (United States)

    Saito, Kosuke; Tamaki, Tetsuro; Hirata, Maki; Hashimoto, Hiroyuki; Nakazato, Kenei; Nakajima, Nobuyuki; Kazuno, Akihito; Sakai, Akihiro; Iida, Masahiro; Okami, Kenji

    2015-01-01

    Head and neck cancer is often diagnosed at advanced stages, and surgical resection with wide margins is generally indicated, despite this treatment being associated with poor postoperative quality of life (QOL). We have previously reported on the therapeutic effects of skeletal muscle-derived multipotent stem cells (Sk-MSCs), which exert reconstitution capacity for muscle-nerve-blood vessel units. Recently, we further developed a 3D patch-transplantation system using Sk-MSC sheet-pellets. The aim of this study is the application of the 3D Sk-MSC transplantation system to the reconstitution of facial complex nerve-vascular networks after severe damage. Mouse experiments were performed for histological analysis and rats were used for functional examinations. The Sk-MSC sheet-pellets were prepared from GFP-Tg mice and SD rats, and were transplanted into the facial resection model (ST). Culture medium was transplanted as a control (NT). In the mouse experiment, facial-nerve-palsy (FNP) scoring was performed weekly during the recovery period, and immunohistochemistry was used for the evaluation of histological recovery after 8 weeks. In rats, contractility of facial muscles was measured via electrical stimulation of facial nerves root, as the marker of total functional recovery at 8 weeks after transplantation. The ST-group showed significantly higher FNP (about three fold) scores when compared to the NT-group after 2-8 weeks. Similarly, significant functional recovery of whisker movement muscles was confirmed in the ST-group at 8 weeks after transplantation. In addition, engrafted GFP+ cells formed complex branches of nerve-vascular networks, with differentiation into Schwann cells and perineurial/endoneurial cells, as well as vascular endothelial and smooth muscle cells. Thus, Sk-MSC sheet-pellet transplantation is potentially useful for functional reconstitution therapy of large defects in facial nerve-vascular networks.

  11. Reconstruction of Multiple Facial Nerve Branches Using Skeletal Muscle-Derived Multipotent Stem Cell Sheet-Pellet Transplantation.

    Directory of Open Access Journals (Sweden)

    Kosuke Saito

    Full Text Available Head and neck cancer is often diagnosed at advanced stages, and surgical resection with wide margins is generally indicated, despite this treatment being associated with poor postoperative quality of life (QOL. We have previously reported on the therapeutic effects of skeletal muscle-derived multipotent stem cells (Sk-MSCs, which exert reconstitution capacity for muscle-nerve-blood vessel units. Recently, we further developed a 3D patch-transplantation system using Sk-MSC sheet-pellets. The aim of this study is the application of the 3D Sk-MSC transplantation system to the reconstitution of facial complex nerve-vascular networks after severe damage. Mouse experiments were performed for histological analysis and rats were used for functional examinations. The Sk-MSC sheet-pellets were prepared from GFP-Tg mice and SD rats, and were transplanted into the facial resection model (ST. Culture medium was transplanted as a control (NT. In the mouse experiment, facial-nerve-palsy (FNP scoring was performed weekly during the recovery period, and immunohistochemistry was used for the evaluation of histological recovery after 8 weeks. In rats, contractility of facial muscles was measured via electrical stimulation of facial nerves root, as the marker of total functional recovery at 8 weeks after transplantation. The ST-group showed significantly higher FNP (about three fold scores when compared to the NT-group after 2-8 weeks. Similarly, significant functional recovery of whisker movement muscles was confirmed in the ST-group at 8 weeks after transplantation. In addition, engrafted GFP+ cells formed complex branches of nerve-vascular networks, with differentiation into Schwann cells and perineurial/endoneurial cells, as well as vascular endothelial and smooth muscle cells. Thus, Sk-MSC sheet-pellet transplantation is potentially useful for functional reconstitution therapy of large defects in facial nerve-vascular networks.

  12. Development of a cell-based treatment for long-term neurotrophin expression and spiral ganglion neuron survival.

    Science.gov (United States)

    Zanin, M P; Hellström, M; Shepherd, R K; Harvey, A R; Gillespie, L N

    2014-09-26

    Spiral ganglion neurons (SGNs), the target cells of the cochlear implant, undergo gradual degeneration following loss of the sensory epithelium in deafness. The preservation of a viable population of SGNs in deafness can be achieved in animal models with exogenous application of neurotrophins such as brain-derived neurotrophic factor (BDNF) and neurotrophin-3. For translation into clinical application, a suitable delivery strategy that provides ongoing neurotrophic support and promotes long-term SGN survival is required. Cell-based neurotrophin treatment has the potential to meet the specific requirements for clinical application, and we have previously reported that Schwann cells genetically modified to express BDNF can support SGN survival in deafness for 4 weeks. This study aimed to investigate various parameters important for the development of a long-term cell-based neurotrophin treatment to support SGN survival. Specifically, we investigated different (i) cell types, (ii) gene transfer methods and (iii) neurotrophins, in order to determine which variables may provide long-term neurotrophin expression and which, therefore, may be the most effective for supporting long-term SGN survival in vivo. We found that fibroblasts that were nucleofected to express BDNF provided the most sustained neurotrophin expression, with ongoing BDNF expression for at least 30 weeks. In addition, the secreted neurotrophin was biologically active and elicited survival effects on SGNs in vitro. Nucleofected fibroblasts may therefore represent a method for safe, long-term delivery of neurotrophins to the deafened cochlea to support SGN survival in deafness. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. Investigation of cell adhesion in chitosan membranes for peripheral nerve regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Cristiana R.; López-Cebral, Rita; Silva-Correia, Joana; Silva, Joana M.; Mano, João F.; Silva, Tiago H. [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark – Parque de Ciência e Tecnologia, 4805-017, Barco, Guimarães (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga, Guimarães (Portugal); Freier, Thomas [MEDOVENT GmbH, Friedrich-Koenig-Str. 3, D-55129 Mainz (Germany); Reis, Rui L. [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark – Parque de Ciência e Tecnologia, 4805-017, Barco, Guimarães (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga, Guimarães (Portugal); Oliveira, Joaquim M., E-mail: miguel.oliveira@dep.uminho.pt [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark – Parque de Ciência e Tecnologia, 4805-017, Barco, Guimarães (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga, Guimarães (Portugal)

    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. - Highlights: • Three chitosan membranes were produced with very specific degrees of acetylation (DA I: 1%, DA II: 2%, DA III: 5%). • Physicochemical characterization of the membranes showed their suitability for peripheral nerve regeneration purposes. • In vitro cellular tests confirmed the potential of the membranes as peripheral nerve regeneration systems. • The results indicated that DA III membrane should be the one considered for further peripheral nerve regeneration studies.

  14. Investigation of cell adhesion in chitosan membranes for peripheral nerve regeneration

    International Nuclear Information System (INIS)

    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.

    2017-01-01

    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. - Highlights: • Three chitosan membranes were produced with very specific degrees of acetylation (DA I: 1%, DA II: 2%, DA III: 5%). • Physicochemical characterization of the membranes showed their suitability for peripheral nerve regeneration purposes. • In vitro cellular tests confirmed the potential of the membranes as peripheral nerve regeneration systems. • The results indicated that DA III membrane should be the one considered for further peripheral nerve regeneration studies.

  15. Data on the effect of in vivo knockdown using artificial ErbB3 miRNA on Remak bundle structure

    Directory of Open Access Journals (Sweden)

    Yuki Miyamoto

    2017-06-01

    Full Text Available Mature Schwann cells, the peripheral nervous system (PNS glial cells, have two major roles for neuronal axons (Bunge, 1993 [1]. For large diameter axons, Schwann cells form myelin sheaths with multiple layers. For small diameter axons, they form Remak bundle composed only of single layer of the Schwann cell plasma membrane. In the PNS, ErbB3 forms a dimer with ErbB2 on the Schwann cell plasma membrane. ErbB3 plays a key role in myelination by myelinating Schwann cells, that is to say, its role in myelin thickness. Herein we provide the data regarding the effect of in vivo knockdown of ErbB3 on the thickness between an axon and a neighboring axon in Remak bundle, which is formed by non-myelinating Schwann cells. Since ErbB3 knockout mice are embryonically lethal, Schwann cell lineage-specific transgenic mice transcribing ErbB3 shRNA with an artificial miRNA backbone were generated and used in these experiments (Torii et al., 2014 [2].

  16. Nerve growth factor, clinical applications and production of the recombinant protei

    Directory of Open Access Journals (Sweden)

    M. Zangi

    2017-01-01

    Full Text Available The mammalian neurotrophin family proteins, nerve growth factor (NGF, brain-derived neurotrophic factor (BDNF, neurotrophin-3 (NT-3 and neurotrophin-4/5 (NT-4/5 are known as neuronal survival factors. NGF, one of the most important cytokines, is composed of 118 amino acids. NGF is involved in the growth and differentiation of neural cells of the vertebrate peripheral sympathetic nerve as well as basal forebrain cholinergic neurons which degenerate in Alzheimer’s disease. In addition, it is implicated in the regulation of synaptic transmission and synaptogenesis in the central nervous system. NGF is produced by a variety of immune cells, including B cells, T cells, monocytes and mast cells as well as nervous system and binds through two distinct receptors, TrkA and p75NTR which signaling through them leads to the neuronal differentiation and cell death respectively. Considering the importance of this protein as a drug, NGF has been proposed for the treatment of neuron degenerative diseases such as Alzheimer's, Parkinson's and multiple sclerosis. To produce enough protein for research and clinical applications, genetic engineering techniques are used to produce recombinant forms. To date, there are no reports about the systems for production of the recombinant human NGF in an effective, low cost, with industrial production. Plants as a safe host generally offer major advantages such as free of animal pathogens, low costs, the ability to produce a protein similar to natural protein, and industrial production in large scale. Then they are suitable for the production of recombinant human NGF.

  17. Enhanced Expression of WD Repeat-Containing Protein 35 via CaMKK/AMPK Activation in Bupivacaine-Treated Neuro2a Cells

    Science.gov (United States)

    Huang, Lei; Kondo, Fumio; Gosho, Masahiko; Feng, Guo-Gang; Harato, Misako; Xia, Zhong-yuan; Ishikawa, Naohisa; Fujiwara, Yoshihiro; Okada, Shoshiro

    2014-01-01

    We previously reported that bupivacaine induces reactive oxygen species (ROS) generation, p38 mitogen-activated protein kinase (MAPK) activation and nuclear factor-kappa B activation, resulting in an increase in expression of WD repeat-containing protein 35 (WDR35) in mouse neuroblastoma Neuro2a cells. However, the identity of signaling upstream of p38 MAPK pathways to WDR35 expression remains unclear. It has been shown that AMP-activated protein kinase (AMPK) can activate p38 MAPK through diverse mechanisms. In addition, several kinases acting upstream of AMPK have been identified including Ca2+/calmodulin-dependent protein kinase kinase (CaMKK). Recent studies reported that AMPK may be involved in bupivacaine-induced cytotoxicity in Schwann cells and in human neuroblastoma SH-SY5Y cells. The present study was undertaken to test whether CaMKK and AMPK are involved in bupivacaine-induced WDR35 expression in Neuro2a cells. Our results showed that bupivacaine induced activation of AMPK and p38 MAPK in Neuro2a cells. The AMPK inhibitors, compound C and iodotubercidin, attenuated the bupivacaine-induced activation of AMPK and p38 MAPK, resulting in an inhibition of the bupivacaine-induced increase in WDR35 expression. Treatment with the CaMKK inhibitor STO-609 also attenuated the bupivacaine-induced activation of AMPK and p38 MAPK, resulting in an inhibition of the bupivacaine-induced increase in WDR35 expression. These results suggest that bupivacaine activates AMPK and p38 MAPK via CaMKK in Neuro2a cells, and that the CaMKK/AMPK/p38 MAPK pathway is involved in regulating WDR35 expression. PMID:24859235

  18. Immunodominant fragments of myelin basic protein initiate T cell-dependent pain

    Directory of Open Access Journals (Sweden)

    Liu Huaqing

    2012-06-01

    Full Text Available Abstract Background The myelin sheath provides electrical insulation of mechanosensory Aβ-afferent fibers. Myelin-degrading matrix metalloproteinases (MMPs damage the myelin sheath. The resulting electrical instability of Aβ-fibers is believed to activate the nociceptive circuitry in Aβ-fibers and initiate pain from innocuous tactile stimulation (mechanical allodynia. The precise molecular mechanisms, responsible for the development of this neuropathic pain state after nerve injury (for example, chronic constriction injury, CCI, are not well understood. Methods and results Using mass spectrometry of the whole sciatic nerve proteome followed by bioinformatics analyses, we determined that the pathways, which are classified as the Infectious Disease and T-helper cell signaling, are readily activated in the nerves post-CCI. Inhibition of MMP-9/MMP-2 suppressed CCI-induced mechanical allodynia and concomitant TNF-α and IL-17A expression in nerves. MMP-9 proteolysis of myelin basic protein (MBP generated the MBP84-104 and MBP68-86 digest peptides, which are prominent immunogenic epitopes. In agreement, the endogenous MBP69-86 epitope co-localized with MHCII and MMP-9 in Schwann cells and along the nodes of Ranvier. Administration of either the MBP84-104 or MBP68-86 peptides into the naïve nerve rapidly produced robust mechanical allodynia with a concomitant increase in T cells and MHCII-reactive cell populations at the injection site. As shown by the genome-wide expression profiling, a single intraneural MBP84-104 injection stimulated the inflammatory, immune cell trafficking, and antigen presentation pathways in the injected naïve nerves and the associated spinal cords. Both MBP84-104-induced mechanical allodynia and characteristic pathway activation were remarkably less prominent in the T cell-deficient athymic nude rats. Conclusions These data implicate MBP as a novel mediator of pain. Furthermore, the action of MMPs expressed within 1

  19. Immunodominant fragments of myelin basic protein initiate T cell-dependent pain.

    Science.gov (United States)

    Liu, Huaqing; Shiryaev, Sergey A; Chernov, Andrei V; Kim, Youngsoon; Shubayev, Igor; Remacle, Albert G; Baranovskaya, Svetlana; Golubkov, Vladislav S; Strongin, Alex Y; Shubayev, Veronica I

    2012-06-07

    The myelin sheath provides electrical insulation of mechanosensory Aβ-afferent fibers. Myelin-degrading matrix metalloproteinases (MMPs) damage the myelin sheath. The resulting electrical instability of Aβ-fibers is believed to activate the nociceptive circuitry in Aβ-fibers and initiate pain from innocuous tactile stimulation (mechanical allodynia). The precise molecular mechanisms, responsible for the development of this neuropathic pain state after nerve injury (for example, chronic constriction injury, CCI), are not well understood. Using mass spectrometry of the whole sciatic nerve proteome followed by bioinformatics analyses, we determined that the pathways, which are classified as the Infectious Disease and T-helper cell signaling, are readily activated in the nerves post-CCI. Inhibition of MMP-9/MMP-2 suppressed CCI-induced mechanical allodynia and concomitant TNF-α and IL-17A expression in nerves. MMP-9 proteolysis of myelin basic protein (MBP) generated the MBP84-104 and MBP68-86 digest peptides, which are prominent immunogenic epitopes. In agreement, the endogenous MBP69-86 epitope co-localized with MHCII and MMP-9 in Schwann cells and along the nodes of Ranvier. Administration of either the MBP84-104 or MBP68-86 peptides into the naïve nerve rapidly produced robust mechanical allodynia with a concomitant increase in T cells and MHCII-reactive cell populations at the injection site. As shown by the genome-wide expression profiling, a single intraneural MBP84-104 injection stimulated the inflammatory, immune cell trafficking, and antigen presentation pathways in the injected naïve nerves and the associated spinal cords. Both MBP84-104-induced mechanical allodynia and characteristic pathway activation were remarkably less prominent in the T cell-deficient athymic nude rats. These data implicate MBP as a novel mediator of pain. Furthermore, the action of MMPs expressed within 1 day post-injury is critical to the generation of tactile allodynia

  20. Ultrastructural changes in the glial cells at neuromuscular synapses of Locusta migratoria occurring after nerve stimulation and subsequent rest: a morphometric analysis.

    Science.gov (United States)

    Reinecke, M

    1979-10-01

    The glial processes ensheathing the motor nerve terminals on the retractor unguis muscle of Locusta migratoria are described. Ultrastructural changes observed after electrical nerve stimulation (20 Hz, 7 min) without or with subsequent rest (2 min, 1 h) are analysed morphometrically. Immediately after stimulation both the average terminal circumference (+ 23%) and its proportion covered by glial processes (+ 16%) are significantly increased. The mean number of Schwann cell processes per micron of terminal circumference (without stimulation: 0.86 +/- 0.04) is also affected: Immediately after stimulation it is increased by about 15% and after 2 min of rest even by 36%. The periaxonal cleft (without stimulation: 16.5 nm +/- 0.36) becomes wider immediately after stimulation by about 19%, an effect which is almost reversed after 1 h of rest. It is suggested that these changes are a consequence of the enlargement of the nerve terminal's surface upon massive exocytotic activity and that they are possibly mediated by mechanical attachment between glial and terminal plasma membranes.

  1. Applications of Acupuncture Therapy in Modulating Plasticity of Central Nervous System.

    Science.gov (United States)

    Xiao, Ling-Yong; Wang, Xue-Rui; Yang, Ye; Yang, Jing-Wen; Cao, Yan; Ma, Si-Ming; Li, Tian-Ran; Liu, Cun-Zhi

    2017-11-07

    Acupuncture is widely applied for treatment of various neurological disorders. This manuscript will review the preclinical evidence of acupuncture in mediating neural plasticity, the mechanisms involved. We searched acupuncture, plasticity, and other potential related words at the following sites: PubMed, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), and VIP information data base. The following keywords were used: acupuncture, electroacupuncture, plasticity, neural plasticity, neuroplasticity, neurogenesis, neuroblast, stem cell, progenitor cell, BrdU, synapse, synapse structure, synaptogenesis, axon, axon regeneration, synaptic plasticity, LTP, LTD, neurotrophin, neurotrophic factor, BDNF, GDNF, VEGF, bFGF, EGF, NT-3, NT-4, NT-5, p75NTR, neurotransmitter, acetylcholine, norepinephrine, noradrenaline, dopamine, monamine. We assessed the effects of acupuncture on plasticity under pathological conditions in this review. Relevant references were reviewed and presented to reflect the effects of acupuncture on neural plasticity. The acquired literatures mainly focused on neurogenesis, alterations of synapses, neurotrophins (NTs), and neurotranimitters. Acupuncture methods mentioned in this article include manual acupuncture and electroacupuncture. The cumulative evidences demonstrated that acupuncture could induce neural plasticity in rodents exposed to cerebral ischemia. Neural plasticity mediated by acupuncture in other neural disorders, such as Alzheimer's disease, Parkinson's disease, and depression, were also investigated and there is evidence of positive role of acupuncture induced plasticity in these disorders as well. Mediation of neural plasticity by acupuncture is likely associated with its modulation on NTs and neurotransmitters. The exact mechanisms underlying acupuncture's effects on neural plasticity remain to be elucidated. Neural plasticity may be the potential bridge between acupuncture and the treatment of various

  2. Cerebrolysin modulates pronerve growth factor/nerve growth factor ratio and ameliorates the cholinergic deficit in a transgenic model of Alzheimer's disease.

    Science.gov (United States)

    Ubhi, Kiren; Rockenstein, Edward; Vazquez-Roque, Ruben; Mante, Michael; Inglis, Chandra; Patrick, Christina; Adame, Anthony; Fahnestock, Margaret; Doppler, Edith; Novak, Philip; Moessler, Herbert; Masliah, Eliezer

    2013-02-01

    Alzheimer's disease (AD) is characterized by degeneration of neocortex, limbic system, and basal forebrain, accompanied by accumulation of amyloid-β and tangle formation. Cerebrolysin (CBL), a peptide mixture with neurotrophic-like effects, is reported to improve cognition and activities of daily living in patients with AD. Likewise, CBL reduces synaptic and behavioral deficits in transgenic (tg) mice overexpressing the human amyloid precursor protein (hAPP). The neuroprotective effects of CBL may involve multiple mechanisms, including signaling regulation, control of APP metabolism, and expression of neurotrophic factors. We investigate the effects of CBL in the hAPP tg model of AD on levels of neurotrophic factors, including pro-nerve growth factor (NGF), NGF, brain-derived neurotrophic factor (BDNF), neurotropin (NT)-3, NT4, and ciliary neurotrophic factor (CNTF). Immunoblot analysis demonstrated that levels of pro-NGF were increased in saline-treated hAPP tg mice. In contrast, CBL-treated hAPP tg mice showed levels of pro-NGF comparable to control and increased levels of mature NGF. Consistently with these results, immunohistochemical analysis demonstrated increased NGF immunoreactivity in the hippocampus of CBL-treated hAPP tg mice. Protein levels of other neurotrophic factors, including BDNF, NT3, NT4, and CNTF, were unchanged. mRNA levels of NGF and other neurotrophins were also unchanged. Analysis of neurotrophin receptors showed preservation of the levels of TrKA and p75(NTR) immunoreactivity per cell in the nucleus basalis. Cholinergic cells in the nucleus basalis were reduced in the saline-treated hAPP tg mice, and treatment with CBL reduced these cholinergic deficits. These results suggest that the neurotrophic effects of CBL might involve modulation of the pro-NGF/NGF balance and a concomitant protection of cholinergic neurons. Copyright © 2012 Wiley Periodicals, Inc.

  3. Local delivery of glial cell line-derived neurotrophic factor improves facial nerve regeneration after late repair.

    Science.gov (United States)

    Barras, Florian M; Kuntzer, Thierry; Zurn, Anne D; Pasche, Philippe

    2009-05-01

    Facial nerve regeneration is limited in some clinical situations: in long grafts, by aged patients, and when the delay between nerve lesion and repair is prolonged. This deficient regeneration is due to the limited number of regenerating nerve fibers, their immaturity and the unresponsiveness of Schwann cells after a long period of denervation. This study proposes to apply glial cell line-derived neurotrophic factor (GDNF) on facial nerve grafts via nerve guidance channels to improve the regeneration. Two situations were evaluated: immediate and delayed grafts (repair 7 months after the lesion). Each group contained three subgroups: a) graft without channel, b) graft with a channel without neurotrophic factor; and c) graft with a GDNF-releasing channel. A functional analysis was performed with clinical observation of facial nerve function, and nerve conduction study at 6 weeks. Histological analysis was performed with the count of number of myelinated fibers within the graft, and distally to the graft. Central evaluation was assessed with Fluoro-Ruby retrograde labeling and Nissl staining. This study showed that GDNF allowed an increase in the number and the maturation of nerve fibers, as well as the number of retrogradely labeled neurons in delayed anastomoses. On the contrary, after immediate repair, the regenerated nerves in the presence of GDNF showed inferior results compared to the other groups. GDNF is a potent neurotrophic factor to improve facial nerve regeneration in grafts performed several months after the nerve lesion. However, GDNF should not be used for immediate repair, as it possibly inhibits the nerve regeneration.

  4. Cells and cell biochemistry.

    Science.gov (United States)

    Farley, Alistair; Hendry, Charles; McLafferty, Ella

    This article, which forms part of the life sciences series, aims to promote understanding of the basic structure and function of cells. It assists healthcare professionals to appreciate the complex anatomy and physiology underpinning the functioning of the human body. Several introductory chemical concepts and terms are outlined. The basic building blocks of all matter, atoms, are examined and the way in which they may interact to form new compounds within the body is discussed. The basic structures and components that make up a typical cell are considered.

  5. Functional organization of an Mbp enhancer exposes striking transcriptional regulatory diversity within myelinating glia

    DEFF Research Database (Denmark)

    Dionne, Nancy; Dib, Samar; Finsen, Bente

    2016-01-01

    regulatory element combinations were found to drive expression in oligodendrocytes and Schwann cells with a minimal 129 bp sequence conferring expression in oligodendrocytes throughout myelin elaboration, maintenance and repair. Unexpectedly, M3 derivatives conferred markedly different spatial and temporal...

  6. 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 (Pchronic spontaneous urticaria compared with controls (Pchronic spontaneous urticaria and controls and no difference in BDNF serum levels between autologous serum skin test-positive (n=23) and -negative (n=27) patients with chronic spontaneous urticaria. This study shows that BDNF is increased in serum and diseased skin of patients with chronic spontaneous urticaria, suggesting a role for neurotrophins 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

  7. A Long-Gap Peripheral Nerve Injury Therapy Using Human Skeletal Muscle-Derived Stem Cells (Sk-SCs): An Achievement of Significant Morphological, Numerical and Functional Recovery.

    Science.gov (United States)

    Tamaki, Tetsuro; Hirata, Maki; Nakajima, Nobuyuki; Saito, Kosuke; Hashimoto, Hiroyuki; Soeda, Shuichi; Uchiyama, Yoshiyasu; Watanabe, Masahiko

    2016-01-01

    Losses in vital functions of the somatic motor and sensory nervous system are induced by severe long-gap peripheral nerve transection injury. In such cases, autologous nerve grafts are the gold standard treatment, despite the unavoidable sacrifice of other healthy functions, whereas the prognosis is not always favorable. Here, we use human skeletal muscle-derived stem cells (Sk-SCs) to reconstitute the function after long nerve-gap injury. Muscles samples were obtained from the amputated legs from 9 patients following unforeseen accidents. The Sk-SCs were isolated using conditioned collagenase solution, and sorted as CD34+/45- (Sk-34) and CD34-/45-/29+ (Sk-DN/29+) cells. Cells were separately cultured/expanded under optimal conditions for 2 weeks, then injected into the athymic nude mice sciatic nerve long-gap model (7-mm) bridging an acellular conduit. After 8-12 weeks, active cell engraftment was observed only in the Sk-34 cell transplanted group, showing preferential differentiation into Schwann cells and perineurial/endoneurial cells, as well as formation of the myelin sheath and perineurium/endoneurium surrounding regenerated axons, resulted in 87% of numerical recovery. Differentiation into vascular cell lineage (pericyte and endothelial cells) were also observed. A significant tetanic tension recovery (over 90%) of downstream muscles following electrical stimulation of the sciatic nerve (at upper portion of the gap) was also achieved. In contrast, Sk-DN/29+ cells were completely eliminated during the first 4 weeks, but relatively higher numerical (83% vs. 41% in axon) and functional (80% vs. 60% in tetanus) recovery than control were observed. Noteworthy, significant increase in the formation of vascular networks in the conduit during the early stage (first 2 weeks) of recovery was observed in both groups with the expression of key factors (mRNA and protein levels), suggesting the paracrine effects to angiogenesis. These results suggested that the human Sk

  8. A Long-Gap Peripheral Nerve Injury Therapy Using Human Skeletal Muscle-Derived Stem Cells (Sk-SCs: An Achievement of Significant Morphological, Numerical and Functional Recovery.

    Directory of Open Access Journals (Sweden)

    Tetsuro Tamaki

    Full Text Available Losses in vital functions of the somatic motor and sensory nervous system are induced by severe long-gap peripheral nerve transection injury. In such cases, autologous nerve grafts are the gold standard treatment, despite the unavoidable sacrifice of other healthy functions, whereas the prognosis is not always favorable. Here, we use human skeletal muscle-derived stem cells (Sk-SCs to reconstitute the function after long nerve-gap injury. Muscles samples were obtained from the amputated legs from 9 patients following unforeseen accidents. The Sk-SCs were isolated using conditioned collagenase solution, and sorted as CD34+/45- (Sk-34 and CD34-/45-/29+ (Sk-DN/29+ cells. Cells were separately cultured/expanded under optimal conditions for 2 weeks, then injected into the athymic nude mice sciatic nerve long-gap model (7-mm bridging an acellular conduit. After 8-12 weeks, active cell engraftment was observed only in the Sk-34 cell transplanted group, showing preferential differentiation into Schwann cells and perineurial/endoneurial cells, as well as formation of the myelin sheath and perineurium/endoneurium surrounding regenerated axons, resulted in 87% of numerical recovery. Differentiation into vascular cell lineage (pericyte and endothelial cells were also observed. A significant tetanic tension recovery (over 90% of downstream muscles following electrical stimulation of the sciatic nerve (at upper portion of the gap was also achieved. In contrast, Sk-DN/29+ cells were completely eliminated during the first 4 weeks, but relatively higher numerical (83% vs. 41% in axon and functional (80% vs. 60% in tetanus recovery than control were observed. Noteworthy, significant increase in the formation of vascular networks in the conduit during the early stage (first 2 weeks of recovery was observed in both groups with the expression of key factors (mRNA and protein levels, suggesting the paracrine effects to angiogenesis. These results suggested that the

  9. Stem cells

    NARCIS (Netherlands)

    Jukes, Jojanneke; Both, Sanne; Post, Janine; van Blitterswijk, Clemens; Karperien, Marcel; de Boer, Jan; van Blitterswijk, Clemens A.

    2008-01-01

    This chapter defines stem cells and their properties. It identifies the major differences between embryonic and adult stem cells. Stem cells can be defined by two properties: the ability to make identical copies of themselves and the ability to form other cell types of the body. These properties are

  10. Cell Biochips

    Science.gov (United States)

    Pioufle, B. Le; Picollet-D'Hahan, N.

    A cell biochip is a microsystem, equipped with electronic and microfluidic functions, designed to manipulate or analyse living cells. The first publications in this emerging area of research appeared toward the end of the 1980s. In 1989 Washizu described a biochip designed to fuse two cells by electropermeabilisation of the cytoplasmic membrane [1]. Research centers have devised a whole range of cell chip structures, for simultaneous or sequential analysis of single cells, cell groups, or cell tissues reconstituted on the chip. The cells are arranged in a square array on a parallel cell chip for parallel analysis, while they are examined and processed one by one in a microchannel in the case of a series cell chip. In contrast to these biochips for high-throughput analysis of a large number of cells, single-cell chips focus on the analysis of a single isolated cell. As in DNA microarrays, where a large number of oligonucleotides are ordered in a matrix array, parallel cell chips order living cells in a similar way. At each point of the array, the cells can be isolated, provided that the cell type allows this, e.g., blood cells, or cultivated in groups (most adhesion cells can only survive in groups). The aim is to allow massively parallel analysis or processing. Le Pioufle et al. describe a microdevice for the culture of single cells or small groups of cells in a micropit array [2]. Each pit is equipped to stimulate the cell or group of cells either electrically or fluidically. Among the applications envisaged are gene transfer, cell sorting, and screening in pharmacology. A complementary approach, combining the DNA microarray and cell biochip ideas, has been put forward by Bailey et al. [3]. Genes previously arrayed on the chip transfect the cultured cells on the substrate depending on their position in the array (see Fig. 19.1). This way of achieving differential lipofection on a chip was then taken up again by Yoshikawa et al. [4] with primary cells, more

  11. Fine structure of subepithelial "free" and corpuscular trigeminal nerve endings in anterior hard palate of the rat.

    Science.gov (United States)

    Byers, M R; Yeh, Y

    1984-01-01

    Axonally transported protein labeled many trigeminal nerve endings in subepithelial regions of the anterior hard palate of the rat. Sensory endings were most numerous in the lamina propria near the tips of the palatal rugae where large connective tissue and epithelial papillae interdigitated. Two kinds of sensory ending were found there: "free" endings, and a variety of corpuscular endings. The "free" sensory endings consisted of bundles of unmyelinated axons separated from the connective tissue by relatively unspecialized Schwann cells covering part or all of their surface and a completely continuous basal lamina; they were commonly found running parallel to the epithelium or near corpuscular endings. The corpuscular sensory endings all had a specialized nerve form, specialized Schwann cells, and axonal fingers projecting into the corpuscular basal lamina or connective tissue. There were at least four distinct types of corpuscular ending: Ruffini-like endings were found among dense collagen bundles, and they had a flattened nerve ending with a flattened Schwann lamella on either side. Meissner endings had an ordered stack of flattened nerve terminals with flattened Schwann cells and much basal lamina within and around the corpuscle. Simple corpuscles were single nerve endings surrounded by several layers of concentric lamellar Schwann processes. Glomerular endings were found in lamina propria papillae or encircling epithelial papillae; they were a tangle of varied neural forms each of which had apposed flattened Schwann cells, and a layer of basal lamina of varied thickness. Fibroblasts often formed incomplete partitions around Meissner and simple corpuscles. The axoplasm of all kinds of subepithelial sensory endings contained numerous mitochondria and vesicles, as well as occasional multivesicular bodies and lysosomes; the axoplasm of all endings was pale with few microtubules and neurofilaments. The specialized lamellar Schwann cells had much pinocytotic

  12. Roles for the pro-neurotrophin receptor sortilin in neuronal development, aging and brain injury

    DEFF Research Database (Denmark)

    Jansen, Pernille; Giehl, Klaus; Nyengaard, Jens R

    2007-01-01

    Neurotrophins are essential for development and maintenance of the vertebrate nervous system. Paradoxically, although mature neurotrophins promote neuronal survival by binding to tropomyosin receptor kinases and p75 neurotrophin receptor (p75(NTR)), pro-neurotrophins induce apoptosis in cultured......)/sortilin receptor complex to neuronal viability. In the developing retina, Sortilin 1 (Sort1)(-/-) mice showed reduced neuronal apoptosis that was indistinguishable from that observed in p75(NTR)-deficient (Ngfr(-/-)) mice. To our surprise, although sortilin deficiency did not affect developmentally regulated...... apoptosis of sympathetic neurons, it did prevent their age-dependent degeneration. Furthermore, in an injury protocol, lesioned corticospinal neurons in Sort1(-/-) mice were protected from death. Thus, the sortilin pathway has distinct roles in pro-neurotrophin-induced apoptotic signaling in pathological...

  13. A Review on Ubiquitination of Neurotrophin Receptors: Facts and Perspectives

    Science.gov (United States)

    Sánchez-Sánchez, Julia; Arévalo, Juan Carlos

    2017-01-01

    Ubiquitination is a reversible post-translational modification involved in a plethora of different physiological functions. Among the substrates that are ubiquitinated, neurotrophin receptors (TrkA, TrkB, TrkC, and p75NTR) have been studied recently. TrkA is the most studied receptor in terms of its ubiquitination, and different E3 ubiquitin ligases and deubiquitinases have been implicated in its ubiquitination, whereas not much is known about the other neurotrophin receptors aside from their ubiquitination. Additional studies are needed that focus on the ubiquitination of TrkB, TrkC, and p75NTR in order to further understand the role of ubiquitination in their physiological and pathological functions. Here we review what is currently known regarding the ubiquitination of neurotrophin receptors and its physiological and pathological relevance. PMID:28335430

  14. Cholinergic Neurons - Keeping Check on Amyloid beta in the Cerebral Cortex

    Directory of Open Access Journals (Sweden)

    Saak V. Ovsepian

    2013-12-01

    Full Text Available The physiological relevance of the uptake of ligands with no apparent trophic functions via the p75 neurotrophin receptor (p75NTR remains unclear. Herein, we propose a homeostatic role for this in clearance of amyloid β (Aβ in the brain. We hypothesize that uptake of Aβ in conjunction with p75NTR followed by its degradation in lysosomes endows cholinergic basalo-cortical projections enriched in this receptor a facility for maintaining physiological levels of Aβ in target areas. Thus, in addition to the diffuse modulator influence and channeling of extra-thalamic signals, cholinergic innervations could supply the cerebral cortex with an elaborate system for Aβ drainage. Interpreting the emerging relationship of new molecular data with established role of cholinergic modulator system in regulating cortical network dynamics should provide new insights into the brain physiology and mechanisms of neuro-degenerative diseases.

  15. Recent advances in understanding neurotrophin signaling.

    Science.gov (United States)

    Bothwell, Mark

    2016-01-01

    The nerve growth factor family of growth factors, collectively known as neurotrophins, are evolutionarily ancient regulators with an enormous range of biological functions. Reflecting this long history and functional diversity, mechanisms for cellular responses to neurotrophins are exceptionally complex. Neurotrophins signal through p75 (NTR), a member of the TNF receptor superfamily member, and through receptor tyrosine kinases (TrkA, TrkB, TrkC), often with opposite functional outcomes. The two classes of receptors are activated preferentially by proneurotrophins and mature processed neurotrophins, respectively. However, both receptor classes also possess neurotrophin-independent signaling functions. Signaling functions of p75 (NTR) and Trk receptors are each influenced by the other class of receptors. This review focuses on the mechanisms responsible for the functional interplay between the two neurotrophin receptor signaling systems.

  16. Reconstitution of the complete rupture in musculotendinous junction using skeletal muscle-derived multipotent stem cell sheet-pellets as a "bio-bond".

    Science.gov (United States)

    Hashimoto, Hiroyuki; Tamaki, Tetsuro; Hirata, Maki; Uchiyama, Yoshiyasu; Sato, Masato; Mochida, Joji

    2016-01-01

    Background. Significant and/or complete rupture in the musculotendinous junction (MTJ) is a challenging lesion to treat because of the lack of reliable suture methods. Skeletal muscle-derived multipotent stem cell (Sk-MSC) sheet-pellets, which are able to reconstitute peripheral nerve and muscular/vascular tissues with robust connective tissue networks, have been applied as a "bio-bond". Methods. Sk-MSC sheet-pellets, derived from GFP transgenic-mice after 7 days of expansion culture, were detached with EDTA to maintain cell-cell connections. A completely ruptured MTJ model was prepared in the right tibialis anterior (TA) of the recipient mice, and was covered with sheet-pellets. The left side was preserved as a contralateral control. The control group received the same amount of the cell-free medium. The sheet-pellet transplantation (SP) group was further divided into two groups; as the short term (4-8 weeks) and long term (14-18 weeks) recovery group. At each time point after transplantation, tetanic tension output was measured through the electrical stimulation of the sciatic nerve. The behavior of engrafted GFP(+) tissues and cells was analyzed by fluorescence immunohistochemistry. Results. The SP short term recovery group showed average 64% recovery of muscle mass, and 36% recovery of tetanic tension output relative to the contralateral side. Then, the SP long term recovery group showed increased recovery of average muscle mass (77%) and tetanic tension output (49%). However, the control group showed no recovery of continuity between muscle and tendon, and demonstrated increased muscle atrophy, with coalescence to the tibia during 4-8 weeks after operation. Histological evidence also supported the above functional recovery of SP group. Engrafted Sk-MSCs primarily formed the connective tissues and muscle fibers, including nerve-vascular networks, and bridged the ruptured tendon-muscle fiber units, with differentiation into skeletal muscle cells, Schwann cells

  17. Cell Motility

    CERN Document Server

    Lenz, Peter

    2008-01-01

    Cell motility is a fascinating example of cell behavior which is fundamentally importan