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Sample records for derived neural precursor

  1. Highly pure and expandable PSA-NCAM-positive neural precursors from human ESC and iPSC-derived neural rosettes.

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    Dae-Sung Kim

    Full Text Available Homogeneous culture of neural precursor cells (NPCs derived from human pluripotent stem cells (hPSCs would provide a powerful tool for biomedical applications. However, previous efforts to expand mechanically dissected neural rosettes for cultivation of NPCs remain concerns regarding non-neural cell contamination. In addition, several attempts to purify NPCs using cell surface markers have not demonstrated the expansion capability of the sorted cells. In the present study, we show that polysialic acid-neural cell adhesion molecule (PSA-NCAM is detected in neural rosette cells derived from hPSCs, and employ PSA-NCAM as a marker for purifying expandable primitive NPCs from the neural rosettes. PSA-NCAM-positive NPCs (termed hNPC(PSA-NCAM+ were isolated from the heterogeneous cell population of mechanically harvested neural rosettes using magnetic-based cell sorting. The hNPC(PSA-NCAM+ extensively expressed neural markers such as Sox1, Sox2, Nestin, and Musashi-1 (80∼98% of the total cells and were propagated for multiple passages while retaining their primitive characteristics in our culture condition. Interestingly, PSA-NCAM-negative cells largely exhibited characteristics of neural crest cells. The hNPC(PSA-NCAM+ showed multipotency and responsiveness to instructive cues towards region-specific neuronal subtypes in vitro. When transplanted into the rat striatum, hNPC(PSA-NCAM+ differentiated into neurons, astrocytes, and oligodendrocytes without particular signs of tumorigenesis. Furthermore, Ki67-positive proliferating cells and non-neural lineage cells were rarely detected in the grafts of hNPC(PSA-NCAM+ compared to those of neural rosette cells. Our results suggest that PSA-NCAM-mediated cell isolation provides a highly expandable population of pure primitive NPCs from hPSCs that will lend themselves as a promising strategy for drug screening and cell therapy for neurodegenerative disorders.

  2. Long-term culture and differentiation of CNS precursors derived from anterior human neural rosettes following exposure to ventralizing factors

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    Colleoni, Silvia, E-mail: silviacolleoni@avantea.it [Laboratorio di Tecnologie della Riproduzione, Avantea, Via Porcellasco 7/f, 26100 Cremona (Italy); Galli, Cesare [Laboratorio di Tecnologie della Riproduzione, Avantea, Via Porcellasco 7/f, 26100 Cremona (Italy); Dipartimento Clinico Veterinario, Universita di Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia (Italy); Giannelli, Serena G. [Stem Cells and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 58, 20132 Milan (Italy); Armentero, Marie-Therese; Blandini, Fabio [Laboratory of Functional Neurochemistry, Interdepartmental Research Center for Parkinson' s Disease, Neurological Institute C. Mondino, Via Mondino 2, 27100 Pavia (Italy); Broccoli, Vania, E-mail: broccoli.vania@hsr.it [Stem Cells and Neurogenesis Unit, Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 58, 20132 Milan (Italy); Lazzari, Giovanna, E-mail: giovannalazzari@avantea.it [Laboratorio di Tecnologie della Riproduzione, Avantea, Via Porcellasco 7/f, 26100 Cremona (Italy)

    2010-04-15

    In this study we demonstrated that neural rosettes derived from human ES cells can give rise either to neural crest precursors, following expansion in presence of bFGF and EGF, or to dopaminergic precursors after exposure to ventralizing factors Shh and FGF8. Both regionalised precursors are capable of extensive proliferation and differentiation towards the corresponding terminally differentiated cell types. In particular, peripheral neurons, cartilage, bone, smooth muscle cells and also pigmented cells were obtained from neural crest precursors while tyrosine hydroxylase and Nurr1 positive dopaminergic neurons were derived from FGF8 and Shh primed rosette cells. Gene expression and immunocytochemistry analyses confirmed the expression of dorsal and neural crest genes such as Sox10, Slug, p75, FoxD3, Pax7 in neural precursors from bFGF-EGF exposed rosettes. By contrast, priming of rosettes with FGF8 and Shh induced the expression of dopaminergic markers Engrailed1, Pax2, Pitx3, floor plate marker FoxA2 and radial glia markers Blbp and Glast, the latter in agreement with the origin of dopaminergic precursors from floor plate radial glia. Moreover, in vivo transplant of proliferating Shh/FGF8 primed precursors in parkinsonian rats demonstrated engraftment and terminal dopaminergic differentiation. In conclusion, we demonstrated the derivation of long-term self-renewing precursors of selected regional identity as potential cell reservoirs for cell therapy applications, such as CNS degenerative diseases, or for the development of toxicological tests.

  3. Long-term culture and differentiation of CNS precursors derived from anterior human neural rosettes following exposure to ventralizing factors

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    Colleoni, Silvia; Galli, Cesare; Giannelli, Serena G.; Armentero, Marie-Therese; Blandini, Fabio; Broccoli, Vania; Lazzari, Giovanna

    2010-01-01

    In this study we demonstrated that neural rosettes derived from human ES cells can give rise either to neural crest precursors, following expansion in presence of bFGF and EGF, or to dopaminergic precursors after exposure to ventralizing factors Shh and FGF8. Both regionalised precursors are capable of extensive proliferation and differentiation towards the corresponding terminally differentiated cell types. In particular, peripheral neurons, cartilage, bone, smooth muscle cells and also pigmented cells were obtained from neural crest precursors while tyrosine hydroxylase and Nurr1 positive dopaminergic neurons were derived from FGF8 and Shh primed rosette cells. Gene expression and immunocytochemistry analyses confirmed the expression of dorsal and neural crest genes such as Sox10, Slug, p75, FoxD3, Pax7 in neural precursors from bFGF-EGF exposed rosettes. By contrast, priming of rosettes with FGF8 and Shh induced the expression of dopaminergic markers Engrailed1, Pax2, Pitx3, floor plate marker FoxA2 and radial glia markers Blbp and Glast, the latter in agreement with the origin of dopaminergic precursors from floor plate radial glia. Moreover, in vivo transplant of proliferating Shh/FGF8 primed precursors in parkinsonian rats demonstrated engraftment and terminal dopaminergic differentiation. In conclusion, we demonstrated the derivation of long-term self-renewing precursors of selected regional identity as potential cell reservoirs for cell therapy applications, such as CNS degenerative diseases, or for the development of toxicological tests.

  4. GDNF facilitates differentiation of the adult dentate gyrus-derived neural precursor cells into astrocytes via STAT3

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    Boku, Shuken, E-mail: shuboku@med.hokudai.ac.jp [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Nakagawa, Shin [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Takamura, Naoki [Pharmaceutical Laboratories, Dainippon Sumitomo Pharma Co. Ltd., Osaka (Japan); Kato, Akiko [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Takebayashi, Minoru [Department of Psychiatry, National Hospital Organization Kure Medical Center, Kure (Japan); Hisaoka-Nakashima, Kazue [Department of Pharmacology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima (Japan); Omiya, Yuki; Inoue, Takeshi; Kusumi, Ichiro [Department of Psychiatry, Hokkaido University Graduate School of Medicine, Sapporo (Japan)

    2013-05-17

    Highlights: •GDNF has no effect on ADP proliferation and apoptosis. •GDNF increases ADP differentiation into astrocyte. •A specific inhibitor of STAT3 decreases the astrogliogenic effect of GDNF. •STAT3 knockdown by lentiviral shRNA vector also decreases the astrogliogenic effect of GDNF. •GDNF increases the phosphorylation of STAT3. -- Abstract: While the pro-neurogenic actions of antidepressants in the adult hippocampal dentate gyrus (DG) are thought to be one of the mechanisms through which antidepressants exert their therapeutic actions, antidepressants do not increase proliferation of neural precursor cells derived from the adult DG. Because previous studies showed that antidepressants increase the expression and secretion of glial cell line-derived neurotrophic factor (GDNF) in C6 glioma cells derived from rat astrocytes and GDNF increases neurogenesis in adult DG in vivo, we investigated the effects of GDNF on the proliferation, differentiation and apoptosis of cultured neural precursor cells derived from the adult DG. Data showed that GDNF facilitated the differentiation of neural precursor cells into astrocytes but had no effect on their proliferation or apoptosis. Moreover, GDNF increased the phosphorylation of STAT3, and both a specific inhibitor of STAT3 and lentiviral shRNA for STAT3 decreased their differentiation into astrocytes. Taken together, our findings suggest that GDNF facilitates astrogliogenesis from neural precursor cells in adult DG through activating STAT3 and that this action might indirectly affect neurogenesis.

  5. GDNF facilitates differentiation of the adult dentate gyrus-derived neural precursor cells into astrocytes via STAT3

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    Boku, Shuken; Nakagawa, Shin; Takamura, Naoki; Kato, Akiko; Takebayashi, Minoru; Hisaoka-Nakashima, Kazue; Omiya, Yuki; Inoue, Takeshi; Kusumi, Ichiro

    2013-01-01

    Highlights: •GDNF has no effect on ADP proliferation and apoptosis. •GDNF increases ADP differentiation into astrocyte. •A specific inhibitor of STAT3 decreases the astrogliogenic effect of GDNF. •STAT3 knockdown by lentiviral shRNA vector also decreases the astrogliogenic effect of GDNF. •GDNF increases the phosphorylation of STAT3. -- Abstract: While the pro-neurogenic actions of antidepressants in the adult hippocampal dentate gyrus (DG) are thought to be one of the mechanisms through which antidepressants exert their therapeutic actions, antidepressants do not increase proliferation of neural precursor cells derived from the adult DG. Because previous studies showed that antidepressants increase the expression and secretion of glial cell line-derived neurotrophic factor (GDNF) in C6 glioma cells derived from rat astrocytes and GDNF increases neurogenesis in adult DG in vivo, we investigated the effects of GDNF on the proliferation, differentiation and apoptosis of cultured neural precursor cells derived from the adult DG. Data showed that GDNF facilitated the differentiation of neural precursor cells into astrocytes but had no effect on their proliferation or apoptosis. Moreover, GDNF increased the phosphorylation of STAT3, and both a specific inhibitor of STAT3 and lentiviral shRNA for STAT3 decreased their differentiation into astrocytes. Taken together, our findings suggest that GDNF facilitates astrogliogenesis from neural precursor cells in adult DG through activating STAT3 and that this action might indirectly affect neurogenesis

  6. Hypoxia Epigenetically Confers Astrocytic Differentiation Potential on Human Pluripotent Cell-Derived Neural Precursor Cells

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    Tetsuro Yasui

    2017-06-01

    Full Text Available Human neural precursor cells (hNPCs derived from pluripotent stem cells display a high propensity for neuronal differentiation, but they require long-term culturing to differentiate efficiently into astrocytes. The mechanisms underlying this biased fate specification of hNPCs remain elusive. Here, we show that hypoxia confers astrocytic differentiation potential on hNPCs through epigenetic gene regulation, and that this was achieved by cooperation between hypoxia-inducible factor 1α and Notch signaling, accompanied by a reduction of DNA methylation level in the promoter region of a typical astrocyte-specific gene, Glial fibrillary acidic protein. Furthermore, we found that this hypoxic culture condition could be applied to rapid generation of astrocytes from Rett syndrome patient-derived hNPCs, and that these astrocytes impaired neuronal development. Thus, our findings shed further light on the molecular mechanisms regulating hNPC differentiation and provide attractive tools for the development of therapeutic strategies for treating astrocyte-mediated neurological disorders.

  7. Tricyclic antidepressant amitriptyline indirectly increases the proliferation of adult dentate gyrus-derived neural precursors: an involvement of astrocytes.

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    Shuken Boku

    Full Text Available Antidepressants increase the proliferation of neural precursors in adult dentate gyrus (DG, which is considered to be involved in the therapeutic action of antidepressants. However, the mechanism underlying it remains unclear. By using cultured adult rat DG-derived neural precursors (ADP, we have already shown that antidepressants have no direct effects on ADP. Therefore, antidepressants may increase the proliferation of neural precursors in adult DG via unknown indirect mechanism. We have also shown that amitriptyline (AMI, a tricyclic antidepressant, induces the expressions of GDNF, BDNF, FGF2 and VEGF, common neurogenic factors, in primary cultured astrocytes (PCA. These suggest that AMI-induced factors in astrocytes may increase the proliferation of neural precursors in adult DG. To test this hypothesis, we examined the effects of AMI-induced factors and conditioned medium (CM from PCA treated with AMI on ADP proliferation. The effects of CM and factors on ADP proliferation were examined with BrdU immunocytochemistry. AMI had no effect on ADP proliferation, but AMI-treated CM increased it. The receptors of GDNF, BDNF and FGF2, but not VEGF, were expressed in ADP. FGF2 significantly increased ADP proliferation, but not BDNF and GDNF. In addition, both of a specific inhibitor of FGF receptors and anti-FGF2 antibody significantly counteracted the increasing effect of CM on ADP proliferation. In addition, FGF2 in brain is mainly derived from astrocytes that are key components of the neurogenic niches in adult DG. These suggest that AMI may increase ADP proliferation indirectly via PCA and that FGF2 may a potential candidate to mediate such an indirect effect of AMI on ADP proliferation via astrocytes.

  8. Role of Amyloid Precursor Protein (APP) and Its Derivatives in the Biology and Cell Fate Specification of Neural Stem Cells.

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    Coronel, Raquel; Bernabeu-Zornoza, Adela; Palmer, Charlotte; Muñiz-Moreno, Mar; Zambrano, Alberto; Cano, Eva; Liste, Isabel

    2018-01-30

    Amyloid precursor protein (APP) is a member of the APP family of proteins, and different enzymatic processing leads to the production of several derivatives that are shown to have distinct biological functions. APP is involved in the pathology of Alzheimer's disease (AD), the most common neurodegenerative disorder causing dementia. Furthermore, it is believed that individuals with Down syndrome (DS) have increased APP expression, due to an extra copy of chromosome 21 (Hsa21), that contains the gene for APP. Nevertheless, the physiological function of APP remains unclear. It is known that APP plays an important role in neural growth and maturation during brain development, possibly by influencing proliferation, cell fate specification and neurogenesis of neural stem cells (NSCs). Proteolytic cleavage of APP occurs mainly via two mutually exclusive pathways, the non-amyloidogenic pathway or the amyloidogenic pathway. Other alternative pathways (η-secretase, δ-secretase and meprin pathways) have also been described for the physiological processing of APP. The different metabolites generated from these pathways, including soluble APPα (sAPPα), soluble APPβ (sAPPβ), β-amyloid (Aβ) peptides and the APP intracellular domain (AICD), have different functions determined by their structural differences, equilibrium and concentration with respect to other fragments derived from APP. This review discusses recent observations regarding possible functions of APP and its proteolytic derivatives in the biology and phenotypic specification of NSCs. This can be important for a better understanding of the pathogenesis and the development of future therapeutic applications for AD and/or DS, diseases in which alterations in neurogenesis have been described.

  9. Functional effects of cannabinoids during dopaminergic specification of human neural precursors derived from induced pluripotent stem cells.

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    Stanslowsky, Nancy; Jahn, Kirsten; Venneri, Anna; Naujock, Maximilian; Haase, Alexandra; Martin, Ulrich; Frieling, Helge; Wegner, Florian

    2017-09-01

    Among adolescents cannabis is one of the most widely used illicit drugs. In adolescence brain development continues, characterized by neuronal maturation and synaptic plasticity. The endocannabinoid system plays an important role during brain development by modulating neuronal function and neurogenesis. Changes in endocannabinoid signaling by Δ 9 -tetrahydrocannabinol (THC), the psychoactive component of cannabis, might therefore lead to neurobiological changes influencing brain function and behavior. We investigated the functional maturation and dopaminergic specification of human cord blood-derived induced pluripotent stem cell (hCBiPSC)-derived small molecule neural precursor cells (smNPCs) after cultivation with the endogenous cannabinoid anandamide (AEA) and the exogenous THC, both potent agonists at the cannabinoid 1 receptor (CB 1 R). Higher dosages of 10-μM AEA or THC significantly decreased functionality of neurons, indicated by reduced ion currents and synaptic activity. A lower concentration of 1-μM THC had no marked effect on neuronal and dopaminergic maturation, while 1-μM AEA significantly enhanced the frequency of synaptic activity. As there were no significant effects on DNA methylation in promotor regions of genes important for neuronal function, these cannabinoid actions seem to be mediated by another than this epigenetic mechanism. Our data suggest that there are concentration-dependent actions of cannabinoids on neuronal function in vitro indicating neurotoxic, dysfunctional effects of 10-μM AEA and THC during human neurogenesis. © 2016 Society for the Study of Addiction.

  10. The effect of magnetic nanoparticles on neuronal differentiation of induced pluripotent stem cell-derived neural precursors

    Czech Academy of Sciences Publication Activity Database

    Jiráková, Klára; Šeneklová, Monika; Jirák, D.; Turnovcová, Karolína; Vosmanská, M.; Babič, Michal; Horák, Daniel; Veverka, Pavel; Jendelová, Pavla

    2016-01-01

    Roč. 11, č. 2016 (2016), s. 6267-6281 E-ISSN 1178-2013 R&D Projects: GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk(CZ) 7F14057 Institutional support: RVO:68378041 ; RVO:61389013 ; RVO:68378271 Keywords : neural precursors * magnetic resonance imaging * cell differentiation Subject RIV: FH - Neurology; EB - Genetics ; Molecular Biology (FGU-C); CD - Macromolecular Chemistry (UMCH-V) Impact factor: 4.300, year: 2016

  11. Beneficial effect of human induced pluripotent stem cell-derived neural precursors in spinal cord injury repair

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    Romanyuk, Nataliya; Amemori, Takashi; Turnovcová, Karolína; Procházka, Pavel; Onteniente, B.; Syková, Eva; Jendelová, Pavla

    2015-01-01

    Roč. 24, č. 9 (2015), s. 1781-1797 ISSN 0963-6897 R&D Projects: GA MŠk LH12024; GA ČR(CZ) GA13-00939S; GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk(CZ) LO1309 Institutional support: RVO:68378041 Keywords : human induced pluripotent stem cells * neural precursors * spinal cord injury Subject RIV: FH - Neurology Impact factor: 3.427, year: 2015

  12. Overexpression of Polysialylated Neural Cell Adhesion Molecule Improves the Migration Capacity of Induced Pluripotent Stem Cell-Derived Oligodendrocyte Precursors

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    Czepiel, Marcin; Leicher, Lasse; Becker, Katja; Boddeke, Erik

    2014-01-01

    Cell replacement therapy aiming at the compensation of lost oligodendrocytes and restoration of myelination in acquired or congenital demyelination disorders has gained considerable interest since the discovery of induced pluripotent stem cells (iPSCs). Patient-derived iPSCs provide an inexhaustible source for transplantable autologous oligodendrocyte precursors (OPCs). The first transplantation studies in animal models for demyelination with iPSC-derived OPCs demonstrated their survival and remyelinating capacity, but also revealed their limited migration capacity. In the present study, we induced overexpression of the polysialylating enzyme sialyltransferase X (STX) in iPSC-derived OPCs to stimulate the production of polysialic acid-neuronal cell adhesion molecules (PSA-NCAMs), known to promote and facilitate the migration of OPCs. The STX-overexpressing iPSC-derived OPCs showed a normal differentiation and maturation pattern and were able to downregulate PSA-NCAMs when they became myelin-forming oligodendrocytes. After implantation in the demyelinated corpus callosum of cuprizone-fed mice, STX-expressing iPSC-derived OPCs demonstrated a significant increase in migration along the axons. Our findings suggest that the reach and efficacy of iPSC-derived OPC transplantation can be improved by stimulating the OPC migration potential via specific gene modulation. PMID:25069776

  13. Decreased neural precursor cell pool in NADPH oxidase 2-deficiency: From mouse brain to neural differentiation of patient derived iPSC

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    Zeynab Nayernia

    2017-10-01

    Full Text Available There is emerging evidence for the involvement of reactive oxygen species (ROS in the regulation of stem cells and cellular differentiation. Absence of the ROS-generating NADPH oxidase NOX2 in chronic granulomatous disease (CGD patients, predominantly manifests as immune deficiency, but has also been associated with decreased cognition. Here, we investigate the role of NOX enzymes in neuronal homeostasis in adult mouse brain and in neural cells derived from human induced pluripotent stem cells (iPSC. High levels of NOX2 were found in mouse adult neurogenic regions. In NOX2-deficient mice, neurogenic regions showed diminished redox modifications, as well as decrease in neuroprecursor numbers and in expression of genes involved in neural differentiation including NES, BDNF and OTX2. iPSC from healthy subjects and patients with CGD were used to study the role of NOX2 in human in vitro neuronal development. Expression of NOX2 was low in undifferentiated iPSC, upregulated upon neural induction, and disappeared during neuronal differentiation. In human neurospheres, NOX2 protein and ROS generation were polarized within the inner cell layer of rosette structures. NOX2 deficiency in CGD-iPSCs resulted in an abnormal neural induction in vitro, as revealed by a reduced expression of neuroprogenitor markers (NES, BDNF, OTX2, NRSF/REST, and a decreased generation of mature neurons. Vector-mediated NOX2 expression in NOX2-deficient iPSCs rescued neurogenesis. Taken together, our study provides novel evidence for a regulatory role of NOX2 during early stages of neurogenesis in mouse and human.

  14. Remyelination Is Correlated with Regulatory T Cell Induction Following Human Embryoid Body-Derived Neural Precursor Cell Transplantation in a Viral Model of Multiple Sclerosis.

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    Warren C Plaisted

    Full Text Available We have recently described sustained clinical recovery associated with dampened neuroinflammation and remyelination following transplantation of neural precursor cells (NPCs derived from human embryonic stem cells (hESCs in a viral model of the human demyelinating disease multiple sclerosis. The hNPCs used in that study were derived by a novel direct differentiation method (direct differentiation, DD-NPCs that resulted in a unique gene expression pattern when compared to hNPCs derived by conventional methods. Since the therapeutic potential of human NPCs may differ greatly depending on the method of derivation and culture, we wanted to determine whether NPCs differentiated using conventional methods would be similarly effective in improving clinical outcome under neuroinflammatory demyelinating conditions. For the current study, we utilized hNPCs differentiated from a human induced pluripotent cell line via an embryoid body intermediate stage (EB-NPCs. Intraspinal transplantation of EB-NPCs into mice infected with the neurotropic JHM strain of mouse hepatitis virus (JHMV resulted in decreased accumulation of CD4+ T cells in the central nervous system that was concomitant with reduced demyelination at the site of injection. Dampened neuroinflammation and remyelination was correlated with a transient increase in CD4+FOXP3+ regulatory T cells (Tregs concentrated within the peripheral lymphatics. However, compared to our earlier study, pathological improvements were modest and did not result in significant clinical recovery. We conclude that the genetic signature of NPCs is critical to their effectiveness in this model of viral-induced neurologic disease. These comparisons will be useful for understanding what factors are critical for the sustained clinical improvement.

  15. Analysis of In Vitro and In Vivo Characteristics of Human Embryonic Stem Cell-Derived Neural Precursors

    Czech Academy of Sciences Publication Activity Database

    Kozubenko, Nataliya; Turnovcová, Karolína; Kapcalová, Miroslava; Butenko, Olena; Anděrová, Miroslava; Rusňáková, Vendula; Kubista, Mikael; Hampl, Aleš; Jendelová, Pavla; Syková, Eva

    2010-01-01

    Roč. 19, č. 4 (2010), s. 471-486 ISSN 0963-6897 R&D Projects: GA MŠk(CZ) LC554; GA ČR GA305/09/0717 Grant - others:GA MŠk(CZ) 1M0538; EC FP6 project ENINET(XE) LSHM-CT-2005-019063; EC FP project STEMS(XE) LSHB-CT-2006-037328; GA AV ČR(CZ) IAA500520809; GA ČR(CZ) GD309/08/H079 Program:1M; IA Institutional research plan: CEZ:AV0Z50390703; CEZ:AV0Z50520701 Keywords : Human embryonic stem cells (hESCs) * Fluorescent-activated cell sorting * Neural differentiation Subject RIV: FH - Neurology Impact factor: 6.204, year: 2010

  16. Radiation response of rodent neural precursor cells

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    Limoli, C.L.; Fike, J.R.

    2003-01-01

    Full text: Therapeutic irradiation of the brain can cause cognitive dysfunction that is not treatable or well understood. Several lines of evidence from our laboratory suggest that radiation induced inhibition of neurogenesis in the hippocampus may be involved. To understand the mechanisms underlying these observations, we initiated studies using neural precursor cells isolated from the adult rat hippocampus. Cells were cultured exponentially and analyzed for acute (0-24h) and chronic (3-33 day) changes in apoptosis and oxidative stress following exposure to X-rays. Oxidative stress was measured using a dye sensitive to reactive oxygen species (ROS) and apoptosis was measured using annexin V binding; each endpoint was quantified by fluorescent automated cell sorting (FACS). Following exposure to X-rays, neural precursor cells exhibit a dose-responsive increase in the level of ROS and apoptosis over acute and chronic time frames. ROS and apoptosis were maximal at 12h, increasing 35 and 37% respectively over that of unirradiated controls. ROS and apoptosis peaked again at 24h, increasing 31 and 21% respectively over controls. Chronic levels of ROS and apoptosis were persistently elevated in a dose-dependent manner. ROS showed significant increases (34-180%) over a 3-4 week interval, while increases in apoptosis were less dramatic, rising 45% by week one before dropping to background. Irradiation of rat neural precursor cells was associated with an increase in p53 protein levels, and the activation of G1/S and G2/M checkpoints. These data suggest that the apoptotic and ROS responses may be tied to p53 dependent regulation of cell cycle control and stress activated pathways. We propose that oxidative stress plays a critical role in the radiation response of neural precursor cells, and discuss how this might contribute to the inhibition of neurogenesis and the cognitive impairment observed in the irradiated CNS

  17. Replicable Expansion and Differentiation of Neural Precursors from Adult Canine Skin

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    Thomas Duncan

    2017-08-01

    Full Text Available Repopulation of brain circuits by neural precursors is a potential therapeutic strategy for neurodegenerative disorders; however, choice of cell is critical. Previously, we introduced a two-step culture system that generates a high yield of neural precursors from small samples of adult canine skin. Here, we probe their gene and protein expression profiles in comparison with dermal fibroblasts and brain-derived neural stem cells and characterize their neuronal potential. To date, we have produced >50 skin-derived neural precursor (SKN lines. SKNs can be cultured in a highly replicable fashion and uniformly express a panel of identifying markers. Upon differentiation, they self-upregulate neural specification genes, generating neurons with basic electrophysiological functionality. This unique population of neural precursors, derived from mature skin, overcomes many of the practical issues that have limited clinical translation of alternative cell types. Easily accessible, neuronally committed, and patient specific, SKNs may have potential for the treatment of brain disorders.

  18. The Use of Human-Induced Pluripotent Stem Cell-Derived Neural Precursors in the Treatment of Brain and Spinal Cord Injury

    Czech Academy of Sciences Publication Activity Database

    Jendelová, Pavla; Kozubenko, Nataliya; Amemori, Takashi; Turnovcová, Karolína; Seminatore, CH.; Jirák, D.; Onteniente, B.; Syková, Eva

    2011-01-01

    Roč. 20, č. 4 (2011), s. 564-564 ISSN 0963-6897. [International Neural Transplantatioin and Repair Meeting/18th Annual Meeting of the American-Society-for-Neural-Therapy- and -Repair /11./. 04.05.2011-08.05.2011, Clearwater] Institutional research plan: CEZ:AV0Z50390703 Keywords : spinal cord * stem cell Subject RIV: FH - Neurology

  19. Transplantation of bone marrow stromal cell-derived neural precursor cells ameliorates deficits in a rat model of complete spinal cord transection.

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    Aizawa-Kohama, Misaki; Endo, Toshiki; Kitada, Masaaki; Wakao, Shohei; Sumiyoshi, Akira; Matsuse, Dai; Kuroda, Yasumasa; Morita, Takahiro; Riera, Jorge J; Kawashima, Ryuta; Tominaga, Teiji; Dezawa, Mari

    2013-01-01

    After severe spinal cord injury, spontaneous functional recovery is limited. Numerous studies have demonstrated cell transplantation as a reliable therapeutic approach. However, it remains unknown whether grafted neuronal cells could replace lost neurons and reconstruct neuronal networks in the injured spinal cord. To address this issue, we transplanted bone marrow stromal cell-derived neural progenitor cells (BM-NPCs) in a rat model of complete spinal cord transection 9 days after the injury. BM-NPCs were induced from bone marrow stromal cells (BMSCs) by gene transfer of the Notch-1 intracellular domain followed by culturing in the neurosphere method. As reported previously, BM-NPCs differentiated into neuronal cells in a highly selective manner in vitro. We assessed hind limb movements of the animals weekly for 7 weeks to monitor functional recovery after local injection of BM-NPCs to the transected site. To test the sensory recovery, we performed functional magnetic resonance imaging (fMRI) using electrical stimulation of the hind limbs. In the injured spinal cord, transplanted BM-NPCs were confirmed to express neuronal markers 7 weeks following the transplantation. Grafted cells successfully extended neurites beyond the transected portion of the spinal cord. Adjacent localization of synaptophysin and PSD-95 in the transplanted cells suggested synaptic formations. These results indicated survival and successful differentiation of BM-NPCs in the severely injured spinal cord. Importantly, rats that received BM-NPCs demonstrated significant motor recovery when compared to the vehicle injection group. Volumes of the fMRI signals in somatosensory cortex were larger in the BM-NPC-grafted animals. However, neuronal activity was diverse and not confined to the original hind limb territory in the somatosensory cortex. Therefore, reconstruction of neuronal networks was not clearly confirmed. Our results indicated BM-NPCs as an effective method to deliver neuronal lineage

  20. Non-Viral Generation of Neural Precursor-like Cells from Adult Human Fibroblasts

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    Maucksch C

    2012-01-01

    Full Text Available Recent studies have reported direct reprogramming of human fibroblasts to mature neurons by the introduction of defined neural genes. This technology has potential use in the areas of neurological disease modeling and drug development. However, use of induced neurons for large-scale drug screening and cell-based replacement strategies is limited due to their inability to expand once reprogrammed. We propose it would be more desirable to induce expandable neural precursor cells directly from human fibroblasts. To date several pluripotent and neural transcription factors have been shown to be capable of converting mouse fibroblasts to neural stem/precursor-like cells when delivered by viral vectors. Here we extend these findings and demonstrate that transient ectopic insertion of the transcription factors SOX2 and PAX6 to adult human fibroblasts through use of non-viral plasmid transfection or protein transduction allows the generation of induced neural precursor (iNP colonies expressing a range of neural stem and pro-neural genes. Upon differentiation, iNP cells give rise to neurons exhibiting typical neuronal morphologies and expressing multiple neuronal markers including tyrosine hydroxylase and GAD65/67. Importantly, iNP-derived neurons demonstrate electrophysiological properties of functionally mature neurons with the capacity to generate action potentials. In addition, iNP cells are capable of differentiating into glial fibrillary acidic protein (GFAP-expressing astrocytes. This study represents a novel virus-free approach for direct reprogramming of human fibroblasts to a neural precursor fate.

  1. Culture of Mouse Neural Stem Cell Precursors

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    Currle, D. Spencer; Hu, Jia Sheng; Kolski-Andreaco, Aaron; Monuki, Edwin S.

    2007-01-01

    Primary neural stem cell cultures are useful for studying the mechanisms underlying central nervous system development. Stem cell research will increase our understanding of the nervous system and may allow us to develop treatments for currently incurable brain diseases and injuries. In addition, stem cells should be used for stem cell research aimed at the detailed study of mechanisms of neural differentiation and transdifferentiation and the genetic and environmental signals that direct the...

  2. Massively parallel signature sequencing profiling of fetal human neural precursor cells.

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    Cai, Jingli; Shin, Soojung; Wright, Lynda; Liu, Ying; Zhou, Daixing; Xue, Haipeng; Khrebtukova, Irina; Mattson, Mark P; Svendsen, Clive N; Rao, Mahendra S

    2006-04-01

    We have examined gene expression in multipotent neural precursor cells (NPCs) derived from human fetal (f) brain tissue and compared its expression profiles with embryonic stem (ESC) cells, embryoid body cell (EBC), and astrocyte precursors using the technique of massively parallel signature sequencing (MPSS). Gene expression profiles show that fNPCs express core neural stem cells markers and share expression profiles with astrocyte precursor cells (APCs) rather than ESC or EBC. Gene expression analysis shows that fNPCs differ from other adult stem and progenitor cells in their marker expression and activation of specific functional networks such as the transforming growth factorbeta (TGFbeta) and Notch signaling pathways. In addition, our results allow us to identify novel genes expressed in fNPCs and provide a detailed profile of fNPCs.

  3. Rejuvenation of MPTP-induced human neural precursor cell senescence by activating autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Liang [East Hospital, Tongji University School of Medicine, Shanghai (China); Dong, Chuanming [East Hospital, Tongji University School of Medicine, Shanghai (China); Department of Anatomy and Neurobiology, The Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong (China); Sun, Chenxi; Ma, Rongjie; Yang, Danjing [East Hospital, Tongji University School of Medicine, Shanghai (China); Zhu, Hongwen, E-mail: hongwen_zhu@hotmail.com [Tianjin Hospital, Tianjin Academy of Integrative Medicine, Tianjin (China); Xu, Jun, E-mail: xunymc2000@yahoo.com [East Hospital, Tongji University School of Medicine, Shanghai (China)

    2015-08-21

    Aging of neural stem cell, which can affect brain homeostasis, may be caused by many cellular mechanisms. Autophagy dysfunction was found in aged and neurodegenerative brains. However, little is known about the relationship between autophagy and human neural stem cell (hNSC) aging. The present study used 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) to treat neural precursor cells (NPCs) derived from human embryonic stem cell (hESC) line H9 and investigate related molecular mechanisms involved in this process. MPTP-treated NPCs were found to undergo premature senescence [determined by increased senescence-associated-β-galactosidase (SA-β-gal) activity, elevated intracellular reactive oxygen species level, and decreased proliferation] and were associated with impaired autophagy. Additionally, the cellular senescence phenotypes were manifested at the molecular level by a significant increase in p21 and p53 expression, a decrease in SOD2 expression, and a decrease in expression of some key autophagy-related genes such as Atg5, Atg7, Atg12, and Beclin 1. Furthermore, we found that the senescence-like phenotype of MPTP-treated hNPCs was rejuvenated through treatment with a well-known autophagy enhancer rapamycin, which was blocked by suppression of essential autophagy gene Beclin 1. Taken together, these findings reveal the critical role of autophagy in the process of hNSC aging, and this process can be reversed by activating autophagy. - Highlights: • We successfully establish hESC-derived neural precursor cells. • MPTP treatment induced senescence-like state in hESC-derived NPCs. • MPTP treatment induced impaired autophagy of hESC-derived NPCs. • MPTP-induced hESC-derived NPC senescence was rejuvenated by activating autophagy.

  4. Brain Region-Dependent Rejection of Neural Precursor Cell Transplants

    Directory of Open Access Journals (Sweden)

    Nina Fainstein

    2018-04-01

    Full Text Available The concept of CNS as an immune-privileged site has been challenged by the occurrence of immune surveillance and allogeneic graft rejection in the brain. Here we examined whether the immune response to allogeneic neural grafts is determined by the site of implantation in the CNS. Dramatic regional differences were observed between immune responses to allogeneic neural precursor/stem cell (NPC grafts in the striatum vs. the hippocampus. Striatal grafts were heavily infiltrated with IBA-1+ microglia/macrophages and CD3+ T cells and completely rejected. In contrast, hippocampal grafts exhibited milder IBA-1+ cell infiltration, were not penetrated efficiently by CD3+ cells, and survived efficiently for at least 2 months. To evaluate whether the hippocampal protective effect is universal, astrocytes were then transplanted. Allogeneic astrocyte grafts elicited a vigorous rejection process from the hippocampus. CD200, a major immune-inhibitory signal, plays an important role in protecting grafts from rejection. Indeed, CD200 knock out NPC grafts were rejected more efficiently than wild type NPCs from the striatum. However, lack of CD200 expression did not elicit NPC graft rejection from the hippocampus. In conclusion, the hippocampus has partial immune-privilege properties that are restricted to NPCs and are CD200-independent. The unique hippocampal milieu may be protective for allogeneic NPC grafts, through host-graft interactions enabling sustained immune-regulatory properties of transplanted NPCs. These findings have implications for providing adequate immunosuppression in clinical translation of cell therapy.

  5. A Protocol for Isolation and Enriched Monolayer Cultivation of Neural Precursor Cells from Mouse Dentate Gyrus

    OpenAIRE

    Babu, Harish; Claasen, Jan-Hendrik; Kannan, Suresh; Rünker, Annette E.; Palmer, Theo; Kempermann, Gerd

    2011-01-01

    In vitro assays are valuable tools to study the characteristics of adult neural precursor cells under controlled conditions with a defined set of parameters. We here present a detailed protocol based on our previous original publication (Babu et al., 2007) to isolate neural precursor cells from the hippocampus of adult mice and maintain and propagate them as adherent monolayer cultures. The strategy is based on the use of Percoll density gradient centrifugation to enrich precursor cells from ...

  6. A protocol for isolation and enriched monolayer cultivation of neural precursor cells from mouse dentate gyrus

    OpenAIRE

    Harish eBabu; Jan-Hendrik eClaasen; Jan-Hendrik eClaasen; Jan-Hendrik eClaasen; Suresh eKannan; Annette E. Rünker; Theo ePalmer; Gerd eKempermann; Gerd eKempermann

    2011-01-01

    In vitro assays are valuable tools to study the characteristics of adult neural precursor cells under controlled conditions with a defined set of parameters. We here present a detailed protocol based on our previous original publication (Babu et al., Enriched monolayer precursor cell cultures from micro-dissected adult mouse dentate gyrus yield functional granule cell-like neurons, PLoS One 2007, 2:e388) to isolate neural precursor cells from the hippocampus of adult mice and maintain and pro...

  7. Identification and characterization of secondary neural tube-derived embryonic neural stem cells in vitro.

    Science.gov (United States)

    Shaker, Mohammed R; Kim, Joo Yeon; Kim, Hyun; Sun, Woong

    2015-05-15

    Secondary neurulation is an embryonic progress that gives rise to the secondary neural tube, the precursor of the lower spinal cord region. The secondary neural tube is derived from aggregated Sox2-expressing neural cells at the dorsal region of the tail bud, which eventually forms rosette or tube-like structures to give rise to neural tissues in the tail bud. We addressed whether the embryonic tail contains neural stem cells (NSCs), namely secondary NSCs (sNSCs), with the potential for self-renewal in vitro. Using in vitro neurosphere assays, neurospheres readily formed at the rosette and neural-tube levels, but less frequently at the tail bud tip level. Furthermore, we identified that sNSC-generated neurospheres were significantly smaller in size compared with cortical neurospheres. Interestingly, various cell cycle analyses revealed that this difference was not due to a reduction in the proliferation rate of NSCs, but rather the neuronal commitment of sNSCs, as sNSC-derived neurospheres contain more committed neuronal progenitor cells, even in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). These results suggest that the higher tendency for sNSCs to spontaneously differentiate into progenitor cells may explain the limited expansion of the secondary neural tube during embryonic development.

  8. Regeneration of neural crest derivatives in the Xenopus tadpole tail

    Directory of Open Access Journals (Sweden)

    Slack Jonathan MW

    2007-05-01

    Full Text Available Abstract Background After amputation of the Xenopus tadpole tail, a functionally competent new tail is regenerated. It contains spinal cord, notochord and muscle, each of which has previously been shown to derive from the corresponding tissue in the stump. The regeneration of the neural crest derivatives has not previously been examined and is described in this paper. Results Labelling of the spinal cord by electroporation, or by orthotopic grafting of transgenic tissue expressing GFP, shows that no cells emigrate from the spinal cord in the course of regeneration. There is very limited regeneration of the spinal ganglia, but new neurons as well as fibre tracts do appear in the regenerated spinal cord and the regenerated tail also contains abundant peripheral innervation. The regenerated tail contains a normal density of melanophores. Cell labelling experiments show that melanophores do not arise from the spinal cord during regeneration, nor from the mesenchymal tissues of the skin, but they do arise by activation and proliferation of pre-existing melanophore precursors. If tails are prepared lacking melanophores, then the regenerates also lack them. Conclusion On regeneration there is no induction of a new neural crest similar to that seen in embryonic development. However there is some regeneration of neural crest derivatives. Abundant melanophores are regenerated from unpigmented precursors, and, although spinal ganglia are not regenerated, sufficient sensory systems are produced to enable essential functions to continue.

  9. Sonic Hedgehog Controls the Phenotypic Fate and Therapeutic Efficacy of Grafted Neural Precursor Cells in a Model of Nigrostriatal Neurodegeneration

    OpenAIRE

    Madhavan, Lalitha; Daley, Brian F.; Davidson, Beverly L.; Boudreau, Ryan L.; Lipton, Jack W.; Cole-Strauss, Allyson; Steece-Collier, Kathy; Collier, Timothy J.

    2015-01-01

    The expression of soluble growth and survival promoting factors by neural precursor cells (NPCs) is suggested to be a prominent mechanism underlying the protective and regenerative effects of these cells after transplantation. Nevertheless, how and to what extent specific NPC-expressed factors contribute to therapeutic effects is not well understood. Using RNA silencing, the current study investigated the roles of two donor NPC molecules, namely glial cell-line derived neurotrophic factor (GD...

  10. Restriction of neural precursor ability to respond to Nurr1 by early regional specification.

    Directory of Open Access Journals (Sweden)

    Chiara Soldati

    Full Text Available During neural development, spatially regulated expression of specific transcription factors is crucial for central nervous system (CNS regionalization, generation of neural precursors (NPs and subsequent differentiation of specific cell types within defined regions. A critical role in dopaminergic differentiation in the midbrain (MB has been assigned to the transcription factor Nurr1. Nurr1 controls the expression of key genes involved in dopamine (DA neurotransmission, e.g. tyrosine hydroxylase (TH and the DA transporter (DAT, and promotes the dopaminergic phenotype in embryonic stem cells. We investigated whether cells derived from different areas of the mouse CNS could be directed to differentiate into dopaminergic neurons in vitro by forced expression of the transcription factor Nurr1. We show that Nurr1 overexpression can promote dopaminergic cell fate specification only in NPs obtained from E13.5 ganglionic eminence (GE and MB, but not in NPs isolated from E13.5 cortex (CTX and spinal cord (SC or from the adult subventricular zone (SVZ. Confirming previous studies, we also show that Nurr1 overexpression can increase the generation of TH-positive neurons in mouse embryonic stem cells. These data show that Nurr1 ability to induce a dopaminergic phenotype becomes restricted during CNS development and is critically dependent on the region of NPs derivation. Our results suggest that the plasticity of NPs and their ability to activate a dopaminergic differentiation program in response to Nurr1 is regulated during early stages of neurogenesis, possibly through mechanisms controlling CNS regionalization.

  11. Niche-dependent development of functional neuronal networks from embryonic stem cell-derived neural populations

    Directory of Open Access Journals (Sweden)

    Siebler Mario

    2009-08-01

    Full Text Available Abstract Background The present work was performed to investigate the ability of two different embryonic stem (ES cell-derived neural precursor populations to generate functional neuronal networks in vitro. The first ES cell-derived neural precursor population was cultivated as free-floating neural aggregates which are known to form a developmental niche comprising different types of neural cells, including neural precursor cells (NPCs, progenitor cells and even further matured cells. This niche provides by itself a variety of different growth factors and extracellular matrix proteins that influence the proliferation and differentiation of neural precursor and progenitor cells. The second population was cultivated adherently in monolayer cultures to control most stringently the extracellular environment. This population comprises highly homogeneous NPCs which are supposed to represent an attractive way to provide well-defined neuronal progeny. However, the ability of these different ES cell-derived immature neural cell populations to generate functional neuronal networks has not been assessed so far. Results While both precursor populations were shown to differentiate into sufficient quantities of mature NeuN+ neurons that also express GABA or vesicular-glutamate-transporter-2 (vGlut2, only aggregate-derived neuronal populations exhibited a synchronously oscillating network activity 2–4 weeks after initiating the differentiation as detected by the microelectrode array technology. Neurons derived from homogeneous NPCs within monolayer cultures did merely show uncorrelated spiking activity even when differentiated for up to 12 weeks. We demonstrated that these neurons exhibited sparsely ramified neurites and an embryonic vGlut2 distribution suggesting an inhibited terminal neuronal maturation. In comparison, neurons derived from heterogeneous populations within neural aggregates appeared as fully mature with a dense neurite network and punctuated

  12. Hippocalcin Is Required for Astrocytic Differentiation through Activation of Stat3 in Hippocampal Neural Precursor Cells.

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    Min-Jeong Kang

    2016-10-01

    Full Text Available Hippocalcin (Hpca is a neuronal calcium sensor protein expressed in the mammalian brain. However, its function in neural stem/precursor cells has not yet been studied. Here, we clarify the function of Hpca in astrocytic differentiation in hippocampal neural precursor cells (HNPCs. When we overexpressed Hpca in HNPCs in the presence or absence of bFGF, expression levels of nerve-growth factors such as neurotrophin-3 (NT-3, neurotrophin-4/5 (NT-4/5 and brain-derived neurotrophic factor (BDNF, together with the proneural basic helix loop helix (bHLH transcription factors neuroD and neurogenin 1 (ngn1, increased significantly. In addition, there was an increase in the number of cells expressing glial fibrillary acidic protein (GFAP, an astrocyte marker, and in dendrite outgrowth, indicating astrocytic differentiation of the HNPCs. Downregulation of Hpca by transfection with Hpca siRNA reduced expression of NT-3, NT-4/5, BDNF, neuroD and ngn1 as well as levels of GFAP protein. Furthermore, overexpression of Hpca increased the phosphorylation of STAT3 (Ser727, and this effect was abolished by treatment with a STAT3 inhibitor (S3I-201, suggesting that STAT3 (Ser727 activation is involved in Hpca-mediated astrocytic differentiation. As expected, treatment with Stat3 siRNA or STAT3 inhibitor caused a complete inhibition of astrogliogenesis induced by Hpca overexpression. Taken together, this is the first report to show that Hpca, acting through Stat3, has an important role in the expression of neurotrophins and proneural bHLH transcription factors, and that it is an essential regulator of astrocytic differentiation and dendrite outgrowth in HNPCs.

  13. Survival and differentiation of human embryonic stem cell-derived neural precursors grafted spinally in spinal ischemia-injured rats or in naive immunosuppressed minipigs: a qualitative and quantitative study

    Czech Academy of Sciences Publication Activity Database

    Kakinohana, O.; Juhásová, Jana; Juhás, Štefan; Motlík, Jan; Platoshyn, O.; Galik, J.; Hefferan, M. P.; Yuan, S. H.; Vidal, J. G.; Carson, C. T.; Van Gorp, S.; Goldberg, D.; Leerink, M.; Lazar, P.; Maršala, S.; Miyanohara, A.; Keshavarzi, S.; Ciacci, J. D.; Maršala, M.

    2012-01-01

    Roč. 21, č. 12 (2012), s. 2603-2619 ISSN 0963-6897 R&D Projects: GA MŠk 1M0538; GA TA ČR TA01011466 Institutional research plan: CEZ:AV0Z50450515 Keywords : spinal cord ischemia * human embryonic stem (ES) cells * neuronal precursors (NPCs) Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.422, year: 2012

  14. Transplanted skin-derived precursor stem cells generate enteric ganglion-like structures in vivo.

    Science.gov (United States)

    Wagner, Justin P; Sullins, Veronica F; Dunn, James C Y

    2014-08-01

    Hirschsprung's disease is characterized by a developmental arrest of neural crest cell migration, causing distal aganglionosis. Transplanted cells derived from the neural crest may regenerate enteric ganglia in this condition. We investigated the potential of skin-derived precursor cells (SKPs) to engraft and to differentiate into enteric ganglia in aganglionic rat intestine in vivo. Adult Lewis rat jejunal segments were separated from intestinal continuity and treated with benzalkonium chloride to induce aganglionosis. Ganglia were identified via immunohistochemical stains for S100 and β-III tubulin (TUJ1). SKPs were procured from neonatal Lewis rats expressing enhanced green fluorescent protein (GFP) and cultured in neuroglial-selective media. SKP cell line expansion was quantified, and immunophenotypes were assessed by immunocytochemistry. Aganglionic segments underwent SKP transplantation 21-79days after benzalkonium chloride treatment. The presence of GFP+cells, mature neurons, and mature glia was evaluated at posttransplant days 1, 6, and 9. Benzalkonium chloride-induced aganglionosis persisted for at least 85days. Prior to differentiation, SKPs expressed S100, denoting neural crest lineage, and nestin, a marker of neuronal precursors. Differentiated SKPs in vitro expressed GFAP, a marker of glial differentiation, as well as TUJ1 and several enteric neurotransmitters. After transplantation, GFP+structures resembling ganglia were identified between longitudinal and circular smooth muscle layers. SKPs are capable of engraftment, migration, and differentiation within aganglionic rodent intestine in vivo. Differentiated SKPs generate structures that resemble enteric ganglia. Our observations suggest that SKPs represent a potential gangliogenic therapeutic agent for Hirschsprung's disease. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. The formation of the cranial ganglia by placodally-derived sensory neuronal precursors.

    Science.gov (United States)

    Blentic, Aida; Chambers, David; Skinner, Adam; Begbie, Jo; Graham, Anthony

    2011-02-01

    The generation of the sensory ganglia involves the migration of a precursor population to the site of ganglion formation and the differentiation of sensory neurons. There is, however, a significant difference between the ganglia of the head and trunk in that while all of the sensory neurons of the trunk are derived from the neural crest, the majority of cranial sensory neurons are generated by the neurogenic placodes. In this study, we have detailed the route through which the placodally-derived sensory neurons are generated, and we find a number of important differences between the head and trunk. Although, the neurogenic placodes release neuroblasts that migrate internally to the site of ganglion formation, we find that there are no placodally-derived progenitor cells within the forming ganglia. The cells released by the placodes differentiate during migration and contribute to the cranial ganglia as post-mitotic neurons. In the trunk, it has been shown that progenitor cells persist in the forming Dorsal Root Ganglia and that much of the process of sensory neuronal differentiation occurs within the ganglion. We also find that the period over which neuronal cells delaminate from the placodes is significantly longer than the time frame over which neural crest cells populate the DRGs. We further show that placodal sensory neuronal differentiation can occur in the absence of local cues. Finally, we find that, in contrast to neural crest cells, the different mature neurogenic placodes seem to lack plasticity. Nodose neuroblasts cannot be diverted to form trigeminal neurons and vice versa. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Nestin-GFP transgene reveals neural precursor cells in adult skeletal muscle.

    Science.gov (United States)

    Birbrair, Alexander; Wang, Zhong-Min; Messi, Maria Laura; Enikolopov, Grigori N; Delbono, Osvaldo

    2011-02-03

    Therapy for neural lesions or degenerative diseases relies mainly on finding transplantable active precursor cells. Identifying them in peripheral tissues accessible for biopsy, outside the central nervous system, would circumvent the serious immunological and ethical concerns impeding cell therapy. In this study, we isolated neural progenitor cells in cultured adult skeletal muscle from transgenic mice in which nestin regulatory elements control GFP expression. These cells also expressed the early neural marker Tuj1 and light and heavy neurofilament but not S100β, indicating that they express typical neural but not Schwann cell markers. GFP+/Tuj1+ cells were also negative for the endothelial and pericyte markers CD31 and α-smooth muscle actin, respectively. We established their a) functional response to glutamate in patch-clamp recordings; b) interstitial mesenchymal origin; c) replicative capacity; and d) the environment necessary for their survival after fluorescence-activated cell sorting. We propose that the decline in nestin-GFP expression in muscle progenitor cells and its persistence in neural precursor cells in muscle cultures provide an invaluable tool for isolating a population of predifferentiated neural cells with therapeutic potential.

  17. Nestin-GFP transgene reveals neural precursor cells in adult skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Alexander Birbrair

    2011-02-01

    Full Text Available Therapy for neural lesions or degenerative diseases relies mainly on finding transplantable active precursor cells. Identifying them in peripheral tissues accessible for biopsy, outside the central nervous system, would circumvent the serious immunological and ethical concerns impeding cell therapy.In this study, we isolated neural progenitor cells in cultured adult skeletal muscle from transgenic mice in which nestin regulatory elements control GFP expression. These cells also expressed the early neural marker Tuj1 and light and heavy neurofilament but not S100β, indicating that they express typical neural but not Schwann cell markers. GFP+/Tuj1+ cells were also negative for the endothelial and pericyte markers CD31 and α-smooth muscle actin, respectively. We established their a functional response to glutamate in patch-clamp recordings; b interstitial mesenchymal origin; c replicative capacity; and d the environment necessary for their survival after fluorescence-activated cell sorting.We propose that the decline in nestin-GFP expression in muscle progenitor cells and its persistence in neural precursor cells in muscle cultures provide an invaluable tool for isolating a population of predifferentiated neural cells with therapeutic potential.

  18. Human Neural Precursor Cells Promote Neurologic Recovery in a Viral Model of Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Lu Chen

    2014-06-01

    Full Text Available Using a viral model of the demyelinating disease multiple sclerosis (MS, we show that intraspinal transplantation of human embryonic stem cell-derived neural precursor cells (hNPCs results in sustained clinical recovery, although hNPCs were not detectable beyond day 8 posttransplantation. Improved motor skills were associated with a reduction in neuroinflammation, decreased demyelination, and enhanced remyelination. Evidence indicates that the reduced neuroinflammation is correlated with an increased number of CD4+CD25+FOXP3+ regulatory T cells (Tregs within the spinal cords. Coculture of hNPCs with activated T cells resulted in reduced T cell proliferation and increased Treg numbers. The hNPCs acted, in part, through secretion of TGF-β1 and TGF-β2. These findings indicate that the transient presence of hNPCs transplanted in an animal model of MS has powerful immunomodulatory effects and mediates recovery. Further investigation of the restorative effects of hNPC transplantation may aid in the development of clinically relevant MS treatments.

  19. A protocol for isolation and enriched monolayer cultivation of neural precursor cells from mouse dentate gyrus

    Directory of Open Access Journals (Sweden)

    Harish eBabu

    2011-07-01

    Full Text Available In vitro assays are valuable tools to study the characteristics of adult neural precursor cells under controlled conditions with a defined set of parameters. We here present a detailed protocol based on our previous original publication (Babu et al., Enriched monolayer precursor cell cultures from micro-dissected adult mouse dentate gyrus yield functional granule cell-like neurons, PLoS One 2007, 2:e388 to isolate neural precursor cells from the hippocampus of adult mice and maintain and propagate them as adherent monolayer cultures. The strategy is based on the use of Percoll density gradient centrifugation to enrich precursor cells from the micro-dissected dentate gyrus. Based on the expression of Nestin and Sox2, a culture-purity of more than 98% can be achieved. The cultures are expanded under serum-free conditions in Neurobasal A medium with addition of the mitogens EGF and FGF2 as well as the supplements Glutamax-1 and B27. Under differentiation conditions, the precursor cells reliably generate approximately 30% neurons with appropriate morphological, molecular and electrophysiological characteristics that might reflect granule cell properties as their in vivo counterpart. We also highlight potential modifications to the protocol.

  20. Ancient evolutionary origin of vertebrate enteric neurons from trunk-derived neural crest.

    Science.gov (United States)

    Green, Stephen A; Uy, Benjamin R; Bronner, Marianne E

    2017-04-06

    The enteric nervous system of jawed vertebrates arises primarily from vagal neural crest cells that migrate to the foregut and subsequently colonize and innervate the entire gastrointestinal tract. Here we examine development of the enteric nervous system in the basal jawless vertebrate the sea lamprey (Petromyzon marinus) to gain insight into its evolutionary origin. Surprisingly, we find no evidence for the existence of a vagally derived enteric neural crest population in the lamprey. Rather, labelling with the lipophilic dye DiI shows that late-migrating cells, originating from the trunk neural tube and associated with nerve fibres, differentiate into neurons within the gut wall and typhlosole. We propose that these trunk-derived neural crest cells may be homologous to Schwann cell precursors, recently shown in mammalian embryos to populate post-embryonic parasympathetic ganglia, including enteric ganglia. Our results suggest that neural-crest-derived Schwann cell precursors made an important contribution to the ancient enteric nervous system of early jawless vertebrates, a role that was largely subsumed by vagal neural crest cells in early gnathostomes.

  1. Enhanced expression of FNDC5 in human embryonic stem cell-derived neural cells along with relevant embryonic neural tissues.

    Science.gov (United States)

    Ghahrizjani, Fatemeh Ahmadi; Ghaedi, Kamran; Salamian, Ahmad; Tanhaei, Somayeh; Nejati, Alireza Shoaraye; Salehi, Hossein; Nabiuni, Mohammad; Baharvand, Hossein; Nasr-Esfahani, Mohammad Hossein

    2015-02-25

    Availability of human embryonic stem cells (hESCs) has enhanced the capability of basic and clinical research in the context of human neural differentiation. Derivation of neural progenitor (NP) cells from hESCs facilitates the process of human embryonic development through the generation of neuronal subtypes. We have recently indicated that fibronectin type III domain containing 5 protein (FNDC5) expression is required for appropriate neural differentiation of mouse embryonic stem cells (mESCs). Bioinformatics analyses have shown the presence of three isoforms for human FNDC5 mRNA. To differentiate which isoform of FNDC5 is involved in the process of human neural differentiation, we have used hESCs as an in vitro model for neural differentiation by retinoic acid (RA) induction. The hESC line, Royan H5, was differentiated into a neural lineage in defined adherent culture treated by RA and basic fibroblast growth factor (bFGF). We collected all cell types that included hESCs, rosette structures, and neural cells in an attempt to assess the expression of FNDC5 isoforms. There was a contiguous increase in all three FNDC5 isoforms during the neural differentiation process. Furthermore, the highest level of expression of the isoforms was significantly observed in neural cells compared to hESCs and the rosette structures known as neural precursor cells (NPCs). High expression levels of FNDC5 in human fetal brain and spinal cord tissues have suggested the involvement of this gene in neural tube development. Additional research is necessary to determine the major function of FDNC5 in this process. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Precursors predicted by artificial neural networks for mass balance calculations: Quantifying hydrothermal alteration in volcanic rocks

    Science.gov (United States)

    Trépanier, Sylvain; Mathieu, Lucie; Daigneault, Réal; Faure, Stéphane

    2016-04-01

    This study proposes an artificial neural networks-based method for predicting the unaltered (precursor) chemical compositions of hydrothermally altered volcanic rock. The method aims at predicting precursor's major components contents (SiO2, FeOT, MgO, CaO, Na2O, and K2O). The prediction is based on ratios of elements generally immobile during alteration processes; i.e. Zr, TiO2, Al2O3, Y, Nb, Th, and Cr, which are provided as inputs to the neural networks. Multi-layer perceptron neural networks were trained on a large dataset of least-altered volcanic rock samples that document a wide range of volcanic rock types, tectonic settings and ages. The precursors thus predicted are then used to perform mass balance calculations. Various statistics were calculated to validate the predictions of precursors' major components, which indicate that, overall, the predictions are precise and accurate. For example, rank-based correlation coefficients were calculated to compare predicted and analysed values from a least-altered test dataset that had not been used to train the networks. Coefficients over 0.87 were obtained for all components, except for Na2O (0.77), indicating that predictions for alkali might be less performant. Also, predictions are performant for most volcanic rock compositions, except for ultra-K rocks. The proposed method provides an easy and rapid solution to the often difficult task of determining appropriate volcanic precursor compositions to rocks modified by hydrothermal alteration. It is intended for large volcanic rock databases and is most useful, for example, to mineral exploration performed in complex or poorly known volcanic settings. The method is implemented as a simple C++ console program.

  3. A protocol for isolation and enriched monolayer cultivation of neural precursor cells from mouse dentate gyrus.

    Science.gov (United States)

    Babu, Harish; Claasen, Jan-Hendrik; Kannan, Suresh; Rünker, Annette E; Palmer, Theo; Kempermann, Gerd

    2011-01-01

    In vitro assays are valuable tools to study the characteristics of adult neural precursor cells under controlled conditions with a defined set of parameters. We here present a detailed protocol based on our previous original publication (Babu et al., 2007) to isolate neural precursor cells from the hippocampus of adult mice and maintain and propagate them as adherent monolayer cultures. The strategy is based on the use of Percoll density gradient centrifugation to enrich precursor cells from the micro-dissected dentate gyrus. Based on the expression of Nestin and Sox2, a culture-purity of more than 98% can be achieved. The cultures are expanded under serum-free conditions in Neurobasal A medium with addition of the mitogens Epidermal growth factor and Fibroblast growth factor 2 as well as the supplements Glutamax-1 and B27. Under differentiation conditions, the precursor cells reliably generate approximately 30% neurons with appropriate morphological, molecular, and electrophysiological characteristics that might reflect granule cell properties as their in vivo counterpart. We also highlight potential modifications to the protocol.

  4. Monitoring the differentiation and migration patterns of neural cells derived from human embryonic stem cells using a microfluidic culture system.

    Science.gov (United States)

    Lee, Nayeon; Park, Jae Woo; Kim, Hyung Joon; Yeon, Ju Hun; Kwon, Jihye; Ko, Jung Jae; Oh, Seung-Hun; Kim, Hyun Sook; Kim, Aeri; Han, Baek Soo; Lee, Sang Chul; Jeon, Noo Li; Song, Jihwan

    2014-06-01

    Microfluidics can provide unique experimental tools to visualize the development of neural structures within a microscale device, which is followed by guidance of neurite growth in the axonal isolation compartment. We utilized microfluidics technology to monitor the differentiation and migration of neural cells derived from human embryonic stem cells (hESCs). We co-cultured hESCs with PA6 stromal cells, and isolated neural rosette-like structures, which subsequently formed neurospheres in suspension culture. Tuj1-positive neural cells, but not nestin-positive neural precursor cells (NPCs), were able to enter the microfluidics grooves (microchannels), suggesting that neural cell-migratory capacity was dependent upon neuronal differentiation stage. We also showed that bundles of axons formed and extended into the microchannels. Taken together, these results demonstrated that microfluidics technology can provide useful tools to study neurite outgrowth and axon guidance of neural cells, which are derived from human embryonic stem cells.

  5. Sonic Hedgehog Controls the Phenotypic Fate and Therapeutic Efficacy of Grafted Neural Precursor Cells in a Model of Nigrostriatal Neurodegeneration.

    Science.gov (United States)

    Madhavan, Lalitha; Daley, Brian F; Davidson, Beverly L; Boudreau, Ryan L; Lipton, Jack W; Cole-Strauss, Allyson; Steece-Collier, Kathy; Collier, Timothy J

    2015-01-01

    The expression of soluble growth and survival promoting factors by neural precursor cells (NPCs) is suggested to be a prominent mechanism underlying the protective and regenerative effects of these cells after transplantation. Nevertheless, how and to what extent specific NPC-expressed factors contribute to therapeutic effects is not well understood. Using RNA silencing, the current study investigated the roles of two donor NPC molecules, namely glial cell-line derived neurotrophic factor (GDNF) and sonic hedgehog (SHH), in the protection of substantia nigra dopamine neurons in rats treated with 6-hydroxydopamine (6-OHDA). Analyses indicate that as opposed to the knock-down of GDNF, SHH inhibition caused a profound decline in nigrostriatal neuroprotection. Further, SHH silencing also curbed endogenous neurogenesis and the migration of host brdU+/dcx+ neural precursors into the striatum, which was present in the animals receiving control or GDNF silenced NPCs. A change in graft phenotype, mainly reflected by a reduced proportion of undifferentiated nestin+ cells, as well as a significantly greater host microglial activity, suggested an important role for these processes in the attenuation of neuroprotection and neurogenesis upon SHH silencing. Overall these studies reveal core mechanisms fundamental to grafted NPC-based therapeutic effects, and delineate the particular contributions of two graft-expressed molecules, SHH and GDNF, in mediating midbrain dopamine neuron protection, and host plasticity after NPC transplantation.

  6. Sonic Hedgehog Controls the Phenotypic Fate and Therapeutic Efficacy of Grafted Neural Precursor Cells in a Model of Nigrostriatal Neurodegeneration.

    Directory of Open Access Journals (Sweden)

    Lalitha Madhavan

    Full Text Available The expression of soluble growth and survival promoting factors by neural precursor cells (NPCs is suggested to be a prominent mechanism underlying the protective and regenerative effects of these cells after transplantation. Nevertheless, how and to what extent specific NPC-expressed factors contribute to therapeutic effects is not well understood. Using RNA silencing, the current study investigated the roles of two donor NPC molecules, namely glial cell-line derived neurotrophic factor (GDNF and sonic hedgehog (SHH, in the protection of substantia nigra dopamine neurons in rats treated with 6-hydroxydopamine (6-OHDA. Analyses indicate that as opposed to the knock-down of GDNF, SHH inhibition caused a profound decline in nigrostriatal neuroprotection. Further, SHH silencing also curbed endogenous neurogenesis and the migration of host brdU+/dcx+ neural precursors into the striatum, which was present in the animals receiving control or GDNF silenced NPCs. A change in graft phenotype, mainly reflected by a reduced proportion of undifferentiated nestin+ cells, as well as a significantly greater host microglial activity, suggested an important role for these processes in the attenuation of neuroprotection and neurogenesis upon SHH silencing. Overall these studies reveal core mechanisms fundamental to grafted NPC-based therapeutic effects, and delineate the particular contributions of two graft-expressed molecules, SHH and GDNF, in mediating midbrain dopamine neuron protection, and host plasticity after NPC transplantation.

  7. Prolonged Expansion Induces Spontaneous Neural Progenitor Differentiation from Human Gingiva-Derived Mesenchymal Stem Cells.

    Science.gov (United States)

    Rajan, Thangavelu Soundara; Scionti, Domenico; Diomede, Francesca; Piattelli, Adriano; Bramanti, Placido; Mazzon, Emanuela; Trubiani, Oriana

    2017-12-01

    Neural crest-derived mesenchymal stem cells (MSCs) obtained from dental tissues received considerable interest in regenerative medicine, particularly in nerve regeneration owing to their embryonic origin and ease of harvest. Proliferation efficacy and differentiation capacity into diverse cell lineages propose dental MSCs as an in vitro tool for disease modeling. In this study, we investigated the spontaneous differentiation efficiency of dental MSCs obtained from human gingiva tissue (hGMSCs) into neural progenitor cells after extended passaging. At passage 41, the morphology of hGMSCs changed from typical fibroblast-like shape into sphere-shaped cells with extending processes. Next-generation transcriptomics sequencing showed increased expression of neural progenitor markers such as NES, MEIS2, and MEST. In addition, de novo expression of neural precursor genes, such as NRN1, PHOX2B, VANGL2, and NTRK3, was noticed in passage 41. Immunocytochemistry results showed suppression of neurogenesis repressors TP53 and p21, whereas Western blot results revealed the expression of neurotrophic factors BDNF and NT3 at passage 41. Our results showed the spontaneous efficacy of hGMSCs to differentiate into neural precursor cells over prolonged passages and that these cells may assist in producing novel in vitro disease models that are associated with neural development.

  8. Sequence conservation and combinatorial complexity of Drosophila neural precursor cell enhancers

    Directory of Open Access Journals (Sweden)

    Kuzin Alexander

    2008-08-01

    Full Text Available Abstract Background The presence of highly conserved sequences within cis-regulatory regions can serve as a valuable starting point for elucidating the basis of enhancer function. This study focuses on regulation of gene expression during the early events of Drosophila neural development. We describe the use of EvoPrinter and cis-Decoder, a suite of interrelated phylogenetic footprinting and alignment programs, to characterize highly conserved sequences that are shared among co-regulating enhancers. Results Analysis of in vivo characterized enhancers that drive neural precursor gene expression has revealed that they contain clusters of highly conserved sequence blocks (CSBs made up of shorter shared sequence elements which are present in different combinations and orientations within the different co-regulating enhancers; these elements contain either known consensus transcription factor binding sites or consist of novel sequences that have not been functionally characterized. The CSBs of co-regulated enhancers share a large number of sequence elements, suggesting that a diverse repertoire of transcription factors may interact in a highly combinatorial fashion to coordinately regulate gene expression. We have used information gained from our comparative analysis to discover an enhancer that directs expression of the nervy gene in neural precursor cells of the CNS and PNS. Conclusion The combined use EvoPrinter and cis-Decoder has yielded important insights into the combinatorial appearance of fundamental sequence elements required for neural enhancer function. Each of the 30 enhancers examined conformed to a pattern of highly conserved blocks of sequences containing shared constituent elements. These data establish a basis for further analysis and understanding of neural enhancer function.

  9. Early Divergence of Central and Peripheral Neural Retina Precursors During Vertebrate Eye Development

    Science.gov (United States)

    Venters, Sara J.; Mikawa, Takashi; Hyer, Jeanette

    2015-01-01

    During development of the vertebrate eye, optic tissue is progressively compartmentalized into functionally distinct tissues. From the central to the peripheral optic cup, the original optic neuroepithelial tissue compartmentalizes, forming retina, ciliary body and iris. The retina can be further sub-divided into peripheral and central compartments, where the central domain is specialized for higher visual acuity, having a higher ratio and density of cone photoreceptors in most species. Classically, models depict a segregation of the early optic cup into only two domains, neural and non-neural. Recent studies, however, uncovered discrete precursors for central and peripheral retina in the optic vesicle, indicating that the neural retina cannot be considered as a single unit with homogeneous specification and development. Instead, central and peripheral retina may be subject to distinct developmental pathways that underlie their specialization. This review focuses on lineage relationships in the retina and revisits the historical context for segregation of central and peripheral retina precursors before overt eye morphogenesis. PMID:25329498

  10. Early divergence of central and peripheral neural retina precursors during vertebrate eye development.

    Science.gov (United States)

    Venters, Sara J; Mikawa, Takashi; Hyer, Jeanette

    2015-03-01

    During development of the vertebrate eye, optic tissue is progressively compartmentalized into functionally distinct tissues. From the central to the peripheral optic cup, the original optic neuroepithelial tissue compartmentalizes, forming retina, ciliary body, and iris. The retina can be further sub-divided into peripheral and central compartments, where the central domain is specialized for higher visual acuity, having a higher ratio and density of cone photoreceptors in most species. Classically, models depict a segregation of the early optic cup into only two domains, neural and non-neural. Recent studies, however, uncovered discrete precursors for central and peripheral retina in the optic vesicle, indicating that the neural retina cannot be considered as a single unit with homogeneous specification and development. Instead, central and peripheral retina may be subject to distinct developmental pathways that underlie their specialization. This review focuses on lineage relationships in the retina and revisits the historical context for segregation of central and peripheral retina precursors before overt eye morphogenesis. © 2014 Wiley Periodicals, Inc.

  11. Sonic Hedgehog Regulation of the Neural Precursor Cell Fate During Chicken Optic Tectum Development.

    Science.gov (United States)

    Yang, Ciqing; Li, Xiaoying; Li, Qiuling; Li, Han; Qiao, Liang; Guo, Zhikun; Lin, Juntang

    2018-02-01

    During nervous system development, neurons project axons over long distances to reach the appropriate targets for correct neural circuit formation. Sonic hedgehog (Shh) is a secreted protein and plays a key role in regulating vertebrate embryogenesis, especially in central nervous system (CNS) patterning, including neuronal migration and axonal projection in the brain and spinal cord. In the developing ventral midbrain, Shh is sufficient to specify a striped pattern of cell fates. Little is known about the molecular mechanisms underlying the Shh regulation of the neural precursor cell fate during the optic tectum development. Here, we aimed at studying how Shh might regulate chicken optic tectum patterning. In the present study, in ovo electroporation methods were employed to achieve the overexpression of Shh in the optic tectum during chicken embryo development. Besides, the study combined in ovo electroporation and neuron isolation culturing to study the function of Shh in vivo and in vitro. The fluorescent immunohistochemistry methods were used to check the related indicators. The results showed that Shh overexpression caused 87.8% of cells to be distributed to the stratum griseum central (SGC) layer, while only 39.3% of the GFP-transfected cells resided in the SGC layer in the control group. Shh overexpression also reduced the axon length in vivo and in vitro. In conclusion, we provide evidence that Shh regulates the neural precursor cell fate during chicken optic tectum development. Shh overexpression impairs neuronal migration and may affect the fate determination of transfected neurons.

  12. Inhibition of glycogen synthase kinase-3 enhances the differentiation and reduces the proliferation of adult human olfactory epithelium neural precursors

    International Nuclear Information System (INIS)

    Manceur, Aziza P.; Tseng, Michael; Holowacz, Tamara; Witterick, Ian; Weksberg, Rosanna; McCurdy, Richard D.; Warsh, Jerry J.; Audet, Julie

    2011-01-01

    The olfactory epithelium (OE) contains neural precursor cells which can be easily harvested from a minimally invasive nasal biopsy, making them a valuable cell source to study human neural cell lineages in health and disease. Glycogen synthase kinase-3 (GSK-3) has been implicated in the etiology and treatment of neuropsychiatric disorders and also in the regulation of murine neural precursor cell fate in vitro and in vivo. In this study, we examined the impact of decreased GSK-3 activity on the fate of adult human OE neural precursors in vitro. GSK-3 inhibition was achieved using ATP-competitive (6-bromoindirubin-3'-oxime and CHIR99021) or substrate-competitive (TAT-eIF2B) inhibitors to eliminate potential confounding effects on cell fate due to off-target kinase inhibition. GSK-3 inhibitors decreased the number of neural precursor cells in OE cell cultures through a reduction in proliferation. Decreased proliferation was not associated with a reduction in cell survival but was accompanied by a reduction in nestin expression and a substantial increase in the expression of the neuronal differentiation markers MAP1B and neurofilament (NF-M) after 10 days in culture. Taken together, these results suggest that GSK-3 inhibition promotes the early stages of neuronal differentiation in cultures of adult human neural precursors and provide insights into the mechanisms by which alterations in GSK-3 signaling affect adult human neurogenesis, a cellular process strongly suspected to play a role in the etiology of neuropsychiatric disorders.

  13. Nanodiamonds with silicon vacancy defects for nontoxic photostable fluorescent labeling of neural precursor cells.

    Science.gov (United States)

    Merson, Tobias D; Castelletto, Stefania; Aharonovich, Igor; Turbic, Alisa; Kilpatrick, Trevor J; Turnley, Ann M

    2013-10-15

    Nanodiamonds (NDs) containing silicon vacancy (SiV) defects were evaluated as a potential biomarker for the labeling and fluorescent imaging of neural precursor cells (NPCs). SiV-containing NDs were synthesized using chemical vapor deposition and silicon ion implantation. Spectrally, SiV-containing NDs exhibited extremely stable fluorescence and narrow bandwidth emission with an excellent signal to noise ratio exceeding that of NDs containing nitrogen-vacancy centers. NPCs labeled with NDs exhibited normal cell viability and proliferative properties consistent with biocompatibility. We conclude that SiV-containing NDs are a promising biomedical research tool for cellular labeling and optical imaging in stem cell research.

  14. ETOH inhibits embryonic neural stem/precursor cell proliferation via PLD signaling

    International Nuclear Information System (INIS)

    Fujita, Yuko; Hiroyama, Masami; Sanbe, Atsushi; Yamauchi, Junji; Murase, Shoko; Tanoue, Akito

    2008-01-01

    While a mother's excessive alcohol consumption during pregnancy is known to have adverse effects on fetal neural development, little is known about the underlying mechanism of these effects. In order to investigate these mechanisms, we investigated the toxic effect of ethanol (ETOH) on neural stem/precursor cell (NSC) proliferation. In cultures of NSCs, phospholipase D (PLD) is activated following stimulation with epidermal growth factor (EGF) and fibroblast growth factor 2 (FGF2). Exposure of NSCs to ETOH suppresses cell proliferation, while it has no effect on cell death. Phosphatidic acid (PA), which is a signaling messenger produced by PLD, reverses ETOH inhibition of NSC proliferation. Blocking the PLD signal by 1-butanol suppresses the proliferation. ETOH-induced suppression of NSC proliferation and the protective effect of PA for ETOH-induced suppression are mediated through extracellular signal-regulated kinase signaling. These results indicate that exposure to ETOH impairs NSC proliferation by altering the PLD signaling pathway

  15. Using superoxide dismutase/catalase mimetics to manipulate the redox environment of neural precursor cells

    International Nuclear Information System (INIS)

    Limoli, C. L.; Giedzinski, E.; Baure, J.; Doctrow, S. R.; Rola, R.; Fike, J. R.

    2006-01-01

    Past work has shown that neural precursor cells are predisposed to redox sensitive changes, and that oxidative stress plays a critical role in the acute and persistent changes that occur within the irradiated CNS. Irradiation leads to a marked rise in reactive oxygen species (ROS) that correlates with oxidative endpoints in vivo and reductions in neuro-genesis. To better understand the impact of oxidative stress on neural precursor cells, and to determine if radiation-induced oxidative damage and precursor cell loss after irradiation could be reduced, a series of antioxidant compounds (EUK-134, EUK-163, EUK-172, EUK-189) were tested, three of which possess both superoxide dismutase (SOD) and catalase activities and one (EUK-163) whose only significant activity is SOD. Our results show that these SOD/catalase mimetics apparently increase the oxidation of a ROS-sensitive fluorescent indicator dye, particularly after short (12 h) treatments, but that longer treatments (24 h) decrease oxidation attributable to radiation-induced ROS. Similarly, other studies found that cells incubated with CuZnSOD showed some increase in intracellular ROS levels. Subsequent data suggested that the dye-oxidising capabilities of the EUK compounds were linked to differences in their catalase activity and, most likely, their ability to catalyse per-oxidative pathways. In unirradiated mice, the EUK-134 analogue induced some decrease of proliferating precursor cells and immature neurons 48 h after radiation, an effect that may be attributable to cytotoxicity and/or inhibition of precursor proliferation. In irradiated mice, a single injection of EUK-134 was not found to be an effective radioprotector at acute times (48 h). The present results support continued development of our in vitro model as a tool for predicting certain in vivo responses, and suggest that in some biological systems the capability to scavenge superoxide but produce excess H 2 O 2 , as is known for CuZnSOD, may be

  16. In vitro culture and characterization of enteric neural precursor cells from human gut biopsy specimens using polymer scaffold.

    Science.gov (United States)

    Krishnamohan, Janardhanam; Senthilnathan, Venugopal S; Vaikundaraman, Tirunelveli Muthiah; Srinivasan, Thangavelu; Balamurugan, Madasamy; Iwasaki, Masaru; Preethy, Senthilkumar; Abraham, Samuel Jk

    2013-08-01

    In vitro expansion and characterization of neural precursor cells from human gut biopsy specimens with or without Hirschsprung's disease using a novel thermoreversible gelation polymer (TGP) is reported aiming at a possible future treatment. Gut biopsy samples were obtained from five patients undergoing gut resection for Hirschsprung's disease (n = 1) or gastrointestinal disorders (n = 4). Cells isolated from the smooth muscle layer and the myenteric plexus were cultured in two groups for 18 to 28 days; Group I: conventional culture as earlier reported and Group II: using TGP scaffold. Neurosphere like bodies (NLBs) were observed in the cultures between 8th to 12th day and H & E staining was positive for neural cells in both groups including aganglionic gut portion from the Hirschsprung's disease patient. Immunohistochemistry using S-100 and neuron specific enolase (NSE) was positive in both groups but the TGP group (Group II) showed more number of cells with intense cytoplasmic granular positivity for both NSE and S-100 compared to Group I. TGP supports the in vitro expansion of human gut derived neuronal cells with seemingly better quality NLBs. Animal Studies can be tried to validate their functional outcome by transplanting the NLBs with TGP scaffolds to see whether this can enhance the outcome of cell based therapies for Hirschsprung's disease.

  17. Concise review: the involvement of SOX2 in direct reprogramming of induced neural stem/precursor cells.

    Science.gov (United States)

    Maucksch, Christof; Jones, Kathryn S; Connor, Bronwen

    2013-08-01

    Since induced pluripotent stem cells were first generated from mouse embryonic fibroblasts in 2006, somatic cell reprogramming has become a powerful and valuable tool in many fields of biomedical research, with the potential to lead to the development of in vitro disease models, cell-based drug screening platforms, and ultimately novel cell therapies. Recent research has now demonstrated the direct conversion of fibroblasts into stem, precursor, or mature cell types that are committed in their fate within a specific lineage, such as hematopoietic precursors or mature neurons. This has been achieved by ectopic expression of defined, tissue-specific transcription factors. Several studies have demonstrated direct reprogramming of mouse and human fibroblasts into immature neural stem or precursor cells, either by transient expression of the four pluripotency genes OCT3/4, KLF4, SOX2, and C-MYC or by application of different combinations of up to 11 neural transcription factors. Interestingly, in all of these studies SOX2 was introduced alone or in combination with other transcription factors. In this review we discuss the different combinations of ectopic transcription factors used to generate neural stem/precursor cells from somatic cells, with particular emphasis on SOX2 and its potential to act as a master regulator for reprogramming to a neural precursor state.

  18. Activating receptor NKG2D targets RAE-1-expressing allogeneic neural precursor cells in a viral model of multiple sclerosis.

    Science.gov (United States)

    Weinger, Jason G; Plaisted, Warren C; Maciejewski, Sonia M; Lanier, Lewis L; Walsh, Craig M; Lane, Thomas E

    2014-10-01

    Transplantation of major histocompatibility complex-mismatched mouse neural precursor cells (NPCs) into mice persistently infected with the neurotropic JHM strain of mouse hepatitis virus (JHMV) results in rapid rejection that is mediated, in part, by T cells. However, the contribution of the innate immune response to allograft rejection in a model of viral-induced neurological disease has not been well defined. Herein, we demonstrate that the natural killer (NK) cell-expressing-activating receptor NKG2D participates in transplanted allogeneic NPC rejection in mice persistently infected with JHMV. Cultured NPCs derived from C57BL/6 (H-2(b) ) mice express the NKG2D ligand retinoic acid early precursor transcript (RAE)-1 but expression was dramatically reduced upon differentiation into either glia or neurons. RAE-1(+) NPCs were susceptible to NK cell-mediated killing whereas RAE-1(-) cells were resistant to lysis. Transplantation of C57BL/6-derived NPCs into JHMV-infected BALB/c (H-2(d) ) mice resulted in infiltration of NKG2D(+) CD49b(+) NK cells and treatment with blocking antibody specific for NKG2D increased survival of allogeneic NPCs. Furthermore, transplantation of differentiated RAE-1(-) allogeneic NPCs into JHMV-infected BALB/c mice resulted in enhanced survival, highlighting a role for the NKG2D/RAE-1 signaling axis in allograft rejection. We also demonstrate that transplantation of allogeneic NPCs into JHMV-infected mice resulted in infection of the transplanted cells suggesting that these cells may be targets for infection. Viral infection of cultured cells increased RAE-1 expression, resulting in enhanced NK cell-mediated killing through NKG2D recognition. Collectively, these results show that in a viral-induced demyelination model, NK cells contribute to rejection of allogeneic NPCs through an NKG2D signaling pathway. © 2014 AlphaMed Press.

  19. Modeling Cerebrovascular Pathophysiology in Amyloid-β Metabolism using Neural-Crest-Derived Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Christine Cheung

    2014-10-01

    Full Text Available Summary: There is growing recognition of cerebrovascular contributions to neurodegenerative diseases. In the walls of cerebral arteries, amyloid-beta (Aβ accumulation is evident in a majority of aged people and patients with cerebral amyloid angiopathy. Here, we leverage human pluripotent stem cells to generate vascular smooth muscle cells (SMCs from neural crest progenitors, recapitulating brain-vasculature-specific attributes of Aβ metabolism. We confirm that the lipoprotein receptor, LRP1, functions in our neural-crest-derived SMCs to mediate Aβ uptake and intracellular lysosomal degradation. Hypoxia significantly compromises the contribution of SMCs to Aβ clearance by suppressing LRP1 expression. This enabled us to develop an assay of Aβ uptake by using the neural crest-derived SMCs with hypoxia as a stress paradigm. We then tested several vascular protective compounds in a high-throughput format, demonstrating the value of stem-cell-based phenotypic screening for novel therapeutics and drug repurposing, aimed at alleviating amyloid burden. : The contribution of blood vessel pathologies to neurodegenerative disorders is relatively neglected, partly due to inadequate human tissues for research. By using human stem cells, Cheung et al. establish a method of generating vascular smooth muscle cells (SMCs from neural crest progenitors, the primary precursors that give rise to brain blood vessels. These stem-cell-derived SMCs display defective amyloid processing under chronic hypoxia, a phenomenon well documented in the cerebral vasculatures of aged people and patients with Alzheimer’s disease.

  20. Abnormal neural precursor cell regulation in the early postnatal Fragile X mouse hippocampus.

    Science.gov (United States)

    Sourial, Mary; Doering, Laurie C

    2017-07-01

    The regulation of neural precursor cells (NPCs) is indispensable for a properly functioning brain. Abnormalities in NPC proliferation, differentiation, survival, or integration have been linked to various neurological diseases including Fragile X syndrome. Yet, no studies have examined NPCs from the early postnatal Fragile X mouse hippocampus despite the importance of this developmental time point, which marks the highest expression level of FMRP, the protein missing in Fragile X, in the rodent hippocampus and is when hippocampal NPCs have migrated to the dentate gyrus (DG) to give rise to lifelong neurogenesis. In this study, we examined NPCs from the early postnatal hippocampus and DG of Fragile X mice (Fmr1-KO). Immunocytochemistry on neurospheres showed increased Nestin expression and decreased Ki67 expression, which collectively indicated aberrant NPC biology. Intriguingly, flow cytometric analysis of the expression of the antigens CD15, CD24, CD133, GLAST, and PSA-NCAM showed a decreased proportion of neural stem cells (GLAST + CD15 + CD133 + ) and an increased proportion of neuroblasts (PSA-NCAM + CD15 + ) in the DG of P7 Fmr1-KO mice. This was mirrored by lower expression levels of Nestin and the mitotic marker phospho-histone H3 in vivo in the P9 hippocampus, as well as a decreased proportion of cells in the G 2 /M phases of the P7 DG. Thus, the absence of FMRP leads to fewer actively cycling NPCs, coinciding with a decrease in neural stem cells and an increase in neuroblasts. Together, these results show the importance of FMRP in the developing hippocampal formation and suggest abnormalities in cell cycle regulation in Fragile X. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  1. Methods for conversion of lignocellulosic-derived products to transportation fuel precursors

    Energy Technology Data Exchange (ETDEWEB)

    Lilga, Michael A.; Padmaperuma, Asanga B.

    2017-10-03

    Methods are disclosed for converting a biomass-derived product containing levulinic acid and/or gamma-valerolactone to a transportation fuel precursor product containing diesel like hydrocarbons. These methods are expected to produce fuel products at a reduced cost relative to conventional approaches.

  2. Efficient generation of dopamine neuron-like cells from skin-derived precursors with a synthetic peptide derived from von Hippel-Lindau protein.

    Science.gov (United States)

    Kubo, Atsuhiko; Yoshida, Tetsuhiko; Kobayashi, Nahoko; Yokoyama, Takaakira; Mimura, Toshiro; Nishiguchi, Takao; Higashida, Tetsuhiro; Yamamoto, Isao; Kanno, Hiroshi

    2009-12-01

    Skin-derived precursors (SKPs) from mammalian dermis represent neural crest-related stem cells capable of differentiating into both neural and mesodermal progency. SKPs are of clinical interest because they serve as accessible autologous donor cells for neuronal repair for neuronal intractable diseases. However, little is known about the efficient generation of neurons from SKPs, and phenotypes of neurons generated from SKPs have been restricted. In addition, the neuronal repair using their generated neurons as donor cells has not been achieved. The von Hippel-Lindau protein (pVHL) is one of the proteins that play an important role during neuronal differentiation, and recently neuronal differentiation of neural progenitor cells by intracellular delivery of a synthetic VHL peptide derived from elongin BC-binding site has been demonstrated. In the present study, a synthetic VHL peptide derived from elongin BC-binding site was conjugated to the protein transduction domain (PTD) of HIV-TAT protein (TATVHL peptide) to facilitate entry into cells, and we demonstrate the efficient generation of cells with dopaminergic phenotype from SKPs with the intracellular delivery of TATVHL peptide, and characterized the generated cells. The TATVHL peptide-treated SKPs expressed neuronal marker proteins, particularly dopamine neuron markers, and also up-regulated mRNA levels of proneural basic helix-loop-helix factors. After the TATVHL peptide treatment, transplanted SKPs into Parkinson's disease (PD) model rats sufficiently differentiated into dopamine neuron-like cells in PD model rats, and partially but significantly corrected behavior of PD model rats. The generated dopamine neuron-like cells are expected to serve as donor cells for neuronal repair for PD.

  3. Cyclosporin A enhances neural precursor cell survival in mice through a calcineurin-independent pathway

    Directory of Open Access Journals (Sweden)

    Nadia Sachewsky

    2014-08-01

    Full Text Available Cyclosporin A (CsA has direct effects on neural stem and progenitor cells (together termed neural precursor cells; NPCs in the adult central nervous system. Administration of CsA in vitro or in vivo promotes the survival of NPCs and expands the pools of NPCs in mice. Moreover, CsA administration is effective in promoting NPC activation, tissue repair and functional recovery in a mouse model of cortical stroke. The mechanism(s by which CsA mediates this cell survival effect remains unknown. Herein, we examined both calcineurin-dependent and calcineurin-independent pathways through which CsA might mediate NPC survival. To examine calcineurin-dependent pathways, we utilized FK506 (Tacrolimus, an immunosuppressive molecule that inhibits calcineurin, as well as drugs that inhibit cyclophilin A-mediated activation of calcineurin. To evaluate the calcineurin-independent pathway, we utilized NIM811, a non-immunosuppressive CsA analog that functions independently of calcineurin by blocking mitochondrial permeability transition pore formation. We found that only NIM811 can entirely account for the pro-survival effects of CsA on NPCs. Indeed, blocking signaling pathways downstream of calcineurin activation using nNOS mice did not inhibit CsA-mediated cell survival, which supports the proposal that the effects are calcinuerin-independent. In vivo studies revealed that NIM811 administration mimics the pro-survival effects of CsA on NPCs and promotes functional recovery in a model of cortical stroke, identical to the effects seen with CsA administration. We conclude that CsA mediates its effect on NPC survival through calcineurin-independent inhibition of mitochondrial permeability transition pore formation and suggest that this pathway has potential therapeutic benefits for developing NPC-mediated cell replacement strategies.

  4. Embryonic cerebrospinal fluid activates neurogenesis of neural precursors within the subventricular zone of the adult mouse brain.

    Science.gov (United States)

    Carnicero, E; Alonso, M I; Carretero, R; Lamus, F; Moro, J A; de la Mano, A; Fernández, J M F; Gato, A

    2013-01-01

    There is a nondeveloped neurogenic potential in the adult mammalian brain, which could be the basis for neuroregenerative strategies. Many research efforts have been made to understand the control mechanisms which regulate the transition from a neural precursor to a neuron in the adult brain. Embryonic cerebrospinal fluid (CSF) is a complex fluid which has been shown to play a key role in neural precursor behavior during development, working as a powerful neurogenic inductor. We tested if the neurogenic properties of embryonic CSF are able to increase the neurogenic activity of neuronal precursors from the subventricular zone (SVZ) in the brains of adult mice. Our results show that mouse embryonic CSF significantly increases the neurogenic activity in precursor cells from adult brain SVZ. This intense neurogenic effect was specific for embryonic CSF and was not induced by adult CSF. Embryonic CSF is a powerful neurogenesis inductor in homologous neuronal precursors in the adult brain. This property of embryonic CSF could be a useful tool in neuroregeneration strategies.

  5. Neural network representation and learning of mappings and their derivatives

    Science.gov (United States)

    White, Halbert; Hornik, Kurt; Stinchcombe, Maxwell; Gallant, A. Ronald

    1991-01-01

    Discussed here are recent theorems proving that artificial neural networks are capable of approximating an arbitrary mapping and its derivatives as accurately as desired. This fact forms the basis for further results establishing the learnability of the desired approximations, using results from non-parametric statistics. These results have potential applications in robotics, chaotic dynamics, control, and sensitivity analysis. An example involving learning the transfer function and its derivatives for a chaotic map is discussed.

  6. Differential proliferation rhythm of neural progenitor and oligodendrocyte precursor cells in the young adult hippocampus.

    Directory of Open Access Journals (Sweden)

    Yoko Matsumoto

    Full Text Available Oligodendrocyte precursor cells (OPCs are a unique type of glial cells that function as oligodendrocyte progenitors while constantly proliferating in the normal condition from rodents to humans. However, the functional roles they play in the adult brain are largely unknown. In this study, we focus on the manner of OPC proliferation in the hippocampus of the young adult mice. Here we report that there are oscillatory dynamics in OPC proliferation that differ from neurogenesis in the subgranular zone (SGZ; the former showed S-phase and M-phase peaks in the resting and active periods, respectively, while the latter only exhibited M-phase peak in the active period. There is coincidence between different modes of proliferation and expression of cyclin proteins that are crucial for cell cycle; cyclin D1 is expressed in OPCs, while cyclin D2 is observed in neural stem cells. Similar to neurogenesis, the proliferation of hippocampal OPCs was enhanced by voluntary exercise that leads to an increase in neuronal activity in the hippocampus. These data suggest an intriguing control of OPC proliferation in the hippocampus.

  7. A review of bioreactor protocols for human neural precursor cell expansion in preparation for clinical trials.

    Science.gov (United States)

    Baghbaderani, Behnam A; Mukhida, Karim; Hong, Murray; Mendez, Ivar; Behie, Leo A

    2011-09-01

    Tissue-specific human neural precursor cells (hNPCs) can be isolated from various regions of the developing or adult central nervous system and may serve as a viable source of cells in cell replacement therapies for the treatment of neurodegenerative disorders. However, in order for cell replacement strategies to become a routine therapeutic option for the treatment of neurodegenerative disorders, hNPCs should be generated under standardized and controlled conditions. Studies over the last two decades have focused on developing cell growth media and cell handling protocols for expansion and differentiation of hNPCs in culture. Key studies have reported the development of serum-free growth media and large-scale computer-controlled suspension bioreactors that can support high cell proliferation rates (doubling times < 3 days), multipotentiality, and potential neurogenic differentiation (more than 60% neurons). Moreover, bioengineering studies have focused on controlling culture conditions in suspension bioreactors including inoculation, hydrodynamics of culture, oxygen and nutrients transfer to the cells, monitoring in situ physiological parameters using process control techniques, and expansion for extended periods of time. In addition, in vitro and in vivo characterization of hNPCs have been performed, providing information on stem/progenitor cell characteristics, cell surface analysis, and appropriate type of cells to use in transplantation studies.

  8. Precursors-Derived Ceramic Membranes for High-Temperature Separation of Hydrogen

    OpenAIRE

    Yuji, Iwamoto

    2007-01-01

    This review describes recent progress in the development of hydrogen-permselective ceramic membranes derived from organometallic precursors. Microstructure and gas transport property of microporous amorphous silica-based membranes are briefly described. Then, high-temperature hydrogen permselectivity, hydrothermal stability as well as hydrogen/steam selectivity of the amorphous silica-based membranes are discussed from a viewpoint of application to membrane reactors for conversion enhancement...

  9. Impaired neurogenesis, learning and memory and low seizure threshold associated with loss of neural precursor cell survivin

    Directory of Open Access Journals (Sweden)

    Eisch Amelia

    2010-01-01

    Full Text Available Abstract Background Survivin is a unique member of the inhibitor of apoptosis protein (IAP family in that it exhibits antiapoptotic properties and also promotes the cell cycle and mediates mitosis as a chromosome passenger protein. Survivin is highly expressed in neural precursor cells in the brain, yet its function there has not been elucidated. Results To examine the role of neural precursor cell survivin, we first showed that survivin is normally expressed in periventricular neurogenic regions in the embryo, becoming restricted postnatally to proliferating and migrating NPCs in the key neurogenic sites, the subventricular zone (SVZ and the subgranular zone (SGZ. We then used a conditional gene inactivation strategy to delete the survivin gene prenatally in those neurogenic regions. Lack of embryonic NPC survivin results in viable, fertile mice (SurvivinCamcre with reduced numbers of SVZ NPCs, absent rostral migratory stream, and olfactory bulb hypoplasia. The phenotype can be partially rescued, as intracerebroventricular gene delivery of survivin during embryonic development increases olfactory bulb neurogenesis, detected postnatally. SurvivinCamcre brains have fewer cortical inhibitory interneurons, contributing to enhanced sensitivity to seizures, and profound deficits in memory and learning. Conclusions The findings highlight the critical role that survivin plays during neural development, deficiencies of which dramatically impact on postnatal neural function.

  10. Constitutively active Notch1 converts cranial neural crest-derived frontonasal mesenchyme to perivascular cells in vivo

    Directory of Open Access Journals (Sweden)

    Sophie R. Miller

    2017-03-01

    Full Text Available Perivascular/mural cells originate from either the mesoderm or the cranial neural crest. Regardless of their origin, Notch signalling is necessary for their formation. Furthermore, in both chicken and mouse, constitutive Notch1 activation (via expression of the Notch1 intracellular domain is sufficient in vivo to convert trunk mesoderm-derived somite cells to perivascular cells, at the expense of skeletal muscle. In experiments originally designed to investigate the effect of premature Notch1 activation on the development of neural crest-derived olfactory ensheathing glial cells (OECs, we used in ovo electroporation to insert a tetracycline-inducible NotchΔE construct (encoding a constitutively active mutant of mouse Notch1 into the genome of chicken cranial neural crest cell precursors, and activated NotchΔE expression by doxycycline injection at embryonic day 4. NotchΔE-targeted cells formed perivascular cells within the frontonasal mesenchyme, and expressed a perivascular marker on the olfactory nerve. Hence, constitutively activating Notch1 is sufficient in vivo to drive not only somite cells, but also neural crest-derived frontonasal mesenchyme and perhaps developing OECs, to a perivascular cell fate. These results also highlight the plasticity of neural crest-derived mesenchyme and glia.

  11. Bleogens: Cactus-Derived Anti-Candida Cysteine-Rich Peptides with Three Different Precursor Arrangements

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    Shining Loo

    2017-12-01

    Full Text Available Cysteine-rich peptides (CRPs play important host-defense roles in plants. However, information concerning CRPs in the Cactaceae (cactus family is limited, with only a single cactus-derived CRP described to date. Here, we report the identification of 15 novel CRPs with three different precursor architectures, bleogens pB1-15 from Pereskia bleo of the Cactaceae family. By combining proteomic and transcriptomic methods, we showed that the prototype, bleogen pB1, contained 36 amino acid residues, a six-cysteine motif typical of the six-cysteine-hevein-like peptide (6C-HLP family, and a type I two-domain precursor consisting of an endoplasmic reticulum (ER and a mature domain. In contrast, the precursors of the other 14 bleogens contained a type II three-domain architecture with a propeptide domain inserted between the ER and the mature bleogen domain. Four of these 14 bleogens display a third type of architecture with a tandemly repeating bleogen domain. A search of the Onekp database revealed that <1% plant species possess three different precursor architectures for the biosynthesis of 6C-HLPs, including Lophophora williamsii, Pereskia aculeate, Portulaca cryptopetala, Portulaca oleracea, Portulaca suffruticosa, and Talinum sp. NMR analysis confirmed that bleogen pB1 has cystine-knot disulfide connectivity as well as a two-beta-sheet and a four-loop structural fold that is similar to other 6C-HLPs. Sequence analysis, structural studies, and in silico modeling revealed that bleogen pB1 has a cation-polar-cation motif, a signature heparin-binding motif that was confirmed by heparin affinity chromatography. Cell-based assays showed that bleogen pB1 is non-toxic to mammalian cells but functions as an anti-Candida peptide. Taken together, our findings provide insight into the occurrence, functions and precursor architectures of CRPs in the cactus family.

  12. The Addiction-Related Protein ANKK1 is Differentially Expressed During the Cell Cycle in Neural Precursors.

    Science.gov (United States)

    España-Serrano, Laura; Guerra Martín-Palanco, Noelia; Montero-Pedrazuela, Ana; Pérez-Santamarina, Estela; Vidal, Rebeca; García-Consuegra, Inés; Valdizán, Elsa María; Pazos, Angel; Palomo, Tomás; Jiménez-Arriero, Miguel Ángel; Guadaño-Ferraz, Ana; Hoenicka, Janet

    2017-05-01

    TaqIA is a polymorphism associated with addictions and dopamine-related traits. It is located in the ankyrin repeat and kinase domain containing 1 gene (ANKK1) nearby the gene for the dopamine D2 receptor (D2R). Since ANKK1 function is unknown, TaqIA-associated traits have been explained only by differences in D2R. Here we report ANKK1 studies in mouse and human brain using quantitative real-time PCR, Western blot, immunohistochemistry, and flow cytometry. ANKK1 mRNA and protein isoforms vary along neurodevelopment in the human and mouse brain. In mouse adult brain ANKK1 is located in astrocytes, nuclei of postmitotic neurons and neural precursors from neurogenic niches. In both embryos and adults, nuclei of neural precursors show significant variation of ANKK1 intensity. We demonstrate a correlation between ANKK1 and the cell cycle. Cell synchronization experiments showed a significant increment of ANKK1-kinase in mitotic cells while ANKK1-kinase overexpression affects G1 and M phase that were found to be modulated by ANKK1 alleles and apomorphine treatment. Furthermore, during embryonic neurogenesis ANKK1 was expressed in slow-dividing neuroblasts and rapidly dividing precursors which are mitotic cells. These results suggest a role of ANKK1 during the cell cycle in neural precursors thus providing biological support to brain structure involvement in the TaqIA-associated phenotypes. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. A Subpopulation of Smooth Muscle Cells, Derived from Melanocyte-Competent Precursors, Prevents Patent Ductus Arteriosus

    Science.gov (United States)

    Puig, Isabel; Champeval, Delphine; Kumasaka, Mayuko; Belloir, Elodie; Bonaventure, Jacky; Mark, Manuel; Yamamoto, Hiroaki; Taketo, Mark M.; Choquet, Philippe; Etchevers, Heather C.; Beermann, Friedrich; Delmas, Véronique; Monassier, Laurent; Larue, Lionel

    2013-01-01

    Background Patent ductus arteriosus is a life-threatening condition frequent in premature newborns but also present in some term infants. Current mouse models of this malformation generally lead to perinatal death, not reproducing the full phenotypic spectrum in humans, in whom genetic inheritance appears complex. The ductus arteriosus (DA), a temporary fetal vessel that bypasses the lungs by shunting the aortic arch to the pulmonary artery, is constituted by smooth muscle cells of distinct origins (SMC1 and SMC2) and many fewer melanocytes. To understand novel mechanisms preventing DA closure at birth, we evaluated the importance of cell fate specification in SMC that form the DA during embryonic development. Upon specific Tyr::Cre-driven activation of Wnt/β-catenin signaling at the time of cell fate specification, melanocytes replaced the SMC2 population of the DA, suggesting that SMC2 and melanocytes have a common precursor. The number of SMC1 in the DA remained similar to that in controls, but insufficient to allow full DA closure at birth. Thus, there was no cellular compensation by SMC1 for the loss of SMC2. Mice in which only melanocytes were genetically ablated after specification from their potential common precursor with SMC2, demonstrated that differentiated melanocytes themselves do not affect DA closure. Loss of the SMC2 population, independent of the presence of melanocytes, is therefore a cause of patent ductus arteriosus and premature death in the first months of life. Our results indicate that patent ductus arteriosus can result from the insufficient differentiation, proliferation, or contractility of a specific smooth muscle subpopulation that shares a common neural crest precursor with cardiovascular melanocytes. PMID:23382837

  14. Applicability of tooth derived stem cells in neural regeneration

    Directory of Open Access Journals (Sweden)

    Ludovica Parisi

    2016-01-01

    Full Text Available Within the nervous system, regeneration is limited, and this is due to the small amount of neural stem cells, the inhibitory origin of the stem cell niche and often to the development of a scar which constitutes a mechanical barrier for the regeneration. Regarding these aspects, many efforts have been done in the research of a cell component that combined with scaffolds and growth factors could be suitable for nervous regeneration in regenerative medicine approaches. Autologous mesenchymal stem cells represent nowadays the ideal candidate for this aim, thank to their multipotency and to their amount inside adult tissues. However, issues in their harvesting, through the use of invasive techniques, and problems involved in their ageing, require the research of new autologous sources. To this purpose, the recent discovery of a stem cells component in teeth, and which derive from neural crest cells, has came to the light the possibility of using dental stem cells in nervous system regeneration. In this work, in order to give guidelines on the use of dental stem cells for neural regeneration, we briefly introduce the concepts of regeneration and regenerative medicine, we then focus the attention on odontogenesis, which involves the formation and the presence of a stem component in different parts of teeth, and finally we describe some experimental approaches which are exploiting dental stem cells for neural studies.

  15. Platelet-derived growth factor BB enhances osteoclast formation and osteoclast precursor cell chemotaxis.

    Science.gov (United States)

    Li, Dian-Qi; Wan, Qi-Long; Pathak, Janak L; Li, Zu-Bing

    2017-07-01

    Enhanced osteoclast formation increases bone resorption, which triggers bone remodeling. Platelet-derived growth factor BB (PDGF-BB) enhances precursor cell homing, angiogenesis, and bone healing, and thereby could also treat osteoporosis. However, the effect of PDGF-BB on osteoclast formation is not fully understood. We investigated whether exogenous recombinant PDGF-BB directly affects osteoclast formation and osteoclast precursor cell chemotaxis. The murine monocyte-macrophage cell line RAW264.7 and bone-marrow-derived macrophages were cultured with recombinant mouse PDGF-BB with or without a platelet-derived growth factor receptor β inhibitor (AG-1295) or a Janus kinase 2 inhibitor (AG-490) to analyze the effect on osteoclastogenesis in vitro. PDGF-BB with or without AG-490 or AG-1295 was locally administrated in the mandibular fracture of 16-week-old Sprague Dawley rats (n = 18) for 1-2 weeks to analyze the effect on osteoclastogenesis in vivo. The effect of the treatments on osteoclast formation, osteoclast precursor cell migration, and expression of osteoclastogenic signaling molecules was analyzed. PDGF-BB enhanced osteoclast formation both in vitro and in vivo, but AG-490 and AG-1295 inhibited this effect. PDGF-BB enhanced phosphorylation of extracellular-signal-regulated kinase 1/2 (ERK1/2), Akt, and signal transducer and activator of transcription 3 (STAT3) in RAW264.7 cells. AG-490 inhibited PDGF-BB-induced STAT3 phosphorylation. PDGF-BB enhanced RAW264.7 cell migration and gene expression of osteoclastogenic signaling molecules (i.e., nuclear factor of activated T cells 1, dendrocyte-expressed seven transmembrane protein, and B-cell lymphoma 2), and treatment with AG-1295, AG-490, or S3I-201 (a STAT3 inhibitor) reduced this effect. PDGF-BB enhanced osteoclast formation, osteoclast precursor cell chemotaxis, and phosphorylation of STAT3, Akt, and ERK1/2. but AG-1295 and AG-490 reduced this effect. These findings reflect the complexity of

  16. Distinct functional and temporal requirements for zebrafish Hdac1 during neural crest-derived craniofacial and peripheral neuron development.

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    Myron S Ignatius

    Full Text Available The regulation of gene expression is accomplished by both genetic and epigenetic means and is required for the precise control of the development of the neural crest. In hdac1(b382 mutants, craniofacial cartilage development is defective in two distinct ways. First, fewer hoxb3a, dlx2 and dlx3-expressing posterior branchial arch precursors are specified and many of those that are consequently undergo apoptosis. Second, in contrast, normal numbers of progenitors are present in the anterior mandibular and hyoid arches, but chondrocyte precursors fail to terminally differentiate. In the peripheral nervous system, there is a disruption of enteric, DRG and sympathetic neuron differentiation in hdac1(b382 mutants compared to wildtype embryos. Specifically, enteric and DRG-precursors differentiate into neurons in the anterior gut and trunk respectively, while enteric and DRG neurons are rarely present in the posterior gut and tail. Sympathetic neuron precursors are specified in hdac1(b382 mutants and they undergo generic neuronal differentiation but fail to undergo noradrenergic differentiation. Using the HDAC inhibitor TSA, we isolated enzyme activity and temporal requirements for HDAC function that reproduce hdac1(b382 defects in craniofacial and sympathetic neuron development. Our study reveals distinct functional and temporal requirements for zebrafish hdac1 during neural crest-derived craniofacial and peripheral neuron development.

  17. Neural stem cell-derived exosomes mediate viral entry

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    Sims B

    2014-10-01

    Full Text Available Brian Sims,1,2,* Linlin Gu,3,* Alexandre Krendelchtchikov,3 Qiana L Matthews3,4 1Division of Neonatology, Department of Pediatrics, 2Department of Cell, Developmental, and Integrative Biology, 3Division of Infectious Diseases, Department of Medicine, 4Center for AIDS Research, University of Alabama at Birmingham, Birmingham, AL, USA *These authors contributed equally to this work Background: Viruses enter host cells through interactions of viral ligands with cellular receptors. Viruses can also enter cells in a receptor-independent fashion. Mechanisms regarding the receptor-independent viral entry into cells have not been fully elucidated. Exosomal trafficking between cells may offer a mechanism by which viruses can enter cells.Methods: To investigate the role of exosomes on cellular viral entry, we employed neural stem cell-derived exosomes and adenovirus type 5 (Ad5 for the proof-of-principle study. Results: Exosomes significantly enhanced Ad5 entry in Coxsackie virus and adenovirus receptor (CAR-deficient cells, in which Ad5 only had very limited entry. The exosomes were shown to contain T-cell immunoglobulin mucin protein 4 (TIM-4, which binds phosphatidylserine. Treatment with anti-TIM-4 antibody significantly blocked the exosome-mediated Ad5 entry.Conclusion: Neural stem cell-derived exosomes mediated significant cellular entry of Ad5 in a receptor-independent fashion. This mediation may be hampered by an antibody specifically targeting TIM-4 on exosomes. This set of results will benefit further elucidation of virus/exosome pathways, which would contribute to reducing natural viral infection by developing therapeutic agents or vaccines. Keywords: neural stem cell-derived exosomes, adenovirus type 5, TIM-4, viral entry, phospholipids

  18. Non-PGM cathode catalysts for fuel cell application derived from heat treated heteroatomic amines precursors

    Energy Technology Data Exchange (ETDEWEB)

    Serov, Alexey; Halevi, Barr; Artyushkova, Kateryna; Atanassov, Plamen B; Martinez, Ulises A

    2017-04-25

    A method of preparing M-N--C catalysts utilizing a sacrificial support approach and inexpensive and readily available polymer precursors as the source of nitrogen and carbon is disclosed. Exemplary polymer precursors include non-porphyrin precursors with no initial catalytic activity. Examples of suitable non-catalytic non-porphyrin precursors include, but are not necessarily limited to low molecular weight precursors that form complexes with iron such as 4-aminoantipirine, phenylenediamine, hydroxysuccinimide, ethanolamine, and the like.

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

    Science.gov (United States)

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

    2017-10-25

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

  20. Local Deformation Precursors of Large Earthquakes Derived from GNSS Observation Data

    Science.gov (United States)

    Kaftan, Vladimir; Melnikov, Andrey

    2017-12-01

    Research on deformation precursors of earthquakes was of immediate interest from the middle to the end of the previous century. The repeated conventional geodetic measurements, such as precise levelling and linear-angular networks, were used for the study. Many examples of studies referenced to strong seismic events using conventional geodetic techniques are presented in [T. Rikitake, 1976]. One of the first case studies of geodetic earthquake precursors was done by Yu.A. Meshcheryakov [1968]. Rare repetitions, insufficient densities and locations of control geodetic networks made difficult predicting future places and times of earthquakes occurrences. Intensive development of Global Navigation Satellite Systems (GNSS) during the recent decades makes research more effective. The results of GNSS observations in areas of three large earthquakes (Napa M6.1, USA, 2014; El Mayor Cucapah M7.2, USA, 2010; and Parkfield M6.0, USA, 2004) are treated and presented in the paper. The characteristics of land surface deformation before, during, and after earthquakes have been obtained. The results prove the presence of anomalous deformations near their epicentres. The temporal character of dilatation and shear strain changes show existence of spatial heterogeneity of deformation of the Earth’s surface from months to years before the main shock close to it and at some distance from it. The revealed heterogeneities can be considered as deformation precursors of strong earthquakes. According to historical data and proper research values of critical deformations which are offered to be used for seismic danger scale creation based on continuous GNSS observations are received in a reference to the mentioned large earthquakes. It is shown that the approach has restrictions owing to uncertainty of the moment in the beginning of deformation accumulation and the place of expectation of another seismic event. Verification and clarification of the derived conclusions are proposed.

  1. Ex Situ Formation of Metal Selenide Quantum Dots Using Bacterially Derived Selenide Precursors

    Energy Technology Data Exchange (ETDEWEB)

    Fellowes, Jonathan W.; Pattrick, Richard; Lloyd, Jon; Charnock, John M.; Coker, Victoria S.; Mosselmans, JFW; Weng, Tsu-Chien; Pearce, Carolyn I.

    2013-04-12

    Luminescent quantum dots were synthesized using bacterially derived selenide (SeII-) as the precursor. Biogenic SeII- was produced by the reduction of Se-IV by Veillonella atypica and compared directly against borohydride-reduced Se-IV for the production of glutathione-stabilized CdSe and beta-mercaptoethanol-stabilized ZnSe nanoparticles by aqueous synthesis. Biological SeII- formed smaller, narrower size distributed QDs under the same conditions. The growth kinetics of biologically sourced CdSe phases were slower. The proteins isolated from filter sterilized biogenic SeII- included a methylmalonyl-CoA decarboxylase previously characterized in the closely related Veillonella parvula. XAS analysis of the glutathione-capped CdSe at the S K-edge suggested that sulfur from the glutathione was structurally incorporated within the CdSe. A novel synchrotron based XAS technique was also developed to follow the nucleation of biological and inorganic selenide phases, and showed that biogenic SeII- is more stable and more resistant to beam-induced oxidative damage than its inorganic counterpart. The bacterial production of quantum dot precursors offers an alternative, 'green' synthesis technique that negates the requirement of expensive, toxic chemicals and suggests a possible link to the exploitation of selenium contaminated waste streams.

  2. Ex situ formation of metal selenide quantum dots using bacterially derived selenide precursors

    International Nuclear Information System (INIS)

    Fellowes, J W; Pattrick, R A D; Lloyd, J R; Charnock, J M; Coker, V S; Mosselmans, J F W; Weng, T-C; Pearce, C I

    2013-01-01

    Luminescent quantum dots were synthesized using bacterially derived selenide (Se II− ) as the precursor. Biogenic Se II− was produced by the reduction of Se IV by Veillonella atypica and compared directly against borohydride-reduced Se IV for the production of glutathione-stabilized CdSe and β-mercaptoethanol-stabilized ZnSe nanoparticles by aqueous synthesis. Biological Se II− formed smaller, narrower size distributed QDs under the same conditions. The growth kinetics of biologically sourced CdSe phases were slower. The proteins isolated from filter sterilized biogenic Se II− included a methylmalonyl-CoA decarboxylase previously characterized in the closely related Veillonella parvula. XAS analysis of the glutathione-capped CdSe at the S K-edge suggested that sulfur from the glutathione was structurally incorporated within the CdSe. A novel synchrotron based XAS technique was also developed to follow the nucleation of biological and inorganic selenide phases, and showed that biogenic Se II− is more stable and more resistant to beam-induced oxidative damage than its inorganic counterpart. The bacterial production of quantum dot precursors offers an alternative, ‘green’ synthesis technique that negates the requirement of expensive, toxic chemicals and suggests a possible link to the exploitation of selenium contaminated waste streams. (paper)

  3. Different mechanisms must be considered to explain the increase in hippocampal neural precursor cell proliferation by physical activity

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    Rupert W Overall

    2016-08-01

    Full Text Available The number of proliferating neural precursor cells in the adult hippocampus is strongly increased by physical activity. The mechanisms through which this behavioral stimulus induces cell proliferation, however, are not yet understood. In fact, even the mode of proliferation of the stem and progenitor cells is not exactly known. Evidence exists for several mechanisms including cell cycle shortening, reduced cell death and stem cell recruitment, but as yet no model can account for all observations. An appreciation of how the cells proliferate, however, is crucial to our ability to model the neurogenic process and predict its behavior in response to pro-neurogenic stimuli. In a recent study, we addressed modulation of the cell cycle length as one possible mode of regulation of precursor cell proliferation in running mice. Our results indicated that the observed increase in number of proliferating cells could not be explained through a shortening of the cell cycle. We must therefore consider other mechanisms by which physical activity leads to enhanced precursor cell proliferation. Here we review the evidence for and against several different hypotheses and discuss the implications for future research in the field.

  4. Mesoporous silica thin films prepared by argon plasma treatment of sol-gel-derived precursor

    International Nuclear Information System (INIS)

    Zhang Jian; Palaniappan, Alagappan; Su Xiaodi; Tay, Francis E.H.

    2005-01-01

    Argon plasma is used to generate the mesoporous silica thin films from sol-gel-derived precursor. Poly(ethylene glycol) (PEG, MW = 400) is employed as the template, i.e., the pore-directing agent as well as the binder. The influence of the plasma parameters (plasma power and processing time) on the mesoscopic properties of silica films are investigated by scanning electron microscopy (SEM), FT-IR, low-angle X-ray scattering (SAXS), and nitrogen adsorption isotherm. It is concluded that the plasma treatment is a promising way to remove organic templates and generate mesoporous thin films. Compared to the conventional thermal calcination methods, the plasma treatment provides a promising low-temperature, low-cost and time-saving preparation process

  5. Stem cells from human exfoliated deciduous tooth exhibit stromal-derived inducing activity and lead to generation of neural crest cells from human embryonic stem cells.

    Science.gov (United States)

    Karbalaie, Khadijeh; Tanhaei, Somayyeh; Rabiei, Farzaneh; Kiani-Esfahani, Abbas; Masoudi, Najmeh Sadat; Nasr-Esfahani, Mohammad Hossein; Baharvand, Hossein

    2015-01-01

    The neural crest is a transient structure of early vertebrate embryos that generates neural crest cells (NCCs). These cells can migrate throughout the body and produce a diverse array of mature tissue types. Due to the ethical and technical problems surrounding the isolation of these early human embryo cells, researchers have focused on in vitro studies to produce NCCs and increase their knowledge of neural crest development. In this experimental study, we cultured human embryonic stem cells (hESCs) on stromal stem cells from human exfoliated deciduous teeth (SHED) for a two-week period. We used different approaches to characterize these differentiated cells as neural precursor cells (NPCs) and NCCs. In the first co-culture week, hESCs appeared as crater-like structures with marginal rosettes. NPCs derived from these structures expressed the early neural crest marker p75 in addition to numerous other genes associated with neural crest induction such as SNAIL, SLUG, PTX3 and SOX9. Flow cytometry analysis showed 70% of the cells were AP2/P75 positive. Moreover, the cells were able to self-renew, sustain multipotent differentiation potential, and readily form neurospheres in suspension culture. SHED, as an adult stem cell with a neural crest origin, has stromal-derived inducing activity (SDIA) and can be used as an NCC inducer from hESCs. These cells provide an invaluable resource to study neural crest differentiation in both normal and disordered human neural crest development.

  6. Two forms of Vibrio cholerae O1 El Tor hemolysin derived from identical precursor protein.

    Science.gov (United States)

    Ikigai, H; Ono, T; Nakae, T; Otsuru, H; Shimamura, T

    1999-01-08

    Vibrio cholerae O1 grown in heart infusion broth produces two forms of El Tor hemolysin (ETH) monomers of 65 and 50 kDa. These monomers form several different sizes of mixed oligomers ranging from 180 to 280 kDa in the liposomal membranes. We found that the N-terminal amino acid sequences, NH2-Trp-Pro-Ala-Pro-Ala-Asn-Ser-Glu, of both the 65- and 50-kDa toxins were identical. We assumed, therefore, that the 65- and 50-kDa toxins were derivatives of the identical precursor protein and the 50-kDa protein was a truncated derivative of 65-kDa ETH. To substantiate this assumption, we treated the 260-kDa oligomer with trypsin and obtained a 190-kDa oligomer. This 190-kDa oligomer consisted of only the 50-kDa subunits. Both 260- and 190-kDa oligomers formed ion channels indistinguishable from each other in planar lipid bilayers. These results suggest that the essential part of the ETH in forming the membrane-damaging aggregate is a 50-kDa protein.

  7. Pulsed DC Electric Field-Induced Differentiation of Cortical Neural Precursor Cells.

    Directory of Open Access Journals (Sweden)

    Hui-Fang Chang

    Full Text Available We report the differentiation of neural stem and progenitor cells solely induced by direct current (DC pulses stimulation. Neural stem and progenitor cells in the adult mammalian brain are promising candidates for the development of therapeutic neuroregeneration strategies. The differentiation of neural stem and progenitor cells depends on various in vivo environmental factors, such as nerve growth factor and endogenous EF. In this study, we demonstrated that the morphologic and phenotypic changes of mouse neural stem and progenitor cells (mNPCs could be induced solely by exposure to square-wave DC pulses (magnitude 300 mV/mm at frequency of 100-Hz. The DC pulse stimulation was conducted for 48 h, and the morphologic changes of mNPCs were monitored continuously. The length of primary processes and the amount of branching significantly increased after stimulation by DC pulses for 48 h. After DC pulse treatment, the mNPCs differentiated into neurons, astrocytes, and oligodendrocytes simultaneously in stem cell maintenance medium. Our results suggest that simple DC pulse treatment could control the fate of NPCs. With further studies, DC pulses may be applied to manipulate NPC differentiation and may be used for the development of therapeutic strategies that employ NPCs to treat nervous system disorders.

  8. Pulsed DC Electric Field-Induced Differentiation of Cortical Neural Precursor Cells.

    Science.gov (United States)

    Chang, Hui-Fang; Lee, Ying-Shan; Tang, Tang K; Cheng, Ji-Yen

    2016-01-01

    We report the differentiation of neural stem and progenitor cells solely induced by direct current (DC) pulses stimulation. Neural stem and progenitor cells in the adult mammalian brain are promising candidates for the development of therapeutic neuroregeneration strategies. The differentiation of neural stem and progenitor cells depends on various in vivo environmental factors, such as nerve growth factor and endogenous EF. In this study, we demonstrated that the morphologic and phenotypic changes of mouse neural stem and progenitor cells (mNPCs) could be induced solely by exposure to square-wave DC pulses (magnitude 300 mV/mm at frequency of 100-Hz). The DC pulse stimulation was conducted for 48 h, and the morphologic changes of mNPCs were monitored continuously. The length of primary processes and the amount of branching significantly increased after stimulation by DC pulses for 48 h. After DC pulse treatment, the mNPCs differentiated into neurons, astrocytes, and oligodendrocytes simultaneously in stem cell maintenance medium. Our results suggest that simple DC pulse treatment could control the fate of NPCs. With further studies, DC pulses may be applied to manipulate NPC differentiation and may be used for the development of therapeutic strategies that employ NPCs to treat nervous system disorders.

  9. Structural Analysis of Three-dimensional Human Neural Tissue derived from Induced Pluripotent Stem Cells

    DEFF Research Database (Denmark)

    Terrence Brooks, Patrick; Rasmussen, Mikkel Aabech; Hyttel, Poul

    2016-01-01

    Objective: The present study aimed at establishing a method for production of a three-dimensional (3D) human neural tissue derived from induced pluripotent stem cells (iPSCs) and analyzing the outcome by a combination of tissue ultrastructure and expression of neural markers. Methods: A two......-step cell culture procedure was implemented by subjecting human iPSCs to a 3D scaffoldbased neural differentiation protocol. First, neural fate-inducing small molecules were used to create a neuroepithelial monolayer. Second, the monolayer was trypsinized into single cells and seeded into a porous...... polystyrene scaffold and further cultured to produce a 3D neural tissue. The neural tissue was characterized by a combination of immunohistochemistry and transmission electron microscopy (TEM). Results: iPSCs developed into a 3D neural tissue expressing markers for neural progenitor cells, early neural...

  10. Isolation of Mature (Peritoneum-Derived Mast Cells and Immature (Bone Marrow-Derived Mast Cell Precursors from Mice.

    Directory of Open Access Journals (Sweden)

    Steffen K Meurer

    Full Text Available Mast cells (MCs are a versatile cell type playing key roles in tissue morphogenesis and host defence against bacteria and parasites. Furthermore, they can enhance immunological danger signals and are implicated in inflammatory disorders like fibrosis. This granulated cell type originates from the myeloid lineage and has similarities to basophilic granulocytes, both containing large quantities of histamine and heparin. Immature murine mast cells mature in their destination tissue and adopt either the connective tissue (CTMC or mucosal (MMC type. Some effector functions are executed by activation/degranulation of MCs which lead to secretion of a typical set of MC proteases (MCPT and of the preformed or newly synthesized mediators from its granules into the local microenvironment. Due to the potential accumulation of mutations in key signalling pathway components of corresponding MC cell-lines, primary cultured MCs are an attractive mean to study general features of MC biology and aspects of MC functions relevant to human disease. Here, we describe a simple protocol for the simultaneous isolation of mature CTMC-like murine MCs from the peritoneum (PMCs and immature MC precursors from the bone marrow (BM. The latter are differentiated in vitro to yield BM-derived MCs (BMMC. These cells display the typical morphological and phenotypic features of MCs, express the typical MC surface markers, and can be propagated and kept in culture for several weeks. The provided protocol allows simple amplification of large quantities of homogenous, non-transformed MCs from the peritoneum and bone marrow-derived mast cells for cell- and tissue-based biomedical research.

  11. Neural Stem Cells Derived by Small Molecules Preserve Vision.

    Science.gov (United States)

    Lu, Bin; Morgans, Catherine W; Girman, Sergey; Luo, Jing; Zhao, Jiagang; Du, Hongjun; Lim, Sioklam; Ding, Sheng; Svendsen, Clive; Zhang, Kang; Wang, Shaomei

    2013-01-01

    The advances in stem cell biology hold a great potential to treat retinal degeneration. Importantly, specific cell types can be generated efficiently with small molecules and maintained stably over numerous passages. Here, we investigated whether neural stem cell (NSC) derived from human embryonic stem cells (hESC) by small molecules can preserve vision following grafting into the Royal College Surgeon (RCS) rats; a model for retinal degeneration. A cell suspension containing 3 × 10 4 NSCs or NSCs labeled with green fluorescent protein (GFP) was injected into the subretinal space or the vitreous cavity of RCS rats at postnatal day (P) 22; animals injected with cell-carry medium and those left untreated were used as controls. The efficacy of treatment was evaluated by testing optokinetic response, recording luminance threshold, and examining retinal histology. NSCs offered significant preservation of both photoreceptors and visual function. The grafted NSCs survived for long term without evidence of tumor formation. Functionally, NSC treated eyes had significantly better visual acuity and lower luminance threshold than controls. Morphologically, photoreceptors and retinal connections were well preserved. There was an increase in expression of cillary neurotrophic factor (CNTF) in Müller cells in the graft-protected retina. This study reveals that NSCs derived from hESC by small molecules can survive and preserve vision for long term following subretinal transplantation in the RCS rats. These cells migrate extensively in the subretinal space and inner retina; there is no evidence of tumor formation or unwanted changes after grafting into the eyes. The NSCs derived from hESC by small molecules can be generated efficiently and provide an unlimited supply of cells for the treatment of some forms of human outer retinal degenerative diseases. The capacity of NSCs migrating into inner retina offers a potential as a vehicle to delivery drugs/factors to treat inner retinal

  12. Nanostructure Development in Alkoxide-Carboxylate-Derived Precursor Films of Barium Titanate

    NARCIS (Netherlands)

    Stawski, Tomasz; Veldhuis, Sjoerd; Besselink, R.; Castricum, H.L.; Portale, G.; Blank, David H.A.; ten Elshof, Johan E.

    2012-01-01

    The structural evolution in wet alkoxide-carboxylate sol–gel precursor films of barium titanate upon drying was investigated by time-resolved small-angle X-ray scattering (SAXS). The morphology of as-dried amorphous precursor thin films was investigated by transmission electron microscopy (TEM) and

  13. Epigenetic activation of the Foxa2 gene is required for maintaining the potential of neural precursor cells to differentiate into dopaminergic neurons after expansion.

    Science.gov (United States)

    Bang, So-Young; Kwon, So Hee; Yi, Sang-Hoon; Yi, Sang Ah; Park, Eun Kyung; Lee, Jae-Cheol; Jang, Choon-Gon; You, Jueng Soo; Lee, Sang-Hun; Han, Jeung-Whan

    2015-02-15

    Dysregulation of forkhead box protein A2 (Foxa2) expression in fetal ventral mesencephalon (VM)-derived neural precursor cells (NPCs) appears to be associated with the loss of their potential to differentiate into dopaminergic (DA) neurons after mitogenic expansion in vitro, hindering their efficient use as a transplantable cell source. Here, we report that epigenetic activation of Foxa2 in VM-derived NPCs by inducing histone hyperacetylation rescues the mitogenic-expansion-dependent decrease of differentiation potential to DA neurons. The silencing of Foxa2 gene expression after expansion is accompanied by repressive histone modifications, including hypoacetylation of histone H3 and H4 and trimethylation of H3K27 on the Foxa2 promoter, as well as on the global level. In addition, histone deacetylase 7 (HDAC7) is highly expressed during differentiation and recruited to the Foxa2 promoter. Induction of histone acetylation in VM-derived NPCs by either knockdown of HDAC7 or treatment with the HDAC inhibitor apicidin upregulates Foxa2 expression via hyperacetylation of H3 and a decrease in H3K27 trimethylation on the promoter regions, leading to the expression of DA neuron developmental genes and enhanced differentiation of DA neurons. These effects are antagonized by the expression of shRNAs specific for Foxa2 but enhanced by shRNA for HDAC7. Collectively, these findings indicate that loss of differentiation potential of expanded VM-derived NPCs is attributed to a decrease in Foxa2 expression and suggest that activation of the endogenous Foxa2 gene by epigenetic regulation might be an approach to enhance the generation of DA neurons.

  14. Rhomboid Enhancer Activity Defines a Subset of Drosophila Neural Precursors Required for Proper Feeding, Growth and Viability.

    Directory of Open Access Journals (Sweden)

    Amy L Gresser

    Full Text Available Organismal growth regulation requires the interaction of multiple metabolic, hormonal and neuronal pathways. While the molecular basis for many of these are well characterized, less is known about the developmental origins of growth regulatory structures and the mechanisms governing control of feeding and satiety. For these reasons, new tools and approaches are needed to link the specification and maturation of discrete cell populations with their subsequent regulatory roles. In this study, we characterize a rhomboid enhancer element that selectively labels four Drosophila embryonic neural precursors. These precursors give rise to the hypopharyngeal sensory organ of the peripheral nervous system and a subset of neurons in the deutocerebral region of the embryonic central nervous system. Post embryogenesis, the rhomboid enhancer is active in a subset of cells within the larval pharyngeal epithelium. Enhancer-targeted toxin expression alters the morphology of the sense organ and results in impaired larval growth, developmental delay, defective anterior spiracle eversion and lethality. Limiting the duration of toxin expression reveals differences in the critical periods for these effects. Embryonic expression causes developmental defects and partially penetrant pre-pupal lethality. Survivors of embryonic expression, however, ultimately become viable adults. In contrast, post-embryonic toxin expression results in fully penetrant lethality. To better define the larval growth defect, we used a variety of assays to demonstrate that toxin-targeted larvae are capable of locating, ingesting and clearing food and they exhibit normal food search behaviors. Strikingly, however, following food exposure these larvae show a rapid decrease in consumption suggesting a satiety-like phenomenon that correlates with the period of impaired larval growth. Together, these data suggest a critical role for these enhancer-defined lineages in regulating feeding, growth and

  15. Rhomboid Enhancer Activity Defines a Subset of Drosophila Neural Precursors Required for Proper Feeding, Growth and Viability.

    Science.gov (United States)

    Gresser, Amy L; Gutzwiller, Lisa M; Gauck, Mackenzie K; Hartenstein, Volker; Cook, Tiffany A; Gebelein, Brian

    2015-01-01

    Organismal growth regulation requires the interaction of multiple metabolic, hormonal and neuronal pathways. While the molecular basis for many of these are well characterized, less is known about the developmental origins of growth regulatory structures and the mechanisms governing control of feeding and satiety. For these reasons, new tools and approaches are needed to link the specification and maturation of discrete cell populations with their subsequent regulatory roles. In this study, we characterize a rhomboid enhancer element that selectively labels four Drosophila embryonic neural precursors. These precursors give rise to the hypopharyngeal sensory organ of the peripheral nervous system and a subset of neurons in the deutocerebral region of the embryonic central nervous system. Post embryogenesis, the rhomboid enhancer is active in a subset of cells within the larval pharyngeal epithelium. Enhancer-targeted toxin expression alters the morphology of the sense organ and results in impaired larval growth, developmental delay, defective anterior spiracle eversion and lethality. Limiting the duration of toxin expression reveals differences in the critical periods for these effects. Embryonic expression causes developmental defects and partially penetrant pre-pupal lethality. Survivors of embryonic expression, however, ultimately become viable adults. In contrast, post-embryonic toxin expression results in fully penetrant lethality. To better define the larval growth defect, we used a variety of assays to demonstrate that toxin-targeted larvae are capable of locating, ingesting and clearing food and they exhibit normal food search behaviors. Strikingly, however, following food exposure these larvae show a rapid decrease in consumption suggesting a satiety-like phenomenon that correlates with the period of impaired larval growth. Together, these data suggest a critical role for these enhancer-defined lineages in regulating feeding, growth and viability.

  16. An In Vivo Characterization of Trophic Factor Production Following Neural Precursor Cell or Bone Marrow Stromal Cell Transplantation for Spinal Cord Injury

    Science.gov (United States)

    Hawryluk, Gregory W.J.; Mothe, Andrea; Wang, Jian; Wang, Shelly; Tator, Charles

    2012-01-01

    Cellular transplantation strategies for repairing the injured spinal cord have shown consistent benefit in preclinical models, and human clinical trials have begun. Interactions between transplanted cells and host tissue remain poorly understood. Trophic factor secretion is postulated a primary or supplementary mechanism of action for many transplanted cells, however, there is little direct evidence to support trophin production by transplanted cells in situ. In the present study, trophic factor expression was characterized in uninjured, injured-untreated, injured-treated with transplanted cells, and corresponding control tissue from the adult rat spinal cord. Candidate trophic factors were identified in a literature search, and primers were designed for these genes. We examined in vivo trophin expression in 3 paradigms involving transplantation of either brain or spinal cord-derived neural precursor cells (NPCs) or bone marrow stromal cells (BMSCs). Injury without further treatment led to a significant elevation of nerve growth factor (NGF), leukemia inhibitory factor (LIF), insulin-like growth factor-1 (IGF-1), and transforming growth factor-β1 (TGF-β1), and lower expression of vascular endothelial growth factor isoform A (VEGF-A) and platelet-derived growth factor-A (PDGF-A). Transplantation of NPCs led to modest changes in trophin expression, and the co-administration of intrathecal trophins resulted in significant elevation of the neurotrophins, glial-derived neurotrophic factor (GDNF), LIF, and basic fibroblast growth factor (bFGF). BMSCs transplantation upregulated NGF, LIF, and IGF-1. NPCs isolated after transplantation into the injured spinal cord expressed the neurotrophins, ciliary neurotrophic factor (CNTF), epidermal growth factor (EGF), and bFGF at higher levels than host cord. These data show that trophin expression in the spinal cord is influenced by injury and cell transplantation, particularly when combined with intrathecal trophin infusion

  17. Mapping Neural Network Derived from the Parzen Window Estimator

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Hartmann, U.

    1992-01-01

    The article presents a general theoretical basis for the construction of mapping neural networks. The theory is based on the Parzen Window estimator for......The article presents a general theoretical basis for the construction of mapping neural networks. The theory is based on the Parzen Window estimator for...

  18. Combined transplantation of neural precursor cells and olfactory ensheathing cells for the treatment of X-linked adrenoleukodystrophy in children

    Directory of Open Access Journals (Sweden)

    Yang H

    2017-04-01

    Full Text Available Hui Yang,1,* Yu Zhang,1,* Zhaoyan Wang,1 Wei Lu,1 Fang Liu,1 Xin Yu,2 Xiaoyan Zheng,1 Yinxiang Yang,1 Zuo Luan,1 Suqing Qu1 1Department of Pediatrics, 2Department of Neurological Surgery, Navy General Hospital, Beijing, People’s Republic of China *These authors contributed equally to this work. Abstract: Hematopoietic stem cell transplantation is only suitable for early-stage adrenoleukodystrophy (ALD. In this study, we observed the therapeutic efficacy of combined transplantation of neural precursor cells (NPCs and olfactory ensheathing cells (OECs on late-stage X-linked ALD in nine children who were admitted in our hospital between June 2009 and January 2014. Related patient information included onset time 3 months to 1 year, magnetic resonance imaging (MRI score 11.02±0.90, and neurologic function score 2–3. All patients received combined transplantation of NPCs and OECs by injection around the lateral angle of the frontotemporal–occipital lesion under MRI guidance. It was found that the visual function, sleep, and communication obstacles were improved significantly without evidence of disease progression in six (66.7% of the nine patients within 1 month after transplantation. In two of the six patients, the lesions became significantly smaller than before, although their MRI scores remained unchanged significantly. In addition, cell therapy did not induce any irreversible adverse event during the study period, indicating that combined transplantation of NPCs and OECs was safe and reliable, and could improve the clinical manifestations of ALD in children within a short time. Although this cell therapy was not able to halt the progression of the disease 1–3 months after transplantation, it could still be used as an early treatment and provide patients with more opportunities for hematopoietic stem cell transplantation, which is the only effective long-term treatment for X-linked ALD at present. The preliminary results from this study

  19. BDNF Increases Survival and Neuronal Differentiation of Human Neural Precursor Cells Cotransplanted with a Nanofiber Gel to the Auditory Nerve in a Rat Model of Neuronal Damage

    Directory of Open Access Journals (Sweden)

    Yu Jiao

    2014-01-01

    Full Text Available Objectives. To study possible nerve regeneration of a damaged auditory nerve by the use of stem cell transplantation. Methods. We transplanted HNPCs to the rat AN trunk by the internal auditory meatus (IAM. Furthermore, we studied if addition of BDNF affects survival and phenotypic differentiation of the grafted HNPCs. A bioactive nanofiber gel (PA gel, in selected groups mixed with BDNF, was applied close to the implanted cells. Before transplantation, all rats had been deafened by a round window niche application of β-bungarotoxin. This neurotoxin causes a selective toxic destruction of the AN while keeping the hair cells intact. Results. Overall, HNPCs survived well for up to six weeks in all groups. However, transplants receiving the BDNF-containing PA gel demonstrated significantly higher numbers of HNPCs and neuronal differentiation. At six weeks, a majority of the HNPCs had migrated into the brain stem and differentiated. Differentiated human cells as well as neurites were observed in the vicinity of the cochlear nucleus. Conclusion. Our results indicate that human neural precursor cells (HNPC integration with host tissue benefits from additional brain derived neurotrophic factor (BDNF treatment and that these cells appear to be good candidates for further regenerative studies on the auditory nerve (AN.

  20. Functional cross-talk between the cellular prion protein and the neural cell adhesion molecule is critical for neuronal differentiation of neural stem/precursor cells.

    Science.gov (United States)

    Prodromidou, Kanella; Papastefanaki, Florentia; Sklaviadis, Theodoros; Matsas, Rebecca

    2014-06-01

    Cellular prion protein (PrP) is prominently expressed in brain, in differentiated neurons but also in neural stem/precursor cells (NPCs). The misfolding of PrP is a central event in prion diseases, yet the physiological function of PrP is insufficiently understood. Although PrP has been reported to associate with the neural cell adhesion molecule (NCAM), the consequences of concerted PrP-NCAM action in NPC physiology are unknown. Here, we generated NPCs from the subventricular zone (SVZ) of postnatal day 5 wild-type and PrP null (-/-) mice and observed that PrP is essential for proper NPC proliferation and neuronal differentiation. Moreover, we found that PrP is required for the NPC response to NCAM-induced neuronal differentiation. In the absence of PrP, NCAM not only fails to promote neuronal differentiation but also induces an accumulation of doublecortin-positive neuronal progenitors at the proliferation stage. In agreement, we noted an increase in cycling neuronal progenitors in the SVZ of PrP-/- mice compared with PrP+/+ mice, as evidenced by double labeling for the proliferation marker Ki67 and doublecortin as well as by 5-bromo-2'-deoxyuridine incorporation experiments. Additionally, fewer newly born neurons were detected in the rostral migratory stream of PrP-/- mice. Analysis of the migration of SVZ cells in microexplant cultures from wild-type and PrP-/- mice revealed no differences between genotypes or a role for NCAM in this process. Our data demonstrate that PrP plays a critical role in neuronal differentiation of NPCs and suggest that this function is, at least in part, NCAM-dependent. © 2014 AlphaMed Press.

  1. Regulatory Role of Redox Balance in Determination of Neural Precursor Cell Fate

    Directory of Open Access Journals (Sweden)

    Mohamed Ariff Iqbal

    2017-01-01

    Full Text Available In 1990s, reports of discovery of a small group of cells capable of proliferation and contribution to formation of new neurons in the central nervous system (CNS reversed a century-old concept on lack of neurogenesis in the adult mammalian brain. These cells are found in all stages of human life and contribute to normal cellular turnover of the CNS. Therefore, the identity of regulating factors that affect their proliferation and differentiation is a highly noteworthy issue for basic scientists and their clinician counterparts for therapeutic purposes. The cues for such control are embedded in developmental and environmental signaling through a highly regulated tempo-spatial expression of specific transcription factors. Novel findings indicate the importance of reactive oxygen species (ROS in the regulation of this signaling system. The elusive nature of ROS signaling in many vital processes from cell proliferation to cell death creates a complex literature in this field. Here, we discuss the emerging thoughts on the importance of redox regulation of proliferation and maintenance in mammalian neural stem and progenitor cells under physiological and pathological conditions. The current knowledge on ROS-mediated changes in redox-sensitive proteins that govern the molecular mechanisms in proliferation and differentiation of these cells is reviewed.

  2. Transplanted astrocytes derived from BMP- or CNTF-treated glial-restricted precursors have opposite effects on recovery and allodynia after spinal cord injury

    Directory of Open Access Journals (Sweden)

    Davies Jeannette E

    2008-09-01

    Full Text Available Abstract Background Two critical challenges in developing cell-transplantation therapies for injured or diseased tissues are to identify optimal cells and harmful side effects. This is of particular concern in the case of spinal cord injury, where recent studies have shown that transplanted neuroepithelial stem cells can generate pain syndromes. Results We have previously shown that astrocytes derived from glial-restricted precursor cells (GRPs treated with bone morphogenetic protein-4 (BMP-4 can promote robust axon regeneration and functional recovery when transplanted into rat spinal cord injuries. In contrast, we now show that transplantation of GRP-derived astrocytes (GDAs generated by exposure to the gp130 agonist ciliary neurotrophic factor (GDAsCNTF, the other major signaling pathway involved in astrogenesis, results in failure of axon regeneration and functional recovery. Moreover, transplantation of GDACNTF cells promoted the onset of mechanical allodynia and thermal hyperalgesia at 2 weeks after injury, an effect that persisted through 5 weeks post-injury. Delayed onset of similar neuropathic pain was also caused by transplantation of undifferentiated GRPs. In contrast, rats transplanted with GDAsBMP did not exhibit pain syndromes. Conclusion Our results show that not all astrocytes derived from embryonic precursors are equally beneficial for spinal cord repair and they provide the first identification of a differentiated neural cell type that can cause pain syndromes on transplantation into the damaged spinal cord, emphasizing the importance of evaluating the capacity of candidate cells to cause allodynia before initiating clinical trials. They also confirm the particular promise of GDAs treated with bone morphogenetic protein for spinal cord injury repair.

  3. Immune regulatory neural stem/precursor cells protect from central nervous system autoimmunity by restraining dendritic cell function.

    Directory of Open Access Journals (Sweden)

    Stefano Pluchino

    Full Text Available BACKGROUND: The systemic injection of neural stem/precursor cells (NPCs provides remarkable amelioration of the clinico-pathological features of experimental autoimmune encephalomyelitis (EAE. This is dependent on the capacity of transplanted NPCs to engage concurrent mechanisms of action within specific microenvironments in vivo. Among a wide range of therapeutic actions alternative to cell replacement, neuroprotective and immune modulatory capacities of transplanted NPCs have been described. However, lacking is a detailed understanding of the mechanisms by which NPCs exert their therapeutic plasticity. This study was designed to identify the first candidate that exemplifies and sustains the immune modulatory capacity of transplanted NPCs. METHODOLOGY/PRINCIPAL FINDINGS: To achieve the exclusive targeting of the peripheral immune system, SJL mice with PLP-induced EAE were injected subcutaneously with NPCs and the treatment commenced prior to disease onset. NPC-injected EAE mice showed significant clinical improvement, as compared to controls. Exogenous NPCs lacking the expression of major neural antigens were reliably (and for long-term found at the level of draining lymph nodes, while establishing sophisticated anatomical interactions with lymph node cells. Importantly, injected NPCs were never found in organs other than lymph nodes, including the brain and the spinal cord. Draining lymph nodes from transplanted mice showed focal up-regulation of major developmental stem cell regulators, such as BMP-4, Noggin and Sonic hedgehog. In lymph nodes, injected NPCs hampered the activation of myeloid dendritic cells (DCs and steadily restrained the expansion of antigen-specific encephalitogenic T cells. Both ex vivo and in vitro experiments identified a novel highly NPC-specific-BMP-4-dependent-mechanism hindering the DC maturation. CONCLUSION/SIGNIFICANCE: The study described herein, identifies the first member of the TGF beta/BMP family of stem cell

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  6. File list: His.PSC.05.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  7. File list: InP.PSC.10.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  8. File list: Pol.PSC.20.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  9. File list: NoD.PSC.05.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  10. File list: DNS.PSC.50.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  11. File list: His.PSC.20.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  12. File list: Pol.PSC.20.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  13. File list: NoD.PSC.50.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  14. File list: DNS.PSC.20.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  15. File list: DNS.PSC.10.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  16. File list: Oth.PSC.50.AllAg.hESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  17. File list: NoD.PSC.50.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  18. File list: Pol.PSC.20.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  19. File list: His.PSC.50.AllAg.hESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  20. File list: ALL.PSC.50.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  1. File list: Oth.PSC.05.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  2. File list: DNS.PSC.05.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  3. File list: Oth.PSC.20.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  4. File list: Unc.PSC.50.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  5. File list: Unc.PSC.20.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  6. File list: Pol.PSC.20.AllAg.hESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  7. File list: His.PSC.20.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  8. File list: Oth.PSC.10.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  9. File list: NoD.PSC.50.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  10. File list: NoD.PSC.05.AllAg.hESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  11. File list: NoD.PSC.05.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  12. File list: Pol.PSC.50.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  13. File list: DNS.PSC.05.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  14. File list: His.PSC.05.AllAg.hESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  15. File list: NoD.PSC.10.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  16. File list: ALL.PSC.10.AllAg.iPS_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  17. File list: His.PSC.20.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  18. File list: His.PSC.10.AllAg.hESC_derived_neural_crests [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available His.PSC.10.AllAg.hESC_derived_neural_crests hg19 Histone Pluripotent stem cell hESC derived neural...3,SRX1091531,SRX059364,SRX1091530 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/His.PSC.10.AllAg.hESC_derived_neural_crests.bed ...

  19. Precursor Derived Nanostructured Si-C-X Materials for Nuclear Applications. Final Report, October 2010 - September 2014

    Energy Technology Data Exchange (ETDEWEB)

    Bordia, Rajendra [Univ. of Washington, Seattle, WA (United States); Tomar, Vikas [Purdue Univ., West Lafayette, IN (United States); Henager, Chuck [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-04-08

    Polymer derived ceramic route is an attractive approach to make structural materials with unique nanostructures that have very desirable high temperature properties. Processing techniques to make a variety of needed shapes and forms (e.g. coatings, matrices for fiber reinforced composites, porous ceramics) have been developed. With appropriate high temperature processing, the precursors can be converted to nano-crystalline materials. In this collaborative project, we investigated the processing, stability and properties of nanostructured Si-C materials, derived from polymeric precursors, and their performance under conditions appropriate for nuclear energy applications. All the milestones of the project were accomplished. Some of the results are being currently analyzed and additional papers being prepared in which support from NEUP will be acknowledged. So far, eight peer-reviewed papers have been published and one invention disclosure made. In this report, we summarize the major findings of this project.

  20. Precursor Derived Nanostructured Si-C-X Materials for Nuclear Applications. Final Report, October 2010 - September 2014

    International Nuclear Information System (INIS)

    Bordia, Rajendra; Tomar, Vikas; Henager, Chuck

    2015-01-01

    Polymer derived ceramic route is an attractive approach to make structural materials with unique nanostructures that have very desirable high temperature properties. Processing techniques to make a variety of needed shapes and forms (e.g. coatings, matrices for fiber reinforced composites, porous ceramics) have been developed. With appropriate high temperature processing, the precursors can be converted to nano-crystalline materials. In this collaborative project, we investigated the processing, stability and properties of nanostructured Si-C materials, derived from polymeric precursors, and their performance under conditions appropriate for nuclear energy applications. All the milestones of the project were accomplished. Some of the results are being currently analyzed and additional papers being prepared in which support from NEUP will be acknowledged. So far, eight peer-reviewed papers have been published and one invention disclosure made. In this report, we summarize the major findings of this project.

  1. Chondroitin sulfate proteoglycans regulate the growth, differentiation and migration of multipotent neural precursor cells through the integrin signaling pathway

    Directory of Open Access Journals (Sweden)

    Lü He-Zuo

    2009-10-01

    Full Text Available Abstract Background Neural precursor cells (NPCs are defined by their ability to proliferate, self-renew, and retain the potential to differentiate into neurons and glia. Deciphering the factors that regulate their behaviors will greatly aid in their use as potential therapeutic agents or targets. Chondroitin sulfate proteoglycans (CSPGs are prominent components of the extracellular matrix (ECM in the central nervous system (CNS and are assumed to play important roles in controlling neuronal differentiation and development. Results In the present study, we demonstrated that CSPGs were constitutively expressed on the NPCs isolated from the E16 rat embryonic brain. When chondroitinase ABC was used to abolish the function of endogenous CSPGs on NPCs, it induced a series of biological responses including the proliferation, differentiation and migration of NPCs, indicating that CSPGs may play a critical role in NPC development and differentiation. Finally, we provided evidence suggesting that integrin signaling pathway may be involved in the effects of CSPGs on NPCs. Conclusion The present study investigating the influence and mechanisms of CSPGs on the differentiation and migration of NPCs should help us to understand the basic biology of NPCs during CNS development and provide new insights into developing new strategies for the treatment of the neurological disorders in the CNS.

  2. Analysis of neural crest-derived clones reveals novel aspects of facial development

    NARCIS (Netherlands)

    Kaucka, Marketa; Ivashkin, Evgeny; Gyllborg, Daniel; Zikmund, Tomas; Tesarova, Marketa; Kaiser, Jozef; Xie, Meng; Petersen, Julian; Pachnis, Vassilis; Nicolis, Silvia K.; Yu, Tian; Sharpe, Paul; Arenas, Ernest; Brismar, Hjalmar; Blom, Hans; Clevers, Hans; Suter, Ueli; Chagin, Andrei S.; Fried, Kaj; Hellander, Andreas; Adameyko, Igor

    2016-01-01

    Cranial neural crest cells populate the future facial region and produce ectomesenchyme-derived tissues, such as cartilage, bone, dermis, smooth muscle, adipocytes, and many others. However, the contribution of individual neural crest cells to certain facial locations and the general spatial clonal

  3. 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.

  4. Study of hafnium (IV) oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods

    KAUST Repository

    Ramos-González, R.

    2010-03-01

    This work reports the preparation and characterization of hafnium (IV) oxide (HfO2) nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network. A comparison between polymerized complex (PC) and polymer precursor (PP) methods is presented. For the PC method, citric acid (CA) and ethylene glycol (EG) are used as the chelating and polymerizable reagents, respectively. In the case of PP method, poly(acrylic acid) (PAA) is used as the chelating reagent. In both cases, different precursor gels were prepared and the hafnium (IV) chloride (HfCl4) molar ratio was varied from 0.1 to 1.0 for the PC method and from 0.05 to 0.5 for the PP method. In order to obtain the nanoparticles, the precursors were heat treated at 500 and 800 °C. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis (TGA) and the structural and morphological characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the samples obtained by both methods shows the formation of HfO2 at 500 °C with monoclinic crystalline phase. The PC method exhibited also the cubic phase. Finally, the HfO2 nanoparticles size (4 to 11 nm) was determined by TEM and XRD patterns. © (2010) Trans Tech Publications.

  5. OTX2 exhibits cell-context-dependent effects on cellular and molecular properties of human embryonic neural precursors and medulloblastoma cells

    Directory of Open Access Journals (Sweden)

    Ravinder Kaur

    2015-10-01

    Full Text Available Medulloblastoma (MB is the most common malignant primary pediatric brain tumor and is currently divided into four subtypes based on different genomic alterations, gene expression profiles and response to treatment: WNT, Sonic Hedgehog (SHH, Group 3 and Group 4. This extensive heterogeneity has made it difficult to assess the functional relevance of genes to malignant progression. For example, expression of the transcription factor Orthodenticle homeobox2 (OTX2 is frequently dysregulated in multiple MB variants; however, its role may be subtype specific. We recently demonstrated that neural precursors derived from transformed human embryonic stem cells (trans-hENs, but not their normal counterparts (hENs, resemble Groups 3 and 4 MB in vitro and in vivo. Here, we tested the utility of this model system as a means of dissecting the role of OTX2 in MB using gain- and loss-of-function studies in hENs and trans-hENs, respectively. Parallel experiments with MB cells revealed that OTX2 exerts inhibitory effects on hEN and SHH MB cells by regulating growth, self-renewal and migration in vitro and tumor growth in vivo. This was accompanied by decreased expression of pluripotent genes, such as SOX2, and was supported by overexpression of SOX2 in OTX2+ SHH MB and hENs that resulted in significant rescue of self-renewal and cell migration. By contrast, OTX2 is oncogenic and promotes self-renewal of trans-hENs and Groups 3 and 4 MB independent of pluripotent gene expression. Our results demonstrate a novel role for OTX2 in self-renewal and migration of hENs and MB cells and reveal a cell-context-dependent link between OTX2 and pluripotent genes. Our study underscores the value of human embryonic stem cell derivatives as alternatives to cell lines and heterogeneous patient samples for investigating the contribution of key developmental regulators to MB progression.

  6. Effective long-term immunosuppression in rats by subcutaneously implanted sustained-release tacrolimus pellet: Effect on spinally grafted human neural precursor survival

    Czech Academy of Sciences Publication Activity Database

    Ševc, J.; Goldberg, D.; van Gorp, S.; Leerink, M.; Juhás, Štefan; Juhásová, Jana; Marsala, S.; Hruška-Plocháň, Marian; Hefferan, M. P.; Motlík, Jan; Rypáček, František; Machová, Luďka; Kakinohana, O.; Santucci, C.; Johe, K.; Lukáčová, N.; Yamada, K.; Bui, J. D.; Marsala, M.

    2013-01-01

    Roč. 248, October (2013), s. 85-99 ISSN 0014-4886 R&D Projects: GA TA ČR TA01011466; GA MŠk ED2.1.00/03.0124 Institutional support: RVO:67985904 ; RVO:61389013 Keywords : immunosuppression * xenograft * human neural precursors Subject RIV: FH - Neurology; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 4.617, year: 2013

  7. Time Course of Spinal Doublecortin Expression in Developing Rat and Porcine Spinal Cord: Implication in In Vivo Neural Precursor Grafting Studies

    Czech Academy of Sciences Publication Activity Database

    Juhásová, Jana; Juhás, Štefan; Hruška-Plocháň, M.; Doležalová, D.; Holubová, Monika; Strnádel, Ján; Marsala, S.; Motlík, Jan; Marsala, M.

    2015-01-01

    Roč. 35, č. 1 (2015), s. 57-70 ISSN 0272-4340 R&D Projects: GA TA ČR(CZ) TA01011466; GA MŠk ED2.1.00/03.0124 Institutional support: RVO:67985904 Keywords : doublecortin * spinal cord development * spinal neural precursor grafting * minipig * rat * GFAP Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.328, year: 2015

  8. Neural Progenitor Cells Derived from Human Embryonic Stem Cells as an Origin of Dopaminergic Neurons

    Directory of Open Access Journals (Sweden)

    Parinya Noisa

    2015-01-01

    Full Text Available Human embryonic stem cells (hESCs are able to proliferate in vitro indefinitely without losing their ability to differentiate into multiple cell types upon exposure to appropriate signals. Particularly, the ability of hESCs to differentiate into neuronal subtypes is fundamental to develop cell-based therapies for several neurodegenerative disorders, such as Alzheimer’s disease, Huntington’s disease, and Parkinson’s disease. In this study, we differentiated hESCs to dopaminergic neurons via an intermediate stage, neural progenitor cells (NPCs. hESCs were induced to neural progenitor cells by Dorsomorphin, a small molecule that inhibits BMP signalling. The resulting neural progenitor cells exhibited neural bipolarity with high expression of neural progenitor genes and possessed multipotential differentiation ability. CBF1 and bFGF responsiveness of these hES-NP cells suggested their similarity to embryonic neural progenitor cells. A substantial number of dopaminergic neurons were derived from hES-NP cells upon supplementation of FGF8 and SHH, key dopaminergic neuron inducers. Importantly, multiple markers of midbrain neurons were detected, including NURR1, PITX3, and EN1, suggesting that hESC-derived dopaminergic neurons attained the midbrain identity. Altogether, this work underscored the generation of neural progenitor cells that retain the properties of embryonic neural progenitor cells. These cells will serve as an unlimited source for the derivation of dopaminergic neurons, which might be applicable for treating patients with Parkinson’s disease.

  9. Regulated expression of transgenes in embryonic stem cell-derived neural cells.

    Science.gov (United States)

    Lorberbaum, David S; Gottlieb, David

    2011-02-01

    Discovery and characterization of gene promoters, enhancers and repressor binding elements is an important research area in neuroscience. Here, the suitability of embryonic stem cells and their neural derivatives as a model system for this research is investigated. Three neural transgenic constructs (from the Mnx1, Fabp7, and tuba1a genes) that have been validated in transgenic mice were inserted into embryonic stem cells as stable transgenes. These transgenic embryonic stem cells were differentiated into neural cultures and the pattern of transgene expression across a series of inducing conditions determined. The pattern of expression matched that predicted from transgenic mouse experiments for each of the three transgenes. The results show that embryonic stem cells and their neural derivatives comprise a promising model for investigating the mechanisms that control cell- and temporal-specific neural gene transcription. Copyright © 2010 Wiley-Liss, Inc.

  10. Si-O-C ceramic foams derived from polymethylphenylsiloxane precursor with starch as foaming agent

    Czech Academy of Sciences Publication Activity Database

    Černý, Martin; Chlup, Zdeněk; Strachota, Adam; Svítilová, Jaroslava; Schweigstillová, Jana; Halasová, Martina; Rýglová, Šárka

    2015-01-01

    Roč. 35, č. 13 (2015), s. 3427-3436 ISSN 0955-2219 R&D Projects: GA ČR GAP107/12/2445 Institutional support: RVO:67985891 ; RVO:68081723 ; RVO:61389013 Keywords : pyrolysis * ceramic foam * precursor * starch * Si-O-C Subject RIV: JI - Composite Materials; JH - Ceramics, Fire-Resistant Materials and Glass (UFM-A) Impact factor: 2.933, year: 2015

  11. Pre-differentiated GABAergic neural precursor transplants for alleviation of dysesthetic central pain following excitotoxic spinal cord injury

    Directory of Open Access Journals (Sweden)

    Jeung Woon eLee

    2012-05-01

    Full Text Available Intraspinal quisqualic acid (QUIS injury induce (i mechanical and thermal hyperalgesia, (ii progressive self-injurious overgrooming of the affected dermatome. The latter is thought to resemble painful dysesthesia observed in spinal cord injury (SCI patients. We have reported previously loss of endogenous GABA immunoreactive (IR cells in the superficial dorsal horn of QUIS rats 2 weeks post-injury. Further histological evaluation showed that GABA-, glycine-, and synaptic vesicular transporter VIAAT-IR persisted but were substantially decreased in the injured spinal cord. In this study, partially-differentiated GABA-IR embryonic neural precursor cells (NPCs were transplanted into the spinal cord of QUIS rats to reverse overgrooming by replenishing lost inhibitory circuitry. Rat E14 NPCs were predifferentiated in 0.1 ng/ml FGF-2 for 4 hrs prior to transplantation. In vitro immunocytochemistry of transplant cohort showed large population of GABA-IR NPCs that double labeled with nestin but few co-localized with NeuN, indicating partial maturation. Two weeks following QUIS lesion at T12-L1, and following the onset of overgrooming, NPCs were transplanted into the QUIS lesion sites; bovine adrenal fibroblast cells were used as control. Overgrooming was reduced in >55.5% of NPC grafted animals, with inverse relationship between the number of surviving GABA-IR cells and the size of overgrooming. Fibroblast-control animals showed a progressive worsening of overgrooming. At 3 weeks post-transplantation, numerous GABA-, nestin-, and GFAP-IR cells were present in the lesion site. Surviving grafted GABA-IR NPCs were NeuN+ and GFAP-. These results indicate that partially-differentiated NPCs survive and differentiate in vivo into neuronal cells following transplantation into an injured spinal cord. GABA-IR NPC transplants can restore lost dorsal horn inhibitory signaling and are useful in alleviating central pain following SCI.

  12. Growth hormone (GH) is a survival rather than a proliferative factor for embryonic striatal neural precursor cells.

    Science.gov (United States)

    Regalado-Santiago, Citlalli; López-Meraz, María Leonor; Santiago-García, Juan; Fernández-Pomares, Cynthia; Juárez-Aguilar, Enrique

    2013-10-01

    A possible role of GH during central nervous system (CNS) development has been suggested by the presence of this hormone and its receptor in brain areas before its production by the pituitary gland. Although several effects have been reported for GH, the specific role of this hormone during CNS development remains unclear. Here, we examined the effect of GH on proliferation, survival and neurosphere formation in primary cultures of striatal tissue from 14-day-old (E14) mouse embryos. GH receptor gene expression was confirmed by RT-PCR. Primary cultures of embryonic striatal cells were treated with different doses of GH in serum free media, then the number of neurospheres was determined. To examine the GH effect on proliferation and survival of the striatal primary cultures, bromodeoxyuridine (BrdU) and TUNEL immunoreactivity was conducted. In the presence of the epidermal growth factor (EGF), GH increased the formation of neurospheres, with a maximal response at 10 ng/ml, higher doses were inhibitory. In absence of EGF, GH failed to stimulate neurosphere formation. Proliferation rate in the primary striatal cultures was inhibited by 24 or 48 h incubation with GH. However, in the absence of EGF, GH increased BrdU incorporation. GH treatment decreases the rate of apoptosis of nestin and GFAP positive cells in the primary striatal cultures, enhancing neurosphere formation. Our in vitro data demonstrate that GH plays a survival role on the original population of embryonic striatal cells, improving Neural Precursor Cells (NPCs) expansion. We suggest that this GH action could be predominant during striatal neurodevelopment. © 2013.

  13. Plasticity of Calcium Signaling Cascades in Human Embryonic Stem Cell-Derived Neural Precursors

    Czech Academy of Sciences Publication Activity Database

    Forostyak, Oksana; Romanyuk, Nataliya; Verkhratsky, A.; Syková, Eva; Dayanithi, Govindan

    2013-01-01

    Roč. 22, č. 10 (2013), s. 1506-1521 ISSN 1547-3287 R&D Projects: GA ČR GAP304/11/2373; GA ČR(CZ) GBP304/12/G069 Grant - others:FP7(XE) PITN-GA-2008-214003 project AXREGEN; FP7(XE) PITN-GA-2009-237956 project EdU-GLIA Institutional support: RVO:68378041 Keywords : human embryonic stem cells * voltage-operated Ca2+ channels * spontaneous Ca2+ oscillations Subject RIV: FH - Neurology Impact factor: 4.202, year: 2013

  14. Physiology of CA2+ signaling in human embryonic stem cell-derived neural precursors

    Czech Academy of Sciences Publication Activity Database

    Forostyak, Oksana; Romanyuk, Nataliya; Syková, Eva; Dayanithi, Govindan

    2011-01-01

    Roč. 59, S1 (2011), S119-S119 ISSN 0894-1491. [European meeting on Glial Cells in Health and Disease /10./. 13.09.2011-17.09.2011, Prague] R&D Projects: GA ČR(CZ) GAP303/11/0192 Institutional research plan: CEZ:AV0Z50390703 Keywords : calcium signaling * ATP * calcium channels Subject RIV: FH - Neurology

  15. Isolation and characterization of neural crest-derived stem cells from dental pulp of neonatal mice.

    Directory of Open Access Journals (Sweden)

    Kajohnkiart Janebodin

    Full Text Available Dental pulp stem cells (DPSCs are shown to reside within the tooth and play an important role in dentin regeneration. DPSCs were first isolated and characterized from human teeth and most studies have focused on using this adult stem cell for clinical applications. However, mouse DPSCs have not been well characterized and their origin(s have not yet been elucidated. Herein we examined if murine DPSCs are neural crest derived and determined their in vitro and in vivo capacity. DPSCs from neonatal murine tooth pulp expressed embryonic stem cell and neural crest related genes, but lacked expression of mesodermal genes. Cells isolated from the Wnt1-Cre/R26R-LacZ model, a reporter of neural crest-derived tissues, indicated that DPSCs were Wnt1-marked and therefore of neural crest origin. Clonal DPSCs showed multi-differentiation in neural crest lineage for odontoblasts, chondrocytes, adipocytes, neurons, and smooth muscles. Following in vivo subcutaneous transplantation with hydroxyapatite/tricalcium phosphate, based on tissue/cell morphology and specific antibody staining, the clones differentiated into odontoblast-like cells and produced dentin-like structure. Conversely, bone marrow stromal cells (BMSCs gave rise to osteoblast-like cells and generated bone-like structure. Interestingly, the capillary distribution in the DPSC transplants showed close proximity to odontoblasts whereas in the BMSC transplants bone condensations were distant to capillaries resembling dentinogenesis in the former vs. osteogenesis in the latter. Thus we demonstrate the existence of neural crest-derived DPSCs with differentiation capacity into cranial mesenchymal tissues and other neural crest-derived tissues. In turn, DPSCs hold promise as a source for regenerating cranial mesenchyme and other neural crest derived tissues.

  16. Metabolism of cryptic peptides derived from neuropeptide FF precursors: the involvement of insulin-degrading enzyme.

    Science.gov (United States)

    Grasso, Giuseppe; Mielczarek, Przemyslaw; Niedziolka, Magdalena; Silberring, Jerzy

    2014-09-22

    The term "cryptome" refers to the subset of cryptic peptides with bioactivities that are often unpredictable and very different from the parent protein. These cryptic peptides are generated by proteolytic cleavage of proteases, whose identification in vivo can be very challenging. In this work, we show that insulin-degrading enzyme (IDE) is able to degrade specific amino acid sequences present in the neuropeptide pro-NPFFA (NPFF precursor), generating some cryptic peptides that are also observed after incubation with rat brain cortex homogenate. The reported experimental findings support the increasingly accredited hypothesis, according to which, due to its wide substrate selectivity, IDE is involved in a wide variety of physiopathological processes.

  17. Neural differentiation of adipose-derived stem cells isolated from GFP transgenic mice

    International Nuclear Information System (INIS)

    Fujimura, Juri; Ogawa, Rei; Mizuno, Hiroshi; Fukunaga, Yoshitaka; Suzuki, Hidenori

    2005-01-01

    Taking advantage of homogeneously marked cells from green fluorescent protein (GFP) transgenic mice, we have recently reported that adipose-derived stromal cells (ASCs) could differentiate into mesenchymal lineages in vitro. In this study, we performed neural induction using ASCs from GFP transgenic mice and were able to induce these ASCs into neuronal and glial cell lineages. Most of the neurally induced cells showed bipolar or multipolar appearance morphologically and expressed neuronal markers. Electron microscopy revealed their neuronal morphology. Some cells also showed glial phenotypes, as shown immunocytochemically. The present study clearly shows that ASCs derived from GFP transgenic mice differentiate into neural lineages in vitro, suggesting that these cells might provide an ideal source for further neural stem cell research with possible therapeutic application for neurological disorders

  18. Chiral pyrrolidinium salts derived from menthol as precursor – synthesis and properties

    Directory of Open Access Journals (Sweden)

    Janus Ewa

    2017-09-01

    Full Text Available Six new chiral pyrolidinium salts with chiral substituent at quaternary nitrogen atom were synthesized with high overall yields from (--menthol as cheap chiral precursor and were identified by NMR and HRMS spectroscopy. It was shown that anion type had the effect on chemical shift of protons adjacent to quaternary nitrogen atom and physical properties of these salts. Salts with NTf2 or NPf2 were in a liquid state at room temperature and characterized with the highest thermal stability among others. Furthermore, chiral ionic liquid with NTf2 anion was used as solvent in Diels-Alder reaction and gave higher yield and stereoselectivity than in ionic liquids with achiral cations. Synthesized chiral salts have the potential as chiral solvents in synthesis and auxiliaries in analytical methods to improve chiral recognition.

  19. Novel precursor-derived Si-C-N ceramic material for purification application.

    Science.gov (United States)

    Roh, Changhyun; Lee, Sea-Hoon; Francois, Villatte

    2008-02-01

    Metagenomic DNA (gDNA) is an important research topic because uncultivated microorganisms represent an interesting reservoir of genes with potential biotechnological applications. Here we describe a novel Si-C-N chromatography approach of gDNA extraction from environmental samples. Amorphous Si-C-N ceramic was obtained by the pyrolysis of a polymer precursor (polycarbosilazane) at 1350 degrees C in Ar. The purified gDNA fragments were at least 12 kilo base pairs in size and were sufficiently free of contaminants, thus were applicable to both restriction enzyme digestion using five different enzymes and polymerase chain reaction amplification for detecting phylogenetic groups of native microorganisms in environmental samples. This Si-C-N material produces pure gDNA that can be utilized in some of the most common molecular biological procedures applied in the purification step.

  20. ZIF-78 membrane derived from amorphous precursors with permselectivity for cyclohexanone/cyclohexanol mixture

    KAUST Repository

    Fan, Lili

    2014-07-01

    Cyclohexanone and cyclohexanol are products of selective oxidation of cyclohexane. They are important industrial intermediates and difficult to be separated due to their close boiling points. In this work, well-intergrown ZIF-78 membrane was successfully synthesized on the porous silica substrate by secondary growth method and applied for separation of cyclohexanone/cyclohexanol mixture for the first time. Meanwhile, a facile method for seeding procedure was developed by utilizing the amorphous ZIF-78 precursors to provide better-distributed nucleation sites. Both XRD and SEM results confirmed the good quality of the membrane. The pervaporation separation of cyclohexanone/ cyclohexanol mixture were carried out at room temperature with permselectivity of 1:2 and total flux around 8.7 × 10-2 kg m-2 h-1. © 2013 Elsevier Inc. All rights reserved.

  1. File list: ALL.PSC.05.AllAg.mESC_derived_neural_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  8. Current progress in the derivation and therapeutic application of neural stem cells.

    Science.gov (United States)

    Tang, Yuewen; Yu, Pei; Cheng, Lin

    2017-10-12

    Neural stem cells (NSCs) have a unique role in neural regeneration. Cell therapy based on NSC transplantation is a promising tool for the treatment of nervous system diseases. However, there are still many issues and controversies associated with the derivation and therapeutic application of these cells. In this review, we summarize the different sources of NSCs and their derivation methods, including direct isolation from primary tissues, differentiation from pluripotent stem cells and transdifferentiation from somatic cells. We also review the current progress in NSC implantation for the treatment of various neural defects and injuries in animal models and clinical trials. Finally, we discuss potential optimization strategies for NSC derivation and propose urgent challenges to the clinical translation of NSC-based therapies in the near future.

  9. 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.

  10. Preparation and Characterization of Various Activated Carbons Derived From Mixed Precursors Using Phosphoric Acid

    International Nuclear Information System (INIS)

    Daifullah, A.A.M.; Sharaf El-Deen, S.E.A.; Elkhalafawy, A.; Shehata, F.A.; Mahmoud, W.H.

    2008-01-01

    Rice straw (RS) and rice husk (RH), a low-cost agricultural by-products, have been used as a mixed precursor (i.e., RS mixed with RH in 1:1; 1:3 and 3:1 ratios) for the production of novel carbons using phosphoric acid as chemical activation. The raw materials were impregnated with 50% and 70% H 3 PO 4 followed by activation at 500 degree C. The latter proved to be the most effective in producing active carbon with good adsorptive capacity. The resulting carbons were characterized by elemental analysis, infrared spectroscopy, density, SEM and S BET . In general, the resulting carbons showed reasonable surface areas with mainly micropore structure. The adsorption capacity was demonstrated by the isotherms of methylene blue (MB), phenol and iodine from aqueous solution. The adsorption data was found to conform with the Langmuir equation with the concentration range studied, and the monolayer coverage was determined for each of the samples. It was found that surface area is mainly attributed to micropore volume so that phenol adsorption and iodine number correspond well with surface area determined by nitrogen adsorption

  11. Human induced pluripotent stem cell-derived models to investigate human cytomegalovirus infection in neural cells.

    Directory of Open Access Journals (Sweden)

    Leonardo D'Aiuto

    Full Text Available Human cytomegalovirus (HCMV infection is one of the leading prenatal causes of congenital mental retardation and deformities world-wide. Access to cultured human neuronal lineages, necessary to understand the species specific pathogenic effects of HCMV, has been limited by difficulties in sustaining primary human neuronal cultures. Human induced pluripotent stem (iPS cells now provide an opportunity for such research. We derived iPS cells from human adult fibroblasts and induced neural lineages to investigate their susceptibility to infection with HCMV strain Ad169. Analysis of iPS cells, iPS-derived neural stem cells (NSCs, neural progenitor cells (NPCs and neurons suggests that (i iPS cells are not permissive to HCMV infection, i.e., they do not permit a full viral replication cycle; (ii Neural stem cells have impaired differentiation when infected by HCMV; (iii NPCs are fully permissive for HCMV infection; altered expression of genes related to neural metabolism or neuronal differentiation is also observed; (iv most iPS-derived neurons are not permissive to HCMV infection; and (v infected neurons have impaired calcium influx in response to glutamate.

  12. Polysiloxanes derived from the controlled hydrolysis of tetraethoxysilane as precursors to silica for use in ceramic processing

    Science.gov (United States)

    Philipp, Warren H.

    1990-01-01

    Synthesis, properties, and potential applications in ceramic processing for two polysiloxane silica precursors derived from the controlled hydrolysis of tetraethoxysilane (TEOS) are presented. The higher molecular weight TEOS-A is a thick adhesive liquid of viscosity 8000 to 12,000 c.p. having a SiO2 char yield of about 55 percent. The lower molecular weight TEOS-B is a more fluid liquid of viscosity 150 to 200 c.p. having a SiO2 char yield of about 52 percent. The acid catalyzed hydrolysis of TEOS to hydrated silica gel goes through a series of polysiloxane intermediates. The rate of this transition increases with the quantity of water added to the TEOS; thus, for ease of polymer isolation, the amount of water added must be carefully determined so as to produce the desired polymer in a reasonable time. The water to TEOS mole ratio falls in the narrow range of 1.05 for TEOS-A and 0.99 for TEOS-B. Further polymerization or gelation is prevented by storing at -5 C in a freezer. Both polysiloxanes thermoset to a glassy solid at 115 C. The liquid polymers are organic in nature in that they are miscible with toluene and ethanol, slightly souble in heptane, but immiscible with water. For both polymers, results on viscosity versus time are given at several temperatures and water additions. Based on these results, some examples of practical utilization of the precursors for ceramic fabrication are given.

  13. Directed differentiation of porcine epiblast-derived neural progenitor cells into neurons and glia

    DEFF Research Database (Denmark)

    Rasmussen, Mikkel Aabech; Hall, Vanessa Jane; Carter, T.F.

    2011-01-01

    Neural progenitor cells (NPCs) are promising candidates for cell-based therapy of neurodegenerative diseases; however, safety concerns must be addressed through transplantation studies in large animal models, such as the pig. The aim of this study was to derive NPCs from porcine blastocysts...

  14. Activation of different neural precursor populations in the adult hippocampus: does this lead to new neurons with discrete functions?

    Science.gov (United States)

    Jhaveri, Dhanisha J; Taylor, Chanel J; Bartlett, Perry F

    2012-07-01

    Resident populations of stem and precursor cells drive the production of new neurons in the adult hippocampus. Recent discoveries have highlighted that a large proportion of these precursor cells are in fact quiescent and can be activated by distinct neuronal activity under both normal physiological and pathological conditions. As growing evidence indicates that newborn neurons play a critical role in cognitive functions such as learning and memory and in mood regulation, it is paramount that we obtain a better understanding of how the reservoirs of stem and precursor cells are maintained and activated. In this review, we critically examine the roles of key molecular mechanisms that have been shown to regulate hippocampal precursor cells, especially their activation. We believe that understanding the mechanistic details of the activity-driven regulation of precursor cells will equip us with the ability to develop tailored strategies to trigger the generation of new neurons, thereby improving the functional outcomes in various neurological and psychiatric conditions. Copyright © 2012 Wiley Periodicals, Inc.

  15. Functional integration of grafted neural stem cell-derived dopaminergic neurons monitored by optogenetics in an in vitro Parkinson model

    DEFF Research Database (Denmark)

    Tønnesen, Jan; Parish, Clare L; Sørensen, Andreas T

    2011-01-01

    Intrastriatal grafts of stem cell-derived dopamine (DA) neurons induce behavioral recovery in animal models of Parkinson's disease (PD), but how they functionally integrate in host neural circuitries is poorly understood. Here, Wnt5a-overexpressing neural stem cells derived from embryonic ventral...

  16. Enhanced growth of neural networks on conductive cellulose-derived nanofibrous scaffolds

    International Nuclear Information System (INIS)

    Kuzmenko, Volodymyr; Kalogeropoulos, Theodoros; Thunberg, Johannes; Johannesson, Sara; Hägg, Daniel; Enoksson, Peter; Gatenholm, Paul

    2016-01-01

    The problem of recovery from neurodegeneration needs new effective solutions. Tissue engineering is viewed as a prospective approach for solving this problem since it can help to develop healthy neural tissue using supportive scaffolds. This study presents effective and sustainable tissue engineering methods for creating biomaterials from cellulose that can be used either as scaffolds for the growth of neural tissue in vitro or as drug screening models. To reach this goal, nanofibrous electrospun cellulose mats were made conductive via two different procedures: carbonization and addition of multi-walled carbon nanotubes. The resulting scaffolds were much more conductive than untreated cellulose material and were used to support growth and differentiation of SH-SY5Y neuroblastoma cells. The cells were evaluated by scanning electron microscopy and confocal microscopy methods over a period of 15 days at different time points. The results showed that the cellulose-derived conductive scaffolds can provide support for good cell attachment, growth and differentiation. The formation of a neural network occurred within 10 days of differentiation, which is a promising length of time for SH-SY5Y neuroblastoma cells. - Highlights: • The conductive scaffolds for neural tissue engineering are derived from cellulose. • The scaffolds are used to support growth and differentiation of SH-SY5Y cells. • Distinctive cell differentiation occurs within 10 days on conductive scaffolds. • Electrical conductivity and nanotopography improve neural network formation.

  17. Hair Follicle and Sebaceous Gland De Novo Regeneration With Cultured Epidermal Stem Cells and Skin-Derived Precursors.

    Science.gov (United States)

    Wang, Xiaoxiao; Wang, Xusheng; Liu, Jianjun; Cai, Ting; Guo, Ling; Wang, Shujuan; Wang, Jinmei; Cao, Yanpei; Ge, Jianfeng; Jiang, Yuyang; Tredget, Edward E; Cao, Mengjun; Wu, Yaojiong

    2016-12-01

    : Stem cell-based organ regeneration is purported to enable the replacement of impaired organs in the foreseeable future. Here, we demonstrated that a combination of cultured epidermal stem cells (Epi-SCs) derived from the epidermis and skin-derived precursors (SKPs) was capable of reconstituting functional hair follicles and sebaceous glands (SG). When Epi-SCs and SKPs were mixed in a hydrogel and implanted into an excisional wound in nude mice, the Epi-SCs formed de novo epidermis along with hair follicles, and SKPs contributed to dermal papilla in the neogenic hair follicles. Notably, a combination of culture-expanded Epi-SCs and SKPs derived from the adult human scalp were sufficient to generate hair follicles and hair. Bone morphogenetic protein 4, but not Wnts, sustained the expression of alkaline phosphatase in SKPs in vitro and the hair follicle-inductive property in vivo when SKPs were engrafted with neonatal epidermal cells into excisional wounds. In addition, Epi-SCs were capable of differentiating into sebocytes and formed de novo SGs, which excreted lipids as do normal SGs. Thus our results indicate that cultured Epi-SCs and SKPs are sufficient to generate de novo hair follicles and SGs, implying great potential to develop novel bioengineered skin substitutes with appendage genesis capacity. In postpartum humans, skin appendages lost in injury are not regenerated, despite the considerable achievement made in skin bioengineering. In this study, transplantation of a combination of culture-expanded epidermal stem cells and skin-derived progenitors from mice and adult humans led to de novo regeneration of functional hair follicles and sebaceous glands. The data provide transferable knowledge for the development of novel bioengineered skin substitutes with epidermal appendage regeneration capacity. ©AlphaMed Press.

  18. Human-Derived Neurons and Neural Progenitor Cells in High Content Imaging Applications.

    Science.gov (United States)

    Harrill, Joshua A

    2018-01-01

    Due to advances in the fields of stem cell biology and cellular engineering, a variety of commercially available human-derived neurons and neural progenitor cells (NPCs) are now available for use in research applications, including small molecule efficacy or toxicity screening. The use of human-derived neural cells is anticipated to address some of the uncertainties associated with the use of nonhuman culture models or transformed cell lines derived from human tissues. Many of the human-derived neurons and NPCs currently available from commercial sources recapitulate critical process of nervous system development including NPC proliferation, neurite outgrowth, synaptogenesis, and calcium signaling, each of which can be evaluated using high content image analysis (HCA). Human-derived neurons and NPCs are also amenable to culture in multiwell plate formats and thus may be adapted for use in HCA-based screening applications. This article reviews various types of HCA-based assays that have been used in conjunction with human-derived neurons and NPC cultures. This article also highlights instances where lower throughput analysis of neurodevelopmental processes has been performed and which demonstrate a potential for adaptation to higher-throughout imaging methods. Finally, a generic protocol for evaluating neurite outgrowth in human-derived neurons using a combination of immunocytochemistry and HCA is presented. The information provided in this article is intended to serve as a resource for cell model and assay selection for those interested in evaluating neurodevelopmental processes in human-derived cells.

  19. The coding sequence of amyloid-beta precursor protein APP contains a neural-specific promoter element.

    NARCIS (Netherlands)

    Collin, R.W.J.; Martens, G.J.M.

    2006-01-01

    The amyloid-beta precursor protein APP is generally accepted to be involved in the pathology of Alzheimer's disease. Since its physiological role is still unclear, we decided to study the function of APP via stable transgenesis in the amphibian Xenopus laevis. However, the application of constructs

  20. Synergic Effect between Adsorption and Photocatalysis of Metal-Free g-C3N4 Derived from Different Precursors.

    Directory of Open Access Journals (Sweden)

    Huan-Yan Xu

    Full Text Available Graphitic carbon nitride (g-C3N4 used in this work was obtained by heating dicyandiamide and melamine, respectively, at different temperatures. The differences of g-C3N4 derived from different precursors in phase composition, functional group, surface morphology, microstructure, surface property, band gap and specific surface area were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-visible diffuse reflection spectroscopy and BET surface area analyzer, respectively. The photocatalytic discoloration of an active cationic dye, Methylene Blue (MB under visible-light irradiation indicated that g-C3N4 derived from melamine at 500°C (CN-M500 had higher adsorption capacity and better photocatalytic activity than that from dicyandiamide at 500°C (CN-D500, which was attributed to the larger surface area of CN-M500. MB discoloration ratio over CN-M500 was affected by initial MB concentration and photocatalyst dosage. After 120 min reaction time, the blue color of MB solution disappeared completely. Subsequently, based on the measurement of the surface Zeta potentials of CN-M500 at different pHs, an active anionic dye, Methyl Orange (MO was selected as the contrastive target pollutant with MB to reveal the synergic effect between adsorption and photocatalysis. Finally, the photocatalytic mechanism was discussed.

  1. Synergic Effect between Adsorption and Photocatalysis of Metal-Free g-C3N4 Derived from Different Precursors

    Science.gov (United States)

    Xu, Huan-Yan; Wu, Li-Cheng; Zhao, Hang; Jin, Li-Guo; Qi, Shu-Yan

    2015-01-01

    Graphitic carbon nitride (g-C3N4) used in this work was obtained by heating dicyandiamide and melamine, respectively, at different temperatures. The differences of g-C3N4 derived from different precursors in phase composition, functional group, surface morphology, microstructure, surface property, band gap and specific surface area were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-visible diffuse reflection spectroscopy and BET surface area analyzer, respectively. The photocatalytic discoloration of an active cationic dye, Methylene Blue (MB) under visible-light irradiation indicated that g-C3N4 derived from melamine at 500°C (CN-M500) had higher adsorption capacity and better photocatalytic activity than that from dicyandiamide at 500°C (CN-D500), which was attributed to the larger surface area of CN-M500. MB discoloration ratio over CN-M500 was affected by initial MB concentration and photocatalyst dosage. After 120 min reaction time, the blue color of MB solution disappeared completely. Subsequently, based on the measurement of the surface Zeta potentials of CN-M500 at different pHs, an active anionic dye, Methyl Orange (MO) was selected as the contrastive target pollutant with MB to reveal the synergic effect between adsorption and photocatalysis. Finally, the photocatalytic mechanism was discussed. PMID:26565712

  2. Group 13 β-ketoiminate compounds: gallium hydride derivatives as molecular precursors to thin films of Ga2O3.

    Science.gov (United States)

    Pugh, David; Marchand, Peter; Parkin, Ivan P; Carmalt, Claire J

    2012-06-04

    Bis(β-ketoimine) ligands, [R{N(H)C(Me)-CHC(Me)═O}(2)] (L(1)H(2), R = (CH(2))(2); L(2)H(2), R = (CH(2))(3)), linked by ethylene (L(1)) and propylene (L(2)) bridges have been used to form aluminum, gallium, and indium chloride complexes [Al(L(1))Cl] (3), [Ga(L(n))Cl] (4, n = 1; 6, n = 2) and [In(L(n))Cl] (5, n = 1; 7, n = 2). Ligand L(1) has also been used to form a gallium hydride derivative [Ga(L(1))H] (8), but indium analogues could not be made. β-ketoimine ligands, [Me(2)N(CH(2))(3)N(H)C(R')-CHC(R')═O] (L(3)H, R' = Me; L(4)H, R' = Ph), with a donor-functionalized Lewis base have also been synthesized and used to form gallium and indium alkyl complexes, [Ga(L(3))Me(2)] (9) and [In(L(3))Me(2)] (10), which were isolated as oils. The related gallium hydride complexes, [Ga(L(n))H(2)] (11, n = 3; 12, n = 4), were also prepared, but again no indium hydride species could be made. The complexes were characterized mainly by NMR spectroscopy, mass spectrometry, and single crystal X-ray diffraction. The β-ketoiminate gallium hydride compounds (8 and 11) have been used as single-source precursors for the deposition of Ga(2)O(3) by aerosol-assisted (AA)CVD with toluene as the solvent. The quality of the films varied according to the precursor used, with the complex [Ga(L(1))H] (8) giving by far the best quality films. Although the films were amorphous as deposited, they could be annealed at 1000 °C to form crystalline Ga(2)O(3). The films were analyzed by powder XRD, SEM, and EDX.

  3. Rescue of neural crest-derived phenotypes in a zebrafish CHARGE model by Sox10 downregulation

    Science.gov (United States)

    Asad, Zainab; Pandey, Aditi; Babu, Aswini; Sun, Yuhan; Shevade, Kaivalya; Kapoor, Shruti; Ullah, Ikram; Ranjan, Shashi; Scaria, Vinod; Bajpai, Ruchi; Sachidanandan, Chetana

    2016-01-01

    CHD7 mutations are implicated in a majority of cases of the congenital disorder, CHARGE syndrome. CHARGE, an autosomal dominant syndrome, is known to affect multiple tissues including eye, heart, ear, craniofacial nerves and skeleton and genital organs. Using a morpholino-antisense-oligonucleotide-based zebrafish model for CHARGE syndrome, we uncover a complex spectrum of abnormalities in the neural crest and the crest-derived cell types. We report for the first time, defects in myelinating Schwann cells, enteric neurons and pigment cells in a CHARGE model. We also observe defects in the specification of peripheral neurons and the craniofacial skeleton as previously reported. Chd7 morphants have impaired migration of neural crest cells and deregulation of sox10 expression from the early stages. Knocking down Sox10 in the zebrafish CHARGE model rescued the defects in Schwann cells and craniofacial cartilage. Our zebrafish CHARGE model thus reveals important regulatory roles for Chd7 at multiple points of neural crest development viz., migration, fate choice and differentiation and we suggest that sox10 deregulation is an important driver of the neural crest-derived aspects of Chd7 dependent CHARGE syndrome. PMID:27418670

  4. Skin-derived precursors from human subjects with Type 2 diabetes yield dysfunctional vascular smooth muscle cells.

    Science.gov (United States)

    Steinbach, Sarah K; Yau, Terrence M; Ouzounian, Maral; Abdel-Qadir, Husam; Chandy, Mark; Waddell, Thomas K; Husain, Mansoor

    2017-08-01

    Objective : Few methods enable molecular and cellular studies of vascular aging or Type 2 diabetes (T2D). Here, we report a new approach to studying human vascular smooth muscle cell (VSMC) pathophysiology by examining VSMCs differentiated from progenitors found in skin. Approach and results : Skin-derived precursors (SKPs) were cultured from biopsies ( N =164, ∼1 cm 2 ) taken from the edges of surgical incisions of older adults ( N =158; males 72%; mean age 62.7 ± 13 years) undergoing cardiothoracic surgery, and differentiated into VSMCs at high efficiency (>80% yield). The number of SKPs isolated from subjects with T2D was ∼50% lower than those without T2D (cells/g: 0.18 ± 0.03, N =58 versus 0.40 ± 0.05, N =100, P <0.05). Importantly, SKP-derived VSMCs from subjects with T2D had higher Fluo-5F-determined baseline cytosolic Ca 2+ concentrations (AU: 1,968 ± 160, N =7 versus 1,386 ± 170, N =13, P <0.05), and a trend toward greater Ca 2+ cycling responses to norepinephrine (NE) (AUC: 177,207 ± 24,669, N =7 versus 101,537 ± 15,881, N =20, P <0.08) despite a reduced frequency of Ca 2+ cycling (events s -1 cell -1 : 0.011 ± 0.004, N =8 versus 0.021 ± 0.003, N =19, P <0.05) than those without T2D. SKP-derived VSMCs from subjects with T2D also manifest enhanced sensitivity to phenylephrine (PE) in an impedance-based assay (EC 50 nM: 72.3 ± 63.6, N =5 versus 3,684 ± 3,122, N =9, P <0.05), and impaired wound closure in vitro (% closure: 21.9 ± 3.6, N =4 versus 67.0 ± 10.3, N =4, P <0.05). Compared with aortic- and saphenous vein-derived primary VSMCs, SKP-derived VSMCs are functionally distinct, but mirror defects of T2D also exhibited by primary VSMCs. Skin biopsies from older adults yield sufficient SKPs to differentiate VSMCs, which reveal abnormal phenotypes of T2D that survive differentiation and persist even after long-term normoglycemic culture. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  5. Bumetanide promotes neural precursor cell regeneration and dendritic development in the hippocampal dentate gyrus in the chronic stage of cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Wang-shu Xu

    2016-01-01

    Full Text Available Bumetanide has been shown to lessen cerebral edema and reduce the infarct area in the acute stage of cerebral ischemia. Few studies focus on the effects of bumetanide on neuroprotection and neurogenesis in the chronic stage of cerebral ischemia. We established a rat model of cerebral ischemia by injecting endothelin-1 in the left cortical motor area and left corpus striatum. Seven days later, bumetanide 200 µg/kg/day was injected into the lateral ventricle for 21 consecutive days with a mini-osmotic pump. Results demonstrated that the number of neuroblasts cells and the total length of dendrites increased, escape latency reduced, and the number of platform crossings increased in the rat hippocampal dentate gyrus in the chronic stage of cerebral ischemia. These findings suggest that bumetanide promoted neural precursor cell regeneration, dendritic development and the recovery of cognitive function, and protected brain tissue in the chronic stage of ischemia.

  6. Activación de la neurogénesis por el CSF-E en precursores neurales de ratón adulto

    OpenAIRE

    Madrigal Fernández, Miguel Ángel

    2012-01-01

    La activación de la neurogénesis a partir de células progenitoras del cerebro de mamíferos adultos abre una expectativa terapéutica en el campo de la neuroregeneración que requiere un control del proceso de neurogénesis y maduración funcional a partir de los Precursores Neurales. La evolución ontogénica de la composición y propiedades del “Nicho Neurogénico” conduce a una neurogénesis muy limitada en el adulto, que puede ser debida a una carencia de estímulos neurogénicos. El CSF es un factor...

  7. Transplanted Human Stem Cell-Derived Interneuron Precursors Mitigate Mouse Bladder Dysfunction and Central Neuropathic Pain after Spinal Cord Injury.

    Science.gov (United States)

    Fandel, Thomas M; Trivedi, Alpa; Nicholas, Cory R; Zhang, Haoqian; Chen, Jiadong; Martinez, Aida F; Noble-Haeusslein, Linda J; Kriegstein, Arnold R

    2016-10-06

    Neuropathic pain and bladder dysfunction represent significant quality-of-life issues for many spinal cord injury patients. Loss of GABAergic tone in the injured spinal cord may contribute to the emergence of these symptoms. Previous studies have shown that transplantation of rodent inhibitory interneuron precursors from the medial ganglionic eminence (MGE) enhances GABAergic signaling in the brain and spinal cord. Here we look at whether transplanted MGE-like cells derived from human embryonic stem cells (hESC-MGEs) can mitigate the pathological effects of spinal cord injury. We find that 6 months after transplantation into injured mouse spinal cords, hESC-MGEs differentiate into GABAergic neuron subtypes and receive synaptic inputs, suggesting functional integration into host spinal cord. Moreover, the transplanted animals show improved bladder function and mitigation of pain-related symptoms. Our results therefore suggest that this approach may be a valuable strategy for ameliorating the adverse effects of spinal cord injury. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Precursor N-cadherin mediates glial cell line-derived neurotrophic factor-promoted human malignant glioma.

    Science.gov (United States)

    Xiong, Ye; Liu, Liyun; Zhu, Shuang; Zhang, Baole; Qin, Yuxia; Yao, Ruiqin; Zhou, Hao; Gao, Dian Shuai

    2017-04-11

    As the most prevalent primary brain tumor, gliomas are highly metastatic, invasive and are characteristic of high levels of glial cell-line derived neurotrophic factor (GDNF). GDNF is an important factor for invasive glioma cell growth; however, the underlying mechanism involved is unclear. In this study, we affirm a significantly higher expression of the precursor of N-cadherin (proN-cadherin) in most gliomas compared with normal brain tissues. Our findings reveal that GDNF interacts with the extracellular domain of proN-cadherin, which suggests that proN-cadherin mediates GDNF-induced glioma cell migration and invasion. We hypothesize that proN-cadherin might cause homotypic adhesion loss within neighboring cells and at the same time promote heterotypic adhesion within the extracellular matrix (ECM) through a certain mechanism. This study also demonstrates that the interaction between GDNF and proN-cadherin activates specific intracellular signaling pathways; furthermore, GDNF promoted the secretion of matrix metalloproteinase-9 (MMP-9), which degrades the ECM via proN-cadherin. To reach the future goal of developing novel therapies of glioma, this study, reveals a unique mechanism of glioma cell migration and invasion.

  9. Passaged neural stem cell-derived neuronal networks for a portable biosensor.

    Science.gov (United States)

    O'Shaughnessy, Thomas J; Liu, Jinny L; Ma, Wu

    2009-04-15

    We have previously demonstrated a portable biosensor that utilizes networks of mammalian neurons on microelectrode arrays (MEAs) as the sensing element. These neuronal cultures on MEAs are derived from primary neuronal tissues and are short-lived. In order to extend the shelf life of neuronal networks for use in a fieldable sensor technology, a renewable source of networks is needed. Neural stem and progenitor cells are capable of self-renewal and differentiation into functional neuronal networks. The purpose of this study was to develop a strategy for growing passaged neural stem and progenitor cells on MEAs under controlled conditions to produce differentiated neurons and glia comprising functional neuronal networks. Primary and passaged neuroepithelial stem and progenitor cells dissociated from embryonic day 13 rat cortex were seeded on MEAs and maintained with serum-free medium containing basic fibroblast growth factor (bFGF) combined with brain-derived neurotrophic factor (BDNF). These culture conditions lead to abundant neurons, with astrocytes as supportive cells, forming synaptically linked networks of neurons. Spontaneous action potentials were best recorded from networks derived from primary or passaged progenitor cells 4-5 weeks after initial culture. The passaged progenitor cell-derived networks on MEAs responded to the GABA(A) antagonist bicuculline, the NMDA glutamate inhibitor APV, and the non-NMDA glutamate antagonist CNQX indicating active synapses were present. Passaged neural stem and progenitor cell-derived networks on MEAs have properties similar to networks derived from primary neuronal cultures and can serve as a renewable supply of sensor elements for detection of environmental threats.

  10. Comparison of precursor structures of the GGNG peptides derived from the earthworm Eisenia foetida and the leech Hirudo nipponia.

    Science.gov (United States)

    Minakata, H; Ikeda, T; Nagahama, T; Oumi, T; Ukena, K; Matsushima, O; Kawano, T; Kimura, Y

    1999-02-01

    Earthworm and leech cDNAs encoding the GGNG peptides, a family of myotropic peptides, were cloned and examined in this study. Both of the predicted precursor proteins are of polyprotein structure and contain several putative peptides distinct from the GGNG peptides. However, the precursors show organizations distinct from each other and no sequence similarity except for the GGNG peptides.

  11. Lead decreases cell survival, proliferation, and neuronal differentiation of primary cultured adult neural precursor cells through activation of the JNK and p38 MAP kinases

    Science.gov (United States)

    Engstrom, Anna; Wang, Hao; Xia, Zhengui

    2015-01-01

    Adult hippocampal neurogenesis is the process whereby adult neural precursor cells (aNPCs) in the subgranular zone (SGZ) of the dentate gyrus (DG) generate adult-born, functional neurons in the hippocampus. This process is modulated by various extracellular and intracellular stimuli, and the adult-born neurons have been implicated in hippocampus-dependent learning and memory. However, studies on how neurotoxic agents affect this process and the underlying mechanisms are limited. The goal of this study was to determine whether lead, a heavy metal, directly impairs critical processes in adult neurogenesis and to characterize the underlying signaling pathways using primary cultured SGZ-aNPCs isolated from adult mice. We report here that lead significantly increases apoptosis and inhibits proliferation in SGZ-aNPCs. In addition, lead significantly impairs spontaneous neuronal differentiation and maturation. Furthermore, we found that activation of the c-Jun NH2-terminal kinase (JNK) and p38 mitogen activated protein (MAP) kinase signaling pathways are important for lead cytotoxicity. Our data suggest that lead can directly act on adult neural stem cells and impair critical processes in adult hippocampal neurogenesis, which may contribute to its neurotoxicity and adverse effects on cognition in adults. PMID:25967738

  12. Comparative performance analysis of human iPSC-derived and primary neural progenitor cells (NPC grown as neurospheres in vitro

    Directory of Open Access Journals (Sweden)

    Maxi Hofrichter

    2017-12-01

    hiPSC-NPCs-derived neurospheres seem to be useful for DNT evaluation representing early neural development in vitro. More system characterization by compound testing is needed to gain higher confidence in this method.

  13. Processing, Microstructure, and Mechanical Properties of Si3N4/SiC Nanocomposites from Precursor Derived Ceramics

    Science.gov (United States)

    Strong, Kevin Thomas, Jr.

    Polymer-derived ceramics (PDCs) provides a unique processing route to create Si3N4/SiC composites. Silazane precursor polyureasilazane (Ceraset PURS20) produce's an amorphous SiCN ceramic at temperatures of ~800 -- 1200 °C and crystallizes to a Si3N4/SiC nanocomposite at temperatures >1500 °C. A novel processing technique was developed where crosslinked polymers were heat-treated in a reactive NH3 atmosphere to control the stoichiometry of the pyrolyzed SiCN ceramic. Using this technique processing parameters were established to produce SiCN powders that resulted in nanocomposites with approximately 0, 5, 10, 20 and 30 vol. % SiC. Lu2O3 was added to these powders as a sintering aid and were densified using Hot Pressing and Field Assisted Sintering. The sintered nanocomposites resulted in microstructures with multiple-length scales. These length-scales included Si3N4 (0.1 -- 5 microm), SiC (10 -- 100 nm) and the intergranular grain boundary phase (<1 nm). Using a combination of SEM and TEM it was possible to quantify some of these microstructural features such as the size and location of the SiC. Hardness and fracture toughness testing was conducted to compared the room temperature mechanical properties of these resultant microstructures. This research was intended to develop robust processing approaches that can be used to control the nanostructures of Si3N4/SiC composites with significant structural features at multiple length scales. The control of their features and the investigation of their affect on the properties of composites can be used to simulate the affect of the structure on properties. These models can then be used to design optimal microstructures for specific applications.

  14. 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.

  15. [Application of precursor ion scanning method in rapid screening of illegally added phosphodiesterase-5 inhibitors and their unknown derivatives in Chinese traditional patent medicines and health foods].

    Science.gov (United States)

    Sun, Jing; Cao, Ling; Feng, Youlong; Tan, Li

    2014-11-01

    The compounds with similar structure often have similar pharmacological activities. So it is a trend for illegal addition that new derivatives of effective drugs are synthesized to avoid the statutory test. This bring challenges to crack down on illegal addition behavior, however, modified derivatives usually have similar product ions, which allow for precursor ion scanning. In this work, precursor ion scanning mode of a triple quadrupole mass spectrometer was first applied to screen illegally added drugs in complex matrix such as Chinese traditional patent medicines and healthy foods. Phosphodiesterase-5 inhibitors were used as experimental examples. Through the analysis of the structure and mass spectrum characteristics of the compounds, phosphodiesterase-5 inhibitors were classified, and their common product ions were screened by full scan of product ions of typical compounds. Then high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method with precursor ion scanning mode was established based on the optimization of MS parameters. The effect of mass parameters and the choice of fragment ions were also studied. The method was applied to determine actual samples and further refined. The results demonstrated that this method can meet the need of rapid screening of unknown derivatives of phosphodiesterase-5 inhibitors in complex matrix, and prevent unknown derivatives undetected. This method shows advantages in sensitivity, specificity and efficiency, and is worth to be further investigated.

  16. Neural differentiation potential of human bone marrow-derived mesenchymal stromal cells: misleading marker gene expression

    Directory of Open Access Journals (Sweden)

    Montzka Katrin

    2009-03-01

    Full Text Available Abstract Background In contrast to pluripotent embryonic stem cells, adult stem cells have been considered to be multipotent, being somewhat more restricted in their differentiation capacity and only giving rise to cell types related to their tissue of origin. Several studies, however, have reported that bone marrow-derived mesenchymal stromal cells (MSCs are capable of transdifferentiating to neural cell types, effectively crossing normal lineage restriction boundaries. Such reports have been based on the detection of neural-related proteins by the differentiated MSCs. In order to assess the potential of human adult MSCs to undergo true differentiation to a neural lineage and to determine the degree of homogeneity between donor samples, we have used RT-PCR and immunocytochemistry to investigate the basal expression of a range of neural related mRNAs and proteins in populations of non-differentiated MSCs obtained from 4 donors. Results The expression analysis revealed that several of the commonly used marker genes from other studies like nestin, Enolase2 and microtubule associated protein 1b (MAP1b are already expressed by undifferentiated human MSCs. Furthermore, mRNA for some of the neural-related transcription factors, e.g. Engrailed-1 and Nurr1 were also strongly expressed. However, several other neural-related mRNAs (e.g. DRD2, enolase2, NFL and MBP could be identified, but not in all donor samples. Similarly, synaptic vesicle-related mRNA, STX1A could only be detected in 2 of the 4 undifferentiated donor hMSC samples. More significantly, each donor sample revealed a unique expression pattern, demonstrating a significant variation of marker expression. Conclusion The present study highlights the existence of an inter-donor variability of expression of neural-related markers in human MSC samples that has not previously been described. This donor-related heterogeneity might influence the reproducibility of transdifferentiation protocols as

  17. Physical exercise counteracts MPTP-induced changes in neural precursor cell proliferation in the hippocampus and restores spatial learning but not memory performance in the water maze.

    Science.gov (United States)

    Klein, C; Rasińska, J; Empl, L; Sparenberg, M; Poshtiban, A; Hain, E G; Iggena, D; Rivalan, M; Winter, Y; Steiner, B

    2016-07-01

    Parkinson's disease (PD) is characterized by a continuous loss of dopaminergic neurons in the substantia nigra, which not only leads to characteristic motor symptoms but also to cognitive impairments. Physical exercise has been shown to improve hippocampus-dependent cognitive functions in PD patients. Animal studies have demonstrated the involvement of adult hippocampal neurogenesis in exercise-induced improvements of visuo-spatial learning and memory. Here, we investigated the direct impact of voluntary wheel running on hippocampal neurogenesis and spatial learning and memory in the Morris water maze (MWM) using the1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. We also analyzed striatal and hippocampal dopamine transmission and mRNA expression levels of dopamine receptors. We show that MPTP-induced spatial learning deficits were alleviated by short-term physical exercise but not MPTP-induced spatial memory impairments in either exercise intervention group. Neural precursor proliferation was transiently altered in MPTP-treated mice, while the cell survival was increased by exercise. Dopamine was progressively depleted by MPTP and its turnover altered by exercise. In addition, gene expression of dopamine receptor D1/D5 was transiently upregulated following MPTP treatment but not affected by physical exercise. Our findings suggest that physical exercise benefits spatial learning but not memory performance in the MWM after MPTP-induced dopamine depletion by restoring precursor cell proliferation in the hippocampus and influencing dopamine transmission. This adds to the understanding of cognitive decline and mechanisms for potential improvements by physical exercise in PD patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. A zebrafish model of lethal congenital contracture syndrome 1 reveals Gle1 function in spinal neural precursor survival and motor axon arborization.

    Science.gov (United States)

    Jao, Li-En; Appel, Bruce; Wente, Susan R

    2012-04-01

    In humans, GLE1 is mutated in lethal congenital contracture syndrome 1 (LCCS1) leading to prenatal death of all affected fetuses. Although the molecular roles of Gle1 in nuclear mRNA export and translation have been documented, no animal models for this disease have been reported. To elucidate the function of Gle1 in vertebrate development, we used the zebrafish (Danio rerio) model system. gle1 mRNA is maternally deposited and widely expressed. Altering Gle1 using an insertional mutant or antisense morpholinos results in multiple defects, including immobility, small eyes, diminished pharyngeal arches, curved body axis, edema, underdeveloped intestine and cell death in the central nervous system. These phenotypes parallel those observed in LCCS1 human fetuses. Gle1 depletion also results in reduction of motoneurons and aberrant arborization of motor axons. Unexpectedly, the motoneuron deficiency results from apoptosis of neural precursors, not of differentiated motoneurons. Mosaic analyses further indicate that Gle1 activity is required extrinsically in the environment for normal motor axon arborization. Importantly, the zebrafish phenotypes caused by Gle1 deficiency are only rescued by expressing wild-type human GLE1 and not by the disease-linked Fin(Major) mutant form of GLE1. Together, our studies provide the first functional characterization of Gle1 in vertebrate development and reveal its essential role in actively dividing cells. We propose that defective GLE1 function in human LCCS1 results in both neurogenic and non-neurogenic defects linked to the apoptosis of proliferative organ precursors.

  19. Radiation-induced apoptosis of neural precursors cell cultures: early modulation of the response mediated by reactive oxygen and nitrogen species (ROS/RNS)

    International Nuclear Information System (INIS)

    Gisone, P.; Dubner, D.; Robello, E.; Michelin, S.; Perez, M. R.

    2004-01-01

    Apoptosis, the typical mode of radiation-induced cell death in developing Central Nervous System (CNS), is closely related with the oxidative status. Enhanced radiation-induced generation of ROS/RNS has been observed after exposures to low radiation doses leading to cellular amplification of signal transduction and further molecular and cellular radiation-responses. Moreover Nitric oxide (NO) and hydroxyl radical are implicated in dopaminergic neurotoxicity in different parading. This study is an attempt to address the participation of radiation-induced free radicals production, the contribution of endogenous NO generation, and the excitonic pathway, in the radiation-induced apoptosis of neural cortical precursors. Cortical cells obtained from at 17 gestational day (gd) were irradiated with doses from 0,2 Gy to 2 Gy at a dose-rate of 0.3 Gy/m. A significant decrease of Luminol-dependent Chemiluminescence was evident 30 m after irradiation reaching basal levels at 120 m follow for a tendency to increasing values Incubations with Superoxide Dismatuse (SOD) decreased significantly the chemiluminescence in irradiated samples NO content estimated by measuring the stable products NO 2 and NO 3 released to the culture medium in the same period, has shown a time-dependent accumulation from 1 h post-irradiation. the apoptosis, determined 24 h post-irradiation by flow cytometry, morphology and DNA fragmentation revealed a dose-effect relationship with significant differences from 0.4 Gy. The samples pre-treated with 10 mM of N-acetyl cysteine (NAC) a precursor of intracellular GSH synthesis, shown a significant decrease of the apoptosis. Apoptosis was significantly increased in irradiated cells after inhibition of nitric oxide synthase (NOS) byL-NAME. We conclude that ROS/RNS play a pivotal role in the early signaling pathways leading to a radiation-induced cell death. (Author) 40 refs

  20. Non-neural tyrosine hydroxylase, via modulation of endocrine pancreatic precursors, is required for normal development of beta cells in the mouse pancreas.

    Science.gov (United States)

    Vázquez, Patricia; Robles, Ana M; de Pablo, Flora; Hernández-Sánchez, Catalina

    2014-11-01

    Apart from transcription factors, little is known about the molecules that modulate the proliferation and differentiation of pancreatic endocrine cells. The early expression of tyrosine hydroxylase (TH) in a subset of glucagon(+) cells led us to investigate whether catecholamines have a role in beta cell development. We studied the immunohistochemical characteristics of TH-expressing cells in wild-type (Th (+/+) ) mice during early pancreas development, and analysed the endocrine pancreas phenotype of TH-deficient (Th (-/-) ) mice. We also studied the effect of dopamine addition and TH-inhibition on insulin-producing cells in explant cultures. In the mouse pancreas at embryonic day (E)12.5-E13.5, the ∼10% of early glucagon(+) cells that co-expressed TH rarely proliferated and did not express the precursor marker neurogenin 3 at E13.5. The number of insulin(+) cells in the Th (-/-) embryonic pancreas was decreased as compared with wild-type embryos at E13.5. While no changes in pancreatic and duodenal homeobox 1 (PDX1)(+)-progenitor cell number were observed between groups at E12.5, the number of neurogenin 3 and NK2 homeobox 2 (NKX2.2)-expressing cells was reduced in Th (-/-) embryonic pancreas, an effect that occurred in parallel with increased expression of the transcriptional repressor Hes1. The potential role of dopamine as a pro-beta cell stimulus was tested by treating pancreas explants with this catecholamine, which resulted in an increase in total insulin content and insulin(+) cells relative to control explants. A non-neural catecholaminergic pathway appears to modulate the pancreatic endocrine precursor and insulin producing cell neogenesis. This finding may have important implications for approaches seeking to promote the generation of beta cells to treat diabetes.

  1. Human neural progenitors derived from integration-free iPSCs for SCI therapy

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2017-03-01

    Full Text Available As a potentially unlimited autologous cell source, patient induced pluripotent stem cells (iPSCs provide great capability for tissue regeneration, particularly in spinal cord injury (SCI. However, despite significant progress made in translation of iPSC-derived neural progenitor cells (NPCs to clinical settings, a few hurdles remain. Among them, non-invasive approach to obtain source cells in a timely manner, safer integration-free delivery of reprogramming factors, and purification of NPCs before transplantation are top priorities to overcome. In this study, we developed a safe and cost-effective pipeline to generate clinically relevant NPCs. We first isolated cells from patients' urine and reprogrammed them into iPSCs by non-integrating Sendai viral vectors, and carried out experiments on neural differentiation. NPCs were purified by A2B5, an antibody specifically recognizing a glycoganglioside on the cell surface of neural lineage cells, via fluorescence activated cell sorting. Upon further in vitro induction, NPCs were able to give rise to neurons, oligodendrocytes and astrocytes. To test the functionality of the A2B5+ NPCs, we grafted them into the contused mouse thoracic spinal cord. Eight weeks after transplantation, the grafted cells survived, integrated into the injured spinal cord, and differentiated into neurons and glia. Our specific focus on cell source, reprogramming, differentiation and purification method purposely addresses timing and safety issues of transplantation to SCI models. It is our belief that this work takes one step closer on using human iPSC derivatives to SCI clinical settings.

  2. Physiological Plasticity of Neural-Crest-Derived Stem Cells in the Adult Mammalian Carotid Body.

    Science.gov (United States)

    Annese, Valentina; Navarro-Guerrero, Elena; Rodríguez-Prieto, Ismael; Pardal, Ricardo

    2017-04-18

    Adult stem cell plasticity, or the ability of somatic stem cells to cross boundaries and differentiate into unrelated cell types, has been a matter of debate in the last decade. Neural-crest-derived stem cells (NCSCs) display a remarkable plasticity during development. Whether adult populations of NCSCs retain this plasticity is largely unknown. Herein, we describe that neural-crest-derived adult carotid body stem cells (CBSCs) are able to undergo endothelial differentiation in addition to their reported role in neurogenesis, contributing to both neurogenic and angiogenic processes taking place in the organ during acclimatization to hypoxia. Moreover, CBSC conversion into vascular cell types is hypoxia inducible factor (HIF) dependent and sensitive to hypoxia-released vascular cytokines such as erythropoietin. Our data highlight a remarkable physiological plasticity in an adult population of tissue-specific stem cells and could have impact on the use of these cells for cell therapy. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  3. Different Tissue-Derived Stem Cells: A Comparison of Neural Differentiation Capability

    Science.gov (United States)

    Bonaventura, Gabriele; Chamayou, Sandrine; Liprino, Annalisa; Guglielmino, Antonino; Fichera, Michele; Caruso, Massimo; Barcellona, Maria Luisa

    2015-01-01

    Background Stem cells are capable of self-renewal and differentiation into a wide range of cell types with multiple clinical and therapeutic applications. Stem cells are providing hope for many diseases that currently lack effective therapeutic methods, including strokes, Huntington's disease, Alzheimer's and Parkinson's disease. However, the paucity of suitable cell types for cell replacement therapy in patients suffering from neurological disorders has hampered the development of this promising therapeutic approach. Aim The innovative aspect of this study has been to evaluate the neural differentiation capability of different tissue-derived stem cells coming from different tissue sources such as bone marrow, umbilical cord blood, human endometrium and amniotic fluid, cultured under the same supplemented media neuro-transcription factor conditions, testing the expression of neural markers such as GFAP, Nestin and Neurofilaments using the immunofluorescence staining assay and some typical clusters of differentiation such as CD34, CD90, CD105 and CD133 by using the cytofluorimetric test assay. Results Amniotic fluid derived stem cells showed a more primitive phenotype compared to the differentiating potential demonstrated by the other stem cell sources, representing a realistic possibility in the field of regenerative cell therapy suitable for neurodegenerative diseases. PMID:26517263

  4. Different Tissue-Derived Stem Cells: A Comparison of Neural Differentiation Capability.

    Directory of Open Access Journals (Sweden)

    Gabriele Bonaventura

    Full Text Available Stem cells are capable of self-renewal and differentiation into a wide range of cell types with multiple clinical and therapeutic applications. Stem cells are providing hope for many diseases that currently lack effective therapeutic methods, including strokes, Huntington's disease, Alzheimer's and Parkinson's disease. However, the paucity of suitable cell types for cell replacement therapy in patients suffering from neurological disorders has hampered the development of this promising therapeutic approach.The innovative aspect of this study has been to evaluate the neural differentiation capability of different tissue-derived stem cells coming from different tissue sources such as bone marrow, umbilical cord blood, human endometrium and amniotic fluid, cultured under the same supplemented media neuro-transcription factor conditions, testing the expression of neural markers such as GFAP, Nestin and Neurofilaments using the immunofluorescence staining assay and some typical clusters of differentiation such as CD34, CD90, CD105 and CD133 by using the cytofluorimetric test assay.Amniotic fluid derived stem cells showed a more primitive phenotype compared to the differentiating potential demonstrated by the other stem cell sources, representing a realistic possibility in the field of regenerative cell therapy suitable for neurodegenerative diseases.

  5. Neural Stem Cells and Its Derivatives as a New Material for Melanin Inhibition.

    Science.gov (United States)

    Hwang, Insik; Hong, Sunghoi

    2017-12-22

    The pigment molecule, melanin, is produced from melanosomes of melanocytes through melanogenesis, which is a complex process involving a combination of chemical and enzymatically catalyzed reactions. The synthesis of melanin is primarily influenced by tyrosinase (TYR), which has attracted interest as a target molecule for the regulation of pigmentation or depigmentation in skin. Thus, direct inhibitors of TYR activity have been sought from various natural and synthetic materials. However, due to issues with these inhibitors, such as weak or permanent ability for depigmentation, allergy, irritant dermatitis and rapid oxidation, in vitro and in vivo, the development of new materials that inhibit melanin production is essential. A conditioned medium (CM) derived from stem cells contains many cell-secreted factors, such as cytokines, chemokines, growth factors and extracellular vesicles including exosomes. In addition, the secreted factors could negatively regulate melanin production through stimulation of a microenvironment of skin tissue in a paracrine manner, which allows the neural stem cell CM to be explored as a new material for skin depigmentation. In this review, we will summarize the current knowledge regulating depigmentation, and discuss the potential of neural stem cells and their derivatives, as a new material for skin depigmentation.

  6. Using human neural crest-derived progenitor cells to investigate osteogenesis: an in vitro study.

    Science.gov (United States)

    Degistirici, Ozer; Grabellus, Florian; Irsen, Stephan; Schmid, Kurt Werner; Thie, Michael

    2010-04-01

    Human tooth contains a distinct population of neural crest-derived progenitor cells (dNC-PCs) which are known to give rise to specialized daughter cells of an osteogenic lineage. We hypothesised that dNC-PCs could develop into neural crest-derived bone in a self-propagating and extracorporal culture system. Thus, we examined the three-dimensional structure obtained from osteogenic-stimulated dNC-PCs by morphological, biochemical and spectroscopic methods. After the onset of stimulation, cells formed a multilayer with outer cells covering the surface and inner cells secreting a hyaline matrix. With prolonged culture, multilayers contracted and formed a three-dimensional construct which subsequently converted to a calcified mass. Differentiation of progenitor cells was associated with apoptosis. Cell types which survived were smooth muscle actin-positive cells and bone-like cells. The expression of osteoblastic markers and the secretion of a collagenous matrix indicate that the bone cells had acquired their functional phenotype. Furthermore, these cells produced and secreted membrane-bound vesicles into the newly forming matrix. Consequently, an early biomineralized extracellular matrix was found with calcium phosphate deposits being associated with the newly formed collagen matrix framework. The molar calcium-phosphorus-ratio of the mineralized collagen indicated that amorphous calcium phosphate was present within this matrix. The data suggest that stimulated cultures of dNC-PCs are able to recapitulate some processes of the early phase of osteogenesis. Copyright 2009 Elsevier B.V. All rights reserved.

  7. Systemic Central Nervous System (CNS)-targeted Delivery of Neuropeptide Y (NPY) Reduces Neurodegeneration and Increases Neural Precursor Cell Proliferation in a Mouse Model of Alzheimer Disease.

    Science.gov (United States)

    Spencer, Brian; Potkar, Rewati; Metcalf, Jeff; Thrin, Ivy; Adame, Anthony; Rockenstein, Edward; Masliah, Eliezer

    2016-01-22

    Neuropeptide Y (NPY) is one of the most abundant protein transmitters in the central nervous system with roles in a variety of biological functions including: food intake, cardiovascular regulation, cognition, seizure activity, circadian rhythms, and neurogenesis. Reduced NPY and NPY receptor expression is associated with numerous neurodegenerative disorders including Alzheimer disease (AD). To determine whether replacement of NPY could ameliorate some of the neurodegenerative and behavioral pathology associated with AD, we generated a lentiviral vector expressing NPY fused to a brain transport peptide (apoB) for widespread CNS delivery in an APP-transgenic (tg) mouse model of AD. The recombinant NPY-apoB effectively reversed neurodegenerative pathology and behavioral deficits although it had no effect on accumulation of Aβ. The subgranular zone of the hippocampus showed a significant increase in proliferation of neural precursor cells without further differentiation into neurons. The neuroprotective and neurogenic effects of NPY-apoB appeared to involve signaling via ERK and Akt through the NPY R1 and NPY R2 receptors. Thus, widespread CNS-targeted delivery of NPY appears to be effective at reversing the neuronal and glial pathology associated with Aβ accumulation while also increasing NPC proliferation. Overall, increased delivery of NPY to the CNS for AD might be an effective therapy especially if combined with an anti-Aβ therapeutic. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. The role of the N-methyl-D-aspartate receptor in the proliferation of adult hippocampal neural stem and precursor cells.

    Science.gov (United States)

    Taylor, Chanel J; He, RongQiao; Bartlett, Perry F

    2014-04-01

    New neurons are continuously generated from resident pools of neural stem and precursor cells (NSPCs) in the adult brain. There are multiple pathways through which adult neurogenesis is regulated, and here we review the role of the N-methyl-D-aspartate receptor (NMDAR) in regulating the proliferation of NSPCs in the adult hippocampus. Hippocampal-dependent learning tasks, enriched environments, running, and activity-dependent synaptic plasticity, all potently up-regulate hippocampal NSPC proliferation. We first consider the requirement of the NMDAR in activity-dependent synaptic plasticity, and the role the induction of synaptic plasticity has in regulating NSPCs and newborn neurons. We address how specific NMDAR agonists and antagonists modulate proliferation, both in vivo and in vitro, and then review the evidence supporting the hypothesis that NMDARs are present on NSPCs. We believe it is important to understand the mechanisms underlying the activation of adult neurogenesis, given the potential that endogenous stem cell populations have for repopulating the hippocampus with functional new neurons. In conditions such as age-related memory decline, neurodegeneration and psychiatric disease, mature neurons are lost or become defective; as such, stimulating adult neurogenesis may provide a therapeutic strategy to overcome these conditions.

  9. PROBING THE IMPACT OF GAMMA-IRRADIATION ON THE METABOLIC STATE OF NEURAL STEM AND PRECURSOR CELLS USING DUAL-WAVELENGTH INTRINSIC SIGNAL TWO-PHOTON EXCITED FLUORESCENCE.

    Science.gov (United States)

    Krasieva, Tatiana B; Giedzinski, Erich; Tran, Katherine; Lan, Mary; Limoli, Charles L; Tromberg, Bruce J

    2011-07-01

    Two-photon excited fluorescence (TPEF) spectroscopy and imaging were used to investigate the effects of gamma-irradiation on neural stem and precursor cells (NSPCs). While the observed signal from reduced nicotinamide adenine dinucleotide (NADH) was localized to the mitochondria, the signal typically associated with oxidized flavoproteins (Fp) was distributed diffusely throughout the cell. The measured TPEF emission and excitation spectra were similar to the established spectra of NAD(P)H and Fp. Fp fluorescence intensity was markedly increased by addition of the electron transport chain (ETC) modulator menadione to the medium, along with a concomitant decrease in the NAD(P)H signal. Three-dimensional (3D) neurospheres were imaged to obtain the cellular metabolic index (CMI), calculated as the ratio of Fp to NAD(P)H fluorescence intensity. Radiation effects were found to differ between low-dose (≤ 50 cGy) and high-dose (≥ 50 cGy) exposures. Low-dose irradiation caused a marked drop in CMI values accompanied by increased cellular proliferation. At higher doses, both NAD(P)H and Fp signals increased, leading to an overall elevation in CMI values. These findings underscore the complex relationship between radiation dose, metabolic state, and proliferation status in NSPCs and highlight the ability of TPEF spectroscopy and imaging to characterize metabolism in 3D spheroids.

  10. Neural Precursors Exhibit Distinctly Different Patterns of Cell Migration Upon Transplantation During Either the Acute or Chronic Phase of EAE: A Serial MR Imaging Study

    Science.gov (United States)

    Muja, Naser; Cohen, Mikhal E.; Zhang, Jiangyang; Kim, Heechul; Gilad, Assaf A.; Walczak, Piotr; Ben-Hur, Tamir; Bulte, Jeff W.M.

    2011-01-01

    As the complex pathogenesis of multiple sclerosis contributes to spatiotemporal variations in the trophic micromilieu of the central nervous system, the optimal intervention period for cell-replacement therapy must be systematically defined. We applied serial, 3D high-resolution magnetic resonance imaging to transplanted neural precursor cells (NPCs) labeled with superparamagnetic iron oxide nanoparticles and 5-bromo-2-deoxyuridine, and compared the migration pattern of NPCs in acute inflamed (n = 10) versus chronic demyelinated (n = 9) brains of mice induced with experimental allergic encephalomyelitis (EAE). Serial in vivo and ex-vivo 3D magnetic resonance imaging revealed that NPCs migrated 2.5 ± 1.3 mm along the corpus callosum in acute EAE. In chronic EAE, cell migration was slightly reduced (2.3 ± 1.3 mm) and only occurred in the lateral side of transplantation. Surprisingly, in 6/10 acute EAE brains, NPCs were found to migrate in a radial pattern along RECA-1+ cortical blood vessels, in a pattern hitherto only reported for migrating glioblastoma cells. This striking radial biodistribution pattern was not detected in either chronic EAE or disease-free control brains. In both acute and chronic EAE brain, Iba1+ microglia/macrophage number was significantly higher in central nervous system regions containing migrating NPCs. The existence of differential NPC migration patterns is an important consideration for implementing future translational studies in multiple sclerosis patients with variable disease. PMID:21305597

  11. Comparison of neurosphere-like cell clusters derived from dental follicle precursor cells and retinal Müller cells

    DEFF Research Database (Denmark)

    Beck, Hans Christian; Petersen, Jørgen; Felthaus, Oliver

    2011-01-01

    Unrelated cells such as dental follicle precursor cells (DFPCs) and retinal Müller cells (MCs) make spheres after cultivation in serum-replacement medium (SRM). Until today, the relation and molecular processes of sphere formation from different cell types remain undescribed. Thus in this study we...

  12. Fluorine-18 labeling of small molecules: the use of 18F-labeled aryl fluorides derived from no-carrier-added [18F]fluoride as labeling precursors.

    Science.gov (United States)

    Wuest, F

    2007-01-01

    The favourable long-half life, the ease of production and the low energy of the emitted positron make 18F an ideal radionuclide for PET imaging. Radiochemistry of 18F basically relies on two distinctive types of reactions: nucleophilic and electrophilic reactions. All syntheses of 18F-labeled radiotracers are based on either [18F]fluoride ion or [18F]fluorine gas as simple primary labeling precursors which are obtained directly from the cyclotron. They can be applied either directly to the radiosynthesis or they can be transformed into more complex labeling precursors enabling the multi-step build-up of organic tracer molecules. The topic of this review is a survey on the application of several 18F-labeled aryl fluorides as building blocks derived from no-carrier-added (n.c.a.) [18F] fluoride to build up small monomeric PET radiotracers at high specific radioactivity by multi-step synthesis procedures.

  13. Derivative-free neural network for optimizing the scoring functions associated with dynamic programming of pairwise-profile alignment.

    Science.gov (United States)

    Yamada, Kazunori D

    2018-01-01

    A profile-comparison method with position-specific scoring matrix (PSSM) is among the most accurate alignment methods. Currently, cosine similarity and correlation coefficients are used as scoring functions of dynamic programming to calculate similarity between PSSMs. However, it is unclear whether these functions are optimal for profile alignment methods. By definition, these functions cannot capture nonlinear relationships between profiles. Therefore, we attempted to discover a novel scoring function, which was more suitable for the profile-comparison method than existing functions, using neural networks. Although neural networks required derivative-of-cost functions, the problem being addressed in this study lacked them. Therefore, we implemented a novel derivative-free neural network by combining a conventional neural network with an evolutionary strategy optimization method used as a solver. Using this novel neural network system, we optimized the scoring function to align remote sequence pairs. Our results showed that the pairwise-profile aligner using the novel scoring function significantly improved both alignment sensitivity and precision relative to aligners using existing functions. We developed and implemented a novel derivative-free neural network and aligner (Nepal) for optimizing sequence alignments. Nepal improved alignment quality by adapting to remote sequence alignments and increasing the expressiveness of similarity scores. Additionally, this novel scoring function can be realized using a simple matrix operation and easily incorporated into other aligners. Moreover our scoring function could potentially improve the performance of homology detection and/or multiple-sequence alignment of remote homologous sequences. The goal of the study was to provide a novel scoring function for profile alignment method and develop a novel learning system capable of addressing derivative-free problems. Our system is capable of optimizing the performance of other

  14. ADAM10 is essential for cranial neural crest-derived maxillofacial bone development

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Yu, E-mail: tanyu2048@163.com; Fu, Runqing, E-mail: furunqing@sjtu.edu.cn; Liu, Jiaqiang, E-mail: liujqmj@163.com; Wu, Yong, E-mail: wyonger@gmail.com; Wang, Bo, E-mail: wb228@126.com; Jiang, Ning, E-mail: 179639060@qq.com; Nie, Ping, E-mail: nieping1011@sina.com; Cao, Haifeng, E-mail: 0412chf@163.com; Yang, Zhi, E-mail: wcums1981@163.com; Fang, Bing, E-mail: fangbing@sjtu.edu.cn

    2016-07-08

    Growth disorders of the craniofacial bones may lead to craniofacial deformities. The majority of maxillofacial bones are derived from cranial neural crest cells via intramembranous bone formation. Any interruption of the craniofacial skeleton development process might lead to craniofacial malformation. A disintegrin and metalloprotease (ADAM)10 plays an essential role in organ development and tissue integrity in different organs. However, little is known about its function in craniofacial bone formation. Therefore, we investigated the role of ADAM10 in the developing craniofacial skeleton, particularly during typical mandibular bone development. First, we showed that ADAM10 was expressed in a specific area of the craniofacial bone and that the expression pattern dynamically changed during normal mouse craniofacial development. Then, we crossed wnt1-cre transgenic mice with adam10-flox mice to generate ADAM10 conditional knockout mice. The stereomicroscopic, radiographic, and von Kossa staining results showed that conditional knockout of ADAM10 in cranial neural crest cells led to embryonic death, craniofacial dysmorphia and bone defects. Furthermore, we demonstrated that impaired mineralization could be triggered by decreased osteoblast differentiation, increased cell death. Overall, these findings show that ADAM10 plays an essential role in craniofacial bone development. -- Highlights: •We firstly reported that ADAM10 was essentially involved in maxillofacial bone development. •ADAM10 cKO mice present craniofacial dysmorphia and bone defects. •Impaired osteoblast differentiation,proliferation and apoptosis underlie the bone deformity.

  15. Robust synchronization of coupled neural oscillators using the derivative-free nonlinear Kalman Filter.

    Science.gov (United States)

    Rigatos, Gerasimos

    2014-12-01

    A synchronizing control scheme for coupled neural oscillators of the FitzHugh-Nagumo type is proposed. Using differential flatness theory the dynamical model of two coupled neural oscillators is transformed into an equivalent model in the linear canonical (Brunovsky) form. A similar linearized description is succeeded using differential geometry methods and the computation of Lie derivatives. For such a model it becomes possible to design a state feedback controller that assures the synchronization of the membrane's voltage variations for the two neurons. To compensate for disturbances that affect the neurons' model as well as for parametric uncertainties and variations a disturbance observer is designed based on Kalman Filtering. This consists of implementation of the standard Kalman Filter recursion on the linearized equivalent model of the coupled neurons and computation of state and disturbance estimates using the diffeomorphism (relations about state variables transformation) provided by differential flatness theory. After estimating the disturbance terms in the neurons' model their compensation becomes possible. The performance of the synchronization control loop is tested through simulation experiments.

  16. The Effects of Low-Dose Bisphenol A and Bisphenol F on Neural Differentiation of a Fetal Brain-Derived Neural Progenitor Cell Line.

    Science.gov (United States)

    Fujiwara, Yuki; Miyazaki, Wataru; Koibuchi, Noriyuki; Katoh, Takahiko

    2018-01-01

    Environmental chemicals are known to disrupt the endocrine system in humans and to have adverse effects on several organs including the developing brain. Recent studies indicate that exposure to environmental chemicals during gestation can interfere with neuronal differentiation, subsequently affecting normal brain development in newborns. Xenoestrogen, bisphenol A (BPA), which is widely used in plastic products, is one such chemical. Adverse effects of exposure to BPA during pre- and postnatal periods include the disruption of brain function. However, the effect of BPA on neural differentiation remains unclear. In this study, we explored the effects of BPA or bisphenol F (BPF), an alternative compound for BPA, on neural differentiation using ReNcell, a human fetus-derived neural progenitor cell line. Maintenance in growth factor-free medium initiated the differentiation of ReNcell to neuronal cells including neurons, astrocytes, and oligodendrocytes. We exposed the cells to BPA or BPF for 3 days from the period of initiation and performed real-time PCR for neural markers such as β III-tubulin and glial fibrillary acidic protein (GFAP), and Olig2. The β III-tubulin mRNA level decreased in response to BPA, but not BPF, exposure. We also observed that the number of β III-tubulin-positive cells in the BPA-exposed group was less than that of the control group. On the other hand, there were no changes in the MAP2 mRNA level. These results indicate that BPA disrupts neural differentiation in human-derived neural progenitor cells, potentially disrupting brain development.

  17. The Effects of Low-Dose Bisphenol A and Bisphenol F on Neural Differentiation of a Fetal Brain-Derived Neural Progenitor Cell Line

    Directory of Open Access Journals (Sweden)

    Yuki Fujiwara

    2018-02-01

    Full Text Available Environmental chemicals are known to disrupt the endocrine system in humans and to have adverse effects on several organs including the developing brain. Recent studies indicate that exposure to environmental chemicals during gestation can interfere with neuronal differentiation, subsequently affecting normal brain development in newborns. Xenoestrogen, bisphenol A (BPA, which is widely used in plastic products, is one such chemical. Adverse effects of exposure to BPA during pre- and postnatal periods include the disruption of brain function. However, the effect of BPA on neural differentiation remains unclear. In this study, we explored the effects of BPA or bisphenol F (BPF, an alternative compound for BPA, on neural differentiation using ReNcell, a human fetus-derived neural progenitor cell line. Maintenance in growth factor-free medium initiated the differentiation of ReNcell to neuronal cells including neurons, astrocytes, and oligodendrocytes. We exposed the cells to BPA or BPF for 3 days from the period of initiation and performed real-time PCR for neural markers such as β III-tubulin and glial fibrillary acidic protein (GFAP, and Olig2. The β III-tubulin mRNA level decreased in response to BPA, but not BPF, exposure. We also observed that the number of β III-tubulin-positive cells in the BPA-exposed group was less than that of the control group. On the other hand, there were no changes in the MAP2 mRNA level. These results indicate that BPA disrupts neural differentiation in human-derived neural progenitor cells, potentially disrupting brain development.

  18. Deriving margins in prostate cancer radiotherapy treatment: comparison of neural network and fuzzy logic models.

    Science.gov (United States)

    Mzenda, Bongile; Gegov, Alexander; Brown, David J; Petrov, Nedyalko

    2012-01-01

    This study investigates the feasibility of using Artificial Neural Network (ANN) and fuzzy logic based techniques to select treatment margins for dynamically moving targets in the radiotherapy treatment of prostate cancer. The use of data from 15 patients relating error effects to the Tumour Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) radiobiological indices was contrasted against the use of data based on the prostate volume receiving 99% of the prescribed dose (V99%) and the rectum volume receiving more than 60Gy (V60). For the same input data, the results of the ANN were compared to results obtained using a fuzzy system, a fuzzy network and current clinically used statistical techniques. Compared to fuzzy and statistical methods, the ANN derived margins were found to be up to 2 mm larger at small and high input errors and up to 3.5 mm larger at medium input error magnitudes.

  19. Roles of chromatin remodelers in maintenance mechanisms of multipotency of mouse trunk neural crest cells in the formation of neural crest-derived stem cells.

    Science.gov (United States)

    Fujita, Kyohei; Ogawa, Ryuhei; Kawawaki, Syunsaku; Ito, Kazuo

    2014-08-01

    We analyzed roles of two chromatin remodelers, Chromodomain Helicase DNA-binding protein 7 (CHD7) and SWItch/Sucrose NonFermentable-B (SWI/SNF-B), and Bone Morphogenetic Protein (BMP)/Wnt signaling in the maintenance of the multipotency of mouse trunk neural crest cells, leading to the formation of mouse neural crest-derived stem cells (mouse NCSCs). CHD7 was expressed in the undifferentiated neural crest cells and in the dorsal root ganglia (DRG) and sciatic nerve, typical tissues containing NCSCs. BMP/Wnt signaling stimulated the expression of CHD7 and participated in maintaining the multipotency of neural crest cells. Furthermore, the promotion of CHD7 expression maintained the multipotency of these cells. The inhibition of CHD7 and SWI/SNF-B expression significantly suppressed the maintenance of the multipotency of these cells. In addition, BMP/Wnt treatment promoted CHD7 expression and caused the increase of the percentage of multipotent cells in DRG. Thus, the present data suggest that the chromatin remodelers as well as BMP/Wnt signaling play essential roles in the maintenance of the multipotency of mouse trunk neural crest cells and in the formation of mouse NCSCs. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Novel Peripherally Derived Neural-Like Stem Cells as Therapeutic Carriers for Treating Glioblastomas.

    Science.gov (United States)

    Birbrair, Alexander; Sattiraju, Anirudh; Zhu, Dongqin; Zulato, Gilberto; Batista, Izadora; Nguyen, Van T; Messi, Maria Laura; Solingapuram Sai, Kiran Kumar; Marini, Frank C; Delbono, Osvaldo; Mintz, Akiva

    2017-02-01

    Glioblastoma (GBM), an aggressive grade IV astrocytoma, is the most common primary malignant adult brain tumor characterized by extensive invasiveness, heterogeneity, and angiogenesis. Standard treatment options such as radiation and chemotherapy have proven to be only marginally effective in treating GBM because of its invasive nature. Therefore, extensive efforts have been put forth to develop tumor-tropic stem cells as viable therapeutic vehicles with potential to treat even the most invasive tumor cells that are harbored within areas of normal brain. To this end, we discovered a newly described NG2-expressing cell that we isolated from a distinct pericyte subtype found abundantly in cultures derived from peripheral muscle. In this work, we show the translational significance of these peripherally derived neural-like stem cells (NLSC) and their potential to migrate toward tumors and act as therapeutic carriers. We demonstrate that these NLSCs exhibit in vitro and in vivo GBM tropism. Furthermore, NLSCs did not promote angiogenesis or transform into tumor-associated stromal cells, which are concerns raised when using other common stem cells, such as mesenchymal stem cells and induced neural stem cells, as therapeutic carriers. We also demonstrate the potential of NLSCs to express a prototype therapeutic, tumor necrosis factor α-related apoptosis-inducing ligand and kill GBM cells in vitro. These data demonstrate the therapeutic potential of our newly characterized NLSC against GBM. Stem Cells Translational Medicine 2017;6:471-481. © 2016 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  1. Changes in expression of the long noncoding RNA FMR4 associate with altered gene expression during differentiation of human neural precursor cells

    Directory of Open Access Journals (Sweden)

    Veronica Julia Peschansky

    2015-08-01

    Full Text Available CGG repeat expansions in the Fragile X mental retardation 1 (FMR1 gene are responsible for a family of associated disorders characterized by either intellectual disability and autism (Fragile X Syndrome, FXS, or adult-onset neurodegeneration (Fragile X-associated Tremor/Ataxia Syndrome, FXTAS. However, the FMR1 locus is complex and encodes several long noncoding RNAs (lncRNAs, whose expression is altered by repeat expansion mutations.The role of these lncRNAs is thus far unknown; therefore we investigated the functionality of FMR4, which we previously identified. Full-length expansions of the FMR1 triplet repeat cause silencing of both FMR1 and FMR4, thus we are interested in potential loss-of-function that may add to phenotypic manifestation of FXS. Since the two transcripts do not exhibit cis-regulation of one another, we examined the potential for FMR4 to regulate target genes at distal genomic loci using gene expression microarrays. We identified FMR4-responsive genes, including the methyl-CpG-binding domain protein 4 (MBD4. Furthermore, we found that in differentiating human neural precursor cells (hNPCs, FMR4 expression is developmentally regulated in opposition to expression of both FMR1 (which is expected to share a bidirectional promoter with FMR4 and MBD4.We therefore propose that FMR4’s function is as a gene-regulatory lncRNA and that this transcript may function in normal development. Closer examination of FMR4 increases our understanding of the role of regulatory lncRNA and the consequences of FMR1 repeat expansions.

  2. Oxytoxins, bioactive molecules produced by the marine opisthobranch mollusc Oxynoe olivacea from a diet-derived precursor.

    Science.gov (United States)

    Cimino, G; Crispino, A; Di Marzo, V; Gavagnin, M; Ros, J D

    1990-07-15

    The ethereal extract of the mucous secretion from the opisthobranch mollusc Oxynoe olivacea was examined and found to contain two novel ichthyotoxic compounds, named oxytoxin 1 and 2 (1,2). The structures of 1 and 2 are closely related to the metabolites previously isolated from the alga Caulerpa prolifera. The activity of the most stable compound was studied in order to investigate the possibility of a further biological role for these metabolites, which represent an uncommon example of bioactive molecules produced in vivo from a dietary precursor.

  3. GABA and Gap Junctions in the Development of Synchronized Activity in Human Pluripotent Stem Cell-Derived Neural Networks

    Science.gov (United States)

    Mäkinen, Meeri Eeva-Liisa; Ylä-Outinen, Laura; Narkilahti, Susanna

    2018-01-01

    The electrical activity of the brain arises from single neurons communicating with each other. However, how single neurons interact during early development to give rise to neural network activity remains poorly understood. We studied the emergence of synchronous neural activity in human pluripotent stem cell (hPSC)-derived neural networks simultaneously on a single-neuron level and network level. The contribution of gamma-aminobutyric acid (GABA) and gap junctions to the development of synchronous activity in hPSC-derived neural networks was studied with GABA agonist and antagonist and by blocking gap junctional communication, respectively. We characterized the dynamics of the network-wide synchrony in hPSC-derived neural networks with high spatial resolution (calcium imaging) and temporal resolution microelectrode array (MEA). We found that the emergence of synchrony correlates with a decrease in very strong GABA excitation. However, the synchronous network was found to consist of a heterogeneous mixture of synchronously active cells with variable responses to GABA, GABA agonists and gap junction blockers. Furthermore, we show how single-cell distributions give rise to the network effect of GABA, GABA agonists and gap junction blockers. Finally, based on our observations, we suggest that the earliest form of synchronous neuronal activity depends on gap junctions and a decrease in GABA induced depolarization but not on GABAA mediated signaling. PMID:29559893

  4. GABA and Gap Junctions in the Development of Synchronized Activity in Human Pluripotent Stem Cell-Derived Neural Networks.

    Science.gov (United States)

    Mäkinen, Meeri Eeva-Liisa; Ylä-Outinen, Laura; Narkilahti, Susanna

    2018-01-01

    The electrical activity of the brain arises from single neurons communicating with each other. However, how single neurons interact during early development to give rise to neural network activity remains poorly understood. We studied the emergence of synchronous neural activity in human pluripotent stem cell (hPSC)-derived neural networks simultaneously on a single-neuron level and network level. The contribution of gamma-aminobutyric acid (GABA) and gap junctions to the development of synchronous activity in hPSC-derived neural networks was studied with GABA agonist and antagonist and by blocking gap junctional communication, respectively. We characterized the dynamics of the network-wide synchrony in hPSC-derived neural networks with high spatial resolution (calcium imaging) and temporal resolution microelectrode array (MEA). We found that the emergence of synchrony correlates with a decrease in very strong GABA excitation. However, the synchronous network was found to consist of a heterogeneous mixture of synchronously active cells with variable responses to GABA, GABA agonists and gap junction blockers. Furthermore, we show how single-cell distributions give rise to the network effect of GABA, GABA agonists and gap junction blockers. Finally, based on our observations, we suggest that the earliest form of synchronous neuronal activity depends on gap junctions and a decrease in GABA induced depolarization but not on GABA A mediated signaling.

  5. GABA and Gap Junctions in the Development of Synchronized Activity in Human Pluripotent Stem Cell-Derived Neural Networks

    Directory of Open Access Journals (Sweden)

    Meeri Eeva-Liisa Mäkinen

    2018-03-01

    Full Text Available The electrical activity of the brain arises from single neurons communicating with each other. However, how single neurons interact during early development to give rise to neural network activity remains poorly understood. We studied the emergence of synchronous neural activity in human pluripotent stem cell (hPSC-derived neural networks simultaneously on a single-neuron level and network level. The contribution of gamma-aminobutyric acid (GABA and gap junctions to the development of synchronous activity in hPSC-derived neural networks was studied with GABA agonist and antagonist and by blocking gap junctional communication, respectively. We characterized the dynamics of the network-wide synchrony in hPSC-derived neural networks with high spatial resolution (calcium imaging and temporal resolution microelectrode array (MEA. We found that the emergence of synchrony correlates with a decrease in very strong GABA excitation. However, the synchronous network was found to consist of a heterogeneous mixture of synchronously active cells with variable responses to GABA, GABA agonists and gap junction blockers. Furthermore, we show how single-cell distributions give rise to the network effect of GABA, GABA agonists and gap junction blockers. Finally, based on our observations, we suggest that the earliest form of synchronous neuronal activity depends on gap junctions and a decrease in GABA induced depolarization but not on GABAA mediated signaling.

  6. Neural crest-derived cells with stem cell features can be traced back to multiple lineages in the adult skin

    NARCIS (Netherlands)

    C.E. Wong (Christine); S. Paratore (Sabrina); M.T. Dours-Zimmermann (María); T. Rochat (Thierry); T. Pietri (Thomas); U. Suter (Ueli); D. Zimmermann (Dieter); S. Dufour (Sylvie); J.P. Thiery (Joachim); D.N. Meijer (Dies); C. Beermann (Christopher); Y. Barrandon (Yann); L. Sommer (Lukas)

    2006-01-01

    textabstractGiven their accessibility, multipotent skin-derived cells might be useful for future cell replacement therapies. We describe the isolation of multipotent stem cell-like cells from the adult trunk skin of mice and humans that express the neural crest stem cell markers p75 and Sox10 and

  7. Pharmacological rescue of mitochondrial deficits in iPSC-derived neural cells from patients with familial Parkinson's disease

    DEFF Research Database (Denmark)

    Cooper, Oliver; Seo, Hyemyung; Andrabi, Shaida

    2012-01-01

    Parkinson's disease (PD) is a common neurodegenerative disorder caused by genetic and environmental factors that results in degeneration of the nigrostriatal dopaminergic pathway in the brain. We analyzed neural cells generated from induced pluripotent stem cells (iPSCs) derived from PD patients ...

  8. Monodisperse embedded nanoparticles derived from an atomic metal-dispersed precursor of layered double hydroxide for architectured carbon nanotube formation

    DEFF Research Database (Denmark)

    Tian, Gui-Li; Zhao, Meng-Qiang; Zhang, Bingsen

    2014-01-01

    understood. Herein, the preparation of metal NPs with tunable areal density from layered double hydroxide (LDH) precursors in which the metal cations were pre-dispersed at an atomic scale was explored. Large quantities of mesopores induced by the Kirkendall effect were formed on the as-calcined layered...... double oxide (LDO) flakes. The O atoms bonded with Fe3+ cations were easy to be extracted at a temperature higher than 750 degrees C, which greatly increased the mobility of Fe. Consequently, coalescence of the reduced Fe atoms into large NPs enhanced the Kirkendall effect, leading to the formation....... When the areal density was increased from 0.039 to 0.55, and to 2.1 x 10(15) m(-2), the Fe NPs embedded on the LDO flakes exhibited good catalytic performance for the growth of entangled carbon nanotubes (CNTs), aligned CNTs, and double helical CNTs, respectively. This work provides not only new...

  9. Production of hemizygous and homozygous embryonic stem cell-derived neural progenitor cells from the transgenic alszheimer göttingen minipis

    DEFF Research Database (Denmark)

    Hall, Vanessa Jane; Jacobsen, J.; Gunnarsson, A.

    2011-01-01

    Production of hemizygous and homozygous embryonic stem cell-derived neural progenitor cells from the transgenic alszheimer göttingen minipis......Production of hemizygous and homozygous embryonic stem cell-derived neural progenitor cells from the transgenic alszheimer göttingen minipis...

  10. Proteome and Secretome Characterization of Glioblastoma-Derived Neural Stem Cells.

    Science.gov (United States)

    Okawa, Satoshi; Gagrica, Sladjana; Blin, Carla; Ender, Christine; Pollard, Steven M; Krijgsveld, Jeroen

    2017-04-01

    Glioblastoma multiforme (GBM) (grade IV astrocytoma) is the most common and aggressive primary brain tumor. GBM consists of heterogeneous cell types including a subset of stem cell-like cells thought to sustain tumor growth. These tumor-initiating glioblastoma multiforme-derived neural stem (GNS) cells as well as their genetically normal neural stem (NS) counterparts can be propagated in culture as relatively pure populations. Here, we perform quantitative proteomics to globally characterize and compare total proteome plus the secreted proteome (secretome) between GNS cells and NS cells. Proteins and pathways that distinguish malignant cancer (GNS) stem cells from their genetically normal counterparts (NS cells) might have value as new biomarkers or therapeutic targets. Our analysis identified and quantified ∼7,500 proteins in the proteome and ∼2,000 in the secretome, 447 and 138 of which were differentially expressed, respectively. Notable tumor-associated processes identified using gene set enrichment analysis included: extracellular matrix interactions, focal adhesion, cell motility, and cell signaling. We focused on differentially expressed surface proteins, and identified 26 that participate in ligand-receptor pairs that play a prominent role in tumorigenesis. Immunocytochemistry and immunoblotting confirmed that CD9, a recently identified marker of adult subventricular zone NS cells, was consistently enriched across a larger set of primary GNS cell lines. CD9 may, therefore, have value as a GNS-specific surface marker and a candidate therapeutic target. Altogether, these findings support the notion that increased cell-matrix and cell-cell adhesion molecules play a crucial role in promoting the tumor initiating and infiltrative properties of GNS cells. Stem Cells 2017;35:967-980. © 2016 AlphaMed Press.

  11. Precursors and BRST symmetry

    Science.gov (United States)

    de Boer, Jan; Freivogel, Ben; Kabir, Laurens; Lokhande, Sagar F.

    2017-07-01

    In the AdS/CFT correspondence, bulk information appears to be encoded in the CFT in a redundant way. A local bulk field corresponds to many different non-local CFT operators (precursors). We recast this ambiguity in the language of BRST symmetry, and propose that in the large N limit, the difference between two precursors is a BRST exact and ghost-free term. This definition of precursor ambiguities has the advantage that it generalizes to any gauge theory. Using the BRST formalism and working in a simple model with global symmetries, we re-derive a precursor ambiguity appearing in earlier work. Finally, we show within this model that the obtained ambiguity has the right number of parameters to explain the freedom to localize precursors within different spatial regions of the boundary order by order in the large N expansion.

  12. Andrographolide Promotes Neural Differentiation of Rat Adipose Tissue-Derived Stromal Cells through Wnt/β-Catenin Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Yan Liang

    2017-01-01

    Full Text Available Adipose tissue-derived stromal cells (ADSCs are a high-yield source of pluripotent stem cells for use in cell-based therapies. We explored the effect of andrographolide (ANDRO, one of the ingredients of the medicinal herb extract on the neural differentiation of rat ADSCs and associated molecular mechanisms. We observed that rat ADSCs were small and spindle-shaped and expressed multiple stem cell markers including nestin. They were multipotent as evidenced by adipogenic, osteogenic, chondrogenic, and neural differentiation under appropriate conditions. The proportion of cells exhibiting neural-like morphology was higher, and neurites developed faster in the ANDRO group than in the control group in the same neural differentiation medium. Expression levels of the neural lineage markers MAP2, tau, GFAP, and β-tubulin III were higher in the ANDRO group. ANDRO induced a concentration-dependent increase in Wnt/β-catenin signaling as evidenced by the enhanced expression of nuclear β-catenin and the inhibited form of GSK-3β (pSer9. Thus, this study shows for the first time how by enhancing the neural differentiation of ADSCs we expect that ANDRO pretreatment may increase the efficacy of adult stem cell transplantation in nervous system diseases, but more exploration is needed.

  13. Sensitivity of hiPSC-derived neural stem cells (NSC) to Pyrroloquinoline quinone depends on their developmental stage.

    Science.gov (United States)

    Augustyniak, J; Lenart, J; Zychowicz, M; Lipka, G; Gaj, P; Kolanowska, M; Stepien, P P; Buzanska, L

    2017-12-01

    Pyrroloquinoline quinone (PQQ) is a factor influencing on the mitochondrial biogenesis. In this study the PQQ effect on viability, total cell number, antioxidant capacity, mitochondrial biogenesis and differentiation potential was investigated in human induced Pluripotent Stem Cells (iPSC) - derived: neural stem cells (NSC), early neural progenitors (eNP) and neural progenitors (NP). Here we demonstrated that sensitivity to PQQ is dependent upon its dose and neural stage of development. Induction of the mitochondrial biogenesis by PQQ at three stages of neural differentiation was evaluated at mtDNA, mRNA and protein level. Changes in NRF1, TFAM and PPARGC1A gene expression were observed at all developmental stages, but only at eNP were correlated with the statistically significant increase in the mtDNA copy numbers and enhancement of SDHA, COX-1 protein level. Thus, the "developmental window" of eNP for PQQ-evoked mitochondrial biogenesis is proposed. This effect was independent of high antioxidant capacity of PQQ, which was confirmed in all tested cell populations, regardless of the stage of hiPSC neural differentiation. Furthermore, a strong induction of GFAP, with down regulation of MAP2 gene expression upon PQQ treatment was observed. This indicates a possibility of shifting the balance of cell differentiation in the favor of astroglia, but more research is needed at this point. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Dual function of Slit2 in repulsion and enhanced migration of trunk, but not vagal, neural crest cells

    OpenAIRE

    De Bellard, Maria Elena; Rao, Yi; Bronner-Fraser, Marianne

    2003-01-01

    Neural crest precursors to the autonomic nervous system form different derivatives depending upon their axial level of origin; for example, vagal, but not trunk, neural crest cells form the enteric ganglia of the gut. Here, we show that Slit2 is expressed at the entrance of the gut, which is selectively invaded by vagal, but not trunk, neural crest. Accordingly, only trunk neural crest cells express Robo receptors. In vivo and in vitro experiments demonstrate that trunk, not vagal, crest cell...

  15. A cell junction pathology of neural stem cells leads to abnormal neurogenesis and hydrocephalus

    NARCIS (Netherlands)

    Rodríguez, Esteban M; Guerra, María M; Vío, Karin; González, César; Ortloff, Alexander; Bátiz, Luis F; Rodríguez, Sara; Jara, María C; Muñoz, Rosa I; Ortega, Eduardo; Jaque, Jaime; Guerra, Francisco; Sival, Deborah A; den Dunnen, Wilfred F A; Jiménez, Antonio J; Domínguez-Pinos, María D; Pérez-Fígares, José M; McAllister, James P; Johanson, Conrad

    2012-01-01

    Most cells of the developing mammalian brain derive from the ventricular (VZ) and the subventricular (SVZ) zones. The VZ is formed by the multipotent radial glia/neural stem cells (NSCs) while the SVZ harbors the rapidly proliferative neural precursor cells (NPCs). Evidence from human and animal

  16. Derivation of corneal endothelial cell-like cells from rat neural crest cells in vitro.

    Directory of Open Access Journals (Sweden)

    Chengqun Ju

    Full Text Available The aim of this study was to investigate the feasibility of inducing rat neural crest cells (NCC to differentiate to functional corneal endothelial cell (CEC-like cells in vitro. Rat NCC were induced with adult CEC-derived conditioned medium. Immunofluorescence, flow cytometry and real time RT-PCR assay were used to detect expression of the corneal endothelium differentiation marker N-cadherin and transcription factors FoxC1 and Pitx2. CFDA SE-labeled CEC-like cells were transplanted to the corneal endothelium of a rat corneal endothelium deficiency model, and an eye-down position was maintained for 24 hours to allow cell attachment. The animals were observed for as long as 2 months after surgery and underwent clinical and histological examination. Spindle-like NCC turned to polygonal CEC-like after induction and expressed N-cadherin, FoxC1, Pitx2, zonula occludens-1 and sodium-potassium pump Na(+/K(+ ATPase. The corneas of the experimental group were much clearer than those of the control group and the mean corneal thickness in the experimental group was significantly less than in the control group7, 14, 21 and 28 days after surgery. Confocal microscopy through focusing and histological analysis confirmed that green fluorescence-positive CEC-like cells formed a monolayer covering the Descemet's membrane in the experimental group. In conclusion, CEC-like cells derived from NCCs displayed characters of native CEC, and the induction protocol provides guidance for future human CEC induction from NCC.

  17. Artificial Neural Network for Production of Antioxidant Peptides Derived from Bighead Carp Muscles with Alcalase

    Directory of Open Access Journals (Sweden)

    Lin Li

    2006-01-01

    Full Text Available Controlled enzymatic modification proteins are currently being used as good sources of bioactive protein ingredients, and hydrolysates derived from bighead carp muscles may serve as antioxidants through the control of the processing-related parameters. The antioxidant ability was evaluated with regard to the scavenging effect on free radical DPPH·, OH· and O2 ·–. Due to the robustness, fault tolerance, high computational speed and self--learning ability, artificial neural network (ANN can be employed to build a predictive model for hydrolysis and optimize the hydrolysis variables: pH, temperature, hydrolysis time, muscle/water ratio and enzyme/substrate ratio (E/S for the production of antioxidant peptides. Optimum conditions to achieve the maximum antioxidant ability were obtained. The hydrolysates, which scavenged most effectively the DPPH·, OH· and O2 ·–, were hydrolyzed for 4.8 h with an activity of alcalase of 4.8 AU/kg, for 6 h with 3.84 AU/kg and for 4.3 h with 4.8 AU/kg, at pH=7.5 and 60 °C. Their respective muscle/water ratio was 1:1.9, 1:1.4 and 1:1. The present study confirmed that ANN could be used to simulate the hydrolysis process and predict hydrolysis conditions under which the hydrolysates could show the most effective scavenging ability on DPPH·, OH· and O2 ·–.

  18. Immunization with a Neural-Derived Peptide Protects the Spinal Cord from Apoptosis after Traumatic Injury

    Directory of Open Access Journals (Sweden)

    Roxana Rodríguez-Barrera

    2013-01-01

    Full Text Available Apoptosis is one of the most destructive mechanisms that develop after spinal cord (SC injury. Immunization with neural-derived peptides (INDPs such as A91 has shown to reduce the deleterious proinflammatory response and the amount of harmful compounds produced after SC injury. With the notion that the aforementioned elements are apoptotic inducers, we hypothesized that INDPs would reduce apoptosis after SC injury. In order to test this assumption, adult rats were subjected to SC contusion and immunized either with A91 or phosphate buffered saline (PBS; control group. Seven days after injury, animals were euthanized to evaluate the number of apoptotic cells at the injury site. Apoptosis was evaluated using DAPI and TUNEL techniques; caspase-3 activity was also evaluated. To further elucidate the mechanisms through which A91 exerts this antiapoptotic effects we quantified tumor necrosis factor-alpha (TNF-α. To also demonstrate that the decrease in apoptotic cells correlated with a functional improvement, locomotor recovery was evaluated. Immunization with A91 significantly reduced the number of apoptotic cells and decreased caspase-3 activity and TNF-α concentration. Immunization with A91 also improved the functional recovery of injured rats. The present study shows the beneficial effect of INDPs on preventing apoptosis and provides more evidence on the neuroprotective mechanisms exerted by this strategy.

  19. Automatic Recognition of fMRI-derived Functional Networks using 3D Convolutional Neural Networks.

    Science.gov (United States)

    Zhao, Yu; Dong, Qinglin; Zhang, Shu; Zhang, Wei; Chen, Hanbo; Jiang, Xi; Guo, Lei; Hu, Xintao; Han, Junwei; Liu, Tianming

    2017-06-15

    Current fMRI data modeling techniques such as Independent Component Analysis (ICA) and Sparse Coding methods can effectively reconstruct dozens or hundreds of concurrent interacting functional brain networks simultaneously from the whole brain fMRI signals. However, such reconstructed networks have no correspondences across different subjects. Thus, automatic, effective and accurate classification and recognition of these large numbers of fMRI-derived functional brain networks are very important for subsequent steps of functional brain analysis in cognitive and clinical neuroscience applications. However, this task is still a challenging and open problem due to the tremendous variability of various types of functional brain networks and the presence of various sources of noises. In recognition of the fact that convolutional neural networks (CNN) has superior capability of representing spatial patterns with huge variability and dealing with large noises, in this paper, we design, apply and evaluate a deep 3D CNN framework for automatic, effective and accurate classification and recognition of large number of functional brain networks reconstructed by sparse representation of whole-brain fMRI signals. Our extensive experimental results based on the Human Connectome Project (HCP) fMRI data showed that the proposed deep 3D CNN can effectively and robustly perform functional networks classification and recognition tasks, while maintaining a high tolerance for mistakenly labelled training instances. Our work provides a new deep learning approach for modeling functional connectomes based on fMRI data.

  20. Characterization and molecular profiling of PSEN1 familial Alzheimer's disease iPSC-derived neural progenitors.

    Directory of Open Access Journals (Sweden)

    Andrew A Sproul

    Full Text Available Presenilin 1 (PSEN1 encodes the catalytic subunit of γ-secretase, and PSEN1 mutations are the most common cause of early onset familial Alzheimer's disease (FAD. In order to elucidate pathways downstream of PSEN1, we characterized neural progenitor cells (NPCs derived from FAD mutant PSEN1 subjects. Thus, we generated induced pluripotent stem cells (iPSCs from affected and unaffected individuals from two families carrying PSEN1 mutations. PSEN1 mutant fibroblasts, and NPCs produced greater ratios of Aβ42 to Aβ40 relative to their control counterparts, with the elevated ratio even more apparent in PSEN1 NPCs than in fibroblasts. Molecular profiling identified 14 genes differentially-regulated in PSEN1 NPCs relative to control NPCs. Five of these targets showed differential expression in late onset AD/Intermediate AD pathology brains. Therefore, in our PSEN1 iPSC model, we have reconstituted an essential feature in the molecular pathogenesis of FAD, increased generation of Aβ42/40, and have characterized novel expression changes.

  1. Reversal of Cellular Phenotypes in Neural Cells Derived from Huntington’s Disease Monkey-Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Richard L. Carter

    2014-10-01

    Full Text Available Huntington’s disease (HD is a dominant neurodegenerative disorder caused by the expansion of glutamine residues in the N-terminal region of the huntingtin (HTT protein. The disease results in progressive neuronal loss, leading to motor, cognitive, and psychiatric impairment. Here, we report the establishment of neural progenitor cell (NPC lines derived from induced pluripotent stem cells (iPSCs of transgenic HD monkeys. Upon differentiation to neurons, HD neural cells develop cellular features of HD, including the formation of nuclear inclusions and oligomeric mutant HTT (mHTT aggregates, as well as increased apoptosis. These phenotypes are rescued by genetic suppression of HTT and pharmacological treatment, demonstrating the ability of our HD cell model to respond to therapeutic treatment. The development and reversal of HD-associated phenotypes in neural cells from HD monkeys provides a unique nonhuman primate (NHP model for exploring HD pathogenesis and evaluating therapeutics that could be assessed further in HD monkeys.

  2. Endogenous diterpenes derived from ent-kaurene, a common gibberellin precursor, regulate protonema differentiation of the moss Physcomitrella patens.

    Science.gov (United States)

    Hayashi, Ken-ichiro; Horie, Keisuke; Hiwatashi, Yuji; Kawaide, Hiroshi; Yamaguchi, Shinjiro; Hanada, Atsushi; Nakashima, Tamotsu; Nakajima, Masatoshi; Mander, Lewis N; Yamane, Hisakazu; Hasebe, Mitsuyasu; Nozaki, Hiroshi

    2010-07-01

    Gibberellins (GAs) are a group of diterpene-type plant hormones biosynthesized from ent-kaurene via ent-kaurenoic acid. GAs are ubiquitously present in seed plants. The GA signal is perceived and transduced by the GID1 GA receptor/DELLA repressor pathway. The lycopod Selaginella moellendorffii biosynthesizes GA and has functional GID1-DELLA signaling components. In contrast, no GAs or functionally orthologous GID1-DELLA components have been found in the moss Physcomitrella patens. However, P. patens produces ent-kaurene, a common precursor for GAs, and possesses a functional ent-kaurene synthase, PpCPS/KS. To assess the biological role of ent-kaurene in P. patens, we generated a PpCPS/KS disruption mutant that does not accumulate ent-kaurene. Phenotypic analysis demonstrates that the mutant has a defect in the protonemal differentiation of the chloronemata to caulonemata. Gas chromatography-mass spectrometry analysis shows that P. patens produces ent-kaurenoic acid, an ent-kaurene metabolite in the GA biosynthesis pathway. The phenotypic defect of the disruptant was recovered by the application of ent-kaurene or ent-kaurenoic acid, suggesting that ent-kaurenoic acid, or a downstream metabolite, is involved in protonemal differentiation. Treatment with uniconazole, an inhibitor of ent-kaurene oxidase in GA biosynthesis, mimics the protonemal phenotypes of the PpCPS/KS mutant, which were also restored by ent-kaurenoic acid treatment. Interestingly, the GA(9) methyl ester, a fern antheridiogen, rescued the protonemal defect of the disruption mutant, while GA(3) and GA(4), both of which are active GAs in angiosperms, did not. Our results suggest that the moss P. patens utilizes a diterpene metabolite from ent-kaurene as an endogenous developmental regulator and provide insights into the evolution of GA functions in land plants.

  3. The neuro-glial properties of adipose-derived adult stromal (ADAS) cells are not regulated by Notch 1 and are not derived from neural crest lineage.

    Science.gov (United States)

    Wrage, Philip C; Tran, Thi; To, Khai; Keefer, Edward W; Ruhn, Kelly A; Hong, John; Hattangadi, Supriya; Treviño, Isaac; Tansey, Malú G

    2008-01-16

    We investigated whether adipose-derived adult stromal (ADAS) are of neural crest origin and the extent to which Notch 1 regulates their growth and differentiation. Mouse ADAS cells cultured in media formulated for neural stem cells (NSC) displayed limited capacity for self-renewal, clonogenicity, and neurosphere formation compared to NSC from the subventricular zone in the hippocampus. Although ADAS cells expressed Nestin, GFAP, NSE and Tuj1 in vitro, exposure to NSC differentiation supplements did not induce mature neuronal marker expression. In contrast, in mesenchymal stem cell (MSC) media, ADAS cells retained their ability to proliferate and differentiate beyond 20 passages and expressed high levels of Nestin. In neuritizing cocktails, ADAS cells extended processes, downregulated Nestin expression, and displayed depolarization-induced Ca(2+) transients but no spontaneous or evoked neural network activity on Multi-Electrode Arrays. Deletion of Notch 1 in ADAS cell cultures grown in NSC proliferation medium did not significantly alter their proliferative potential in vitro or the differentiation-induced downregulation of Nestin. Co-culture of ADAS cells with fibroblasts that stably expressed the Notch ligand Jagged 1 or overexpression of the Notch intracellular domain (NICD) did not alter ADAS cell growth, morphology, or cellular marker expression. ADAS cells did not display robust expression of neural crest transcription factors or genes (Sox, CRABP2, and TH); and lineage tracing analyses using Wnt1-Cre;Rosa26R-lacZ or -EYFP reporter mice confirmed that fewer than 2% of the ADAS cell population derived from a Wnt1-positive population during development. In summary, although media formulations optimized for MSCs or NSCs enable expansion of mouse ADAS cells in vitro, we find no evidence that these cells are of neural crest origin, that they can undergo robust terminal differentiation into functionally mature neurons, and that Notch 1 is likely to be a key

  4. Bone Marrow-Derived, Neural-Like Cells Have the Characteristics of Neurons to Protect the Peripheral Nerve in Microenvironment

    Directory of Open Access Journals (Sweden)

    Shi-lei Guo

    2015-01-01

    Full Text Available Effective repair of peripheral nerve defects is difficult because of the slow growth of new axonal growth. We propose that “neural-like cells” may be useful for the protection of peripheral nerve destructions. Such cells should prolong the time for the disintegration of spinal nerves, reduce lesions, and improve recovery. But the mechanism of neural-like cells in the peripheral nerve is still unclear. In this study, bone marrow-derived neural-like cells were used as seed cells. The cells were injected into the distal end of severed rabbit peripheral nerves that were no longer integrated with the central nervous system. Electromyography (EMG, immunohistochemistry, and transmission electron microscopy (TEM were employed to analyze the development of the cells in the peripheral nerve environment. The CMAP amplitude appeared during the 5th week following surgery, at which time morphological characteristics of myelinated nerve fiber formation were observed. Bone marrow-derived neural-like cells could protect the disintegration and destruction of the injured peripheral nerve.

  5. Phenotypic and functional properties of murine thymocytes. II. Quantitation of host- and donor-derived cytolytic T lymphocyte precursors in regenerating radiation bone marrow chimeras

    International Nuclear Information System (INIS)

    Ceredig, R.; McDonald, H.R.

    1982-01-01

    Thymocytes from radiation bone marrow chimeras, in which donor bone marrow and irradiated recipient differed at the Thy-1 locus, were stained by indirect immunofluorescence with monoclonal anti-Thy-1 antibodies and analyzed by flow microfluorometry (FMF). Kinetic studies indicated an early appearance of host-derived (CBA, Thy-1.2 + ) thymocytes, which reaches maximum number of 10 to 20 x 10 6 cells at 12 to 16 days after bone marrow reconstitution. Donor-derived (AKR, Thy-1.1 + ) cells were not detectable until 10 to 12 days after reconstitution; subsequently, they increased exponentially in number until 28 days, when they accounted for essentially all cells in the thymus (50 x 10 6 ). Concomitant with the appearance and disappearance of host-derived cells was a change in their Thy-1 surface phenotype. In particular, the proportion of host cells having a ''mature'' phenotype (weakly Thy-1.2 staining) increased progressively with time after irradiation. Functional studies using a sensitive mixed leukocyte microculture system to quantitate cytolytic T lymphocyte precursors (CTL-P) were also carried out in regenerating chimeric thymuses. Initially, the regenerating thymus contained few CTL-P, but by 4 wk after reconstitution, frequencies similar to control adult thymuses were obtained. Analysis of the CTL-P content of host and donor-derived subpopulations, separated either by appropriate anti-Thy-1 antibody plus complement or by direct cell sorting, indicated that both host- and donor-derived cells contained appreciable numbers of CTL-P. Furthermore, increases in CTL-P frequency of both host and donor subpopulations correlated with changes in their surface Thy-1 phenotype

  6. Phenotypic and functional properties of murine thymocytes. II. Quantitation of host- and donor-derived cytolytic T lymphocyte precursors in regenerating radiation bone marrow chimeras

    Energy Technology Data Exchange (ETDEWEB)

    Ceredig, R.; McDonald, H.R.

    1982-02-01

    Thymocytes from radiation bone marrow chimeras, in which donor bone marrow and irradiated recipient differed at the Thy-1 locus, were stained by indirect immunofluorescence with monoclonal anti-Thy-1 antibodies and analyzed by flow microfluorometry (FMF). Kinetic studies indicated an early appearance of host-derived (CBA, Thy-1.2/sup +/) thymocytes, which reaches maximum number of 10 to 20 x 10/sup 6/ cells at 12 to 16 days after bone marrow reconstitution. Donor-derived (AKR, Thy-1.1/sup +/) cells were not detectable until 10 to 12 days after reconstitution; subsequently, they increased exponentially in number until 28 days, when they accounted for essentially all cells in the thymus (50 x 10/sup 6/). Concomitant with the appearance and disappearance of host-derived cells was a change in their Thy-1 surface phenotype. In particular, the proportion of host cells having a ''mature'' phenotype (weakly Thy-1.2 staining) increased progressively with time after irradiation. Functional studies using a sensitive mixed leukocyte microculture system to quantitate cytolytic T lymphocyte precursors (CTL-P) were also carried out in regenerating chimeric thymuses. Initially, the regenerating thymus contained few CTL-P, but by 4 wk after reconstitution, frequencies similar to control adult thymuses were obtained. Analysis of the CTL-P content of host and donor-derived subpopulations, separated either by appropriate anti-Thy-1 antibody plus complement or by direct cell sorting, indicated that both host- and donor-derived cells contained appreciable numbers of CTL-P. Furthermore, increases in CTL-P frequency of both host and donor subpopulations correlated with changes in their surface Thy-1 phenotype.

  7. IAP-Based Cell Sorting Results in Homogeneous Transplantable Dopaminergic Precursor Cells Derived from Human Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Daniela Lehnen

    2017-10-01

    Full Text Available Human pluripotent stem cell (hPSC-derived mesencephalic dopaminergic (mesDA neurons can relieve motor deficits in animal models of Parkinson's disease (PD. Clinical translation of differentiation protocols requires standardization of production procedures, and surface-marker-based cell sorting is considered instrumental for reproducible generation of defined cell products. Here, we demonstrate that integrin-associated protein (IAP is a cell surface marker suitable for enrichment of hPSC-derived mesDA progenitor cells. Immunomagnetically sorted IAP+ mesDA progenitors showed increased expression of ventral midbrain floor plate markers, lacked expression of pluripotency markers, and differentiated into mature dopaminergic (DA neurons in vitro. Intrastriatal transplantation of IAP+ cells sorted at day 16 of differentiation in a rat model of PD resulted in functional recovery. Grafts from sorted IAP+ mesDA progenitors were more homogeneous in size and DA neuron density. Thus, we suggest IAP-based sorting for reproducible prospective enrichment of mesDA progenitor cells in clinical cell replacement strategies.

  8. The postischemic environment differentially impacts teratoma or tumor formation after transplantation of human embryonic stem cell-derived neural progenitors

    DEFF Research Database (Denmark)

    Seminatore, Christine; Polentes, Jerome; Ellman, Ditte

    2010-01-01

    Risk of tumorigenesis is a major obstacle to human embryonic and induced pluripotent stem cell therapy. Likely linked to the stage of differentiation of the cells at the time of implantation, formation of teratoma/tumors can also be influenced by factors released by the host tissue. We have...... analyzed the relative effects of the stage of differentiation and the postischemic environment on the formation of adverse structures by transplanted human embryonic stem cell-derived neural progenitors....

  9. The Reference Ability Neural Network Study: Life-time stability of reference-ability neural networks derived from task maps of young adults.

    Science.gov (United States)

    Habeck, C; Gazes, Y; Razlighi, Q; Steffener, J; Brickman, A; Barulli, D; Salthouse, T; Stern, Y

    2016-01-15

    Analyses of large test batteries administered to individuals ranging from young to old have consistently yielded a set of latent variables representing reference abilities (RAs) that capture the majority of the variance in age-related cognitive change: Episodic Memory, Fluid Reasoning, Perceptual Processing Speed, and Vocabulary. In a previous paper (Stern et al., 2014), we introduced the Reference Ability Neural Network Study, which administers 12 cognitive neuroimaging tasks (3 for each RA) to healthy adults age 20-80 in order to derive unique neural networks underlying these 4 RAs and investigate how these networks may be affected by aging. We used a multivariate approach, linear indicator regression, to derive a unique covariance pattern or Reference Ability Neural Network (RANN) for each of the 4 RAs. The RANNs were derived from the neural task data of 64 younger adults of age 30 and below. We then prospectively applied the RANNs to fMRI data from the remaining sample of 227 adults of age 31 and above in order to classify each subject-task map into one of the 4 possible reference domains. Overall classification accuracy across subjects in the sample age 31 and above was 0.80±0.18. Classification accuracy by RA domain was also good, but variable; memory: 0.72±0.32; reasoning: 0.75±0.35; speed: 0.79±0.31; vocabulary: 0.94±0.16. Classification accuracy was not associated with cross-sectional age, suggesting that these networks, and their specificity to the respective reference domain, might remain intact throughout the age range. Higher mean brain volume was correlated with increased overall classification accuracy; better overall performance on the tasks in the scanner was also associated with classification accuracy. For the RANN network scores, we observed for each RANN that a higher score was associated with a higher corresponding classification accuracy for that reference ability. Despite the absence of behavioral performance information in the

  10. Structure-activity relationships for novel drug precursor N-substituted-6-acylbenzothiazolon derivatives: A theoretical approach

    Science.gov (United States)

    Sıdır, Yadigar Gülseven; Sıdır, İsa

    2013-08-01

    In this study, the twelve new modeled N-substituted-6-acylbenzothiazolon derivatives having analgesic analog structure have been investigated by quantum chemical methods using a lot of electronic parameters and structure-activity properties; such as molecular polarizability (α), dipole moment (μ), EHOMO, ELUMO, q-, qH+, molecular volume (Vm), ionization potential (IP), electron affinity (EA), electronegativity (χ), molecular hardness (η), molecular softness (S), electrophilic index (ω), heat of formation (HOF), molar refractivity (MR), octanol-water partition coefficient (log P), thermochemical properties (entropy (S), capacity of heat (Cv)); as to investigate activity relationships with molecular structure. The correlations of log P with Vm, MR, ω, EA, EHOMO - ELUMO (ΔE), HOF in aqueous phase, χ, μ, S, η parameters, respectively are obtained, while the linear relation of log P with IP, Cv, HOF in gas phase are not observed. The log P parameter is obtained to be depending on different properties of compounds due to their complexity.

  11. Differentiation defect in neural crest-derived smooth muscle cells in patients with aortopathy associated with bicuspid aortic valves

    Directory of Open Access Journals (Sweden)

    Jiao Jiao

    2016-08-01

    Full Text Available Individuals with bicuspid aortic valves (BAV are at a higher risk of developing thoracic aortic aneurysms (TAA than patients with trileaflet aortic valves (TAV. The aneurysms associated with BAV most commonly involve the ascending aorta and spare the descending aorta. Smooth muscle cells (SMCs in the ascending and descending aorta arise from neural crest (NC and paraxial mesoderm (PM, respectively. We hypothesized defective differentiation of the neural crest stem cells (NCSCs-derived SMCs but not paraxial mesoderm cells (PMCs-derived SMCs contributes to the aortopathy associated with BAV. When induced pluripotent stem cells (iPSCs from BAV/TAA patients were differentiated into NCSC-derived SMCs, these cells demonstrated significantly decreased expression of marker of SMC differentiation (MYH11 and impaired contraction compared to normal control. In contrast, the PMC-derived SMCs were similar to control cells in these aspects. The NCSC-SMCs from the BAV/TAA also showed decreased TGF-β signaling based on phosphorylation of SMAD2, and increased mTOR signaling. Inhibition of mTOR pathway using rapamycin rescued the aberrant differentiation. Our data demonstrates that decreased differentiation and contraction of patient's NCSC-derived SMCs may contribute to that aortopathy associated with BAV.

  12. Study of neuroprotective function of Ginkgo biloba extract (EGb761) derived-flavonoid monomers using a three-dimensional stem cell-derived neural model.

    Science.gov (United States)

    Wu, Yueting; Sun, Jiachen; George, Julian; Ye, Hua; Cui, Zhanfeng; Li, Zhaohui; Liu, Qingxi; Zhang, Yaozhou; Ge, Dan; Liu, Yang

    2016-05-01

    An in vitro three-dimensional (3D) cell culture system that can mimic organ and tissue structure and function in vivo will be of great benefit for drug discovery and toxicity testing. In this study, the neuroprotective properties of the three most prevalent flavonoid monomers extracted from EGb 761 (isorharmnetin, kaempferol, and quercetin) were investigated using the developed 3D stem cell-derived neural co-culture model. Rat neural stem cells were differentiated into co-culture of both neurons and astrocytes at an equal ratio in the developed 3D model and standard two-dimensional (2D) model using a two-step differentiation protocol for 14 days. The level of neuroprotective effect offered by each flavonoid was found to be aligned with its effect as an antioxidant and its ability to inhibit Caspase-3 activity in a dose-dependent manner. Cell exposure to quercetin (100 µM) following oxidative insult provided the highest levels of neuroprotection in both 2D and 3D models, comparable with exposure to 100 µM of Vitamin E, whilst exposure to isorhamnetin and kaempferol provided a reduced level of neuroprotection in both 2D and 3D models. At lower dosages (10 µM flavonoid concentration), the 3D model was more representative of results previously reported in vivo. The co-cultures of stem cell derived neurons and astrocytes in 3D hydrogel scaffolds as an in vitro neural model closely replicates in vivo results for routine neural drug toxicity and efficacy testing. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:735-744, 2016. © 2016 American Institute of Chemical Engineers.

  13. Synaptic network activity induces neuronal differentiation of adult hippocampal precursor cells through BDNF signaling

    Directory of Open Access Journals (Sweden)

    Harish Babu

    2009-09-01

    Full Text Available Adult hippocampal neurogenesis is regulated by activity. But how do neural precursor cells in the hippocampus respond to surrounding network activity and translate increased neural activity into a developmental program? Here we show that long-term potential (LTP-like synaptic activity within a cellular network of mature hippocampal neurons promotes neuronal differentiation of newly generated cells. In co-cultures of precursor cells with primary hippocampal neurons, LTP-like synaptic plasticity induced by addition of glycine in Mg2+-free media for 5 min, produced synchronous network activity and subsequently increased synaptic strength between neurons. Furthermore, this synchronous network activity led to a significant increase in neuronal differentiation from the co-cultured neural precursor cells. When applied directly to precursor cells, glycine and Mg2+-free solution did not induce neuronal differentiation. Synaptic plasticity-induced neuronal differentiation of precursor cells was observed in the presence of GABAergic neurotransmission blockers but was dependent on NMDA-mediated Ca2+ influx. Most importantly, neuronal differentiation required the release of brain-derived neurotrophic factor (BDNF from the underlying substrate hippocampal neurons as well as TrkB receptor phosphorylation in precursor cells. This suggests that activity-dependent stem cell differentiation within the hippocampal network is mediated via synaptically evoked BDNF signaling.

  14. GAS-PHASE SYNTHESIS OF PRECURSORS OF INTERSTELLAR GLYCINE: A COMPUTATIONAL STUDY OF THE REACTIONS OF ACETIC ACID WITH HYDROXYLAMINE AND ITS IONIZED AND PROTONATED DERIVATIVES

    Energy Technology Data Exchange (ETDEWEB)

    Barrientos, Carmen; Redondo, Pilar; Largo, Laura; Rayon, Victor M.; Largo, Antonio, E-mail: alargo@qf.uva.es [Departamento de Quimica Fisica y Quimica Inorganica, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid (Spain)

    2012-04-01

    A computational study of the reactions of hydroxylamine and its ionized and protonated derivatives with acetic acid is provided. The reaction of neutral hydroxylamine with acetic acid, despite being clearly exothermic, involves a very large energy barrier. The reaction of ionized hydroxylamine with acetic acid is also clearly exothermic, but again a significant energy barrier is found (around 24 kcal mol{sup -1} at the CCSD(T) level). The reaction of the most stable protonated isomer of hydroxylamine, NH{sub 3}OH{sup +}, with acetic acid also involves a high barrier (more than 27 kcal mol{sup -1} at the CCSD(T) level). Only the higher energy isomer, NH{sub 2}OH{sup +}{sub 2}, leads to a sensibly lower energy barrier (about 2.3 kcal mol{sup -1} at the CCSD(T) level). Nevertheless, an estimate of the reaction coefficient at low temperatures such as those reigning in the interstellar medium gives very low values. Therefore, it seems that precursors of interstellar glycine could not be efficiently produced from the reactions of hydroxylamine-derived ions with acetic acid.

  15. In Vitro and In Vivo Evaluation of Sol-Gel Derived TiO2 Coatings Based on a Variety of Precursors and Synthesis Conditions

    Directory of Open Access Journals (Sweden)

    Krzysztof Marycz

    2014-01-01

    Full Text Available The effect of synthesis way of TiO2 coatings on biocompatibility of transplanted materials using an in vitro and in vivo rat model was investigated. TiO2 layers were synthesized by a nonaqueous sol-gel dip-coating method on stainless steel 316L substrates applying two different precursors and their combination. Morphology and topography of newly formed biomaterials were determined as well as chemical composition and elemental distribution of a surface samples. In vitro tests were conducted by adipose-derived mesenchymal stem cells cultured on TiO2 coatings and stainless steel without coatings to assess the bioreactivity of obtained materials. A positive biological effect of TiO2/316L/1 coatings—based on titanium(IV ethoxide—was found in both in vitro and in vivo models. The TiO2/316L/1 exhibited the highest roughness and the lowest titanium concentration in TiO2 than TiO2/316L/2—based on titanium(IV propoxide and TiO2/316L/3—based on both above-mentioned precursors. The proper fibroblast-like morphology and higher proliferation rate of cells cultured on TiO2/316L/1 were observed when compared to the other biomaterials. No inflammatory response in the bone surrounding implant covered by each of the obtained TiO2 was present. Our results showed that improvement of routinely used stainless steel 316L with TiO2/316L/1 layer can stimulate beneficial biological response.

  16. Neural retina identity is specified by lens-derived BMP signals.

    Science.gov (United States)

    Pandit, Tanushree; Jidigam, Vijay K; Patthey, Cedric; Gunhaga, Lena

    2015-05-15

    The eye has served as a classical model to study cell specification and tissue induction for over a century. Nevertheless, the molecular mechanisms that regulate the induction and maintenance of eye-field cells, and the specification of neural retina cells are poorly understood. Moreover, within the developing anterior forebrain, how prospective eye and telencephalic cells are differentially specified is not well defined. In the present study, we have analyzed these issues by manipulating signaling pathways in intact chick embryo and explant assays. Our results provide evidence that at blastula stages, BMP signals inhibit the acquisition of eye-field character, but from neural tube/optic vesicle stages, BMP signals from the lens are crucial for the maintenance of eye-field character, inhibition of dorsal telencephalic cell identity and specification of neural retina cells. Subsequently, our results provide evidence that a Rax2-positive eye-field state is not sufficient for the progress to a neural retina identity, but requires BMP signals. In addition, our results argue against any essential role of Wnt or FGF signals during the specification of neural retina cells, but provide evidence that Wnt signals together with BMP activity are sufficient to induce cells of retinal pigment epithelial character. We conclude that BMP activity emanating from the lens ectoderm maintains eye-field identity, inhibits telencephalic character and induces neural retina cells. Our findings link the requirement of the lens ectoderm for neural retina specification with the molecular mechanism by which cells in the forebrain become specified as neural retina by BMP activity. © 2015. Published by The Company of Biologists Ltd.

  17. Neural retina identity is specified by lens-derived BMP signals

    Science.gov (United States)

    Pandit, Tanushree; Jidigam, Vijay K.; Patthey, Cedric; Gunhaga, Lena

    2015-01-01

    The eye has served as a classical model to study cell specification and tissue induction for over a century. Nevertheless, the molecular mechanisms that regulate the induction and maintenance of eye-field cells, and the specification of neural retina cells are poorly understood. Moreover, within the developing anterior forebrain, how prospective eye and telencephalic cells are differentially specified is not well defined. In the present study, we have analyzed these issues by manipulating signaling pathways in intact chick embryo and explant assays. Our results provide evidence that at blastula stages, BMP signals inhibit the acquisition of eye-field character, but from neural tube/optic vesicle stages, BMP signals from the lens are crucial for the maintenance of eye-field character, inhibition of dorsal telencephalic cell identity and specification of neural retina cells. Subsequently, our results provide evidence that a Rax2-positive eye-field state is not sufficient for the progress to a neural retina identity, but requires BMP signals. In addition, our results argue against any essential role of Wnt or FGF signals during the specification of neural retina cells, but provide evidence that Wnt signals together with BMP activity are sufficient to induce cells of retinal pigment epithelial character. We conclude that BMP activity emanating from the lens ectoderm maintains eye-field identity, inhibits telencephalic character and induces neural retina cells. Our findings link the requirement of the lens ectoderm for neural retina specification with the molecular mechanism by which cells in the forebrain become specified as neural retina by BMP activity. PMID:25968316

  18. Cell polarity and neurogenesis in embryonic stem cell-derived neural rosettes.

    Science.gov (United States)

    Banda, Erin; McKinsey, Anna; Germain, Noelle; Carter, James; Anderson, Nickesha Camille; Grabel, Laura

    2015-04-15

    Embryonic stem cells (ESCs) undergoing neural differentiation form radial arrays of neural stem cells, termed neural rosettes. These structures manifest many of the properties associated with embryonic and adult neurogenesis, including cell polarization, interkinetic nuclear migration (INM), and a gradient of neuronal differentiation. We now identify novel rosette structural features that serve to localize key regulators of neurogenesis. Cells within neural rosettes have specialized basal as well as apical surfaces, based on localization of the extracellular matrix receptor β1 integrin. Apical processes of cells in mature rosettes terminate at the lumen, where adherens junctions are apparent. Primary cilia are randomly distributed in immature rosettes and tightly associated with the neural stem cell's apical domain as rosettes mature. Components of two signaling pathways known to regulate neurogenesis in vivo and in rosettes, Hedgehog and Notch, are apically localized, with the Hedgehog effector Smoothened (Smo) associated with primary cilia and the Notch pathway γ-secretase subunit Presenilin 2 associated with the adherens junction. Increased neuron production upon treatment with the Notch inhibitor DAPT suggests a major role for Notch signaling in maintaining the neural stem cell state, as previously described. A less robust outcome was observed with manipulation of Hedgehog levels, though consistent with a role in neural stem cell survival or proliferation. Inhibition of both pathways resulted in an additive effect. These data support a model by which cells extending a process to the rosette lumen maintain neural stem cell identity whereas release from this association, either through asymmetric cell division or apical abscission, promotes neuronal differentiation.

  19. A brain slice culture model for studies of endogenous and exogenous precursor cell migration in the rostral migratory stream

    DEFF Research Database (Denmark)

    Tanvig, Mette; Blaabjerg, Morten; Andersen, Rikke K

    2009-01-01

    week old cultures. For testing the migratory abilities of exogenous precursor cells, rat SVZ neurospheres and human neural (HNS1 cells) and mesenchymal (hMSC-TERT) stem cell lines were micrografted to the rostral SVZ of 1 and 7 day old cultures. Two weeks later graft derivatives were identified...

  20. Focal Transplantation of Human iPSC-Derived Glial-Rich Neural Progenitors Improves Lifespan of ALS Mice

    Directory of Open Access Journals (Sweden)

    Takayuki Kondo

    2014-08-01

    Full Text Available Transplantation of glial-rich neural progenitors has been demonstrated to attenuate motor neuron degeneration and disease progression in rodent models of mutant superoxide dismutase 1 (SOD1-mediated amyotrophic lateral sclerosis (ALS. However, translation of these results into a clinical setting requires a renewable human cell source. Here, we derived glial-rich neural progenitors from human iPSCs and transplanted them into the lumbar spinal cord of ALS mouse models. The transplanted cells differentiated into astrocytes, and the treated mouse group showed prolonged lifespan. Our data suggest a potential therapeutic mechanism via activation of AKT signal. The results demonstrated the efficacy of cell therapy for ALS by the use of human iPSCs as cell source.

  1. In vitro evaluation of inorganic and methyl mercury mediated cytotoxic effect on neural cells derived from different animal species.

    Science.gov (United States)

    Tong, Jing; Wang, Youwei; Lu, Yuanan

    2016-03-01

    To extend the current understanding of the mercury-mediated cytotoxic effect, five neural cell lines established from different animal species were comparatively analyzed using three different endpoint bioassays: thiazolyl blue tetrazolium bromide, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay (MTT), neutral red uptake assay (NRU), and Coomassie blue assay (CB). Following a 24-hr exposure to selected concentrations of mercury chloride (HgCl2) and methylmercury (II) chloride (MeHgCl), the cytotoxic effect on test cells was characterized by comparing their 50% inhibition concentration (IC50) values. Experimental results indicated that both these forms of mercury were toxic to all the neural cells, but at very different degrees. The IC50 values of MeHgCl among these cell lines ranged from 1.15±0.22 to 10.31±0.70μmol/L while the IC50 values for HgCl2 were much higher, ranging from 6.44±0.36 to 160.97±19.63μmol/L, indicating the more toxic nature of MeHgCl. The IC50 ratio between HgCl2 and MeHgCl ranged from 1.75 to 96.0, which confirms that organic mercury is much more toxic to these neural cells than inorganic mercury. Among these cell lines, HGST-BR and TriG44 derived from marine sea turtles showed a significantly high tolerance to HgCl2 as compared to the three mammalian neural cells. Among these neural cells, SK-N-SH represented the most sensitive cells to both chemical forms of mercury. Copyright © 2015. Published by Elsevier B.V.

  2. Female mice deficient in alpha-fetoprotein show female-typical neural responses to conspecific-derived pheromones.

    Directory of Open Access Journals (Sweden)

    Olivier Brock

    Full Text Available The neural mechanisms controlling sexual behavior are sexually differentiated by the perinatal actions of sex steroid hormones. We recently observed using female mice deficient in alpha-fetoprotein (AFP-KO and which lack the protective actions of AFP against maternal estradiol, that exposure to prenatal estradiol completely defeminized the potential to show lordosis behavior in adulthood. Furthermore, AFP-KO females failed to show any male-directed mate preferences following treatment with estradiol and progesterone, indicating a reduced sexual motivation to seek out the male. In the present study, we asked whether neural responses to male- and female-derived odors are also affected in AFP-KO female mice. Therefore, we compared patterns of Fos, the protein product of the immediate early gene, c-fos, commonly used as a marker of neuronal activation, between wild-type (WT and AFP-KO female mice following exposure to male or estrous female urine. We also tested WT males to confirm the previously observed sex differences in neural responses to male urinary odors. Interestingly, AFP-KO females showed normal, female-like Fos responses, i.e. exposure to urinary odors from male but not estrous female mice induced equivalent levels of Fos protein in the accessory olfactory pathways (e.g. the medial part of the preoptic nucleus, the bed nucleus of the stria terminalis, the amygdala, and the lateral part of the ventromedial hypothalamic nucleus as well as in the main olfactory pathways (e.g. the piriform cortex and the anterior cortical amygdaloid nucleus, as WT females. By contrast, WT males did not show any significant induction of Fos protein in these brain areas upon exposure to either male or estrous female urinary odors. These results thus suggest that prenatal estradiol is not involved in the sexual differentiation of neural Fos responses to male-derived odors.

  3. Molecular precursor derived silicon boron carbonitride/carbon nanotube and silicon oxycarbide/carbon nanotube composite nanowires for energy based applications

    Science.gov (United States)

    Bhandavat, Romil

    Molecular precursor derived ceramics (also known as polymer-derived ceramics or PDCs) are high temperature glasses that have been studied for applications involving operation at elevated temperatures. Prepared from controlled thermal degradation of liquid-phase organosilicon precursors, these ceramics offer remarkable engineering properties such as resistance to crystallization up to 1400 °C, semiconductor behavior at high temperatures and intense photoluminescence. These properties are a direct result of their covalent bonded amorphous network and free (-sp2) carbon along with mixed Si/B/C/N/O bonds, which otherwise can not be obtained through conventional ceramic processing techniques. This thesis demonstrates synthesis of a unique core/shell type nanowire structure involving either siliconboroncarbonitride (SiBCN) or siliconoxycarbide (SiOC) as the shell with carbon nanotube (CNT) acting as the core. This was made possible by liquid phase functionalization of CNT surfaces with respective polymeric precursor (e.g., home-made boron-modified polyureamethylvinylsilazane for SiBCN/CNT and commercially obtained polysiloxane for SiOC/CNT), followed by controlled pyrolysis in inert conditions. This unique architecture has several benefits such as high temperature oxidation resistance (provided by the ceramic shell), improved electrical conductivity and mechanical toughness (attributed to the CNT core) that allowed us to explore its use in energy conversion and storage devices. The first application involved use of SiBCN/CNT composite as a high temperature radiation absorbant material for laser thermal calorimeter. SiBCN/CNT spray coatings on copper substrate were exposed to high energy laser beams (continuous wave at 10.6 mum 2.5 kW CO2 laser, 10 seconds) and resulting change in its microstructure was studied ex-situ. With the aid of multiple techniques we ascertained the thermal damage resistance to be 15 kW/cm -2 with optical absorbance exceeding 97%. This represents

  4. Continuous-Flow O-Alkylation of Biobased Derivatives with Dialkyl Carbonates in the Presence of Magnesium-Aluminium Hydrotalcites as Catalyst Precursors.

    Science.gov (United States)

    Cattelan, Lisa; Perosa, Alvise; Riello, Piero; Maschmeyer, Thomas; Selva, Maurizio

    2017-04-10

    The base-catalysed reactions of OH-bearing biobased derivatives (BBDs) including glycerol formal, solketal, glycerol carbonate, furfuryl alcohol and tetrahydrofurfuryl alcohol with non-toxic dialkyl carbonates (dimethyl and diethyl carbonate) were explored under continuous-flow (CF) conditions in the presence of three Na-exchanged Y- and X-faujasites (FAUs) and four Mg-Al hydrotalcites (HTs). Compared to previous etherification protocols mediated by dialkyl carbonates, the reported procedure offers substantial improvements not only in terms of (chemo)selectivity but also for the recyclability of the catalysts, workup, ease of product purification and, importantly, process intensification. Characterisation studies proved that both HT30 and KW2000 hydrotalcites acted as catalyst precursors: during the thermal activation pre-treatments, the typical lamellar structure of the hydrotalcite was broken down gradually into a MgO-like phase (periclase) or rather a magnesia-alumina solid solution, which was the genuine catalytic phase. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Functional integration of grafted neural stem cell-derived dopaminergic neurons monitored by optogenetics in an in vitro Parkinson model.

    Directory of Open Access Journals (Sweden)

    Jan Tønnesen

    Full Text Available Intrastriatal grafts of stem cell-derived dopamine (DA neurons induce behavioral recovery in animal models of Parkinson's disease (PD, but how they functionally integrate in host neural circuitries is poorly understood. Here, Wnt5a-overexpressing neural stem cells derived from embryonic ventral mesencephalon of tyrosine hydroxylase-GFP transgenic mice were expanded as neurospheres and transplanted into organotypic cultures of wild type mouse striatum. Differentiated GFP-labeled DA neurons in the grafts exhibited mature neuronal properties, including spontaneous firing of action potentials, presence of post-synaptic currents, and functional expression of DA D₂ autoreceptors. These properties resembled those recorded from identical cells in acute slices of intrastriatal grafts in the 6-hydroxy-DA-induced mouse PD model and from DA neurons in intact substantia nigra. Optogenetic activation or inhibition of grafted cells and host neurons using channelrhodopsin-2 (ChR2 and halorhodopsin (NpHR, respectively, revealed complex, bi-directional synaptic interactions between grafted cells and host neurons and extensive synaptic connectivity within the graft. Our data demonstrate for the first time using optogenetics that ectopically grafted stem cell-derived DA neurons become functionally integrated in the DA-denervated striatum. Further optogenetic dissection of the synaptic wiring between grafted and host neurons will be crucial to clarify the cellular and synaptic mechanisms underlying behavioral recovery as well as adverse effects following stem cell-based DA cell replacement strategies in PD.

  6. Development of protective autoimmunity by immunization with a neural-derived peptide is ineffective in severe spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Susana Martiñón

    Full Text Available Protective autoimmunity (PA is a physiological response to central nervous system trauma that has demonstrated to promote neuroprotection after spinal cord injury (SCI. To reach its beneficial effect, PA should be boosted by immunizing with neural constituents or neural-derived peptides such as A91. Immunizing with A91 has shown to promote neuroprotection after SCI and its use has proven to be feasible in a clinical setting. The broad applications of neural-derived peptides make it important to determine the main features of this anti-A91 response. For this purpose, adult Sprague-Dawley rats were subjected to a spinal cord contusion (SCC; moderate or severe or a spinal cord transection (SCT; complete or incomplete. Immediately after injury, animals were immunized with PBS or A91. Motor recovery, T cell-specific response against A91 and the levels of IL-4, IFN-γ and brain-derived neurotrophic factor (BDNF released by A91-specific T (T(A91 cells were evaluated. Rats with moderate SCC, presented a better motor recovery after A91 immunization. Animals with moderate SCC or incomplete SCT showed significant T cell proliferation against A91 that was characterized chiefly by the predominant production of IL-4 and the release of BDNF. In contrast, immunization with A91 did not promote a better motor recovery in animals with severe SCC or complete SCT. In fact, T cell proliferation against A91 was diminished in these animals. The present results suggest that the effective development of PA and, consequently, the beneficial effects of immunizing with A91 significantly depend on the severity of SCI. This could mainly be attributed to the lack of T(A91 cells which predominantly showed to have a Th2 phenotype capable of producing BDNF, further promoting neuroprotection.

  7. Quantitative Live Imaging of Human Embryonic Stem Cell Derived Neural Rosettes Reveals Structure-Function Dynamics Coupled to Cortical Development.

    Science.gov (United States)

    Ziv, Omer; Zaritsky, Assaf; Yaffe, Yakey; Mutukula, Naresh; Edri, Reuven; Elkabetz, Yechiel

    2015-10-01

    Neural stem cells (NSCs) are progenitor cells for brain development, where cellular spatial composition (cytoarchitecture) and dynamics are hypothesized to be linked to critical NSC capabilities. However, understanding cytoarchitectural dynamics of this process has been limited by the difficulty to quantitatively image brain development in vivo. Here, we study NSC dynamics within Neural Rosettes--highly organized multicellular structures derived from human pluripotent stem cells. Neural rosettes contain NSCs with strong epithelial polarity and are expected to perform apical-basal interkinetic nuclear migration (INM)--a hallmark of cortical radial glial cell development. We developed a quantitative live imaging framework to characterize INM dynamics within rosettes. We first show that the tendency of cells to follow the INM orientation--a phenomenon we referred to as radial organization, is associated with rosette size, presumably via mechanical constraints of the confining structure. Second, early forming rosettes, which are abundant with founder NSCs and correspond to the early proliferative developing cortex, show fast motions and enhanced radial organization. In contrast, later derived rosettes, which are characterized by reduced NSC capacity and elevated numbers of differentiated neurons, and thus correspond to neurogenesis mode in the developing cortex, exhibit slower motions and decreased radial organization. Third, later derived rosettes are characterized by temporal instability in INM measures, in agreement with progressive loss in rosette integrity at later developmental stages. Finally, molecular perturbations of INM by inhibition of actin or non-muscle myosin-II (NMII) reduced INM measures. Our framework enables quantification of cytoarchitecture NSC dynamics and may have implications in functional molecular studies, drug screening, and iPS cell-based platforms for disease modeling.

  8. Suspended sediment profiles derived from spectral attenuation coefficients measurements using neural network method

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, G.; Suresh, T.; Matondkar, S.G.P.; Desa, E.; Kamath, S.S.

    the AC-9 instrument. The ANN model has been trained using beam attenuation values obtained from the cruise in the Arabian Sea, SK-149 and the net was tested using the data from the cruise SK-152. The feed forward multi-layer perceptron neural network...

  9. Microparticle Shedding from Neural Progenitor Cells and Vascular Compartment Cells Is Increased in Ischemic Stroke.

    Science.gov (United States)

    Chiva-Blanch, Gemma; Suades, Rosa; Crespo, Javier; Peña, Esther; Padró, Teresa; Jiménez-Xarrié, Elena; Martí-Fàbregas, Joan; Badimon, Lina

    2016-01-01

    Ischemic stroke has shown to induce platelet and endothelial microparticle shedding, but whether stroke induces microparticle shedding from additional blood and vascular compartment cells is unclear. Neural precursor cells have been shown to replace dying neurons at sites of brain injury; however, if neural precursor cell activation is associated to microparticle shedding, and whether this activation is maintained at long term and associates to stroke type and severity remains unknown. We analyzed neural precursor cells and blood and vascular compartment cells microparticle shedding after an acute ischemic stroke. Forty-four patients were included in the study within the first 48h after the onset of stroke. The cerebral lesion size was evaluated at 3-7 days of the stroke. Circulating microparticles from neural precursor cells and blood and vascular compartment cells (platelets, endothelial cells, erythrocytes, leukocytes, lymphocytes, monocytes and smooth muscle cells) were analyzed by flow cytometry at the onset of stroke and at 7 and 90 days. Forty-four age-matched high cardiovascular risk subjects without documented vascular disease were used as controls. Compared to high cardiovascular risk controls, patients showed higher number of neural precursor cell- and all blood and vascular compartment cell-derived microparticles at the onset of stroke, and after 7 and 90 days. At 90 days, neural precursor cell-derived microparticles decreased and smooth muscle cell-derived microparticles increased compared to levels at the onset of stroke, but only in those patients with the highest stroke-induced cerebral lesions. Stroke increases blood and vascular compartment cell and neural precursor cell microparticle shedding, an effect that is chronically maintained up to 90 days after the ischemic event. These results show that stroke induces a generalized blood and vascular cell activation and the initiation of neuronal cell repair process after stroke. Larger cerebral lesions

  10. Neural tissue-spheres

    DEFF Research Database (Denmark)

    Andersen, Rikke K; Johansen, Mathias; Blaabjerg, Morten

    2007-01-01

    maintained their neurogenic potential throughout 77 days of propagation, while the ability of anterior NTS to generate neurons severely declined from day 40. The present procedure describes isolation and long-term expansion of forebrain SVZ tissue with potential preservation of the endogenous cellular......By combining new and established protocols we have developed a procedure for isolation and propagation of neural precursor cells from the forebrain subventricular zone (SVZ) of newborn rats. Small tissue blocks of the SVZ were dissected and propagated en bloc as free-floating neural tissue...... derived from three rostro-caudal levels of the lateral ventricles (anterior, intermediate and posterior) and propagated separately. Explants from all three levels produced proliferating NTS, but "anterior" NTS in general grew to smaller sizes than "intermediate" and "posterior" NTS. Posterior NTS moreover...

  11. Neural crest and placode interaction during the development of the cranial sensory system.

    Science.gov (United States)

    Steventon, Ben; Mayor, Roberto; Streit, Andrea

    2014-05-01

    In the vertebrate head, the peripheral components of the sensory nervous system are derived from two embryonic cell populations, the neural crest and cranial sensory placodes. Both arise in close proximity to each other at the border of the neural plate: neural crest precursors abut the future central nervous system, while placodes originate in a common preplacodal region slightly more lateral. During head morphogenesis, complex events organise these precursors into functional sensory structures, raising the question of how their development is coordinated. Here we review the evidence that neural crest and placode cells remain in close proximity throughout their development and interact repeatedly in a reciprocal manner. We also review recent controversies about the relative contribution of the neural crest and placodes to the otic and olfactory systems. We propose that a sequence of mutual interactions between the neural crest and placodes drives the coordinated morphogenesis that generates functional sensory systems within the head. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. FGL-functionalized self-assembling nanofiber hydrogel as a scaffold for spinal cord-derived neural stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian [Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zheng, Jin [Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zheng, Qixin, E-mail: zheng-qx@163.com [Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Wu, Yongchao; Wu, Bin; Huang, Shuai; Fang, Weizhi; Guo, Xiaodong [Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China)

    2015-01-01

    A class of designed self-assembling peptide nanofiber scaffolds has been shown to be a good biomimetic material in tissue engineering. Here, we specifically made a new peptide hydrogel scaffold FGLmx by mixing the pure RADA{sub 16} and designer functional peptide RADA{sub 16}-FGL solution, and we analyzed the physiochemical properties of each peptide with atomic force microscopy (AFM) and circular dichroism (CD). In addition, we examined the biocompatibility and bioactivity of FGLmx as well as RADA{sub 16} scaffold on spinal cord-derived neural stem cells (SC-NSCs) isolated from neonatal rats. Our results showed that RADA{sub 16}-FGL displayed a weaker β-sheet structure and FGLmx could self-assemble into nanofibrous morphology. Moreover, we found that FGLmx was not only noncytotoxic to SC-NSCs but also promoted SC-NSC proliferation and migration into the three-dimensional (3-D) scaffold, meanwhile, the adhesion and lineage differentiation of SC-NSCs on FGLmx were similar to that on RADA{sub 16}. Our results indicated that the FGL-functionalized peptide scaffold might be very beneficial for tissue engineering and suggested its further application for spinal cord injury (SCI) repair. - Highlights: • RADA{sub 16} and RADA{sub 16}-FGL peptides were synthesized and characterized. • Rat spinal cord neural stem cells were successfully isolated and characterized. • We provided an induction method for mixed differentiation of neural stem cells. • FGL scaffold had good biocompatibility and bioactivity with neural stem cells.

  13. Neural Stem Cell Transplantation Promotes Functional Recovery from Traumatic Brain Injury via Brain Derived Neurotrophic Factor-Mediated Neuroplasticity.

    Science.gov (United States)

    Xiong, Liu-Lin; Hu, Yue; Zhang, Piao; Zhang, Zhuo; Li, Li-Hong; Gao, Guo-Dong; Zhou, Xin-Fu; Wang, Ting-Hua

    2017-04-18

    Traumatic brain injury (TBI) induces cognitive impairments, motor and behavioral deficits. Previous evidences have suggested that neural stem cell (NSC) transplantation could facilitate functional recovery from brain insults, but their underlying mechanisms remains to be elucidated. Here, we established TBI model by an electromagnetic-controlled cortical impact device in the rats. Then, 5 μl NSCs (5.0 × 10 5 /μl), derived from green fluorescent protein (GFP) transgenic mouse, was transplanted into the traumatic brain regions of rats at 24 h after injury. After differentiation of the NSCs was determined using immunohistochemistry, neurological severity scores (NSS) and rotarod test were conducted to detect the neurological behavior. Western blot and RT-PCR as well as ELASA were used to evaluate the expression of synaptophysin and brain-derived neurotrophic factor (BDNF). In order to elucidate the role of BDNF on the neural recovery after NSC transplantation, BDNF knockdown in NSC was performed and transplanted into the rats with TBI, and potential mechanism for BDNF knockdown in the NSC was analyzed using microassay analysis. Meanwhile, BDNF antibody blockade was conducted to further confirm the effect of BDNF on neural activity. As a result, an increasing neurological function improvement was seen in NSC transplanted rats, which was associated with the upregulation of synaptophysin and BDNF expression. Moreover, transplantation of BDNF knockdown NSCs and BDNF antibody block reduced not only the level of synaptophysin but also exacerbated neurological function deficits. Microassay analysis showed that 14 genes such as Wnt and Gsk3-β were downregulated after BDNF knockdown. The present data therefore showed that BDNF-mediated neuroplasticity underlie the mechanism of NSC transplantation for the treatment of TBI in adult rats.

  14. Cryopreservation of GABAergic Neuronal Precursors for Cell-Based Therapy

    Science.gov (United States)

    2017-01-01

    Cryopreservation protocols are essential for stem cells storage in order to apply them in the clinic. Here we describe a new standardized cryopreservation protocol for GABAergic neural precursors derived from the medial glanglionic eminence (MGE), a promising source of GABAergic neuronal progenitors for cell therapy against interneuron-related pathologies. We used 10% Me2SO as cryoprotectant and assessed the effects of cell culture amplification and cellular organization, as in toto explants, neurospheres, or individualized cells, on post-thaw cell viability and retrieval. We confirmed that in toto cryopreservation of MGE explants is an optimal preservation system to keep intact the interneuron precursor properties for cell transplantation, together with a high cell viability (>80%) and yield (>70%). Post-thaw proliferation and self-renewal of the cryopreserved precursors were tested in vitro. In addition, their migration capacity, acquisition of mature neuronal morphology, and potency to differentiate into multiple interneuron subtypes were also confirmed in vivo after transplantation. The results show that the cryopreserved precursor features remained intact and were similar to those immediately transplanted after their dissection from the MGE. We hope this protocol will facilitate the generation of biobanks to obtain a permanent and reliable source of GABAergic precursors for clinical application in cell-based therapies against interneuronopathies. PMID:28122047

  15. Cryopreservation of GABAergic Neuronal Precursors for Cell-Based Therapy.

    Directory of Open Access Journals (Sweden)

    Daniel Rodríguez-Martínez

    Full Text Available Cryopreservation protocols are essential for stem cells storage in order to apply them in the clinic. Here we describe a new standardized cryopreservation protocol for GABAergic neural precursors derived from the medial glanglionic eminence (MGE, a promising source of GABAergic neuronal progenitors for cell therapy against interneuron-related pathologies. We used 10% Me2SO as cryoprotectant and assessed the effects of cell culture amplification and cellular organization, as in toto explants, neurospheres, or individualized cells, on post-thaw cell viability and retrieval. We confirmed that in toto cryopreservation of MGE explants is an optimal preservation system to keep intact the interneuron precursor properties for cell transplantation, together with a high cell viability (>80% and yield (>70%. Post-thaw proliferation and self-renewal of the cryopreserved precursors were tested in vitro. In addition, their migration capacity, acquisition of mature neuronal morphology, and potency to differentiate into multiple interneuron subtypes were also confirmed in vivo after transplantation. The results show that the cryopreserved precursor features remained intact and were similar to those immediately transplanted after their dissection from the MGE. We hope this protocol will facilitate the generation of biobanks to obtain a permanent and reliable source of GABAergic precursors for clinical application in cell-based therapies against interneuronopathies.

  16. Functionalized derivatives of 1,4-dimethylnaphthalene as precursors for biomedical applications: synthesis, structures, spectroscopy and photochemical activation in the presence of dioxygen.

    Science.gov (United States)

    Posavec, Damir; Zabel, Manfred; Bogner, Udo; Bernhardt, Günther; Knör, Günther

    2012-09-21

    Decomposition of endoperoxide containing molecules is an attractive approach for the delayed release of singlet oxygen under mild reaction conditions. Here we describe a new method for the adaptation of the corresponding decay times by controlling the supramolecular functional structure of the surrounding matrix in the immediate vicinity of embedded singlet oxygen precursors. Thus, a significant prolongation of the lifetime of the endoperoxide species is possible by raising the energy barrier of the thermal (1)O(2)-releasing step via a restriction of the free volume of the applied carrier material. Enabling such a prolonged decomposition period is crucial for potential biomedical applications of endoperoxide containing molecules, since sufficient time for appropriate cell uptake and transport to the desired target region must be available under physiological conditions before the tissue damaging-power of the reactive oxygen species formed is completely exhausted. Two novel polyaromatic systems for the intermediate storage and transport of endoperoxides and the controlled release of singlet oxygen in the context of anticancer and antibiotic activity have been prepared and characterized. These compounds are based on functionalized derivatives of the 1,4-dimethylnaphthalene family which are readily forming metastable endoperoxide species in the presence of dioxygen, a photosensitizer molecule such as methylene blue and visible light. In contrast to previously known systems of similar photoreactivity, the endoperoxide carrying molecules have been designed with optimized molecular properties in terms of potential chemotherapeutic applications. These include modifications of polarity to improve their incorporation into various biocompatible carrier materials, the introduction of hydrogen bonding motifs to additionally influence the endoperoxide decay kinetics, and the synthesis of bifunctional derivatives to enable synergistic effects of multiple singlet oxygen binding

  17. In vivo impact of Dlx3 conditional inactivation in Neural Crest-Derived Craniofacial Bones

    Science.gov (United States)

    Duverger, Olivier; Isaac, Juliane; Zah, Angela; Hwang, Joonsung; Berdal, Ariane; Lian, Jane B.; Morasso, Maria I.

    2012-01-01

    Mutations in DLX3 in humans lead to defects in craniofacial and appendicular bones, yet the in vivo activity related to Dlx3 function during normal skeletal development have not been fully elucidated. Here we used a conditional knockout approach to analyze the effects of neural crest deletion of Dlx3 on craniofacial bones development. At birth, mutant mice exhibit a normal overall positioning of the skull bones, but a change in the shape of the calvaria was observed. Molecular analysis of the genes affected in the frontal bones and mandibles from these mice identified several bone markers known to affect bone development, with a strong prediction for increased bone formation and mineralization in vivo. Interestingly, while a subset of these genes were similarly affected in frontal bones and mandibles (Sost, Mepe, Bglap, Alp, Ibsp, Agt), several genes, including Lect1 and Calca, were specifically affected in frontal bones. Consistent with these molecular alterations, cells isolated from the frontal bone of mutant mice exhibited increased differentiation and mineralization capacities ex vivo, supporting cell autonomous defects in neural crest cells. However, adult mutant animals exhibited decreased bone mineral density in both mandibles and calvaria, as well as a significant increase in bone porosity. Together, these observations suggest that mature osteoblasts in the adult respond to signals that regulate adult bone mass and remodeling. This study provides new downstream targets for Dlx3 in craniofacial bone, and gives additional evidence of the complex regulation of bone formation and homeostasis in the adult skeleton. PMID:22886599

  18. Comparison of the differentiation potential of neural crest derived progenitor cells from apical papilla (dNC-PCs) and stem cells from exfoliated deciduous teeth (SHED) into mineralising cells.

    Science.gov (United States)

    Gosau, Martin; Götz, Werner; Felthaus, Oliver; Ettl, Tobias; Jäger, Andreas; Morsczeck, Christian

    2013-06-01

    Recently, cells from the apical papilla of retained human third molars (dental neural crest-derived progenitor cells, dNC-PCs) have been isolated and characterised as multipotent progenitor cells. Nonetheless, molecular processes during differentiation into mineralising cells are still unknown. This study evaluated the osteogenic/odontogenic differentiation of dNC-PCs under in vitro conditions and compared these cells with already known odontoblast precursor cells (dental stem cells from exfoliated human deciduous teeth, SHED). The differentiation of dNC-PCs and SHED under in vitro conditions was verified by Alizarin red staining (mineralisation), alkaline phosphatase activity and the expression of osteogenic/odontogenic markers (RT-PCRs). The genome wide expression-profiles were investigated with Affymetrix DNA-microarrays and the cell migration with a gel spot cell migration assay. In our study dNC-PCs differentiated like SHED in mineralising cells. The expression of odontoblast markers suggested that dNC-PCs and SHED differentiated into different types of odontoblasts. This supposition was supported by genome wide gene expression profiles of dNC-PCs and SHED after cell differentiation. Typical biological processes of undifferentiated cells, for example "mitosis", were regulated in dNC-PCs. In SHED biological processes like "response to wounding" or "cell migration" were regulated, which are associated with replacement odontoblasts and their precursors. Moreover, a gel-spot assay revealed that SHED migrated faster than dNC-PCs. Our results suggest that dNC-PCs are precursors for primary odontoblasts, whereas SHED differentiate into replacement odontoblasts. These different odontogenic differentiation potentials of dNC-PCs and SHED have to be considered for cellular therapies and tissue engineering approaches in the future. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Relationship between ketamine-induced developmental neurotoxicity and NMDA receptor-mediated calcium influx in neural stem cell-derived neurons.

    Science.gov (United States)

    Wang, Cheng; Liu, Fang; Patterson, Tucker A; Paule, Merle G; Slikker, William

    2017-05-01

    Ketamine, a noncompetitive NMDA receptor antagonist, is used as a general anesthetic and recent data suggest that general anesthetics can cause neuronal damage when exposure occurs during early brain development. To elucidate the underlying mechanisms associated with ketamine-induced neurotoxicity, stem cell-derived models, such as rodent neural stem cells harvested from rat fetuses and/or neural stem cells derived from human induced pluripotent stem cells (iPSC) can be utilized. Prolonged exposure of rodent neural stem cells to clinically-relevant concentrations of ketamine resulted in elevated NMDA receptor levels as indicated by NR1subunit over-expression in neurons. This was associated with enhanced damage in neurons. In contrast, the viability and proliferation rate of undifferentiated neural stem cells were not significantly affected after ketamine exposure. Calcium imaging data indicated that 50μM NMDA did not cause a significant influx of calcium in typical undifferentiated neural stem cells; however, it did produce an immediate elevation of intracellular free Ca 2+ [Ca 2+ ] i in differentiated neurons derived from the same neural stem cells. This paper reviews the literature on this subject and previous findings suggest that prolonged exposure of developing neurons to ketamine produces an increase in NMDA receptor expression (compensatory up-regulation) which allows for a higher/toxic influx of calcium into neurons once ketamine is removed from the system, leading to neuronal cell death likely due to elevated reactive oxygen species generation. The absence of functional NMDA receptors in cultured neural stem cells likely explains why clinically-relevant concentrations of ketamine did not affect undifferentiated neural stem cell viability. Published by Elsevier B.V.

  20. Transcriptional profiling of MEF2-regulated genes in human neural progenitor cells derived from embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Shing Fai Chan

    2015-03-01

    Full Text Available The myocyte enhancer factor 2 (MEF2 family of transcription factors is highly expressed in the brain and constitutes a key determinant of neuronal survival, differentiation, and synaptic plasticity. However, genome-wide transcriptional profiling of MEF2-regulated genes has not yet been fully elucidated, particularly at the neural stem cell stage. Here we report the results of microarray analysis comparing mRNAs isolated from human neural progenitor/stem cells (hNPCs derived from embryonic stem cells expressing a control vector versus progenitors expressing a constitutively-active form of MEF2 (MEF2CA, which increases MEF2 activity. Microarray experiments were performed using the Illumina Human HT-12 V4.0 expression beadchip (GEO#: GSE57184. By comparing vector-control cells to MEF2CA cells, microarray analysis identified 1880 unique genes that were differentially expressed. Among these genes, 1121 genes were up-regulated and 759 genes were down-regulated. Our results provide a valuable resource for identifying transcriptional targets of MEF2 in hNPCs.

  1. Delivery of Brain-Derived Neurotrophic Factor by 3D Biocompatible Polymeric Scaffolds for Neural Tissue Engineering and Neuronal Regeneration

    KAUST Repository

    Limongi, Tania

    2018-04-04

    Biopolymers are increasingly employed for neuroscience applications as scaffolds to drive and promote neural regrowth, thanks to their ability to mediate the upload and subsequent release of active molecules and drugs. Synthetic degradable polymers are characterized by different responses ranging from tunable distension or shrinkage to total dissolution, depending on the function they are designed for. In this paper we present a biocompatible microfabricated poly-ε-caprolactone (PCL) scaffold for primary neuron growth and maturation that has been optimized for the in vitro controlled release of brain-derived neurotrophic factor (BDNF). We demonstrate that the designed morphology confers to these devices an enhanced drug delivery capability with respect to monolithic unstructured supports. After incubation with BDNF, micropillared PCL devices progressively release the neurotrophin over 21 days in vitro. Moreover, the bioactivity of released BDNF is confirmed using primary neuronal cultures, where it mediates a consistent activation of BDNF signaling cascades, increased synaptic density, and neuronal survival. These results provide the proof-of-principle on the fabrication process of micropatterned PCL devices, which represent a promising therapeutic option to enhance neuronal regeneration after lesion and for neural tissue engineering and prosthetics.

  2. Thermoset precursor

    International Nuclear Information System (INIS)

    Yamamoto, Y.

    1983-04-01

    This invention pertains to a distinctive thermoset precursor which is prepared by mixing a resin composition (A) which can be hardened by ionizing radiation, and a resin composition (B) which can be hardened by heat but cannot be hardened by, or is resistant to, ionizing radiation, and by coating or impregnating a molding or other substrate with a sheet or film of this mixture and irradiating this with an ionizing radiation. The principal components of composition (A) and (B) can be the following: (1) an acrylate or methacrylate and an epoxy resin and an epoxy resin hardener; (2) an unsaturated polyester resin and epoxy resin and an epoxy resin hardener; (3) a diacrylate or dimethacrylate or polyethylene glycol and an epoxy resin; (4) an epoxy acrylates or epoxy methacrylate obtained by the addition reaction of epoxy resin and acrylic or methacrylic acid

  3. DESIGN OF LOW CYTOTOXICITY DIARYLANILINE DERIVATIVES BASED ON QSAR RESULTS: AN APPLICATION OF ARTIFICIAL NEURAL NETWORK MODELLING

    Directory of Open Access Journals (Sweden)

    Ihsanul Arief

    2016-11-01

    Full Text Available Study on cytotoxicity of diarylaniline derivatives by using quantitative structure-activity relationship (QSAR has been done. The structures and cytotoxicities of  diarylaniline derivatives were obtained from the literature. Calculation of molecular and electronic parameters was conducted using Austin Model 1 (AM1, Parameterized Model 3 (PM3, Hartree-Fock (HF, and density functional theory (DFT methods.  Artificial neural networks (ANN analysis used to produce the best equation with configuration of input data-hidden node-output data = 5-8-1, value of r2 = 0.913; PRESS = 0.069. The best equation used to design and predict new diarylaniline derivatives.  The result shows that compound N1-(4′-Cyanophenyl-5-(4″-cyanovinyl-2″,6″-dimethyl-phenoxy-4-dimethylether benzene-1,2-diamine is the best-proposed compound with cytotoxicity value (CC50 of 93.037 μM.

  4. A neural cell adhesion molecule-derived peptide reduces neuropathological signs and cognitive impairment induced by Abeta25-35

    DEFF Research Database (Denmark)

    Klementiev, B; Novikova, T; Novitskaya, V

    2007-01-01

    death and brain atrophy in response to Abeta25-35. Finally, the Abeta25-35-administration led to a reduced short-term memory as determined by the social recognition test. A synthetic peptide termed FGL derived from the neural cell adhesion molecule (NCAM) was able to prevent or, if already manifest......, strongly reduce all investigated signs of Abeta25-35-induced neuropathology and cognitive impairment. The FGL peptide was recently demonstrated to be able to cross the blood-brain-barrier. Accordingly, we found that the beneficial effects of FGL were achieved not only by intracisternal, but also...... and cognitive impairment involves the modulation of intracellular signal-transduction mediated through GSK3beta....

  5. Neural activity in relation to clinically derived personality syndromes in depression using a psychodynamic fMRI paradigm

    Directory of Open Access Journals (Sweden)

    Svenja eTaubner

    2013-12-01

    Full Text Available Objective: The heterogeneity between patients with depression cannot be captured adequately with existing descriptive systems of diagnosis and neurobiological models of depression. Furthermore, considering the highly individual nature of depression, the application of general stimuli in past research efforts may not capture the essence of the disorder. This study aims to identify subtypes of depression by using empirically-derived personality-syndromes, and to explore neural correlates of the derived personality syndromes.Method: In the present exploratory study an individually tailored and psychodynamically based fMRI paradigm using dysfunctional relationship patterns was presented to 20 chronically depressed patients. Results from the Shedler-Westen-Assessment-Procedure (SWAP-200 were analyzed by Q-factor analysis to identify clinically relevant subgroups of depression and related brain activation.Results: The principle component analysis of SWAP-200 items from all 20 patients lead to a 2-factor solution: Depressive Personality and Emotional-Hostile-Externalizing Personality. Both factors were used in a whole-brain correlational analysis but only the second factor yielded significant positive correlations in four regions: A large cluster in the right orbitofrontal cortex (OFC, the left ventral striatum, a small cluster in the left temporal pole and another small cluster in the right middle frontal gyrus. Discussion: The degree to which patients with depression score high on the factor Emotional-Hostile-Externalizing Personality correlated with relatively higher activity in three key areas involved in emotion processing, evaluation of reward/punishment, negative cognitions, depressive pathology and social knowledge (OFC, ventral striatum, temporal pole. Results may contribute to an alternative description of neural correlates of depression showing differential brain activation dependent on the extent of specific personality syndromes in

  6. Six Peptide Wound Signals Derived from a Single Precursor Protein in Ipomoea batatas Leaves Activate the Expression of the Defense Gene Sporamin*

    Science.gov (United States)

    Chen, Yu-Chi; Siems, William F.; Pearce, Gregory; Ryan, Clarence A.

    2008-01-01

    A mixture of three homologous bioactive hydroxyproline-rich glycopeptides (HypSys peptides) of 18 amino acids in length, differing only at two residues, was isolated from leaves of Ipomoea batatas, the common sweet potato. One of the peptides represented over 95% of the isolated isopeptides, which, at 2.5 nm concentration, induced the expression of sporamin, a major defense protein of I. batatas. The sequence of the major isoform was used to synthesize a primer that identified a cDNA encoding a precursor protein. The protein contained six proline-rich regions whose sequences suggested that they might be HypSys defense signals. One of the encoded peptides, called IbHypSys IV, was identical to one of two minor components of the isolated isopeptides, but neither the major isopeptide nor the other minor isoform was found within the precursor. The six peptides encoded by the precursor gene were synthesized but with hydroxyproline residues at positions found in the native isoforms and lacking carbohydrate moieties. All of the peptides were biologically active when supplied to leaves of sweet potato plants. The gene is the first ortholog of the preproHypSys gene family to be found outside of the Solanaceae family, and its encoded peptide precursor is the first example in plants of a precursor protein with six potential peptide defense signals, a scenario only found previously in animals. The data indicate that multiple copies of the HypSys peptides in a single precursor may have an important role in amplifying wound signaling in leaves in response to herbivore attacks. PMID:18299332

  7. Contribution of MODIS Derived Snow Cover Satellite Data into Artificial Neural Network for Streamflow Estimation

    Science.gov (United States)

    Uysal, Gokcen; Arda Sorman, Ali; Sensoy, Aynur

    2014-05-01

    Contribution of snowmelt and correspondingly snow observations are highly important in mountainous basins for modelers who deal with conceptual, physical or soft computing models in terms of effective water resources management. Long term archived continuous data are needed for appropriate training and testing of data driven approaches like artificial neural networks (ANN). Data is scarce at the upper elevations due to the difficulty of installing sufficient automated SNOTEL stations; thus in literatures many attempts are made on the rainfall dominated basins for streamflow estimation studies. On the other hand, optical satellites can easily detect snow because of its high reflectance property. MODIS (Moderate Resolution Imaging Spectroradiometer) satellite that has two platforms (Terra and Aqua) provides daily and 8-daily snow images for different time periods since 2000, therefore snow cover data (SCA) may be useful as an input layer for ANN applications. In this study, a multi-layer perceptron (MLP) model is trained and tested with precipitation, temperature, radiation, previous day discharges as well as MODIS daily SCA data. The weights and biases are optimized with fastest and robust Levenberg-Marquardt backpropagation algorithm. MODIS snow cover images are removed from cloud coverage using certain filtering techniques. The Upper Euphrates River Basin in eastern part of Turkey (10 250 km2) is selected as the application area since it is fed by snowmelt approximately 2/3 of total annual volume during spring and early summer. Several input models and ANN structures are investigated to see the effect of the contributions using 10 years of data (2001-2010) for training and validation. The accuracy of the streamflow estimations is checked with statistical criteria (coefficient of determination, Nash-Sutcliffe model efficiency, root mean square error, mean absolute error) and the results seem to improve when SCA data is introduced. Furthermore, a forecast study is

  8. Physical activity and environmental enrichment regulate the generation of neural precursors in the adult mouse substantia nigra in a dopamine-dependent manner

    Directory of Open Access Journals (Sweden)

    Klaissle Philipp

    2012-10-01

    Full Text Available Abstract Background Parkinson’s disease is characterized by a continuous loss of neurons within the substantia nigra (SN leading to a depletion of dopamine. Within the adult SN as a non-neurogenic region, cells with mainly oligodendrocytic precursor characteristics, expressing the neuro-glial antigen-2 (NG2 are continuously generated. Proliferation of these cells is altered in animal models of Parkinson’s disease (PD. Exercise and environmental enrichment re-increase proliferation of NG2+ cells in PD models, however, a possible mechanistic role of dopamine for this increase is not completely understood. NG2+ cells can differentiate into oligodendrocytes but also into microglia and neurons as observed in vitro suggesting a possible hint for endogenous regenerative capacity of the SN. We investigated the role of dopamine in NG2-generation and differentiation in the adult SN stimulated by physical activity and environmental enrichment. Results We used the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP-model for dopamine depletion and analysed newborn cells in the SN at different maturation stages and time points depending on voluntary physical activity, enriched environment and levodopa-treatment. We describe an activity- induced increase of new NG2-positive cells and also mature oligodendrocytes in the SN of healthy mice. Running and enriched environment refused to stimulate NG2-generation and oligodendrogenesis in MPTP-mice, an effect which could be reversed by pharmacological levodopa-induced rescue. Conclusion We suggest dopamine being a key regulator for activity-induced generation of NG2-cells and oliogodendrocytes in the SN as a potentially relevant mechanism in endogenous nigral cellular plasticity.

  9. Differentiation of human olfactory bulb-derived neural stem cells toward oligodendrocyte.

    Science.gov (United States)

    Marei, Hany E; Shouman, Zeinab; Althani, Asma; Afifi, Nahla; A, Abd-Elmaksoud; Lashen, Samah; Hasan, Anwarul; Caceci, Thomas; Rizzi, Roberto; Cenciarelli, Carlo; Casalbore, Patrizia

    2018-02-01

    In the central nervous system (CNS), oligodendrocytes are the glial element in charge of myelin formation. Obtaining an overall presence of oligodendrocyte precursor cells/oligodendrocytes (OPCs/OLs) in culture from different sources of NSCs is an important research area, because OPCs/OLs may provide a promising therapeutic strategy for diseases affecting myelination of axons. The present study was designed to differentiate human olfactory bulb NSCs (OBNSCs) into OPCs/OLs and using expression profiling (RT-qPCR) gene, immunocytochemistry, and specific protein expression to highlight molecular mechanism(s) underlying differentiation of human OBNSCs into OPCs/OLs. The differentiation of OBNSCs was characterized by a simultaneous appearance of neurons and glial cells. The differentiation medium, containing cAMP, PDGFA, T3, and all-trans-retinoic acid (ATRA), promotes OBNSCs to generate mostly oligodendrocytes (OLs) displaying morphological changes, and appearance of long cytoplasmic processes. OBNSCs showed, after 5 days in OLs differentiation medium, a considerable decrease in the number of nestin positive cells, which was associated with a concomitant increase of NG2 immunoreactive cells and few O4(+)-OPCs. In addition, a significant up regulation in gene and protein expression profile of stage specific cell markers for OPCs/OLs (CNPase, Galc, NG2, MOG, OLIG1, OLIG2, MBP), neurons, and astrocytes (MAP2, β-TubulinIII, GFAP) and concomitant decrease of OBNSCs pluripotency markers (Oct4, Sox2, Nestin), was demonstrated following induction of OBNSCs differentiation. Taken together, the present study demonstrate the marked ability of a cocktail of factors containing PDGFA, T3, cAMP, and ATRA, to induce OBNSCs differentiation into OPCs/OLs and shed light on the key genes and pathological pathways involved in this process. © 2017 Wiley Periodicals, Inc.

  10. QSAR Study of Insecticides of Phthalamide Derivatives Using Multiple Linear Regression and Artificial Neural Network Methods

    Directory of Open Access Journals (Sweden)

    Adi Syahputra

    2014-03-01

    Full Text Available Quantitative structure activity relationship (QSAR for 21 insecticides of phthalamides containing hydrazone (PCH was studied using multiple linear regression (MLR, principle component regression (PCR and artificial neural network (ANN. Five descriptors were included in the model for MLR and ANN analysis, and five latent variables obtained from principle component analysis (PCA were used in PCR analysis. Calculation of descriptors was performed using semi-empirical PM6 method. ANN analysis was found to be superior statistical technique compared to the other methods and gave a good correlation between descriptors and activity (r2 = 0.84. Based on the obtained model, we have successfully designed some new insecticides with higher predicted activity than those of previously synthesized compounds, e.g.2-(decalinecarbamoyl-5-chloro-N’-((5-methylthiophen-2-ylmethylene benzohydrazide, 2-(decalinecarbamoyl-5-chloro-N’-((thiophen-2-yl-methylene benzohydrazide and 2-(decaline carbamoyl-N’-(4-fluorobenzylidene-5-chlorobenzohydrazide with predicted log LC50 of 1.640, 1.672, and 1.769 respectively.

  11. Transcriptome analysis of Drosophila neural stem cells.

    Science.gov (United States)

    Gold, Katrina S; Brand, Andrea H

    2012-01-01

    In Drosophila, the central nervous system is populated by a set of asymmetrically dividing neural stem cells called neuroblasts. Neuroblasts are derived from epithelial or neuroepithelial precursors, and divide along their apico-basal axes to produce a large apical neuroblast and a smaller basal ganglion mother cell. The ganglion mother cell will divide once again to produce two post-mitotic neurons or glia. In this chapter we outline a method for labeling different types of neural precursors in the Drosophila central nervous system, followed by their extraction and processing for transcriptome analysis. This technique has allowed us to capture and compare the expression profiles of neuroblasts and neuroepithelial cells, resulting in the identification of key genes required for the regulation of self-renewal and differentiation.

  12. Differentiated human midbrain-derived neural progenitor cells express excitatory strychnine-sensitive glycine receptors containing α2β subunits.

    Science.gov (United States)

    Wegner, Florian; Kraft, Robert; Busse, Kathy; Härtig, Wolfgang; Ahrens, Jörg; Leffler, Andreas; Dengler, Reinhard; Schwarz, Johannes

    2012-01-01

    Human fetal midbrain-derived neural progenitor cells (NPCs) may deliver a tissue source for drug screening and regenerative cell therapy to treat Parkinson's disease. While glutamate and GABA(A) receptors play an important role in neurogenesis, the involvement of glycine receptors during human neurogenesis and dopaminergic differentiation as well as their molecular and functional characteristics in NPCs are largely unknown. Here we investigated NPCs in respect to their glycine receptor function and subunit expression using electrophysiology, calcium imaging, immunocytochemistry, and quantitative real-time PCR. Whole-cell recordings demonstrate the ability of NPCs to express functional strychnine-sensitive glycine receptors after differentiation for 3 weeks in vitro. Pharmacological and molecular analyses indicate a predominance of glycine receptor heteromers containing α2β subunits. Intracellular calcium measurements of differentiated NPCs suggest that glycine evokes depolarisations mediated by strychnine-sensitive glycine receptors and not by D-serine-sensitive excitatory glycine receptors. Culturing NPCs with additional glycine, the glycine-receptor antagonist strychnine, or the Na(+)-K(+)-Cl(-) co-transporter 1 (NKCC1)-inhibitor bumetanide did not significantly influence cell proliferation and differentiation in vitro. These data indicate that NPCs derived from human fetal midbrain tissue acquire essential glycine receptor properties during neuronal maturation. However, glycine receptors seem to have a limited functional impact on neurogenesis and dopaminergic differentiation of NPCs in vitro.

  13. Differentiated human midbrain-derived neural progenitor cells express excitatory strychnine-sensitive glycine receptors containing α2β subunits.

    Directory of Open Access Journals (Sweden)

    Florian Wegner

    Full Text Available BACKGROUND: Human fetal midbrain-derived neural progenitor cells (NPCs may deliver a tissue source for drug screening and regenerative cell therapy to treat Parkinson's disease. While glutamate and GABA(A receptors play an important role in neurogenesis, the involvement of glycine receptors during human neurogenesis and dopaminergic differentiation as well as their molecular and functional characteristics in NPCs are largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigated NPCs in respect to their glycine receptor function and subunit expression using electrophysiology, calcium imaging, immunocytochemistry, and quantitative real-time PCR. Whole-cell recordings demonstrate the ability of NPCs to express functional strychnine-sensitive glycine receptors after differentiation for 3 weeks in vitro. Pharmacological and molecular analyses indicate a predominance of glycine receptor heteromers containing α2β subunits. Intracellular calcium measurements of differentiated NPCs suggest that glycine evokes depolarisations mediated by strychnine-sensitive glycine receptors and not by D-serine-sensitive excitatory glycine receptors. Culturing NPCs with additional glycine, the glycine-receptor antagonist strychnine, or the Na(+-K(+-Cl(- co-transporter 1 (NKCC1-inhibitor bumetanide did not significantly influence cell proliferation and differentiation in vitro. CONCLUSIONS/SIGNIFICANCE: These data indicate that NPCs derived from human fetal midbrain tissue acquire essential glycine receptor properties during neuronal maturation. However, glycine receptors seem to have a limited functional impact on neurogenesis and dopaminergic differentiation of NPCs in vitro.

  14. Leukemia inhibitory factor (LIF) enhances MAP2 + and HUC/D + neurons and influences neurite extension during differentiation of neural progenitors derived from human embryonic stem cells.

    Science.gov (United States)

    Leukemia Inhibitory Factor (L1F), a member of the Interleukin 6 cytokine family, has a role in differentiation of Human Neural Progenitor (hNP) cells in vitro. hNP cells, derived from Human Embryonic Stem (hES) cells, have an unlimited capacity for self-renewal in monolayer cultu...

  15. A recurrent neural network approach to quantitatively studying solar wind effects on TEC derived from GPS; preliminary results

    Directory of Open Access Journals (Sweden)

    J. B. Habarulema

    2009-05-01

    Full Text Available This paper attempts to describe the search for the parameter(s to represent solar wind effects in Global Positioning System total electron content (GPS TEC modelling using the technique of neural networks (NNs. A study is carried out by including solar wind velocity (Vsw, proton number density (Np and the Bz component of the interplanetary magnetic field (IMF Bz obtained from the Advanced Composition Explorer (ACE satellite as separate inputs to the NN each along with day number of the year (DN, hour (HR, a 4-month running mean of the daily sunspot number (R4 and the running mean of the previous eight 3-hourly magnetic A index values (A8. Hourly GPS TEC values derived from a dual frequency receiver located at Sutherland (32.38° S, 20.81° E, South Africa for 8 years (2000–2007 have been used to train the Elman neural network (ENN and the result has been used to predict TEC variations for a GPS station located at Cape Town (33.95° S, 18.47° E. Quantitative results indicate that each of the parameters considered may have some degree of influence on GPS TEC at certain periods although a decrease in prediction accuracy is also observed for some parameters for different days and seasons. It is also evident that there is still a difficulty in predicting TEC values during disturbed conditions. The improvements and degradation in prediction accuracies are both close to the benchmark values which lends weight to the belief that diurnal, seasonal, solar and magnetic variabilities may be the major determinants of TEC variability.

  16. A recurrent neural network approach to quantitatively studying solar wind effects on TEC derived from GPS; preliminary results

    Directory of Open Access Journals (Sweden)

    J. B. Habarulema

    2009-05-01

    Full Text Available This paper attempts to describe the search for the parameter(s to represent solar wind effects in Global Positioning System total electron content (GPS TEC modelling using the technique of neural networks (NNs. A study is carried out by including solar wind velocity (Vsw, proton number density (Np and the Bz component of the interplanetary magnetic field (IMF Bz obtained from the Advanced Composition Explorer (ACE satellite as separate inputs to the NN each along with day number of the year (DN, hour (HR, a 4-month running mean of the daily sunspot number (R4 and the running mean of the previous eight 3-hourly magnetic A index values (A8. Hourly GPS TEC values derived from a dual frequency receiver located at Sutherland (32.38° S, 20.81° E, South Africa for 8 years (2000–2007 have been used to train the Elman neural network (ENN and the result has been used to predict TEC variations for a GPS station located at Cape Town (33.95° S, 18.47° E. Quantitative results indicate that each of the parameters considered may have some degree of influence on GPS TEC at certain periods although a decrease in prediction accuracy is also observed for some parameters for different days and seasons. It is also evident that there is still a difficulty in predicting TEC values during disturbed conditions. The improvements and degradation in prediction accuracies are both close to the benchmark values which lends weight to the belief that diurnal, seasonal, solar and magnetic variabilities may be the major determinants of TEC variability.

  17. Bioluminescence Imaging of Olig2-Neural Stem Cells Reveals Improved Engraftment in a Demyelination Mouse Model

    NARCIS (Netherlands)

    Sher, Falak; van Dam, Go; Boddeke, Erik; Copray, Sjef

    2009-01-01

    A major issue in the potential application of neural stem cell (NSC)-based cell replacement therapy for demyelinating diseases is the question of the survival, functional behavior, and stability of implanted NSC-derived oligodendrocyte precursor cells (OPCs) over an extended period. To address this

  18. Functionalized derivatives of 1,4-dimethylnaphthalene as precursors for biomedical applications: synthesis, structures, spectroscopy and photochemical activation in the presence of dioxygen

    OpenAIRE

    Posavec, Damir; Zabel, Manfred; Bogner, Udo; Bernhardt, Günther; Knör, Günther

    2012-01-01

    Decomposition of endoperoxide containing molecules is an attractive approach for the delayed release of singlet oxygen under mild reaction conditions. Here we describe a new method for the adaptation of the corresponding decay times by controlling the supramolecular functional structure of the surrounding matrix in the immediate vicinity of embedded singlet oxygen precursors. Thus, a significant prolongation of the lifetime of the endoperoxide species is possible by raising the energy barrier...

  19. Neural correlates of derived relational responding on tests of stimulus equivalence

    Directory of Open Access Journals (Sweden)

    Cataldo Michael F

    2008-02-01

    Full Text Available Abstract Background An essential component of cognition and language involves the formation of new conditional relations between stimuli based upon prior experiences. Results of investigations on transitive inference (TI highlight a prominent role for the medial temporal lobe in maintaining associative relations among sequentially arranged stimuli (A > B > C > D > E. In this investigation, medial temporal lobe activity was assessed while subjects completed "Stimulus Equivalence" (SE tests that required deriving conditional relations among stimuli within a class (A ≡ B ≡ C. Methods Stimuli consisted of six consonant-vowel-consonant triads divided into two classes (A1, B1, C1; A2, B2, C2. A simultaneous matching-to-sample task and differential reinforcement were employed during pretraining to establish the conditional relations A1:B1 and B1:C1 in class 1 and A2:B2 and B2:C2 in class 2. During functional neuroimaging, recombined stimulus pairs were presented and subjects judged (yes/no whether stimuli were related. SE tests involved presenting three different types of within-class pairs: Symmetrical (B1 A1; C1 B1; B2 A2; C2 B2, and Transitive (A1 C1; A2 C2 and Equivalence (C1 A1; C2 A2 relations separated by a nodal stimulus. Cross-class 'Foils' consisting of unrelated stimuli (e.g., A1 C2 were also presented. Results Relative to cross-class Foils, Transitive and Equivalence relations requiring inferential judgments elicited bilateral activation in the anterior hippocampus while Symmetrical relations elicited activation in the parahippocampus. Relative to each derived relation, Foils generally elicited bilateral activation in the parahippocampus, as well as in frontal and parietal lobe regions. Conclusion Activation observed in the hippocampus to nodal-dependent derived conditional relations (Transitive and Equivalence relations highlights its involvement in maintaining relational structure and flexible memory expression among stimuli within a

  20. The neural plasticity of early-passage human bone marrow-derived mesenchymal stem cells and their modulation with chromatin-modifying agents.

    Science.gov (United States)

    Zhang, Zhiying; Alexanian, Arshak R

    2014-05-01

    Mesenchymal stem cells (MSCs) in their immature state express a variety of genes of the three germ layers at relatively low or moderate levels that might explain their phenomenal plasticity. Numerous recent studies have demonstrated that under the appropriate conditions in vitro and in vivo the expression of different sets of these genes can be upregulated, turning MSCs into variety of cell lineages of mesodermal, ectodermal and endodermal origin. While transdifferentiation of MSCs is still controversial, these unique properties make MSCs an ideal autologous source of easily reprogrammable cells. Recently, using the approach of cell reprogramming by biological active compounds that interfere with chromatin structure and function, as well as with specific signalling pathways that promote neural fate commitment, we have been able to generate neural-like cells from human bone marrow (BM)-derived MSCs (hMSCs). However, the efficiency of neural transformation of hMSCs induced by this approach gradually declined with passaging. To elucidate the mechanisms that underlie the higher plasticity of early-passage hMSCs, comparative analysis of the expression levels of several pluripotent and neural genes was conducted for early- and late-passage hMSCs. The results demonstrated that early-passage hMSCs expressed the majority of these genes at low and moderate levels that gradually declined at late passages. Neural induction further increased the expression of some of these genes in hMSCs, accompanied by morphological changes into neural-like cells. We concluded that low and moderate expression of several pluripotent and neural genes in early-passage hMSCs could explain their higher plasticity and pliability for neural induction. Copyright © 2012 John Wiley & Sons, Ltd.

  1. Morphological comparison of the craniofacial phenotypes of mouse models expressing the Apert FGFR2 S252W mutation in neural crest- or mesoderm-derived tissues.

    Science.gov (United States)

    Heuzé, Yann; Singh, Nandini; Basilico, Claudio; Jabs, Ethylin Wang; Holmes, Greg; Richtsmeier, Joan T

    2014-06-01

    Bones of the craniofacial skeleton are derived from two distinct cell lineages, cranial neural crest and mesoderm, and articulate at sutures and synchondroses which represent major bone growth sites. Premature fusion of cranial suture(s) is associated with craniofacial dysmorphogenesis caused in part by alteration in the growth potential at sutures and can occur as an isolated birth defect or as part of a syndrome, such as Apert syndrome. Conditional expression of the Apert FGFR2 S252W mutation in cells derived from mesoderm was previously shown to be necessary and sufficient to cause coronal craniosynostosis. Here we used micro computed tomography images of mice expressing the Apert mutation constitutively in either mesoderm- or neural crest-derived cells to quantify craniofacial shape variation and suture fusion patterns, and to identify shape changes in craniofacial bones derived from the lineage not expressing the mutation, referred to here as secondary shape changes. Our results show that at postnatal day 0: (i) conditional expression of the FGFR2 S252W mutation in neural crest-derived tissues causes a more severe craniofacial phenotype than when expressed in mesoderm-derived tissues; and (ii) both mesoderm- and neural crest-specific mouse models display secondary shape changes. We also show that premature suture fusion is not necessarily dependent on the expression of the FGFR2 S252W mutation in the sutural mesenchyme. More specifically, it appears that suture fusion patterns in both mouse models are suture-specific resulting from a complex combination of the influence of primary abnormalities of biogenesis or signaling within the sutures, and timing. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Thymic and lymph node mesenchymal subsets can be derived from PDGFRα/β+Gp38+CD34+ICAM1- vascular adventitial precursors

    DEFF Research Database (Denmark)

    Sitnik, Katarzyna Maria; Wendland, Kerstin; Weishaupt, Holger

    developed from a common PDGFRα/β+Gp38+CD34-ICAM1- embryonic precursor population. Notably, precursor-progeny studies involving transfer of adult thymus- and adipose tissue-derived BP3-Gp38+PDGFRα+CD34+ICAM1- cells into thymic and LN re-aggregate organ grafts uncovered a precursor activity towards not only...... (FDC), both organs were populated by two corresponding subsets of BP3- PDGFRβ+ cells, PDGFRα-Gp38-ITGA7+ pericytes and PDGFRα+Gp38+CD34+ cells localized in the vascular adventitia and in the capsule. Focusing on the thymus as a model organ we obtain evidence that the latter two subsets initially...... pericytes but also BP3+ FRC, MRC and FDC and provided evidence of local environmental imprinting of BP3-Gp38+ cells with organ-specific features. Finally, we demonstrate that BP3-Gp38+ mesenchymal cell maintenance/maturation in the thymus requires LTβR signaling while this pathway appeared dispensable...

  3. Investigation of Content, Stoichiometry and Transfer of miRNA from Human Neural Stem Cell Line Derived Exosomes.

    Directory of Open Access Journals (Sweden)

    Lara Stevanato

    Full Text Available Exosomes are small (30-100 nm membrane vesicles secreted by a variety of cell types and only recently have emerged as a new avenue for cell-to-cell communication. They are natural shuttles of RNA and protein cargo, making them attractive as potential therapeutic delivery vehicles. MicroRNAs (miRNAs are short non-coding RNAs which regulate biological processes and can be found in exosomes. Here we characterized the miRNA contents of exosomes derived from human neural stem cells (hNSCs. Our investigated hNSC line is a clonal, conditionally immortalized cell line, compliant with good manufacturing practice (GMP, and in clinical trials for stroke and critical limb ischemia in the UK (clinicaltrials.gov: NCT01151124, NCT02117635, and NCT01916369. By using next generation sequencing (NGS technology we identified the presence of a variety of miRNAs in both exosomal and cellular preparations. Many of these miRNAs were enriched in exosomes indicating that cells specifically sort them for extracellular release. Although exosomes have been proven to contain miRNAs, the copy number quantification per exosome of a given miRNA remains unclear. Herein we quantified by real-time PCR a highly shuttled exosomal miRNA subtype (hsa-miR-1246 in order to assess its stoichiometry per exosome. Furthermore, we utilized an in vitro system to confirm its functional transfer by measuring the reduction in luciferase expression using a 3' untranslated region dual luciferase reporter assay. In summary, NGS analysis allowed the identification of a unique set of hNSC derived exosomal miRNAs. Stoichiometry and functional transfer analysis of one of the most abundant identified miRNA, hsa-miR-1246, were measured to support biological relevance of exosomal miRNA delivery.

  4. A Human Neural Crest Stem Cell-Derived Dopaminergic Neuronal Model Recapitulates Biochemical Abnormalities in GBA1 Mutation Carriers

    Directory of Open Access Journals (Sweden)

    Shi-Yu Yang

    2017-03-01

    Full Text Available Numerically the most important risk factor for the development of Parkinson's disease (PD is the presence of mutations in the glucocerebrosidase GBA1 gene. In vitro and in vivo studies show that GBA1 mutations reduce glucocerebrosidase (GCase activity and are associated with increased α-synuclein levels, reflecting similar changes seen in idiopathic PD brain. We have developed a neural crest stem cell-derived dopaminergic neuronal model that recapitulates biochemical abnormalities in GBA1 mutation-associated PD. Cells showed reduced GCase protein and activity, impaired macroautophagy, and increased α-synuclein levels. Advantages of this approach include easy access to stem cells, no requirement to reprogram, and retention of the intact host genome. Treatment with a GCase chaperone increased GCase protein levels and activity, rescued the autophagic defects, and decreased α-synuclein levels. These results provide the basis for further investigation of GCase chaperones or similar drugs to slow the progression of PD.

  5. Neural network modelling of antifungal activity of a series of oxazole derivatives based on in silico pharmacokinetic parameters

    Directory of Open Access Journals (Sweden)

    Kovačević Strahinja Z.

    2013-01-01

    Full Text Available In the present paper, the antifungal activity of a series of benzoxazole and oxazolo[ 4,5-b]pyridine derivatives was evaluated against Candida albicans by using quantitative structure-activity relationships chemometric methodology with artificial neural network (ANN regression approach. In vitro antifungal activity of the tested compounds was presented by minimum inhibitory concentration expressed as log(1/cMIC. In silico pharmacokinetic parameters related to absorption, distribution, metabolism and excretion (ADME were calculated for all studied compounds by using PreADMET software. A feedforward back-propagation ANN with gradient descent learning algorithm was applied for modelling of the relationship between ADME descriptors (blood-brain barrier penetration, plasma protein binding, Madin-Darby cell permeability and Caco-2 cell permeability and experimental log(1/cMIC values. A 4-6-1 ANN was developed with the optimum momentum and learning rates of 0.3 and 0.05, respectively. An excellent correlation between experimental antifungal activity and values predicted by the ANN was obtained with a correlation coefficient of 0.9536. [Projekat Ministarstva nauke Republike Srbije, br. 172012 i br. 172014

  6. Neuroprotective Properties of Endocannabinoids N-Arachidonoyl Dopamine and N-Docosahexaenoyl Dopamine Examined in Neuronal Precursors Derived from Human Pluripotent Stem Cells.

    Science.gov (United States)

    Novosadova, E V; Arsenyeva, E L; Manuilova, E S; Khaspekov, L G; Bobrov, M Yu; Bezuglov, V V; Illarioshkin, S N; Grivennikov, I A

    2017-11-01

    Neuroprotective properties of endocannabinoids N-arachidonoyl dopamine (NADA) and N-docosahexaenoyl dopamine (DHDA) were examined in neuronal precursor cells differentiated from human induced pluripotent stem cells and subjected to oxidative stress. Both compounds exerted neuroprotective activity, which was enhanced by elevating the concentration of the endocannabinoids within the 0.1-10 µM range. However, both agents at 10 µM concentration showed a marked toxic effect resulting in death of ~30% of the cells. Finally, antagonists of cannabinoid receptors as well as the receptor of the TRPV1 endovanilloid system did not hamper the neuroprotective effects of these endocannabinoids.

  7. Development of Ni-Based Catalysts Derived from Hydrotalcite-Like Compounds Precursors for Synthesis Gas Production via Methane or Ethanol Reforming

    Directory of Open Access Journals (Sweden)

    Ya-Li Du

    2017-02-01

    Full Text Available As a favorably clean fuel, syngas (synthesis gas production has been the focus of concern in past decades. Substantial literatures reported the syngas production by various catalytic reforming reactions particularly in methane or ethanol reforming. Among the developed catalysts in these reforming processes, Ni-based catalysts from hydrotalcite-like compounds (HTLcs precursors have drawn considerable attention for their preferable structural traits. This review covers the recent literature reporting syngas production with Ni-based catalysts from HTLc precursors via methane or ethanol reforming. The discussion was initiated with catalyst preparation (including conventional and novel means, followed by subsequent thermal treatment processes, then composition design and the addition of promoters in these catalysts. As Ni-based catalysts have thermodynamic potential to deactivate because of carbon deposition or metal sintering, measures for dealing with these problems were finally summarized. To obtain optimal catalytic performances and resultantly better syngas production, based on analyzing the achievements of the references, some perspectives were finally proposed.

  8. Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor

    Energy Technology Data Exchange (ETDEWEB)

    Vallet, Ana, E-mail: avallet@quim.ucm.es [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Besson, Michele, E-mail: michele.besson@ircelyon.univ-lyon1.fr [IRCELYON, Institut de recherches sur la catalyse et l' environnement de Lyon, UMR5256 CNRS-Universite Lyon1, 2 Avenue Albert Einstein, F-69626 Villeurbanne Cedex (France); Ovejero, Gabriel; Garcia, Juan [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Ni supported over hydrotalcite calcined precursors as catalyst. Black-Right-Pointing-Pointer Catalytic wet air oxidation in trickle bed reactor for Basic Yellow 11 removal. Black-Right-Pointing-Pointer Dye removal depends on temperature, initial dye concentration and flow rate. Black-Right-Pointing-Pointer The catalyst proved to be stable and efficient for the dye degradation. - Abstract: Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550 Degree-Sign C. An increase in the reaction temperature (120-180 Degree-Sign C), and a decrease in dye concentration (1000-3000 ppm) or liquid flow rate (0.1-0.7 mL min{sup -1}) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min{sup -1} and 180 Degree-Sign C under 5 MPa air.

  9. Vitamin E-Mediated Modulation of Glutamate Receptor Expression in an Oxidative Stress Model of Neural Cells Derived from Embryonic Stem Cell Cultures

    Directory of Open Access Journals (Sweden)

    Afifah Abd Jalil

    2017-01-01

    Full Text Available Glutamate is the primary excitatory neurotransmitter in the central nervous system. Excessive concentrations of glutamate in the brain can be excitotoxic and cause oxidative stress, which is associated with Alzheimer’s disease. In the present study, the effects of vitamin E in the form of tocotrienol-rich fraction (TRF and alpha-tocopherol (α-TCP in modulating the glutamate receptor and neuron injury markers in an in vitro model of oxidative stress in neural-derived embryonic stem (ES cell cultures were elucidated. A transgenic mouse ES cell line (46C was differentiated into a neural lineage in vitro via induction with retinoic acid. These cells were then subjected to oxidative stress with a significantly high concentration of glutamate. Measurement of reactive oxygen species (ROS was performed after inducing glutamate excitotoxicity, and recovery from this toxicity in response to vitamin E was determined. The gene expression levels of glutamate receptors and neuron-specific enolase were elucidated using real-time PCR. The results reveal that neural cells derived from 46C cells and subjected to oxidative stress exhibit downregulation of NMDA, kainate receptor, and NSE after posttreatment with different concentrations of TRF and α-TCP, a sign of neurorecovery. Treatment of either TRF or α-TCP reduced the levels of ROS in neural cells subjected to glutamate-induced oxidative stress; these results indicated that vitamin E is a potent antioxidant.

  10. Self-assembled SnO2 micro- and nanosphere-based gas sensor thick films from an alkoxide-derived high purity aqueous colloid precursor

    Science.gov (United States)

    Kelp, G.; Tätte, T.; Pikker, S.; Mändar, H.; Rozhin, A. G.; Rauwel, P.; Vanetsev, A. S.; Gerst, A.; Merisalu, M.; Mäeorg, U.; Natali, M.; Persson, I.; Kessler, V. G.

    2016-03-01

    Tin oxide is considered to be one of the most promising semiconductor oxide materials for use as a gas sensor. However, a simple route for the controllable build-up of nanostructured, sufficiently pure and hierarchical SnO2 structures for gas sensor applications is still a challenge. In the current work, an aqueous SnO2 nanoparticulate precursor sol, which is free of organic contaminants and sorbed ions and is fully stable over time, was prepared in a highly reproducible manner from an alkoxide Sn(OR)4 just by mixing it with a large excess of pure neutral water. The precursor is formed as a separate liquid phase. The structure and purity of the precursor is revealed using XRD, SAXS, EXAFS, HRTEM imaging, FTIR, and XRF analysis. An unconventional approach for the estimation of the particle size based on the quantification of the Sn-Sn contacts in the structure was developed using EXAFS spectroscopy and verified using HRTEM. To construct sensors with a hierarchical 3D structure, we employed an unusual emulsification technique not involving any additives or surfactants, using simply the extraction of the liquid phase, water, with the help of dry butanol under ambient conditions. The originally generated crystalline but yet highly reactive nanoparticles form relatively uniform spheres through self-assembly and solidify instantly. The spheres floating in butanol were left to deposit on the surface of quartz plates bearing sputtered gold electrodes, producing ready-for-use gas sensors in the form of ca. 50 μm thick sphere-based-films. The films were dried for 24 h and calcined at 300 °C in air before use. The gas sensitivity of the structures was tested in the temperature range of 150-400 °C. The materials showed a very quickly emerging and reversible (20-30 times) increase in electrical conductivity as a response to exposure to air containing 100 ppm of H2 or CO and short (10 s) recovery times when the gas flow was stopped.Tin oxide is considered to be one of the

  11. Integrative analysis of genes and miRNA alterations in human embryonic stem cells-derived neural cells after exposure to silver nanoparticles.

    Science.gov (United States)

    Oh, Jung-Hwa; Son, Mi-Young; Choi, Mi-Sun; Kim, Soojin; Choi, A-Young; Lee, Hyang-Ae; Kim, Ki-Suk; Kim, Janghwan; Song, Chang Woo; Yoon, Seokjoo

    2016-05-15

    Given the rapid growth of engineered and customer products made of silver nanoparticles (Ag NPs), understanding their biological and toxicological effects on humans is critically important. The molecular developmental neurotoxic effects associated with exposure to Ag NPs were analyzed at the physiological and molecular levels, using an alternative cell model: human embryonic stem cell (hESC)-derived neural stem/progenitor cells (NPCs). In this study, the cytotoxic effects of Ag NPs (10-200μg/ml) were examined in these hESC-derived NPCs, which have a capacity for neurogenesis in vitro, at 6 and 24h. The results showed that Ag NPs evoked significant toxicity in hESC-derived NPCs at 24h in a dose-dependent manner. In addition, Ag NPs induced cell cycle arrest and apoptosis following a significant increase in oxidative stress in these cells. To further clarify the molecular mechanisms of the toxicological effects of Ag NPs at the transcriptional and post-transcriptional levels, the global expression profiles of genes and miRNAs were analyzed in hESC-derived NPCs after Ag NP exposure. The results showed that Ag NPs induced oxidative stress and dysfunctional neurogenesis at the molecular level in hESC-derived NPCs. Based on this hESC-derived neural cell model, these findings have increased our understanding of the molecular events underlying developmental neurotoxicity induced by Ag NPs in humans. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Comparison of intraspinal and intrathecal implantation of induced pluripotent stem cell-derived neural precursors for the treatment of spinal cord injury in rats

    Czech Academy of Sciences Publication Activity Database

    Amemori, Takashi; Růžička, Jiří; Romanyuk, Nataliya; Jhanwar-Uniyal, M.; Syková, Eva; Jendelová, Pavla

    2015-01-01

    Roč. 6, Dec (2015), s. 257 ISSN 1757-6512 R&D Projects: GA MŠk(CZ) LH12024 Institutional support: RVO:68378041 Keywords : spinal cord injury * human induced pluripotent stem cells * cell therapy * cell application route Subject RIV: FH - Neurology Impact factor: 4.504, year: 2015

  13. Cu/Cu2O/CuO loaded on the carbon layer derived from novel precursors with amazing catalytic performance.

    Science.gov (United States)

    Zhao, Xiaoli; Tan, Yixin; Wu, Fengchang; Niu, Hongyun; Tang, Zhi; Cai, Yaqi; Giesy, John P

    2016-11-15

    A simple, novel method for synthesis of Cu/Cu2O/CuO on surfaces of carbon (Cu/Cu2O/CuO@C) as a non-noble-metal catalyst for reduction of organic compounds is presented. Compared with noble metals, Cu/Cu2O/CuO@C particles are more efficient and less expensive. Characterization of the Cu/Cu2O/CuO@C composites by high-resolution transmission electron microscope (HRTEM), x-ray diffraction (XRD), infrared spectroscopy and Raman analysis, revealed that it was composed of graphitized carbon with numerous nanoparticles (100nm in diameter) of Cu/CuO/Cu2O that were uniformly distributed on internal and external surfaces of the carbon support. Gallic acid (GA) has been used as both organic ligand and carbon precursor with metal organic frameworks (MOFs) as the sacrificial template and metal oxide precursor in this green synthesis. The material combined the advantages of MOFs and Cu-containing materials, the porous structure provided a large contact area and channels for the pollutions, which results in more rapid catalytic degradation of pollutants and leads to greater efficiency of catalysis. The material gave excellent catalytic performance for organic dyes and phenols. In this study, Cu/Cu2O/CuO@C was used as catalytic to reduce 4-NP, which has been usually adopted as a model reaction to check the catalytic ability. Catalytic experiment results show that 4-NP was degraded approximately 3min by use of 0.04mg of catalyst and the conversion of pollutants can reach more than 99%. The catalyst exhibited little change in efficacy after being utilized five times. Rates of degradation of dyes, such as Methylene blue (MB) and Rhodamine B (RhB) and phenolic compounds such as O-Nitrophenol (O-NP) and 2-Nitroaniline (2-NA) were all similar. Copyright © 2016. Published by Elsevier B.V.

  14. Integrative analysis of genes and miRNA alterations in human embryonic stem cells-derived neural cells after exposure to silver nanoparticles

    International Nuclear Information System (INIS)

    Oh, Jung-Hwa; Son, Mi-Young; Choi, Mi-Sun; Kim, Soojin; Choi, A-young; Lee, Hyang-Ae; Kim, Ki-Suk; Kim, Janghwan; Song, Chang Woo; Yoon, Seokjoo

    2016-01-01

    Given the rapid growth of engineered and customer products made of silver nanoparticles (Ag NPs), understanding their biological and toxicological effects on humans is critically important. The molecular developmental neurotoxic effects associated with exposure to Ag NPs were analyzed at the physiological and molecular levels, using an alternative cell model: human embryonic stem cell (hESC)-derived neural stem/progenitor cells (NPCs). In this study, the cytotoxic effects of Ag NPs (10–200 μg/ml) were examined in these hESC-derived NPCs, which have a capacity for neurogenesis in vitro, at 6 and 24 h. The results showed that Ag NPs evoked significant toxicity in hESC-derived NPCs at 24 h in a dose-dependent manner. In addition, Ag NPs induced cell cycle arrest and apoptosis following a significant increase in oxidative stress in these cells. To further clarify the molecular mechanisms of the toxicological effects of Ag NPs at the transcriptional and post-transcriptional levels, the global expression profiles of genes and miRNAs were analyzed in hESC-derived NPCs after Ag NP exposure. The results showed that Ag NPs induced oxidative stress and dysfunctional neurogenesis at the molecular level in hESC-derived NPCs. Based on this hESC-derived neural cell model, these findings have increased our understanding of the molecular events underlying developmental neurotoxicity induced by Ag NPs in humans. - Highlights: • This system served as a suitable model for developmental neurotoxicity testing. • Ag NPs induce the apoptosis in human neural cells by ROS generation. • Genes for development of neurons were dysregulated in response to Ag NPs. • Molecular events during early developmental neurotoxicity were proposed.

  15. Caudalized human iPSC-derived neural progenitor cells produce neurons and glia but fail to restore function in an early chronic spinal cord injury model

    Science.gov (United States)

    Nutt, Samuel E.; Chang, Eun-Ah; Suhr, Steven T.; Schlosser, Laura O.; Mondello, Sarah E.; Moritz, Chet T.; Cibelli, Jose B.; Horner, Philip J.

    2014-01-01

    Neural progenitor cells (NPCs) have shown modest potential and some side effects (e.g. allodynia) for treatment of spinal cord injury (SCI). In only a few cases, however, have NPCs shown promise at the chronic stage. Given the 1.275 million people living with chronic paralysis, there is a significant need to rigorously evaluate the cell types and methods for safe and efficacious treatment of this devastating condition. For the first time, we examined the pre-clinical potential of NPCs derived from human induced pluripotent stem cells (hiPSCs) to repair chronic SCI. hiPSCs were differentiated into region-specific (i.e. caudal) NPCs, then transplanted into a new, clinically relevant model of early chronic cervical SCI. We established the conditions for successful transplantation of caudalized hiPSC-NPCs and demonstrate their remarkable ability to integrate and produce multiple neural lineages in the early chronic injury environment. In contrast to prior reports in acute and sub-acute injury models, survival and integration of hiPSC-derived neural cells in the early chronic cervical model did not lead to significant improvement in forelimb function or induce allodynia. These data indicate that while hiPSCs show promise, future work needs to focus on the specific hiPSC-derivatives or co-therapies that will restore function in the early chronic injury setting. PMID:23891888

  16. Healthy human CSF promotes glial differentiation of hESC-derived neural cells while retaining spontaneous activity in existing neuronal networks

    Directory of Open Access Journals (Sweden)

    Heikki Kiiski

    2013-05-01

    The possibilities of human pluripotent stem cell-derived neural cells from the basic research tool to a treatment option in regenerative medicine have been well recognized. These cells also offer an interesting tool for in vitro models of neuronal networks to be used for drug screening and neurotoxicological studies and for patient/disease specific in vitro models. Here, as aiming to develop a reductionistic in vitro human neuronal network model, we tested whether human embryonic stem cell (hESC-derived neural cells could be cultured in human cerebrospinal fluid (CSF in order to better mimic the in vivo conditions. Our results showed that CSF altered the differentiation of hESC-derived neural cells towards glial cells at the expense of neuronal differentiation. The proliferation rate was reduced in CSF cultures. However, even though the use of CSF as the culture medium altered the glial vs. neuronal differentiation rate, the pre-existing spontaneous activity of the neuronal networks persisted throughout the study. These results suggest that it is possible to develop fully human cell and culture-based environments that can further be modified for various in vitro modeling purposes.

  17. Interaction of adult human neural crest-derived stem cells with a nanoporous titanium surface is sufficient to induce their osteogenic differentiation

    Directory of Open Access Journals (Sweden)

    Matthias Schürmann

    2014-07-01

    Full Text Available Osteogenic differentiation of various adult stem cell populations such as neural crest-derived stem cells is of great interest in the context of bone regeneration. Ideally, exogenous differentiation should mimic an endogenous differentiation process, which is partly mediated by topological cues. To elucidate the osteoinductive potential of porous substrates with different pore diameters (30 nm, 100 nm, human neural crest-derived stem cells isolated from the inferior nasal turbinate were cultivated on the surface of nanoporous titanium covered membranes without additional chemical or biological osteoinductive cues. As controls, flat titanium without any topological features and osteogenic medium was used. Cultivation of human neural crest-derived stem cells on 30 nm pores resulted in osteogenic differentiation as demonstrated by alkaline phosphatase activity after seven days as well as by calcium deposition after 3 weeks of cultivation. In contrast, cultivation on flat titanium and on membranes equipped with 100 nm pores was not sufficient to induce osteogenic differentiation. Moreover, we demonstrate an increase of osteogenic transcripts including Osterix, Osteocalcin and up-regulation of Integrin β1 and α2 in the 30 nm pore approach only. Thus, transplantation of stem cells pre-cultivated on nanostructured implants might improve the clinical outcome by support of the graft adherence and acceleration of the regeneration process.

  18. Cryopreservation of embryonic stem cell-derived multicellular neural aggregates labeled with micron-sized particles of iron oxide for magnetic resonance imaging.

    Science.gov (United States)

    Yan, Yuanwei; Sart, Sébastien; Calixto Bejarano, Fabian; Muroski, Megan E; Strouse, Geoffrey F; Grant, Samuel C; Li, Yan

    2015-01-01

    Magnetic resonance imaging (MRI) provides an effective approach to track labeled pluripotent stem cell (PSC)-derived neural progenitor cells (NPCs) for neurological disorder treatments after cell labeling with a contrast agent, such as an iron oxide derivative. Cryopreservation of pre-labeled neural cells, especially in three-dimensional (3D) structure, can provide a uniform cell population and preserve the stem cell niche for the subsequent applications. In this study, the effects of cryopreservation on PSC-derived multicellular NPC aggregates labeled with micron-sized particles of iron oxide (MPIO) were investigated. These NPC aggregates were labeled prior to cryopreservation because labeling thawed cells can be limited by inefficient intracellular uptake, variations in labeling efficiency, and increased culture time before use, minimizing their translation to clinical settings. The results indicated that intracellular MPIO incorporation was retained after cryopreservation (70-80% labeling efficiency), and MPIO labeling had little adverse effects on cell recovery, proliferation, cytotoxicity and neural lineage commitment post-cryopreservation. MRI analysis showed comparable detectability for the MPIO-labeled cells before and after cryopreservation indicated by T2 and T2* relaxation rates. Cryopreserving MPIO-labeled 3D multicellular NPC aggregates can be applied in in vivo cell tracking studies and lead to more rapid translation from preservation to clinical implementation. © 2015 American Institute of Chemical Engineers.

  19. Neural Progenitor Cell Implants Modulate Vascular Endothelial Growth Factor and Brain-Derived Neurotrophic Factor Expression in Rat Axotomized Neurons

    Science.gov (United States)

    Talaverón, Rocío; Matarredona, Esperanza R.; de la Cruz, Rosa R.; Pastor, Angel M.

    2013-01-01

    Axotomy of central neurons leads to functional and structural alterations which largely revert when neural progenitor cells (NPCs) are implanted in the lesion site. The new microenvironment created by NPCs in the host tissue might modulate in the damaged neurons the expression of a high variety of molecules with relevant roles in the repair mechanisms, including neurotrophic factors. In the present work, we aimed to analyze changes in neurotrophic factor expression in axotomized neurons induced by NPC implants. For this purpose, we performed immunofluorescence followed by confocal microscopy analysis for the detection of vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and nerve growth factor (NGF) on brainstem sections from rats with axotomy of abducens internuclear neurons that received NPC implants (implanted group) or vehicle injections (axotomized group) in the lesion site. Control abducens internuclear neurons were strongly immunoreactive to VEGF and BDNF but showed a weak staining for NT-3 and NGF. Comparisons between groups revealed that lesioned neurons from animals that received NPC implants showed a significant increase in VEGF content with respect to animals receiving vehicle injections. However, the immunoreactivity for BDNF, which was increased in the axotomized group as compared to control, was not modified in the implanted group. The modifications induced by NPC implants on VEGF and BDNF content were specific for the population of axotomized abducens internuclear neurons since the neighboring abducens motoneurons were not affected. Similar levels of NT-3 and NGF immunolabeling were obtained in injured neurons from axotomized and implanted animals. Among all the analyzed neurotrophic factors, only VEGF was expressed by the implanted cells in the lesion site. Our results point to a role of NPC implants in the modulation of neurotrophic factor expression by lesioned central neurons, which might

  20. Neural progenitor cell implants modulate vascular endothelial growth factor and brain-derived neurotrophic factor expression in rat axotomized neurons.

    Directory of Open Access Journals (Sweden)

    Rocío Talaverón

    Full Text Available Axotomy of central neurons leads to functional and structural alterations which largely revert when neural progenitor cells (NPCs are implanted in the lesion site. The new microenvironment created by NPCs in the host tissue might modulate in the damaged neurons the expression of a high variety of molecules with relevant roles in the repair mechanisms, including neurotrophic factors. In the present work, we aimed to analyze changes in neurotrophic factor expression in axotomized neurons induced by NPC implants. For this purpose, we performed immunofluorescence followed by confocal microscopy analysis for the detection of vascular endothelial growth factor (VEGF, brain-derived neurotrophic factor (BDNF, neurotrophin-3 (NT-3 and nerve growth factor (NGF on brainstem sections from rats with axotomy of abducens internuclear neurons that received NPC implants (implanted group or vehicle injections (axotomized group in the lesion site. Control abducens internuclear neurons were strongly immunoreactive to VEGF and BDNF but showed a weak staining for NT-3 and NGF. Comparisons between groups revealed that lesioned neurons from animals that received NPC implants showed a significant increase in VEGF content with respect to animals receiving vehicle injections. However, the immunoreactivity for BDNF, which was increased in the axotomized group as compared to control, was not modified in the implanted group. The modifications induced by NPC implants on VEGF and BDNF content were specific for the population of axotomized abducens internuclear neurons since the neighboring abducens motoneurons were not affected. Similar levels of NT-3 and NGF immunolabeling were obtained in injured neurons from axotomized and implanted animals. Among all the analyzed neurotrophic factors, only VEGF was expressed by the implanted cells in the lesion site. Our results point to a role of NPC implants in the modulation of neurotrophic factor expression by lesioned central neurons

  1. Modified feed-forward neural network structures and combined-function-derivative approximations incorporating exchange symmetry for potential energy surface fitting.

    Science.gov (United States)

    Nguyen, Hieu T T; Le, Hung M

    2012-05-10

    The classical interchange (permutation) of atoms of similar identity does not have an effect on the overall potential energy. In this study, we present feed-forward neural network structures that provide permutation symmetry to the potential energy surfaces of molecules. The new feed-forward neural network structures are employed to fit the potential energy surfaces for two illustrative molecules, which are H(2)O and ClOOCl. Modifications are made to describe the symmetric interchange (permutation) of atoms of similar identity (or mathematically, the permutation of symmetric input parameters). The combined-function-derivative approximation algorithm (J. Chem. Phys. 2009, 130, 134101) is also implemented to fit the neural-network potential energy surfaces accurately. The combination of our symmetric neural networks and the function-derivative fitting effectively produces PES fits using fewer numbers of training data points. For H(2)O, only 282 configurations are employed as the training set; the testing root-mean-squared and mean-absolute energy errors are respectively reported as 0.0103 eV (0.236 kcal/mol) and 0.0078 eV (0.179 kcal/mol). In the ClOOCl case, 1693 configurations are required to construct the training set; the root-mean-squared and mean-absolute energy errors for the ClOOCl testing set are 0.0409 eV (0.943 kcal/mol) and 0.0269 eV (0.620 kcal/mol), respectively. Overall, we find good agreements between ab initio and NN prediction in term of energy and gradient errors, and conclude that the new feed-forward neural-network models advantageously describe the molecules with excellent accuracy.

  2. Crestospheres: Long-Term Maintenance of Multipotent, Premigratory Neural Crest Stem Cells

    Directory of Open Access Journals (Sweden)

    Laura Kerosuo

    2015-10-01

    Full Text Available Premigratory neural crest cells comprise a transient, embryonic population that arises within the CNS, but subsequently migrates away and differentiates into many derivatives. Previously, premigratory neural crest could not be maintained in a multipotent, adhesive state without spontaneous differentiation. Here, we report conditions that enable maintenance of neuroepithelial “crestospheres” that self-renew and retain multipotency for weeks. Moreover, under differentiation conditions, these cells can form multiple derivatives in vitro and in vivo after transplantation into chick embryos. Similarly, human embryonic stem cells directed to a neural crest fate can be maintained as crestospheres and subsequently differentiated into several derivatives. By devising conditions that maintain the premigratory state in vitro, these results demonstrate that neuroepithelial neural crest precursors are capable of long-term self-renewal. This approach will help uncover mechanisms underlying their developmental potential, differentiation and, together with the induced pluripotent stem cell techniques, the pathology of human neurocristopathies.

  3. Cu/Cu{sub 2}O/CuO loaded on the carbon layer derived from novel precursors with amazing catalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaoli, E-mail: zhaoxiaoli_zxl@126.com [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Tan, Yixin [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Wu, Fengchang, E-mail: wu_fengchang@126.com [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Niu, Hongyun [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Tang, Zhi [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Cai, Yaqi [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Giesy, John P. [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan (Canada)

    2016-11-15

    A simple, novel method for synthesis of Cu/Cu{sub 2}O/CuO on surfaces of carbon (Cu/Cu{sub 2}O/CuO@C) as a non-noble-metal catalyst for reduction of organic compounds is presented. Compared with noble metals, Cu/Cu{sub 2}O/CuO@C particles are more efficient and less expensive. Characterization of the Cu/Cu{sub 2}O/CuO@C composites by high-resolution transmission electron microscope (HRTEM), x-ray diffraction (XRD), infrared spectroscopy and Raman analysis, revealed that it was composed of graphitized carbon with numerous nanoparticles (100 nm in diameter) of Cu/CuO/Cu{sub 2}O that were uniformly distributed on internal and external surfaces of the carbon support. Gallic acid (GA) has been used as both organic ligand and carbon precursor with metal organic frameworks (MOFs) as the sacrificial template and metal oxide precursor in this green synthesis. The material combined the advantages of MOFs and Cu-containing materials, the porous structure provided a large contact area and channels for the pollutions, which results in more rapid catalytic degradation of pollutants and leads to greater efficiency of catalysis. The material gave excellent catalytic performance for organic dyes and phenols. In this study, Cu/Cu{sub 2}O/CuO@C was used as catalytic to reduce 4-NP, which has been usually adopted as a model reaction to check the catalytic ability. Catalytic experiment results show that 4-NP was degraded approximately 3 min by use of 0.04 mg of catalyst and the conversion of pollutants can reach more than 99%. The catalyst exhibited little change in efficacy after being utilized five times. Rates of degradation of dyes, such as Methylene blue (MB) and Rhodamine B (RhB) and phenolic compounds such as O-Nitrophenol (O-NP) and 2-Nitroaniline (2-NA) were all similar. - Highlights: • We present an effective catalyst for reductive degradation of organic dyes and phenols in water. • Compared with noble metals, Cu/Cu{sub 2}O/CuO@C particles are more efficient and less

  4. Enhanced detectability of fluorinated derivatives of N,N-dialkylamino alcohols and precursors of nitrogen mustards by gas chromatography coupled to Fourier transform infrared spectroscopy analysis for verification of chemical weapons convention.

    Science.gov (United States)

    Garg, Prabhat; Purohit, Ajay; Tak, Vijay K; Dubey, D K

    2009-11-06

    N,N-Dialkylamino alcohols, N-methyldiethanolamine, N-ethyldiethanolamine and triethanolamine are the precursors of VX type nerve agents and three different nitrogen mustards respectively. Their detection and identification is of paramount importance for verification analysis of chemical weapons convention. GC-FTIR is used as complimentary technique to GC-MS analysis for identification of these analytes. One constraint of GC-FTIR, its low sensitivity, was overcome by converting the analytes to their fluorinated derivatives. Owing to high absorptivity in IR region, these derivatives facilitated their detection by GC-FTIR analysis. Derivatizing reagents having trimethylsilyl, trifluoroacyl and heptafluorobutyryl groups on imidazole moiety were screened. Derivatives formed there were analyzed by GC-FTIR quantitatively. Of these reagents studied, heptafluorobutyrylimidazole (HFBI) produced the greatest increase in sensitivity by GC-FTIR detection. 60-125 folds of sensitivity enhancement were observed for the analytes by HFBI derivatization. Absorbance due to various functional groups responsible for enhanced sensitivity were compared by determining their corresponding relative molar extinction coefficients ( [Formula: see text] ) considering uniform optical path length. The RSDs for intraday repeatability and interday reproducibility for various derivatives were 0.2-1.1% and 0.3-1.8%. Limit of detection (LOD) was achieved up to 10-15ng and applicability of the method was tested with unknown samples obtained in international proficiency tests.

  5. Transplanted neurally modified bone marrow-derived mesenchymal stem cells promote tissue protection and locomotor recovery in spinal cord injured rats.

    Science.gov (United States)

    Alexanian, Arshak R; Fehlings, Michael G; Zhang, Zhiying; Maiman, Dennis J

    2011-01-01

    Stem cell-based therapy for repair and replacement of lost neural cells is a promising treatment for central nervous system (CNS) diseases. Bone marrow (BM)-derived mesenchymal stem cells (MSCs) can differentiate into neural phenotypes and be isolated and expanded for autotransplantation with no risk of rejection. The authors examined whether transplanted neurally induced human MSCs (NI hMSCs), developed by a new procedure, can survive, differentiate, and promote tissue protection and functional recovery in injured spinal cord (ISC) rats. Neural induction was achieved by exposing cells simultaneously to inhibitors of DNA methylation, histone deacetylation, and pharmacological agents that increased cAMP levels. Three groups of adult female Sprague-Dawley rats were injected immediately rostral and caudal to the midline lesion with phosphate-buffered saline, MSCs, or NI hMSCs, 1 week after a spinal cord impact injury at T-8. Functional outcome was measured using the Basso Beattie Bresnahan (BBB) locomotor rating scale and thermal sensitivity test on a weekly basis up to 12 weeks postinjury. Graft integration and anatomy of spinal cord was assessed by stereological, histochemical, and immunohistochemical techniques. The transplanted NI hMSCs survived, differentiated, and significantly improved locomotor recovery of ISC rats. Transplantation also reduced the volume of lesion cavity and white matter loss. This method of hMSC modification may provide an alternative source of autologous adult stem cells for CNS repair.

  6. X-ray Structures of Precursors of Styrylpyridine-Derivatives Used to Obtain 4-((E-2-(Pyridin-2-ylvinylbenzamido-TEMPO: Synthesis and Characterization

    Directory of Open Access Journals (Sweden)

    Guillermo Soriano-Moro

    2015-04-01

    Full Text Available The synthesis and characterization of the precursor isomers trans-4-(2-(pyridin-2-ylvinylbenzaldehyde (I, trans-4-(2-(pyridin-4-ylvinylbenzaldehyde (II, trans-4-(2-(pyridin-2-ylvinylbenzoic acid (III and (E-4-(2-(pydridin-4-ylvinylbenzoic acid (IV are reported. These compounds were prepared in order to obtain trans-4-((E-2-(pyridin-2-ylvinylbenzamide-TEMPO (V. Compounds I and II were obtained by using a Knoevenagel reaction in the absence of a condensing agent and solvent. Oxidation of the aldehyde group using the Jones reagent afforded the corresponding acid forms III and IV. A condensation reaction with 4-amino-TEMPO using oxalyl chloride/DMF/CH2Cl2 provided the 4-((E-2-(pyridin-2-ylvinylbenzamide-TEMPO. Single crystals of compounds I, II and III were obtained and characterized by X-ray diffraction. Compound I belongs to space group P21/c, a = 12.6674(19 Å, b = 7.2173(11 Å, c = 11.5877(14 Å, b = 97.203(13° and the asymmetric unit was Z = 4, whereas compound II was in the space group P21, with a = 3.85728(9 Å, b = 10.62375(19 Å, c = 12.8625(2 Å, b = 91.722 (2° and the asymmetric unit was Z = 2. Compound III crystallized as single colorless needle crystals, belonging to the monoclinic system with space group P21, with Z = 2, with a = 3.89359(7 Å, b = 17.7014(3 Å, c = 8.04530(12 Å, b = 94.4030 (16°. All compounds were completely characterized by IR, 1H-NMR, EI-MS and UV-Vis.

  7. Regenerative therapy for vestibular disorders using human induced pluripotent stem cells (iPSCs): neural differentiation of human iPSC-derived neural stem cells after in vitro transplantation into mouse vestibular epithelia.

    Science.gov (United States)

    Taura, Akiko; Nakashima, Noriyuki; Ohnishi, Hiroe; Nakagawa, Takayuki; Funabiki, Kazuo; Ito, Juichi; Omori, Koichi

    2016-10-01

    Vestibular ganglion cells, which convey sense of motion from vestibular hair cells to the brainstem, are known to degenerate with aging and after vestibular neuritis. Thus, regeneration of vestibular ganglion cells is important to aid in the recovery of balance for associated disorders. The present study derived hNSCs from induced pluripotent stem cells (iPSCs) and transplanted these cells into mouse utricle tissues. After a 7-day co-culture period, histological and electrophysiological examinations of transplanted hNSCs were performed. Injected hNSC-derived cells produced elongated axon-like structures within the utricle tissue that made contact with vestibular hair cells. A proportion of hNSC-derived cells showed spontaneous firing activities, similar to those observed in cultured mouse vestibular ganglion cells. However, hNSC-derived cells around the mouse utricle persisted as immature neurons or occasionally differentiated into putative astrocytes. Moreover, electrophysiological examination showed hNSC-derived cells around utricles did not exhibit any obvious spontaneous firing activities. Injected human neural stem cells (hNSCs) showed signs of morphological maturation including reconnection to denervated hair cells and partial physiological maturation, suggesting hNSC-derived cells possibly differentiated into neurons.

  8. [PROFILE OF THE MARROW-DERIVED STROMAL PRECURSORS POPULATION IN C57BL/6N MICE FLOWN ON BIOSATELLITE BION-M1].

    Science.gov (United States)

    Markina, E A; Bobyleva, P I; Andrianova, I V; Andreeva, E R; Buravkova, L B

    2015-01-01

    The CFU-F number, proliferative activity and spontaneous differentiation potential of stromal cells derived from the tibia marrow of C57BL/6N mice readapted to the 1-g gravity following a long-term flight on biosatellite Bion-M1 were evaluated. The CFU-F number, proliferative activity and spontaneous adipogenic and osteogenic differentiation of marrow-derived stromal cells from the space flown group were no different from the group of vivarium control. However, the proliferative activity and adhesion properties of the cells were down-regulated on day 7 of readaptation. These results suggest that space flight factors did not impact the stromal differon of the mouse marrow. The decline of stromal cells activity indicates the decompensation of their functions under 1g gravity.

  9. Discovery of the 3-Imino-1,2,4-thiadiazinane 1,1-Dioxide Derivative Verubecestat (MK-8931)–A β-Site Amyloid Precursor Protein Cleaving Enzyme 1 Inhibitor for the Treatment of Alzheimer’s Disease

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Jack D.; Li, Sarah W.; Brunskill, Andrew P.J.; Chen, Xia; Cox, Kathleen; Cumming, Jared N.; Forman, Mark; Gilbert, Eric J.; Hodgson, Robert A.; Hyde, Lynn A.; Jiang, Qin; Iserloh, Ulrich; Kazakevich, Irina; Kuvelkar, Reshma; Mei, Hong; Meredith, John; Misiaszek, Jeffrey; Orth, Peter; Rossiter, Lana M.; Slater, Meagan; Stone, Julie; Strickland, Corey O.; Voigt, Johannes H.; Wang, Ganfeng; Wang, Hongwu; Wu, Yusheng; Greenlee, William J.; Parker, Eric M.; Kennedy, Matthew E.; Stamford, Andrew W. (Merck)

    2016-12-08

    Verubecestat 3 (MK-8931), a diaryl amide-substituted 3-imino-1,2,4-thiadiazinane 1,1-dioxide derivative, is a high-affinity β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitor currently undergoing Phase 3 clinical evaluation for the treatment of mild to moderate and prodromal Alzheimer’s disease. Although not selective over the closely related aspartyl protease BACE2, verubecestat has high selectivity for BACE1 over other key aspartyl proteases, notably cathepsin D, and profoundly lowers CSF and brain Aβ levels in rats and nonhuman primates and CSF Aβ levels in humans. In this annotation, we describe the discovery of 3, including design, validation, and selected SAR around the novel iminothiadiazinane dioxide core as well as aspects of its preclinical and Phase 1 clinical characterization.

  10. Self-renewal and differentiation of reactive astrocyte-derived neural stem/progenitor cells isolated from the cortical peri-infarct area after stroke.

    Science.gov (United States)

    Shimada, Issei S; LeComte, Matthew D; Granger, Jerrica C; Quinlan, Noah J; Spees, Jeffrey L

    2012-06-06

    In response to stroke, subpopulations of cortical reactive astrocytes proliferate and express proteins commonly associated with neural stem/progenitor cells such as glial fibrillary acidic protein (GFAP) and Nestin. To examine the stem cell-related properties of cortical reactive astrocytes after injury, we generated GFAP-CreER(TM);tdRFP mice to permanently label reactive astrocytes. We isolated cells from the cortical peri-infarct area 3 d after stroke, and cultured them in neural stem cell medium containing epidermal growth factor and basic fibroblast growth factor. We observed tdRFP-positive neural spheres in culture, suggestive of tdRFP-positive reactive astrocyte-derived neural stem/progenitor cells (Rad-NSCs). Cultured Rad-NSCs self-renewed and differentiated into neurons, astrocytes, and oligodendrocytes. Pharmacological inhibition and conditional knock-out mouse studies showed that Presenilin 1 and Notch 1 controlled neural sphere formation by Rad-NSCs after stroke. To examine the self-renewal and differentiation potential of Rad-NSCs in vivo, Rad-NSCs were transplanted into embryonic, neonatal, and adult mouse brains. Transplanted Rad-NSCs were observed to persist in the subventricular zone and secondary Rad-NSCs were isolated from the host brain 28 d after transplantation. In contrast with neurogenic postnatal day 4 NSCs and adult NSCs from the subventricular zone, transplanted Rad-NSCs differentiated into astrocytes and oligodendrocytes, but not neurons, demonstrating that Rad-NSCs had restricted differentiation in vivo. Our results indicate that Rad-NSCs are unlikely to be suitable for neuronal replacement in the absence of genetic or epigenetic modification.

  11. COAL DERIVED MATRIX PITCHES FOR CARBON-CARBON COMPOSITE MANUFACTURE/PRODUCTION OF FIBERS AND COMPOSITES FROM COAL-BASED PRECURSORS

    Energy Technology Data Exchange (ETDEWEB)

    Peter G. Stansberry; John W. Zondlo

    2001-07-01

    The Consortium for premium Carbon Products from Coal, with funding from the US Department of Energy, National Energy Technology Laboratory continue with the development of innovative technologies that will allow coal or coal-derived feedstocks to be used in the production of value-added carbon materials. In addition to supporting eleven independent projects during budget period 3, three meetings were held at two separate locations for the membership. The first was held at Nemacolin Woodlands Resort on May 15-16, 2000. This was followed by two meetings at Penn State, a tutorial on August 11, 2000 and a technical progress meeting on October 26-27.

  12. The Neural Cell Adhesion Molecule-Derived Peptide FGL Facilitates Long-Term Plasticity in the Dentate Gyrus in Vivo

    Science.gov (United States)

    Dallerac, Glenn; Zerwas, Meike; Novikova, Tatiana; Callu, Delphine; Leblanc-Veyrac, Pascale; Bock, Elisabeth; Berezin, Vladimir; Rampon, Claire; Doyere, Valerie

    2011-01-01

    The neural cell adhesion molecule (NCAM) is known to play a role in developmental and structural processes but also in synaptic plasticity and memory of the adult animal. Recently, FGL, a NCAM mimetic peptide that binds to the Fibroblast Growth Factor Receptor 1 (FGFR-1), has been shown to have a beneficial impact on normal memory functioning, as…

  13. Female Mice Deficient in Alpha-Fetoprotein Show Female-Typical Neural Responses to Conspecific-Derived Pheromones

    NARCIS (Netherlands)

    Brock, O.; Keller, M.; Douhard, Q.; Bakker, J.

    2012-01-01

    The neural mechanisms controlling sexual behavior are sexually differentiated by the perinatal actions of sex steroid hormones. We recently observed using female mice deficient in alpha-fetoprotein (AFP-KO) and which lack the protective actions of AFP against maternal estradiol, that exposure to

  14. The Postischemic Environment Differentially Impacts Teratoma or Tumor Formation After Transplantation of Human Embryonic Stem Cell-Derived Neural Progenitors

    Czech Academy of Sciences Publication Activity Database

    Seminatore, CH.; Polentes, J.; Ellman, D.; Kozubenko, Nataliya; Itier, V.; Tine, S.; Tritschler, L.; Brenot, M.; Guidou, E.; Blondeau, J.; Lhuillier, M.; Bugi, A.; Aubry, L.; Jendelová, Pavla; Syková, Eva; Perrier, A. L.; Finsen, B.; Onteniente, B.

    2010-01-01

    Roč. 41, č. 1 (2010), s. 153-159 ISSN 0039-2499 Institutional research plan: CEZ:AV0Z50390703 Keywords : brain transplantation * human embryonic stem cells * neural differentiation Subject RIV: FH - Neurology Impact factor: 5.756, year: 2010

  15. A rosette-type, self-renewing human ES cell-derived neural stem cell with potential for in vitro instruction and synaptic integration

    OpenAIRE

    Koch, Philipp; Opitz, Thoralf; Steinbeck, Julius A.; Ladewig, Julia; Brüstle, Oliver

    2009-01-01

    An intriguing question in human embryonic stem cell (hESC) biology is whether these pluripotent cells can give rise to stably expandable somatic stem cells, which are still amenable to extrinsic fate instruction. Here, we present a pure population of long-term self-renewing rosette-type hESC-derived neural stem cells (lt-hESNSCs), which exhibit extensive self-renewal, clonogenicity, and stable neurogenesis. Although lt-hESNSCs show a restricted expression of regional transcription factors, th...

  16. Using Graph Components Derived from an Associative Concept Dictionary to Predict fMRI Neural Activation Patterns that Represent the Meaning of Nouns.

    Science.gov (United States)

    Akama, Hiroyuki; Miyake, Maki; Jung, Jaeyoung; Murphy, Brian

    2015-01-01

    In this study, we introduce an original distance definition for graphs, called the Markov-inverse-F measure (MiF). This measure enables the integration of classical graph theory indices with new knowledge pertaining to structural feature extraction from semantic networks. MiF improves the conventional Jaccard and/or Simpson indices, and reconciles both the geodesic information (random walk) and co-occurrence adjustment (degree balance and distribution). We measure the effectiveness of graph-based coefficients through the application of linguistic graph information for a neural activity recorded during conceptual processing in the human brain. Specifically, the MiF distance is computed between each of the nouns used in a previous neural experiment and each of the in-between words in a subgraph derived from the Edinburgh Word Association Thesaurus of English. From the MiF-based information matrix, a machine learning model can accurately obtain a scalar parameter that specifies the degree to which each voxel in (the MRI image of) the brain is activated by each word or each principal component of the intermediate semantic features. Furthermore, correlating the voxel information with the MiF-based principal components, a new computational neurolinguistics model with a network connectivity paradigm is created. This allows two dimensions of context space to be incorporated with both semantic and neural distributional representations.

  17. Using Graph Components Derived from an Associative Concept Dictionary to Predict fMRI Neural Activation Patterns that Represent the Meaning of Nouns.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Akama

    Full Text Available In this study, we introduce an original distance definition for graphs, called the Markov-inverse-F measure (MiF. This measure enables the integration of classical graph theory indices with new knowledge pertaining to structural feature extraction from semantic networks. MiF improves the conventional Jaccard and/or Simpson indices, and reconciles both the geodesic information (random walk and co-occurrence adjustment (degree balance and distribution. We measure the effectiveness of graph-based coefficients through the application of linguistic graph information for a neural activity recorded during conceptual processing in the human brain. Specifically, the MiF distance is computed between each of the nouns used in a previous neural experiment and each of the in-between words in a subgraph derived from the Edinburgh Word Association Thesaurus of English. From the MiF-based information matrix, a machine learning model can accurately obtain a scalar parameter that specifies the degree to which each voxel in (the MRI image of the brain is activated by each word or each principal component of the intermediate semantic features. Furthermore, correlating the voxel information with the MiF-based principal components, a new computational neurolinguistics model with a network connectivity paradigm is created. This allows two dimensions of context space to be incorporated with both semantic and neural distributional representations.

  18. Quantitative Structure-Activity Relationships of Noncompetitive Antagonists of the NMDA Receptor: A Study of a Series of MK801 Derivative Molecules Using Statistical Methods and Neural Network

    Directory of Open Access Journals (Sweden)

    T. Lakhlifi

    2003-04-01

    Full Text Available Abstract: From a series of 50 MK801 derivative molecules, a selected set of 44 compounds was submitted to a principal components analysis (PCA, a multiple regression analysis (MRA, and a neural network (NN. This study shows that the compounds' activity correlates reasonably well with the selected descriptors encoding the chemical structures. The correlation coefficients calculated by MRA and there after by NN, r = 0.986 and r = 0.974 respectively, are fairly good to evaluate a quantitative model, and to predict activity for MK801 derivatives. To test the performance of this model, the activities of the remained set of 6 compounds are deduced from the proposed quantitative model, by NN. This study proved that the predictive power of this model is relevant.

  19. Kinetic modeling of the polymer-derived ceramics route: investigation of the thermal decomposition kinetics of poly[B-(methylamino)borazine] precursors into boron nitride.

    Science.gov (United States)

    Bernard, Samuel; Fiaty, Koffi; Cornu, David; Miele, Philippe; Laurent, Pierre

    2006-05-11

    A complete kinetic modeling of the polymer-derived ceramics (PDCs) route is achieved for the first time through the investigation of the solid-state decomposition of a typical melt-spinnable poly[B-(methylamino)borazine] into boron nitride fibers at various heating rates. Through the use of the Lorentz fitting approach, it is shown that the two-step weight loss associated with the polymer-to-ceramic conversion is governed by a complex interplay of five diffusion-type transport mechanisms that are independent of the applied heating schedule. The application of the Friedman method to dynamic thermogravimetry data yields Ea and ln A values that are seen to increase with the extent of the ceramic conversion from region one (Ea = 38.73 kJ mol(-1)) to region five (Ea = 146.64 kJ mol(-1)). This fact indicates that both the mechanisms within those regions are parallel routes to the formation of the final solid-state material and their complexity increases with the conversion progress. The cross-linking process (first weight loss) of the polymer is governed by three dependent poorly energetic mechanisms. The first weight loss is activated by ammonolysis reactions that provide a modified polymer capable of undergoing condensation reactions in regions two and three to yield a highly cross-linked polymer. A large evolution of methylamine is identified during this process. Mineralization (region four) and ceramization (region five) steps are represented by two highly energetic multistep mechanisms. The mineralization step is associated with a large evolution of methylamine and occurs during the transition between the cross-linking and ceramization processes through the cleavage of the inter-ring B-N bonds. Ceramization represents the end of the polymer-to-ceramic conversion in which the planar consolidation of BN hexagons occurs through complex structural rearrangements of the borazine units (cleavage of the intraring B-N bonds) accompanied with an ammonia evolution. Finally

  20. Application of adaptive boosting to EP-derived multilayer feed-forward neural networks (MLFN) to improve benign/malignant breast cancer classification

    Science.gov (United States)

    Land, Walker H., Jr.; Masters, Timothy D.; Lo, Joseph Y.; McKee, Dan

    2001-07-01

    A new neural network technology was developed for improving the benign/malignant diagnosis of breast cancer using mammogram findings. A new paradigm, Adaptive Boosting (AB), uses a markedly different theory in solutioning Computational Intelligence (CI) problems. AB, a new machine learning paradigm, focuses on finding weak learning algorithm(s) that initially need to provide slightly better than random performance (i.e., approximately 55%) when processing a mammogram training set. Then, by successive development of additional architectures (using the mammogram training set), the adaptive boosting process improves the performance of the basic Evolutionary Programming derived neural network architectures. The results of these several EP-derived hybrid architectures are then intelligently combined and tested using a similar validation mammogram data set. Optimization focused on improving specificity and positive predictive value at very high sensitivities, where an analysis of the performance of the hybrid would be most meaningful. Using the DUKE mammogram database of 500 biopsy proven samples, on average this hybrid was able to achieve (under statistical 5-fold cross-validation) a specificity of 48.3% and a positive predictive value (PPV) of 51.8% while maintaining 100% sensitivity. At 97% sensitivity, a specificity of 56.6% and a PPV of 55.8% were obtained.

  1. FGF and BMP signaling are required for specifying pre-chondrogenic identity in neural crest derived mesenchyme and initiating the chondrogenic program

    Science.gov (United States)

    Kumar, Megha; Ray, Poulomi; Chapman, Susan C.

    2012-01-01

    Summary The pharyngeal endoderm is hypothesized as the source of local signals that specify the identity of neural crest-derived mesenchyme in the arches. Sox9 is induced and maintained in pre-chondrogenic cells during condensation formation and endochondral ossification. Using explant culture we determined that pharyngeal endoderm was sufficient, but not necessary for specifying pre-chondrogenic identity, as surrounding tissues including the otic vesicle can compensate for signals from the pharyngeal endoderm. Multiple Fgf genes are expressed specifically in the pharyngeal endoderm subjacent to the neural crest-derived mesenchyme. FGF signaling is both sufficient and required for specification of Sox9 expression and specification of pre-chondrogenic identity, as demonstrated by the addition of recombinant FGF protein or the FGF receptor inhibitor (SU5402) to explanted tissue, respectively. However, FGF signaling cannot maintain Sox9 expression or initiate the chondrogenic program as indicated by the absence of Col2a1 transcripts. BMP4 signaling can induce and maintain Sox9 expression in isolated mesenchyme, but only in combination with FGF signaling induce Col2a1 expression, and thus, chondrogenesis. Given the spatio-temporal expression patterns of FGFs and BMPs in the pharyngeal arches, we suggest that this may represent a general mechanism of local signals specifying pre-chondrogenic identity and initiation of the chondrogenic program. PMID:22411638

  2. A simple, xeno-free method for oligodendrocyte generation from human neural stem cells derived from umbilical cord: engagement of gelatinases in cell commitment and differentiation.

    Science.gov (United States)

    Sypecka, Joanna; Ziemka-Nalecz, Małgorzata; Dragun-Szymczak, Patrycja; Zalewska, Teresa

    2017-05-01

    Oligodendrocyte progenitors (OPCs) are ranked among the most likely candidates for cell-based strategies aimed at treating neurodegenerative diseases accompanied by dys/demyelination of the central nervous system (CNS). In this regard, different sources of stem cells are being tested to elaborate xeno-free protocols for efficient generation of OPCs for clinical applications. In the present study, neural stem cells of human umbilical cord blood (HUCB-NSCs) have been used to derive OPCs and subsequently to differentiate them into mature, GalC-expressing oligodendrocytes. Applied components of the extracellular matrix (ECM) and the analogues of physiological substances known to increase glial commitment of neural stem cells have been shown to significantly increase the yield of the resulting OPC fraction. The efficiency of ECM components in promoting oligodendrocyte commitment and differentiation prompted us to investigate the potential role of gelatinases in those processes. Subsequently, endogenous and ECM metalloproteinases (MMPs) activity has been compared with that detected in primary cultures of rat oligodendrocytes in vitro, as well as in rat brains in vivo. The data indicate that gelatinases are engaged in gliogenesis both in vitro and in vivo, although differently, which presumably results from distinct extracellular conditions. In conclusion, the study presents an efficient xeno-free method of deriving oligodendrocyte from HUCB-NSCs and analyses the engagement of MMP-2/MMP-9 in the processes of cell commitment and maturation. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  3. Efficient Transduction of Feline Neural Progenitor Cells for Delivery of Glial Cell Line-Derived Neurotrophic Factor Using a Feline Immunodeficiency Virus-Based Lentiviral Construct

    Directory of Open Access Journals (Sweden)

    X. Joann You

    2011-01-01

    Full Text Available Work has shown that stem cell transplantation can rescue or replace neurons in models of retinal degenerative disease. Neural progenitor cells (NPCs modified to overexpress neurotrophic factors are one means of providing sustained delivery of therapeutic gene products in vivo. To develop a nonrodent animal model of this therapeutic strategy, we previously derived NPCs from the fetal cat brain (cNPCs. Here we use bicistronic feline lentiviral vectors to transduce cNPCs with glial cell-derived neurotrophic factor (GDNF together with a GFP reporter gene. Transduction efficacy is assessed, together with transgene expression level and stability during induction of cellular differentiation, together with the influence of GDNF transduction on growth and gene expression profile. We show that GDNF overexpressing cNPCs expand in vitro, coexpress GFP, and secrete high levels of GDNF protein—before and after differentiation—all qualities advantageous for use as a cell-based approach in feline models of neural degenerative disease.

  4. A cGMP-applicable expansion method for aggregates of human neural stem and progenitor cells derived from pluripotent stem cells or fetal brain tissue.

    Science.gov (United States)

    Shelley, Brandon C; Gowing, Geneviève; Svendsen, Clive N

    2014-06-15

    A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the stem cell community. Many current expansion methods are laborious and costly, and those involving complete dissociation may cause several stem and progenitor cell types to undergo differentiation or early senescence. To overcome these problems, we have developed an automated mechanical passaging method referred to as "chopping" that is simple and inexpensive. This technique avoids chemical or enzymatic dissociation into single cells and instead allows for the large-scale expansion of suspended, spheroid cultures that maintain constant cell/cell contact. The chopping method has primarily been used for fetal brain-derived neural progenitor cells or neurospheres, and has recently been published for use with neural stem cells derived from embryonic and induced pluripotent stem cells. The procedure involves seeding neurospheres onto a tissue culture Petri dish and subsequently passing a sharp, sterile blade through the cells effectively automating the tedious process of manually mechanically dissociating each sphere. Suspending cells in culture provides a favorable surface area-to-volume ratio; as over 500,000 cells can be grown within a single neurosphere of less than 0.5 mm in diameter. In one T175 flask, over 50 million cells can grow in suspension cultures compared to only 15 million in adherent cultures. Importantly, the chopping procedure has been used under current good manufacturing practice (cGMP), permitting mass quantity production of clinical-grade cell products.

  5. The positional identity of iPSC-derived neural progenitor cells along the anterior-posterior axis is controlled in a dosage-dependent manner by bFGF and EGF

    DEFF Research Database (Denmark)

    Zhou, Shuling; Ochalek, Anna; Szczesna, Karolina

    2016-01-01

    Neural rosettes derived from human induced pluripotent stem cells (iPSCs) have been claimed to be a highly robust in vitro cellular model for biomedical application. They are able to propagate in vitro in the presence of mitogens, including basic fibroblast growth factor (bFGF) and epidermal growth...... factor (EGF). However, these two mitogens are also involved in anterior-posterior patterning in a gradient dependent manner along the neural tube axis. Here, we compared the regional identity of neural rosette cells and specific neural subtypes of their progeny propagated with low and high concentrations...... of bFGF and EGF. We observed that low concentrations of bFGF and EGF in the culturing system were able to induce forebrain identity of the neural rosettes and promote subsequent cortical neuronal differentiation. On the contrary, high concentrations of these mitogens stimulate a mid-hindbrain fate...

  6. Sortilin-Related Receptor Expression in Human Neural Stem Cells Derived from Alzheimer’s Disease Patients Carrying the APOE Epsilon 4 Allele

    Directory of Open Access Journals (Sweden)

    Alen Zollo

    2017-01-01

    Full Text Available Alzheimer’s disease (AD is the most common form of dementia in the elderly; important risk factors are old age and inheritance of the apolipoprotein E4 (APOE4 allele. Changes in amyloid precursor protein (APP binding, trafficking, and sorting may be important AD causative factors. Secretase-mediated APP cleavage produces neurotoxic amyloid-beta (Aβ peptides, which form lethal deposits in the brain. In vivo and in vitro studies have implicated sortilin-related receptor (SORL1 as an important factor in APP trafficking and processing. Recent in vitro evidence has associated the APOE4 allele and alterations in the SORL1 pathway with AD development and progression. Here, we analyzed SORL1 expression in neural stem cells (NSCs from AD patients carrying null, one, or two copies of the APOE4 allele. We show reduced SORL1 expression only in NSCs of a patient carrying two copies of APOE4 allele with increased Aβ/SORL1 localization along the degenerated neurites. Interestingly, SORL1 binding to APP was largely compromised; this could be almost completely reversed by γ-secretase (but not β-secretase inhibitor treatment. These findings may yield new insights into the complex interplay of SORL1 and AD pathology and point to NSCs as a valuable tool to address unsolved AD-related questions in vitro.

  7. The siRNA-mediated knockdown of GluN3A in 46C-derived neural stem cells affects mRNA expression levels of neural genes, including known iGluR interactors

    Science.gov (United States)

    Eilebrecht, Elke; Schöneborn, Hendrik; Neumann, Sebastian; Benecke, Arndt G.; Hollmann, Michael

    2018-01-01

    For years, GluN3A was solely considered to be a dominant-negative modulator of NMDARs, since its incorporation into receptors alters hallmark features of conventional NMDARs composed of GluN1/GluN2 subunits. Only recently, increasing evidence has accumulated that GluN3A plays a more diversified role. It is considered to be critically involved in the maturation of glutamatergic synapses, and it might act as a molecular brake to prevent premature synaptic strengthening. Its expression pattern supports a putative role during neural development, since GluN3A is predominantly expressed in early pre- and postnatal stages. In this study, we used RNA interference to efficiently knock down GluN3A in 46C-derived neural stem cells (NSCs) both at the mRNA and at the protein level. Global gene expression profiling upon GluN3A knockdown revealed significantly altered expression of a multitude of neural genes, including genes encoding small GTPases, retinal proteins, and cytoskeletal proteins, some of which have been previously shown to interact with GluN3A or other iGluR subunits. Canonical pathway enrichment studies point at important roles of GluN3A affecting key cellular pathways involved in cell growth, proliferation, motility, and survival, such as the mTOR pathway. This study for the first time provides insights into transcriptome changes upon the specific knockdown of an NMDAR subunit in NSCs, which may help to identify additional functions and downstream pathways of GluN3A and GluN3A-containing NMDARs. PMID:29438442

  8. Stromal cell-derived factor-1 alpha (SDF-1 alpha) improves neural recovery after spinal cord contusion in rats

    NARCIS (Netherlands)

    Zendedel, A.; Nobakht, M.; Bakhtiyari, M.; Beyer, C.; Kipp, M.; Baazm, M.; Joghataie, M.T.

    2012-01-01

    Stromal cell-derived factor-1 alpha (SDF-1α) is an important cytokine, implicated in the control of stem cell trafficking and bone marrow-derived stem cell mobilization. Generally, SDF-1α regulates multiple physiological processes such as embryonic development and organ homeostasis. There is also

  9. Neural Stem Cell or Human Induced Pluripotent Stem Cell-Derived GABA-ergic Progenitor Cell Grafting in an Animal Model of Chronic Temporal Lobe Epilepsy.

    Science.gov (United States)

    Upadhya, Dinesh; Hattiangady, Bharathi; Shetty, Geetha A; Zanirati, Gabriele; Kodali, Maheedhar; Shetty, Ashok K

    2016-08-17

    Grafting of neural stem cells (NSCs) or GABA-ergic progenitor cells (GPCs) into the hippocampus could offer an alternative therapy to hippocampal resection in patients with drug-resistant chronic epilepsy, which afflicts >30% of temporal lobe epilepsy (TLE) cases. Multipotent, self-renewing NSCs could be expanded from multiple regions of the developing and adult brain, human embryonic stem cells (hESCs), and human induced pluripotent stem cells (hiPSCs). On the other hand, GPCs could be generated from the medial and lateral ganglionic eminences of the embryonic brain and from hESCs and hiPSCs. To provide comprehensive methodologies involved in testing the efficacy of transplantation of NSCs and GPCs in a rat model of chronic TLE, NSCs derived from the rat medial ganglionic eminence (MGE) and MGE-like GPCs derived from hiPSCs are taken as examples in this unit. The topics comprise description of the required materials, reagents and equipment, methods for obtaining rat MGE-NSCs and hiPSC-derived MGE-like GPCs in culture, generation of chronically epileptic rats, intrahippocampal grafting procedure, post-grafting evaluation of the effects of grafts on spontaneous recurrent seizures and cognitive and mood impairments, analyses of the yield and the fate of graft-derived cells, and the effects of grafts on the host hippocampus. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  10. Human neural stem cell-derived cultures in three-dimensional substrates form spontaneously functional neuronal networks.

    Science.gov (United States)

    Smith, Imogen; Silveirinha, Vasco; Stein, Jason L; de la Torre-Ubieta, Luis; Farrimond, Jonathan A; Williamson, Elizabeth M; Whalley, Benjamin J

    2017-04-01

    Differentiated human neural stem cells were cultured in an inert three-dimensional (3D) scaffold and, unlike two-dimensional (2D) but otherwise comparable monolayer cultures, formed spontaneously active, functional neuronal networks that responded reproducibly and predictably to conventional pharmacological treatments to reveal functional, glutamatergic synapses. Immunocytochemical and electron microscopy analysis revealed a neuronal and glial population, where markers of neuronal maturity were observed in the former. Oligonucleotide microarray analysis revealed substantial differences in gene expression conferred by culturing in a 3D vs a 2D environment. Notable and numerous differences were seen in genes coding for neuronal function, the extracellular matrix and cytoskeleton. In addition to producing functional networks, differentiated human neural stem cells grown in inert scaffolds offer several significant advantages over conventional 2D monolayers. These advantages include cost savings and improved physiological relevance, which make them better suited for use in the pharmacological and toxicological assays required for development of stem cell-based treatments and the reduction of animal use in medical research. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Neuronal regeneration in injured rat spinal cord after human dental pulp derived neural crest stem cell transplantation.

    Science.gov (United States)

    Kabatas, S; Demir, C S; Civelek, E; Yilmaz, I; Kircelli, A; Yilmaz, C; Akyuva, Y; Karaoz, E

    2018-01-01

    This study aimed to analyze the effect of human Dental Pulp-Neural Crest Stem Cells (hDP-NCSCs) delivery on lesion site after spinal cord injury (SCI), and to observe the functional recovery after transplantation. Neural Crest Stem Cells (NCSCs) were isolated from human Dental Pulp (hDP). The experimental rat population was divided into four groups (n = 6/24). Their behavioral motility was scored regularly. After 4-weeks, rats were sacrificed, and their spinal cords were examined for Green Fluorescent Protein (GFP) labeled hDP-NCSCs by immunofluorescence (IF) staining. In early post-injury (p.i) period, the ultrastructure of spinal cord tissue was preserved in Group 4. The majority of cells forming the ependymal region around the central canal were found to be hDP-NCSCs. While the grey-and-white-matter around the ependymal region was composed of e.g. GFP cells, with astrocytic-like appearance. The scores showed significant motor recovery in hind limb functions in Group 4. However, no obvious change was observed in other groups. Cells e.g., mesenchymal (Vimentin+) which express GFP+ cells in the gray-and-white-matter around the ependymal region could indicate the potential to self-renewal and plasticity. Thus, transplantation of hDP-NCSCs might be an effective strategy to improve functional recovery following spinal cord trauma (Fig. 10, Ref. 32).

  12. Smooth Muscle Cells Derived From Second Heart Field and Cardiac Neural Crest Reside in Spatially Distinct Domains in the Media of the Ascending Aorta-Brief Report.

    Science.gov (United States)

    Sawada, Hisashi; Rateri, Debra L; Moorleghen, Jessica J; Majesky, Mark W; Daugherty, Alan

    2017-09-01

    Smooth muscle cells (SMCs) of the proximal thoracic aorta are embryonically derived from the second heart field (SHF) and cardiac neural crest (CNC). However, distributions of these embryonic origins are not fully defined. The regional distribution of SMCs of different origins is speculated to cause region-specific aortopathies. Therefore, the aim of this study was to determine the distribution of SMCs of SHF and CNC origins in the proximal thoracic aorta. Mice with repressed LacZ in the ROSA26 locus were bred to those expressing Cre controlled by either the Wnt1 or Mef2c (myocyte-specific enhancer factor 2c) promoter to trace CNC- and SHF-derived SMCs, respectively. Thoracic aortas were harvested, and activity of β-galactosidase was determined. Aortas from Wnt1- Cre mice had β-galactosidase-positive areas throughout the region from the proximal ascending aorta to just distal of the subclavian arterial branch. Unexpectedly, β-galactosidase-positive areas in Mef2c- Cre mice extended from the aortic root throughout the ascending aorta. This distribution occurred independent of sex and aging. Cross and sagittal aortic sections demonstrated that CNC-derived cells populated the inner medial aspect of the anterior region of the ascending aorta and transmurally in the media of the posterior region. Interestingly, outer medial cells throughout anterior and posterior ascending aortas were derived from the SHF. β-Galactosidase-positive medial cells of both origins colocalized with an SMC marker, α-actin. Both CNC- and SHF-derived SMCs populate the media throughout the ascending aorta. The outer medial cells of the ascending aorta form a sleeve populated by SHF-derived SMCs. © 2017 American Heart Association, Inc.

  13. Growth of ferroelectric Ba{sub 0.8}Sr{sub 0.2}TiO{sub 3} epitaxial films by ultraviolet pulsed laser irradiation of chemical solution derived precursor layers

    Energy Technology Data Exchange (ETDEWEB)

    Queraltó, A.; Pérez del Pino, A., E-mail: aperez@icmab.es; Mata, M. de la; Tristany, M.; Gómez, A.; Obradors, X.; Puig, T. [Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Catalonia (Spain); Arbiol, J. [Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Catalonia (Spain); Institució Catalana de Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys, 23, 08010 Barcelona, Catalonia (Spain)

    2015-06-29

    Highly crystalline epitaxial Ba{sub 0.8}Sr{sub 0.2}TiO{sub 3} (BST) thin-films are grown on (001)-oriented LaNiO{sub 3}-buffered LaAlO{sub 3} substrates by pulsed laser irradiation of solution derived barium-zirconium-titanium precursor layers using a UV Nd:YAG laser source at atmospheric conditions. The structural analyses of the obtained films, studied by X-ray diffractometry and transmission electron microscopy, demonstrate that laser processing allows the growth of tens of nm-thick BST epitaxial films with crystalline structure similar to that of films obtained through conventional thermal annealing methods. However, the fast pulsed nature of the laser employed leads to crystallization kinetic evolution orders of magnitude faster than in thermal treatments. The combination of specific photothermal and photochemical mechanisms is the main responsible for the ultrafast epitaxial laser-induced crystallization. Piezoresponse microscopy measurements demonstrate equivalent ferroelectric behavior in laser and thermally annealed films, being the piezoelectric constant ∼25 pm V{sup −1}.

  14. Polyurethane/polylactide-based biomaterials combined with rat olfactory bulb-derived glial cells and adipose-derived mesenchymal stromal cells for neural regenerative medicine applications

    Energy Technology Data Exchange (ETDEWEB)

    Grzesiak, Jakub, E-mail: grzesiak.kuba@gmail.com [Electron Microscopy Laboratory, University of Environmental and Life Sciences, Kozuchowska 5b, 51-631 Wroclaw (Poland); Marycz, Krzysztof [Electron Microscopy Laboratory, University of Environmental and Life Sciences, Kozuchowska 5b, 51-631 Wroclaw (Poland); Szarek, Dariusz [Department of Neurosurgery, Lower Silesia Specialist Hospital of T. Marciniak, Emergency Medicine Center, Traugutta 116, 50-420 Wroclaw (Poland); Bednarz, Paulina [State Higher Vocational School in Tarnów, Mickiewicza 8, 33-100 Tarnów (Poland); Laska, Jadwiga [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Mickiewicza 30, 30-059 Kraków (Poland)

    2015-07-01

    Research concerning the elaboration and application of biomaterial which may support the nerve tissue regeneration is currently one of the most promising directions. Biocompatible polymer devices are noteworthy group among the numerous types of potentially attractive biomaterials for regenerative medicine application. Polylactides and polyurethanes may be utilized for developing devices for supporting the nerve regeneration, like nerve guide conduits or bridges connecting the endings of broken nerve tracts. Moreover, the combination of these biomaterial devices with regenerative cell populations, like stem or precursor cells should significantly improve the final therapeutic effect. Therefore, the composition and structure of final device should support the proper adhesion and growth of cells destined for clinical application. In current research, the three polymer mats elaborated for connecting the broken nerve tracts, made from polylactide, polyurethane and their blend were evaluated both for physical properties and in vitro, using the olfactory-bulb glial cells and mesenchymal stem cells. The evaluation of Young's modulus, wettability and roughness of obtained materials showed the differences between analyzed samples. The analysis of cell adhesion, proliferation and morphology showed that the polyurethane–polylactide blend was the most neutral for cells in culture, while in the pure polymer samples there were significant alterations observed. Our results indicated that polyurethane–polylactide blend is an optimal composition for culturing and delivery of glial and mesenchymal stem cells. - Highlights: • Polyurethane–polylactide blends exhibit different characteristics from pure polymers. • Pure PU and PLA negatively influence on morphology of glial and mesenchymal cells. • PU/PLA blend was neutral for glial and mesenchymal cell proliferation and morphology.

  15. Neural Networks

    International Nuclear Information System (INIS)

    Smith, Patrick I.

    2003-01-01

    Physicists use large detectors to measure particles created in high-energy collisions at particle accelerators. These detectors typically produce signals indicating either where ionization occurs along the path of the particle, or where energy is deposited by the particle. The data produced by these signals is fed into pattern recognition programs to try to identify what particles were produced, and to measure the energy and direction of these particles. Ideally, there are many techniques used in this pattern recognition software. One technique, neural networks, is particularly suitable for identifying what type of particle caused by a set of energy deposits. Neural networks can derive meaning from complicated or imprecise data, extract patterns, and detect trends that are too complex to be noticed by either humans or other computer related processes. To assist in the advancement of this technology, Physicists use a tool kit to experiment with several neural network techniques. The goal of this research is interface a neural network tool kit into Java Analysis Studio (JAS3), an application that allows data to be analyzed from any experiment. As the final result, a physicist will have the ability to train, test, and implement a neural network with the desired output while using JAS3 to analyze the results or output. Before an implementation of a neural network can take place, a firm understanding of what a neural network is and how it works is beneficial. A neural network is an artificial representation of the human brain that tries to simulate the learning process [5]. It is also important to think of the word artificial in that definition as computer programs that use calculations during the learning process. In short, a neural network learns by representative examples. Perhaps the easiest way to describe the way neural networks learn is to explain how the human brain functions. The human brain contains billions of neural cells that are responsible for processing

  16. CD133-enriched Xeno-Free human embryonic-derived neural stem cells expand rapidly in culture and do not form teratomas in immunodeficient mice

    Directory of Open Access Journals (Sweden)

    Daniel L. Haus

    2014-09-01

    Full Text Available Common methods for the generation of human embryonic-derived neural stem cells (hNSCs result in cells with potentially compromised safety profiles due to maintenance of cells in conditions containing non-human proteins (e.g. in bovine serum or on mouse fibroblast feeders. Additionally, sufficient expansion of resulting hNSCs for scaling out or up in a clinically relevant time frame has proven to be difficult. Here, we report a strategy that produces hNSCs in completely “Xeno-Free” culture conditions. Furthermore, we have enriched the hNSCs for the cell surface marker CD133 via magnetic sorting, which has led to an increase in the expansion rate and neuronal fate specification of the hNSCs in vitro. Critically, we have also confirmed neural lineage specificity upon sorted hNSC transplantation into the immunodeficient NOD-scid mouse brain. The future use or adaptation of these protocols has the potential to better facilitate the advancement of pre-clinical strategies from the bench to the bedside.

  17. Protease-activated receptor-1 negatively regulates proliferation of neural stem/progenitor cells derived from the hippocampal dentate gyrus of the adult mouse

    Directory of Open Access Journals (Sweden)

    Masayuki Tanaka

    2016-07-01

    Full Text Available Thrombin-activated protease-activated receptor (PAR-1 regulates the proliferation of neural cells following brain injury. To elucidate the involvement of PAR-1 in the neurogenesis that occurs in the adult hippocampus, we examined whether PAR-1 regulated the proliferation of neural stem/progenitor cells (NPCs derived from the murine hippocampal dentate gyrus. NPC cultures expressed PAR-1 protein and mRNA encoding all subtypes of PAR. Direct exposure of the cells to thrombin dramatically attenuated the cell proliferation without causing cell damage. This thrombin-induced attenuation was almost completely abolished by the PAR antagonist RWJ 56110, as well as by dabigatran and 4-(2-aminoethylbenzenesulfonyl fluoride (AEBSF, which are selective and non-selective thrombin inhibitors, respectively. Expectedly, the PAR-1 agonist peptide (AP SFLLR-NH2 also attenuated the cell proliferation. The cell proliferation was not affected by the PAR-1 negative control peptide RLLFT-NH2, which is an inactive peptide for PAR-1. Independently, we determined the effect of in vivo treatment with AEBSF or AP on hippocampal neurogenesis in the adult mouse. The administration of AEBSF, but not that of AP, significantly increased the number of newly-generated cells in the hippocampal subgranular zone. These data suggest that PAR-1 negatively regulated adult neurogenesis in the hippocampus by inhibiting the proliferative activity of the NPCs.

  18. Neural Activity during Voluntary Movements in Each Body Representation of the Intracortical Microstimulation-Derived Map in the Macaque Motor Cortex.

    Science.gov (United States)

    Higo, Noriyuki; Kunori, Nobuo; Murata, Yumi

    2016-01-01

    In order to accurately interpret experimental data using the topographic body map identified by conventional intracortical microstimulation (ICMS), it is important to know how neurons in each division of the map respond during voluntary movements. Here we systematically investigated neuronal responses in each body representation of the ICMS map during a reach-grasp-retrieval task that involves the movements of multiple body parts. The topographic body map in the primary motor cortex (M1) generally corresponds to functional divisions of voluntary movements; neurons at the recording sites in each body representation with movement thresholds of 10 μA or less were differentially activated during the task, and the timing of responses was consistent with the movements of the body part represented. Moreover, neurons in the digit representation responded differently for the different types of grasping. In addition, the present study showed that neural activity depends on the ICMS current threshold required to elicit body movements and the location of the recording on the cortical surface. In the ventral premotor cortex (PMv), no correlation was found between the response properties of neurons and the body representation in the ICMS map. Neural responses specific to forelimb movements were often observed in the rostral part of PMv, including the lateral bank of the lower arcuate limb, in which ICMS up to 100 μA evoked no detectable movement. These results indicate that the physiological significance of the ICMS-derived maps is different between, and even within, areas M1 and PMv.

  19. Potent tumor tropism of induced pluripotent stem cells and induced pluripotent stem cell-derived neural stem cells in the mouse intracerebral glioma model.

    Science.gov (United States)

    Yamazoe, Tomohiro; Koizumi, Shinichiro; Yamasaki, Tomohiro; Amano, Shinji; Tokuyama, Tsutomu; Namba, Hiroki

    2015-01-01

    Although neural and mesenchymal stem cells have been well-known to have a strong glioma tropism, this activity in induced pluripotent stem cells (iPSCs) has not yet been fully studied. In the present study, we tested tumor tropic activity of mouse iPSCs and neural stem cells derived from the iPSC (iPS-NSCs) using in vitro Matrigel invasion chamber assay and in vivo mouse intracranial tumor model. Both iPSC and iPS-NSC had a similar potent in vitro tropism for glioma conditioned media. The migrated iPSCs to the gliomas kept expressing Nanog-GFP gene, suggesting no neuronal or glial differentiation. iPSCs or iPS-NSCs labeled with 5-bromo-2-deoxyuridine were intracranially implanted in the contralateral hemisphere to the GL261 glioma cell implantation in the allogeneic C57BL/6 mouse. Active migration of both stem cells was observed 7 days after implantation. Again, the iPSCs located in the tumor area expressed Nanog-GFP gene, suggesting that the migrated cells were still iPSCs. These findings demonstrated that both iPSCs and iPS-NSCs had potent glioma tropism and could be candidates as vehicles in stem cell-based glioma therapy.

  20. 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

  1. In vitro evaluation of biocompatibility of uncoated thermally reduced graphene and carbon nanotube-loaded PVDF membranes with adult neural stem cell-derived neurons and glia

    Directory of Open Access Journals (Sweden)

    Çagla Defterali

    2016-12-01

    Full Text Available Graphene, graphene-based nanomaterials (GBNs and carbon nanotubes (CNTs are being investigated as potential substrates for the growth of neural cells. However, in most in vitro studies the cells were seeded on these materials coated with various proteins implying that the observed effects on the cells could not solely be attributed to the GBN and CNT properties. Here we studied the biocompatibility of uncoated thermally reduced graphene (TRG and poly-vinylidene fluoride (PVDF membranes loaded with multi walled CNTs (MWCNTs using neural stem cells (NSCs isolated from the adult mouse olfactory bulb (termed aOBSCs. When aOBSCs were induced to differentiate on coverslips treated with TRG or control materials (polyethyleneimine-PEI and polyornithine plus fibronectin-PLO/F in a serum-free medium, neurons, astrocytes, and oligodendrocytes were generated in all conditions, indicating that TRG permits the multi-lineage differentiation of aOBSCs. However, the total number of cells was reduced on both PEI and TRG. In a serum-containing medium, aOBSC-derived neurons and oligodendrocytes grown on TRG were more numerous than in controls; the neurons developed synaptic boutons and oligodendrocytes were more branched. In contrast, neurons growing on PVDF membranes had reduced neurite branching and on MWCNTs-loaded membranes, oligodendrocytes were lower in numbers than in controls. Overall, these findings indicate that uncoated TRG may be biocompatible with the generation, differentiation, and maturation of aOBSC-derived neurons and glial cells, implying a potential use for TRG to study functional neuronal networks.

  2. Earthquakes: hydrogeochemical precursors

    Science.gov (United States)

    Ingebritsen, Steven E.; Manga, Michael

    2014-01-01

    Earthquake prediction is a long-sought goal. Changes in groundwater chemistry before earthquakes in Iceland highlight a potential hydrogeochemical precursor, but such signals must be evaluated in the context of long-term, multiparametric data sets.

  3. Chicken trunk neural crest migration visualized with HNK1.

    Science.gov (United States)

    Giovannone, Dion; Ortega, Blanca; Reyes, Michelle; El-Ghali, Nancy; Rabadi, Maes; Sao, Sothy; de Bellard, Maria Elena

    2015-04-01

    The development of the nervous system involves cells remaining within the neural tube (CNS) and a group of cells that delaminate from the dorsal neural tube and migrate extensively throughout the developing embryo called neural crest cells (NCC). These cells are a mesenchymal highly migratory group of cells that give rise to a wide variety of cell derivatives: melanocytes, sensory neurons, bone, Schwann cells, etc. But not all NCC can give rise to all derivatives, they have fate restrictions based on their axial level of origin: cranial, vagal, trunk and sacral. Our aim was to provide a thorough presentation on how does trunk neural crest cell migration looks in the chicken embryo, in wholemount and in sections using the unique chicken marker HNK1. The description presented here makes a good guideline for those interested in viewing trunk NCC migration patterns. We show how before HH14 there are few trunk NCC delaminating and migrating, but between HH15 through HH19 trunk NCC delaminate in large numbers. Melanocytes precursors begin to enter the dorsolateral pathway by HH17. We found that by HH20 HNK1 is not a valid good marker for NCC and that HNK1 is a better marker than Sox10 when looking at neural crest cells morphology and migration details. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

  4. Amphibian tachykinin precursor.

    Science.gov (United States)

    Li, Jianxu; Liu, Tongguang; Xu, Xueqing; Wang, Xu; Wu, Min; Yang, Hailong; Lai, Ren

    2006-12-01

    The precursor of amphibian tachykinin has not been found although more than 30 tachykinins have been isolated from amphibians since 1964. In this report, two tachykinin-like peptides are identified from the skin secretions of the frog, Odorrana grahami. Their amino acid sequences are DDTEDLANKFIGLM-NH(2) (named tachykinin OG1) and DDASDRAKKFYGLM-NH(2) that is the same with ranamargarin found in Rana margaretae, respectively, with a conserved FXGLM-NH(2) C-terminal consensus motif. By cDNA cloning, their precursors were screened from the skin cDNA library of O. grahami. The precursors are composed of 61 amino acid (aa) residues including a signal peptide followed by an acidic spacer peptide and one copy of mature tachykinin-like peptide. Their overall structure is different from structures of other tachykinin precursors such as human protachykinin 1 precursor containing 143 aa including one copy of substance P (SP) and neurokinin A (NKA), and ascidian tachykinin 1 precursor containing 164 aa including two copies of tachykinin-like peptides. The current results demonstrate that the biosynthesis mode of tachykinins in amphibians is different from other animals.

  5. Changes in numbers and types of mast cell colony-forming cells in the peritoneal cavity of mice after injection of distilled water: evidence that mast cells suppress differentiation of bone marrow-derived precursors

    International Nuclear Information System (INIS)

    Kanakura, Y.; Kuriu, A.; Waki, N.; Nakano, T.; Asai, H.; Yonezawa, T.; Kitamura, Y.

    1988-01-01

    Two different types of cells in the peritoneal cavity of mice produce mast cell colonies in methylcellulose. Large mast cell colonies are produced by bone marrow-derived precursors resembling lymphoid cells by light microscopy (L-CFU-Mast), whereas medium and small mast cell colonies are produced by morphologically identifiable mast cells (M-CFU-Mast and S-CFU-Mast, respectively). In the present study we eradicated peritoneal mast cells by intraperitoneal (IP) injection of distilled water. The regeneration process was investigated to clarify the relationship between L-CFU-Mast, M-CFU-Mast, and S-CFU-Mast. After injection of distilled water, M-CFU-Mast and S-CFU-Mast disappeared, but L-CFU-Mast increased, and then M-CFU-Mast and S-CFU-Mast appeared, suggesting the presence of a hierarchic relationship. When purified peritoneal mast cells were injected two days after the water injection, the L-CFU-Mast did not increase. In the peritoneal cavity of WBB6F1-+/+ mice that had been lethally irradiated and rescued by bone marrow cells of C57BL/6-bgJ/bgJ (beige, Chediak-Higashi syndrome) mice, L-CFU-Mast were of bgJ/bgJ type, but M-CFU-Mast and S-CFU-Mast were of +/+ type. The injection of distilled water to the radiation chimeras resulted in the development of bgJ/bgJ-type M-CFU-Mast and then S-CFU-Mast. The presence of mast cells appeared to suppress the recruitment of L-CFU-Mast from the bloodstream and to inhibit the differentiation of L-CFU-Mast to M-CFU-Mast

  6. Changes in numbers and types of mast cell colony-forming cells in the peritoneal cavity of mice after injection of distilled water: evidence that mast cells suppress differentiation of bone marrow-derived precursors

    Energy Technology Data Exchange (ETDEWEB)

    Kanakura, Y.; Kuriu, A.; Waki, N.; Nakano, T.; Asai, H.; Yonezawa, T.; Kitamura, Y.

    1988-03-01

    Two different types of cells in the peritoneal cavity of mice produce mast cell colonies in methylcellulose. Large mast cell colonies are produced by bone marrow-derived precursors resembling lymphoid cells by light microscopy (L-CFU-Mast), whereas medium and small mast cell colonies are produced by morphologically identifiable mast cells (M-CFU-Mast and S-CFU-Mast, respectively). In the present study we eradicated peritoneal mast cells by intraperitoneal (IP) injection of distilled water. The regeneration process was investigated to clarify the relationship between L-CFU-Mast, M-CFU-Mast, and S-CFU-Mast. After injection of distilled water, M-CFU-Mast and S-CFU-Mast disappeared, but L-CFU-Mast increased, and then M-CFU-Mast and S-CFU-Mast appeared, suggesting the presence of a hierarchic relationship. When purified peritoneal mast cells were injected two days after the water injection, the L-CFU-Mast did not increase. In the peritoneal cavity of WBB6F1-+/+ mice that had been lethally irradiated and rescued by bone marrow cells of C57BL/6-bgJ/bgJ (beige, Chediak-Higashi syndrome) mice, L-CFU-Mast were of bgJ/bgJ type, but M-CFU-Mast and S-CFU-Mast were of +/+ type. The injection of distilled water to the radiation chimeras resulted in the development of bgJ/bgJ-type M-CFU-Mast and then S-CFU-Mast. The presence of mast cells appeared to suppress the recruitment of L-CFU-Mast from the bloodstream and to inhibit the differentiation of L-CFU-Mast to M-CFU-Mast.

  7. Epigenetic regulation of gene expression in porcine epiblast, hypoblast, trophectoderm and epiblast-derived neural progenitor cells

    DEFF Research Database (Denmark)

    Gao, Yu; Jammes, Helen; Rasmussen, Mikkel Aabech

    2011-01-01

    After fertilization, lineage specification is governed by a complicated molecular network in which permissiveness and repression of expression of pluripotency- and differentiation-associated genes are regulated by epigenetic modifications. DNA methylation operates as a very stable repressive mark...... of its promoter. In conclusion, DNA methylation is an inconsistently operating epigenetic mechanism in porcine E10 blastocysts, whereas in porcine epiblast-derived NPCs, expression of pluripotency-associated and differentiation genes appear to be regulated by this modification....

  8. Modulation of the major histocompatibility complex by neural stem cell-derived neurotrophic factors used for regenerative therapy in a rat model of stroke

    Directory of Open Access Journals (Sweden)

    Sun Chongran

    2010-08-01

    Full Text Available Abstract Background The relationship between functional improvements in ischemic rats given a neural stem cell (NSC transplant and the modulation of the class I major histocompatibility complex (MHC mediated by NSC-derived neurotrophins was investigated. Methods The levels of gene expression of nerve growth factor (NGF, brain-derived neurotropic factor (BDNF and neurotrophin-3 (NT-3 were assayed from cultures of cortical NSC from Sprague-Dawley rat E16 embryos. The levels of translated NGF in spent culture media from NSC cultures and the cerebral spinal fluid (CSF of rats with and without NGF injection or NSC transplant were also measured. Results We found a significant increase of NGF, BDNF and NT-3 transcripts and NGF proteins in both the NSC cultures and the CSF of the rats. The immunochemical staining for MHC in brain sections and the enzyme-linked immunosorbent assay of CSF were carried out in sham-operated rats and rats with surgically induced focal cerebral ischemia. These groups were further divided into animals that did and did not receive NGF administration or NSC transplant into the cisterna magna. Our results show an up-regulation of class I MHC in the ischemic rats with NGF and NSC administration. The extent of caspase-III immunoreactivity was comparable among three arms in the ischemic rats. Conclusion Readouts of somatosensory evoked potential and the trap channel test illustrated improvements in the neurological function of ischemic rats treated with NGF administration and NSC transplant.

  9. Targeted suicide gene therapy for glioma using human embryonic stem cell-derived neural stem cells genetically modified by baculoviral vectors.

    Science.gov (United States)

    Zhao, Y; Lam, D H; Yang, J; Lin, J; Tham, C K; Ng, W H; Wang, S

    2012-02-01

    Tumor-tropic neural stem cells (NSCs) can be used in the Trojan horse approach as cellular vehicles for targeted delivery of therapeutic agents to distant tumor sites. To realize this cancer therapy potential, it is important to have a renewable source to generate large quantities of uniform human NSCs. Here, we reported that NSCs derived from HES1 human embryonic stem cell line were capable of migrating into intracranial glioma xenografts after systemic injection or after intracranial injection at a site distant from the tumor. To test whether the HES1-derived NSCs can be used for cancer gene therapy, we used a baculoviral vector to introduce the herpes simplex virus thymidine kinase suicide gene into the cells and demonstrated that baculovirus-mediated transgene expression may last for at least 3 weeks in NSCs. After being injected into the cerebral hemisphere opposite the tumor site and in the presence of ganciclovir, NSCs expressing the suicide gene were able to inhibit the growth of human glioma xenografts and prolong survival of tumor-bearing mice. Our findings suggest that human embryonic stem cells could potentially serve as a clinically viable source for production of cellular vehicles suitable for targeted anticancer gene therapy.

  10. Neural effects of gut- and brain-derived glucagon-like peptide-1 and its receptor agonist.

    Science.gov (United States)

    Katsurada, Kenichi; Yada, Toshihiko

    2016-04-01

    Glucagon-like peptide-1 (GLP-1) is derived from both the enteroendocrine L cells and preproglucagon-expressing neurons in the nucleus tractus solitarius (NTS) of the brain stem. As GLP-1 is cleaved by dipeptidyl peptidase-4 yielding a half-life of less than 2 min, it is plausible that the gut-derived GLP-1, released postprandially, exerts its effects on the brain mainly by interacting with vagal afferent neurons located at the intestinal or hepatic portal area. GLP-1 neurons in the NTS widely project in the central nervous system and act as a neurotransmitter. One of the physiological roles of brain-derived GLP-1 is restriction of feeding. GLP-1 receptor agonists have recently been used to treat type 2 diabetic patients, and have been shown to exhibit pleiotropic effects beyond incretin action, which involve brain functions. GLP-1 receptor agonist administered in the periphery is stable because of its resistance to dipeptidyl peptidase-4, and is highly likely to act on the brain by passing through the blood-brain barrier (BBB), as well as interacting with vagal afferent nerves. Central actions of GLP-1 have various roles including regulation of feeding, weight, glucose and lipid metabolism, cardiovascular functions, cognitive functions, and stress and emotional responses. In the present review, we focus on the source of GLP-1 and the pathway by which peripheral GLP-1 informs the brain, and then discuss recent findings on the central effects of GLP-1 and GLP-1 receptor agonists.

  11. Pre-evaluated safe human iPSC-derived neural stem cells promote functional recovery after spinal cord injury in common marmoset without tumorigenicity.

    Directory of Open Access Journals (Sweden)

    Yoshiomi Kobayashi

    Full Text Available Murine and human iPSC-NS/PCs (induced pluripotent stem cell-derived neural stem/progenitor cells promote functional recovery following transplantation into the injured spinal cord in rodents. However, for clinical applicability, it is critical to obtain proof of the concept regarding the efficacy of grafted human iPSC-NS/PCs (hiPSC-NS/PCs for the repair of spinal cord injury (SCI in a non-human primate model. This study used a pre-evaluated "safe" hiPSC-NS/PC clone and an adult common marmoset (Callithrix jacchus model of contusive SCI. SCI was induced at the fifth cervical level (C5, followed by transplantation of hiPSC-NS/PCs at 9 days after injury. Behavioral analyses were performed from the time of the initial injury until 12 weeks after SCI. Grafted hiPSC-NS/PCs survived and differentiated into all three neural lineages. Furthermore, transplantation of hiPSC-NS/PCs enhanced axonal sparing/regrowth and angiogenesis, and prevented the demyelination after SCI compared with that in vehicle control animals. Notably, no tumor formation occurred for at least 12 weeks after transplantation. Quantitative RT-PCR showed that mRNA expression levels of human neurotrophic factors were significantly higher in cultured hiPSC-NS/PCs than in human dermal fibroblasts (hDFs. Finally, behavioral tests showed that hiPSC-NS/PCs promoted functional recovery after SCI in the common marmoset. Taken together, these results indicate that pre-evaluated safe hiPSC-NS/PCs are a potential source of cells for the treatment of SCI in the clinic.

  12. Muscle-derived stem cells isolated as non-adherent population give rise to cardiac, skeletal muscle and neural lineages

    International Nuclear Information System (INIS)

    Arsic, Nikola; Mamaeva, Daria; Lamb, Ned J.; Fernandez, Anne

    2008-01-01

    Stem cells with the ability to differentiate in specialized cell types can be extracted from a wide array of adult tissues including skeletal muscle. Here we have analyzed a population of cells isolated from skeletal muscle on the basis of their poor adherence on uncoated or collagen-coated dishes that show multi-lineage differentiation in vitro. When analysed under proliferative conditions, these cells express stem cell surface markers Sca-1 (65%) and Bcrp-1 (80%) but also MyoD (15%), Neuronal β III-tubulin (25%), GFAP (30%) or Nkx2.5 (1%). Although capable of growing as non-attached spheres for months, when given an appropriate matrix, these cells adhere giving rise to skeletal muscle, neuronal and cardiac muscle cell lineages. A similar cell population could not be isolated from either bone marrow or cardiac tissue suggesting their specificity to skeletal muscle. When injected into damaged muscle, these non-adherent muscle-derived cells are retrieved expressing Pax7, in a sublaminar position characterizing satellite cells and participate in forming new myofibers. These data show that a non-adherent stem cell population can be specifically isolated and expanded from skeletal muscle and upon attachment to a matrix spontaneously differentiate into muscle, cardiac and neuronal lineages in vitro. Although competing with resident satellite cells, these cells are shown to significantly contribute to repair of injured muscle in vivo supporting that a similar muscle-derived non-adherent cell population from human muscle may be useful in treatment of neuromuscular disorders

  13. Global high-resolution monthly pCO2 climatology for the coastal ocean derived from neural network interpolation

    Directory of Open Access Journals (Sweden)

    G. G. Laruelle

    2017-10-01

    Full Text Available In spite of the recent strong increase in the number of measurements of the partial pressure of CO2 in the surface ocean (pCO2, the air–sea CO2 balance of the continental shelf seas remains poorly quantified. This is a consequence of these regions remaining strongly under-sampled in both time and space and of surface pCO2 exhibiting much higher temporal and spatial variability in these regions compared to the open ocean. Here, we use a modified version of a two-step artificial neural network method (SOM-FFN; Landschützer et al., 2013 to interpolate the pCO2 data along the continental margins with a spatial resolution of 0.25° and with monthly resolution from 1998 to 2015. The most important modifications compared to the original SOM-FFN method are (i the much higher spatial resolution and (ii the inclusion of sea ice and wind speed as predictors of pCO2. The SOM-FFN is first trained with pCO2 measurements extracted from the SOCATv4 database. Then, the validity of our interpolation, in both space and time, is assessed by comparing the generated pCO2 field with independent data extracted from the LDVEO2015 database. The new coastal pCO2 product confirms a previously suggested general meridional trend of the annual mean pCO2 in all the continental shelves with high values in the tropics and dropping to values beneath those of the atmosphere at higher latitudes. The monthly resolution of our data product permits us to reveal significant differences in the seasonality of pCO2 across the ocean basins. The shelves of the western and northern Pacific, as well as the shelves in the temperate northern Atlantic, display particularly pronounced seasonal variations in pCO2,  while the shelves in the southeastern Atlantic and in the southern Pacific reveal a much smaller seasonality. The calculation of temperature normalized pCO2 for several latitudes in different oceanic basins confirms that the seasonality in shelf pCO2 cannot solely be explained by

  14. A study on precursors leading to geomagnetic storms using artificial ...

    Indian Academy of Sciences (India)

    Space weather prediction involves advance forecasting of the magnitude and onset time of major geomagneticstorms on Earth. In this paper, we discuss the development of an artificial neural network-basedmodel to study the precursor leading to intense and moderate geomagnetic storms, following halo coronalmass ...

  15. Precursor Additive Manufacturing Inventions

    Science.gov (United States)

    Roberts, C.; Bourell, D.

    2018-03-01

    Most modern Additive Manufacturing (AM) processes were invented and commercialized in a short period of time spanning 1984-2000. This paper reports on AM processes invented in the 1974-1987 time period, known as precursor AM processes. The critical difference between the two periods is public knowledge and utilization of distributed computing.

  16. Combined effects of flow-induced shear stress and electromagnetic field on neural differentiation of mesenchymal stem cells.

    Science.gov (United States)

    Mascotte-Cruz, Juan Uriel; Ríos, Amelia; Escalante, Bruno

    2016-01-01

    Differentiation of bone marrow-derived mesenchymal stem cells (MSCs) into neural phenotype has been induced by either flow-induced shear stress (FSS) or electromagnetic fields (EMF). However, procedures are still expensive and time consuming. In the present work, induction for 1 h with the combination of both forces showed the presence of the neural precursor nestin as early as 9 h in culture after treatment and this result lasted for the following 6 d. In conclusion, the use of a combination of FSS and EMF for a short-time renders in neurite-like cells, although further investigation is required to analyze cell functionality.

  17. Protecting Neural Structures and Cognitive Function During Prolonged Space Flight by Targeting the Brain Derived Neurotrophic Factor Molecular Network

    Science.gov (United States)

    Schmidt, M. A.; Goodwin, T. J.

    2014-01-01

    Brain derived neurotrophic factor (BDNF) is the main activity-dependent neurotrophin in the human nervous system. BDNF is implicated in production of new neurons from dentate gyrus stem cells (hippocampal neurogenesis), synapse formation, sprouting of new axons, growth of new axons, sprouting of new dendrites, and neuron survival. Alterations in the amount or activity of BDNF can produce significant detrimental changes to cortical function and synaptic transmission in the human brain. This can result in glial and neuronal dysfunction, which may contribute to a range of clinical conditions, spanning a number of learning, behavioral, and neurological disorders. There is an extensive body of work surrounding the BDNF molecular network, including BDNF gene polymorphisms, methylated BDNF gene promoters, multiple gene transcripts, varied BDNF functional proteins, and different BDNF receptors (whose activation differentially drive the neuron to neurogenesis or apoptosis). BDNF is also closely linked to mitochondrial biogenesis through PGC-1alpha, which can influence brain and muscle metabolic efficiency. BDNF AS A HUMAN SPACE FLIGHT COUNTERMEASURE TARGET Earth-based studies reveal that BDNF is negatively impacted by many of the conditions encountered in the space environment, including oxidative stress, radiation, psychological stressors, sleep deprivation, and many others. A growing body of work suggests that the BDNF network is responsive to a range of diet, nutrition, exercise, drug, and other types of influences. This section explores the BDNF network in the context of 1) protecting the brain and nervous system in the space environment, 2) optimizing neurobehavioral performance in space, and 3) reducing the residual effects of space flight on the nervous system on return to Earth

  18. Transplantation of iPS cell-derived neural progenitors overexpressing SDF-1α increases regeneration and functional recovery after ischemic stroke.

    Science.gov (United States)

    Chau, Monica; Deveau, Todd C; Song, Mingke; Wei, Zheng Z; Gu, Xiaohuan; Yu, Shan Ping; Wei, Ling

    2017-11-14

    Ischemic stroke is a leading cause of human death and disability while clinical treatments are limited. The adult brain possesses endogenous regenerative activities that may benefit tissue repair after stroke. Trophic factors such as stromal cell-derived factor 1 alpha (SDF-1α) are upregulated in the ischemic brain, which promote endogenous regeneration. The regenerative response, however, is normally insufficient. Transplantation of exogenous cells has been explored as regenerative therapies. One promising cell type for transplantation is induced pluripotent stem (iPS) cells which are cells genetically reprogrammed from adult somatic cells. We hypothesized that transplanting neural progenitor cells derived from iPS cells (iPS-NPCs) could provide cell replacement and trophic support. The trophic factor SDF-1α was overexpressed in iPS-NPCs by lentiviral transduction to test if SDF-1α could increase regeneration in the ischemic brain. These SDF-1α-iPS-NPCs were differentiated in vitro to express mature neuronal and synaptic markers. Differentiated cells expressed functional Na + and K + channels, and fired action potentials. In the oxygen glucose deprivation (OGD) test, SDF-1α-iPS-NPCs survived significantly better compared to control iPS-NPCs. In mice subjected to focal cerebral ischemia in the sensorimotor cortex, iPS-NPCs and SDF-1α-iPS-NPCs were intracranially transplanted into the ischemic cortex 7 days after stroke. Neuronal differentiation of transplanted cells was identified using NeuN 14 days after transplantation. Mice that received SDF-1α-iPS-NPCs had greater numbers of NeuN/BrdU and Glut-1/BrdU co-labeled cells in the peri-infarct area and improved locomotion compared to the control iPS-NPC transplantation. Thus, SDF-1α upregulation in transplanted cells may be a therapeutic strategy to enhance endogenous neurovascular repair after ischemic stroke in adult mice.

  19. Rapid generation of sub-type, region-specific neurons and neural networks from human pluripotent stem cell-derived neurospheres

    Directory of Open Access Journals (Sweden)

    Aynun N. Begum

    2015-11-01

    Full Text Available Stem cell-based neuronal differentiation has provided a unique opportunity for disease modeling and regenerative medicine. Neurospheres are the most commonly used neuroprogenitors for neuronal differentiation, but they often clump in culture, which has always represented a challenge for neurodifferentiation. In this study, we report a novel method and defined culture conditions for generating sub-type or region-specific neurons from human embryonic and induced pluripotent stem cells derived neurosphere without any genetic manipulation. Round and bright-edged neurospheres were generated in a supplemented knockout serum replacement medium (SKSRM with 10% CO2, which doubled the expression of the NESTIN, PAX6 and FOXG1 genes compared with those cultured with 5% CO2. Furthermore, an additional step (AdSTEP was introduced to fragment the neurospheres and facilitate the formation of a neuroepithelial-type monolayer that we termed the “neurosphederm”. The large neural tube-type rosette (NTTR structure formed from the neurosphederm, and the NTTR expressed higher levels of the PAX6, SOX2 and NESTIN genes compared with the neuroectoderm-derived neuroprogenitors. Different layers of cortical, pyramidal, GABAergic, glutamatergic, cholinergic neurons appeared within 27 days using the neurosphederm, which is a shorter period than in traditional neurodifferentiation-protocols (42–60 days. With additional supplements and timeline dopaminergic and Purkinje neurons were also generated in culture too. Furthermore, our in vivo results indicated that the fragmented neurospheres facilitated significantly better neurogenesis in severe combined immunodeficiency (SCID mouse brains compared with the non-fragmented neurospheres. Therefore, this neurosphere-based neurodifferentiation protocol is a valuable tool for studies of neurodifferentiation, neuronal transplantation and high throughput screening assays.

  20. Decreased proliferative, migrative and neuro-differentiative potential of postnatal rat enteric neural crest-derived cells during culture in vitro

    International Nuclear Information System (INIS)

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

    2016-01-01

    A growing body of evidence supports the potential use of enteric neural crest-derived cells (ENCCs) as a cell replacement therapy for Hirschsprung's disease. Based on previous observations of robust propagation of primary ENCCs, as opposed to their progeny, it is suggested that their therapeutic potential after in vitro expansion may be restricted. We therefore examined the growth and differentiation activities and phenotypic characteristics of continuous ENCC cultures. ENCCs were isolated from the intestines of postnatal rats and were identified using an immunocytochemical approach. During continuous ENCC culture expansion, proliferation, migration, apoptosis, and differentiation potentials were monitored. The Cell Counting Kit-8 was used for assessment of ENCC vitality, Transwell inserts for cell migration, immunocytochemistry for cell counts and identification, and flow cytometry for apoptosis. Over six continuous generations, ENCC proliferation potency was reduced and with prolonged culture, the ratio of migratory ENCCs was decreased. The percentage of apoptosis showed an upward trend with prolonged intragenerational culture, but showed a downward trend with prolonged culture of combined generations. Furthermore, the percentage of peripherin + cells decreased whilst the percentage of GFAP + cells increased with age. The results demonstrated that alterations in ENCC growth characteristics occur with increased culture time, which may partially account for the poor results of proposed cell therapies. - Highlights: • Differences were identified between primary and daughter ENCCs. • Daughter ENCCs had reduced proliferation, migration and differentiation. • Daughter ENCCs also had increased apoptosis. • These altered characteristics warrant further investigation.

  1. Clinical Trial of Human Fetal Brain-Derived Neural Stem/Progenitor Cell Transplantation in Patients with Traumatic Cervical Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Ji Cheol Shin

    2015-01-01

    Full Text Available In a phase I/IIa open-label and nonrandomized controlled clinical trial, we sought to assess the safety and neurological effects of human neural stem/progenitor cells (hNSPCs transplanted into the injured cord after traumatic cervical spinal cord injury (SCI. Of 19 treated subjects, 17 were sensorimotor complete and 2 were motor complete and sensory incomplete. hNSPCs derived from the fetal telencephalon were grown as neurospheres and transplanted into the cord. In the control group, who did not receive cell implantation but were otherwise closely matched with the transplantation group, 15 patients with traumatic cervical SCI were included. At 1 year after cell transplantation, there was no evidence of cord damage, syrinx or tumor formation, neurological deterioration, and exacerbating neuropathic pain or spasticity. The American Spinal Injury Association Impairment Scale (AIS grade improved in 5 of 19 transplanted patients, 2 (A → C, 1 (A → B, and 2 (B → D, whereas only one patient in the control group showed improvement (A → B. Improvements included increased motor scores, recovery of motor levels, and responses to electrophysiological studies in the transplantation group. Therefore, the transplantation of hNSPCs into cervical SCI is safe and well-tolerated and is of modest neurological benefit up to 1 year after transplants. This trial is registered with Clinical Research Information Service (CRIS, Registration Number: KCT0000879.

  2. [Learning and memory amelioration of transplantation of the neural stem cells modified with human brain-derived neurotrophic factor gene on Alzheimer disease model rat].

    Science.gov (United States)

    Zhao, Zhiying; Hu, Haitao; Feng, Gaifeng

    2005-05-01

    To investigate the memory amelioration of the Alzheimer disease (AD) model rat after being transplanted the single neural stem cells (NSC) and NSC modified with human brain-derived neurotrophic factor (hBDNF) gene. Forty SD rats were divided evenly into 4 groups randomly. The AD model rats were made by cutting unilaterally the fibria-fornix of male rats. Ten to twelve days after surgery, the genetically modified and unmodified NSC were implanted into the lateral cerebral ventricle of group III and group IV respectively. Two weeks after transplantation, the amelioration of memory impairment of the rats was detected by Morris water maze. The average escaping latency of the group III and group IV (41.84 +/- 21.76 s, 25.23 +/- 17.06 s respectively) was shorter than that of the group II (70.91 +/- 23.67 s) (P0.05). More lineal and oriented strategies were used in group IV. The behavioral amelioration of AD model rat was obtained by transplanting single NSC and hBDNF-gene-modified NSC. The effect of the NSC group modified with hBDNF gene is better than that of the group III.

  3. Glial cell line-derived neurotrophic factor (GDNF) induces neuritogenesis in the cochlear spiral ganglion via neural cell adhesion molecule (NCAM)

    Science.gov (United States)

    Euteneuer, Sara; Yang, Kuo H.; Chavez, Eduardo; Leichtle, Anke; Loers, Gabriele; Olshansky, Adel; Pak, Kwang; Schachner, Melitta; Ryan, Allen F.

    2013-01-01

    Glial cell line-derived neurotrophic factor (GDNF) increases survival and neurite extension of spiral ganglion neurons (SGNs), the primary neurons of the auditory system, via yet unknown signaling mechanisms. In other cell types, signaling is achieved by the GPI-linked GDNF family receptor α1 (GFRα1) via recruitment of transmembrane receptors: Ret (re-arranged during transformation) and/or NCAM (neural cell adhesion molecule). Here we show that GDNF enhances neuritogenesis in organotypic cultures of spiral ganglia from 5-day-old rats and mice. Addition of GFRα1-Fc increases this effect. GDNF/GFRα1-Fc stimulation activates intracellular PI3K/Akt and MEK/Erk signaling cascades as detected by Western blot analysis of cultures prepared from rats at postnatal days 5 (P5, before the onset of hearing) and 20 (P20, after the onset of hearing). Both cascades mediate GDNF stimulation of neuritogenesis, since application of the Akt inhibitor Wortmannin or the Erk inhibitor U0126 abolished GDNF/GFRα1-Fc stimulated neuritogenesis in P5 rats. Since cultures of P5 NCAM-deficient mice failed to respond by neuritogenesis to GDNF/GFRα1-Fc, we conclude that NCAM serves as a receptor for GDNF signaling responsible for neuritogenesis in early postnatal spiral ganglion. PMID:23262364

  4. Neural Mobilization Treatment Decreases Glial Cells and Brain-Derived Neurotrophic Factor Expression in the Central Nervous System in Rats with Neuropathic Pain Induced by CCI in Rats.

    Science.gov (United States)

    Giardini, Aline Carolina; Dos Santos, Fabio Martinez; da Silva, Joyce Teixeira; de Oliveira, Mara Evany; Martins, Daniel Oliveira; Chacur, Marucia

    2017-01-01

    Background . Glial cells are implicated in the development of chronic pain and brain-derived neurotropic factor (BDNF) released from activated microglia contributes to the nociceptive transmission. Neural mobilization (NM) technique is a method clinically effective in reducing pain sensitivity. Here we examined the involvement of glial cells and BDNF expression in the thalamus and midbrain after NM treatment in rats with chronic constriction injury (CCI). CCI was induced and rats were subsequently submitted to 10 sessions of NM, every other day, beginning 14 days after CCI. Thalamus and midbrain were analyzed for glial fibrillary acidic protein (GFAP), microglial cell OX-42, and BDNF using Immunohistochemistry and Western blot assays. Results . Thalamus and midbrain of CCI group showed increases in GFAP, OX-42, and BDNF expression compared with control group and, in contrast, showed decreases in GFAP, OX-42, and BDNF after NM when compared with CCI group. The decreased immunoreactivity for GFAP, OX-42, and BDNF in ventral posterolateral nucleus in thalamus and the periaqueductal gray in midbrain was shown by immunohistochemistry. Conclusions . These findings may improve the knowledge about the involvement of astrocytes, microglia, and BDNF in the chronic pain and show that NM treatment, which alleviates neuropathic pain, affects glial cells and BDNF expression.

  5. Roles of db-cAMP, IBMX and RA in aspects of neural differentiation of cord blood derived mesenchymal-like stem cells.

    Directory of Open Access Journals (Sweden)

    Murni Tio

    Full Text Available Mesenchymal stem cells (MSCs have multilineage differentiation potential which includes cell lineages of the central nervous system; hence MSCs might be useful in the treatment of neurodegenerative diseases such as Parkinson's disease. Although mesenchymal stem cells have been shown to differentiate into the neural lineage, there is still little knowledge about the underlying mechanisms of differentiation particularly towards specialized neurons such as dopaminergic neurons. Here, we show that MSCs derived from human umbilical cord blood (MSC(hUCBs are capable of expressing tyrosine hydroxylase (TH and Nurr1, markers typically associated with DA neurons. We also found differential phosphorylation of TH isoforms indicating the presence of post-translational mechanisms possibly activating and modifying TH in MSC(hUCB. Furthermore, functional dissection of components in the differentiation medium revealed that dibutyryl-cAMP (db-cAMP, 3-isobutyl-1-methylxanthine (IBMX and retinoic acid (RA are involved in the regulation of Nurr1 and Neurofilament-L expression as well as in the differential phosphorylation of TH. We also demonstrate a possible inhibitory role of the protein kinase A signaling pathway in the phosphorylation of specific TH isoforms.

  6. Colonic mesenchyme differentiates into smooth muscle before its colonization by vagal enteric neural crest-derived cells in the chick embryo.

    Science.gov (United States)

    Bourret, Annick; Chauvet, Norbert; de Santa Barbara, Pascal; Faure, Sandrine

    2017-06-01

    During development, the gastrointestinal (GI) tract arises from a primary tube composed of mesoderm and endoderm. The mesoderm gives rise to the digestive mesenchyme, which in turn differentiates into multiple tissues, namely the submucosa, the interstitial cells of Cajal and the smooth muscle cells (SMCs). Concomitant with these early patterning events, the primitive GI tract is colonized by vagal enteric neural crest-derived cells (vENCDCs), a population of cells that gives rise to the enteric nervous system, the intrinsic innervation of the GI tract. Reciprocal neuro-mesenchymal interactions are essential for the coordinated development of GI musculature. The aim of this study is to examine and compare the kinetics of mesenchymal cell differentiation into SMCs along the anterior-posterior axis to the pattern of vENCDCs migration using whole-mount in situ hybridization and paraffin section immunofluorescence analyses on chick embryonic GI tracts from E4-Stage 23 to E7-Stages 30-31. We confirmed that gastric and pre-umbilical intestine mesenchyme differentiation into SMCs occurs after vENCDCs colonization. However, we found that colonic and post-umbilical intestine mesenchyme differentiation occurs before vENCDCs colonization. These findings suggest that regional-specific mechanisms are involved in the mesenchyme differentiation into SMCs along the GI anterior-posterior axis.

  7. Decreased proliferative, migrative and neuro-differentiative potential of postnatal rat enteric neural crest-derived cells during culture in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hui [Department of Pediatric Surgery, the Second Affiliated Hospital, Xi’an Jiaotong University, No 157, Xi Wu Road, Xi’an 710004, Shaanxi (China); Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi’an Jiaotong University, No 96, Yan Ta Xi Road, Xi’an 710061, Shaanxi (China); Pan, Wei-Kang; Zheng, Bai-Jun; Wang, Huai-Jie [Department of Pediatric Surgery, the Second Affiliated Hospital, Xi’an Jiaotong University, No 157, Xi Wu Road, Xi’an 710004, Shaanxi (China); Chen, Xin-Lin; Liu, Yong [Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi’an Jiaotong University, No 96, Yan Ta Xi Road, Xi’an 710061, Shaanxi (China); Gao, Ya, E-mail: ygao@mail.xjtu.edu.cn [Department of Pediatric Surgery, the Second Affiliated Hospital, Xi’an Jiaotong University, No 157, Xi Wu Road, Xi’an 710004, Shaanxi (China)

    2016-05-01

    A growing body of evidence supports the potential use of enteric neural crest-derived cells (ENCCs) as a cell replacement therapy for Hirschsprung's disease. Based on previous observations of robust propagation of primary ENCCs, as opposed to their progeny, it is suggested that their therapeutic potential after in vitro expansion may be restricted. We therefore examined the growth and differentiation activities and phenotypic characteristics of continuous ENCC cultures. ENCCs were isolated from the intestines of postnatal rats and were identified using an immunocytochemical approach. During continuous ENCC culture expansion, proliferation, migration, apoptosis, and differentiation potentials were monitored. The Cell Counting Kit-8 was used for assessment of ENCC vitality, Transwell inserts for cell migration, immunocytochemistry for cell counts and identification, and flow cytometry for apoptosis. Over six continuous generations, ENCC proliferation potency was reduced and with prolonged culture, the ratio of migratory ENCCs was decreased. The percentage of apoptosis showed an upward trend with prolonged intragenerational culture, but showed a downward trend with prolonged culture of combined generations. Furthermore, the percentage of peripherin{sup +} cells decreased whilst the percentage of GFAP{sup +} cells increased with age. The results demonstrated that alterations in ENCC growth characteristics occur with increased culture time, which may partially account for the poor results of proposed cell therapies. - Highlights: • Differences were identified between primary and daughter ENCCs. • Daughter ENCCs had reduced proliferation, migration and differentiation. • Daughter ENCCs also had increased apoptosis. • These altered characteristics warrant further investigation.

  8. Neuritogenic and survival-promoting effects of the P2 peptide derived from a homophilic binding site in the neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Pedersen, Martin V; Køhler, Lene B; Ditlevsen, Dorte K

    2004-01-01

    The neural cell adhesion molecule (NCAM) plays a pivotal role in neural development, regeneration, and plasticity. NCAM mediates adhesion and subsequent signal transduction through NCAM-NCAM binding. Recently, a peptide ligand termed P2 corresponding to a 12-amino-acid sequence in the FG loop...

  9. Rotary orbital suspension culture of embryonic stem cell-derived neural stem/progenitor cells: impact of hydrodynamic culture on aggregate yield, morphology and cell phenotype.

    Science.gov (United States)

    Laundos, Tiago L; Silva, Joana; Assunção, Marisa; Quelhas, Pedro; Monteiro, Cátia; Oliveira, Carla; Oliveira, Maria J; Pêgo, Ana P; Amaral, Isabel F

    2017-08-01

    Embryonic stem (ES)-derived neural stem/progenitor cells (ES-NSPCs) constitute a promising cell source for application in cell therapies for the treatment of central nervous system disorders. In this study, a rotary orbital hydrodynamic culture system was applied to single-cell suspensions of ES-NSPCs, to obtain homogeneously-sized ES-NSPC cellular aggregates (neurospheres). Hydrodynamic culture allowed the formation of ES-NSPC neurospheres with a narrower size distribution than statically cultured neurospheres, increasing orbital speeds leading to smaller-sized neurospheres and higher neurosphere yield. Neurospheres formed under hydrodynamic conditions (72 h at 55 rpm) showed higher cell compaction and comparable percentages of viable, dead, apoptotic and proliferative cells. Further characterization of cellular aggregates provided new insights into the effect of hydrodynamic shear on ES-NSPC behaviour. Rotary neurospheres exhibited reduced protein levels of N-cadherin and β-catenin, and higher deposition of laminin (without impacting fibronectin deposition), matrix metalloproteinase-2 (MMP-2) activity and percentage of neuronal cells. In line with the increased MMP-2 activity levels found, hydrodynamically-cultured neurospheres showed higher outward migration on laminin. Moreover, when cultured in a 3D fibrin hydrogel, rotary neurospheres generated an increased percentage of neuronal cells. In conclusion, the application of a constant orbital speed to single-cell suspensions of ES-NSPCs, besides allowing the formation of homogeneously-sized neurospheres, promoted ES-NSPC differentiation and outward migration, possibly by influencing the expression of cell-cell adhesion molecules and the secretion of proteases/extracellular matrix proteins. These findings are important when establishing the culture conditions needed to obtain uniformly-sized ES-NSPC aggregates, either for use in regenerative therapies or in in vitro platforms for biomaterial development or

  10. Fluoxetine up-regulates expression of cellular FLICE-inhibitory protein and inhibits LPS-induced apoptosis in hippocampus-derived neural stem cell

    International Nuclear Information System (INIS)

    Chiou, S.-H.; Chen, S.-J.; Peng, C-H.; Chang, Y.-L.; Ku, H.-H.; Hsu, W.-M.; Ho, Larry L.-T.; Lee, C.-H.

    2006-01-01

    Fluoxetine is a widely used antidepressant compound which inhibits the reuptake of serotonin in the central nervous system. Recent studies have shown that fluoxetine can promote neurogenesis and improve the survival rate of neurons. However, whether fluoxetine modulates the proliferation or neuroprotection effects of neural stem cells (NSCs) needs to be elucidated. In this study, we demonstrated that 20 μM fluoxetine can increase the cell proliferation of NSCs derived from the hippocampus of adult rats by MTT test. The up-regulated expression of Bcl-2, Bcl-xL and the cellular FLICE-inhibitory protein (c-FLIP) in fluoxetine-treated NSCs was detected by real-time RT-PCR. Our results further showed that fluoxetine protects the lipopolysaccharide-induced apoptosis in NSCs, in part, by activating the expression of c-FLIP. Moreover, c-FLIP induction by fluoxetine requires the activation of the c-FLIP promoter region spanning nucleotides -414 to -133, including CREB and SP1 sites. This effect appeared to involve the phosphatidylinositol-3-kinase-dependent pathway. Furthermore, fluoxetine treatment significantly inhibited the induction of proinflammatory factor IL-1β, IL-6, and TNF-α in the culture medium of LPS-treated NSCs (p < 0.01). The results of high performance liquid chromatography coupled to electrochemical detection further confirmed that fluoxentine increased the functional production of serotonin in NSCs. Together, these data demonstrate the specific activation of c-FLIP by fluoxetine and indicate the novel role of fluoxetine for neuroprotection in the treatment of depression

  11. Combination of exogenous cell transplantation and 5-HT{sub 4} receptor agonism induce endogenous enteric neural crest-derived cells in a rat hypoganglionosis model

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hui [Department of Pediatric Surgery, the Second Affiliated Hospital, Xi’an Jiaotong University, No 157, Xi Wu Road, Xi’an 710004, Shaanxi (China); Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi’an Jiaotong University, No 96, Yan Ta Xi Road, Xi’an 710061, Shaanxi (China); Zheng, Bai-Jun; Pan, Wei-Kang; Wang, Huai-Jie; Xie, Chong; Zhao, Yu-Ying [Department of Pediatric Surgery, the Second Affiliated Hospital, Xi’an Jiaotong University, No 157, Xi Wu Road, Xi’an 710004, Shaanxi (China); Chen, Xin-Lin; Liu, Yong [Institute of Neurobiology, Environment and Genes Related to Diseases Key Laboratory of Chinese Ministry of Education, Xi’an Jiaotong University, No 96, Yan Ta Xi Road, Xi’an 710061, Shaanxi (China); Gao, Ya, E-mail: ygao@mail.xjtu.edu.cn [Department of Pediatric Surgery, the Second Affiliated Hospital, Xi’an Jiaotong University, No 157, Xi Wu Road, Xi’an 710004, Shaanxi (China)

    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{sub 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{sub 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{sup 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{sub 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. Whole-Genome DNA Methylation Analyses Revealed Epigenetic Instability in Tumorigenic Human iPS Cell-Derived Neural Stem/Progenitor Cells.

    Science.gov (United States)

    Iida, Tsuyoshi; Iwanami, Akio; Sanosaka, Tsukasa; Kohyama, Jun; Miyoshi, Hiroyuki; Nagoshi, Narihito; Kashiwagi, Rei; Toyama, Yoshiaki; Matsumoto, Morio; Nakamura, Masaya; Okano, Hideyuki

    2017-05-01

    Although human induced pluripotent stem cell (hiPSC) derivatives are considered promising cellular resources for regenerative medicine, their tumorigenicity potentially limits their clinical application in hiPSC technologies. We previously demonstrated that oncogenic hiPSC-derived neural stem/progenitor cells (hiPSC-NS/PCs) produced tumor-like tissues that were distinct from teratomas. To gain insight into the mechanisms underlying the regulation of tumorigenicity in hiPSC-NS/PCs, we performed an integrated analysis using the Infinium HumanMethylation450 BeadChip array and the HumanHT-12 v4.0 Expression BeadChip array to compare the comprehensive DNA methylation and gene expression profiles of tumorigenic hiPSC-NS/PCs (253G1-NS/PCs) and non-tumorigenic cells (201B7-NS/PCs). Although the DNA methylation profiles of 253G1-hiPSCs and 201B7-hiPSCs were similar regardless of passage number, the methylation status of the global DNA methylation profiles of 253G1-NS/PCs and 201B7-NS/PCs differed; the genomic regions surrounding the transcriptional start site of the CAT and PSMD5 genes were hypermethylated in 253G1-NS/PCs but not in 201B7-NS/PCs. Interestingly, the aberrant DNA methylation profile was more pronounced in 253G1-NS/PCs that had been passaged more than 15 times. In addition, we identified aberrations in DNA methylation at the RBP1 gene locus; the DNA methylation frequency in RBP1 changed as 253G1-NS/PCs were sequentially passaged. These results indicate that different NS/PC clones have different DNA methylomes and that DNA methylation patterns are unstable as cells are passaged. Therefore, DNA methylation profiles should be included in the criteria used to evaluate the tumorigenicity of hiPSC-NS/PCs in the clinical setting. Stem Cells 2017;35:1316-1327. © 2017 AlphaMed Press.

  13. Precursor of color superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Kitazawa, M. [Kyoto Univ., Dept. of Physics, Kyoto (Japan); Koide, T.; Kunihiro, T. [Kyoto Univ., Yukawa Institute for Theoretical Physics, Kyoto (Japan); Nemoto, Y. [Brookhaven National Laboratory, RIKEN BNL Research Center, Upton, NY (United States)

    2002-09-01

    We investigate possible precursory phenomena of color superconductivity in quark matter at finite temperature T with use of a simple Nambu-Jona-Lasinio model. It is found that the fluctuating pair field exists with a prominent strength even well above the critical temperature T{sub c}. We show that the collective pair field has a complex energy located in the second Riemann sheet, which approaches the origin as T is lowered to T{sub c}. We discuss the possible relevance of the precursor to the observables to be detected in heavy ion collisions. (author)

  14. Neural cryptography with feedback.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Shacham, Lanir; Kanter, Ido

    2004-04-01

    Neural cryptography is based on a competition between attractive and repulsive stochastic forces. A feedback mechanism is added to neural cryptography which increases the repulsive forces. Using numerical simulations and an analytic approach, the probability of a successful attack is calculated for different model parameters. Scaling laws are derived which show that feedback improves the security of the system. In addition, a network with feedback generates a pseudorandom bit sequence which can be used to encrypt and decrypt a secret message.

  15. Alternative group V precursors for CVD applications

    Science.gov (United States)

    Lum, R. M.; Klingert, J. K.

    1991-01-01

    The chemical vapor deposition (CVD) techniques used to grow III/V semiconductors films, such as metalorganic vapor phase epitaxy (MOVPE), hydride VPE, chemical beam epitaxy (CBE) and gas source molecular beam epitaxy (GS-MBE), all use hydrides (AsH 3 and PH 3) as the Group V source. However, the hydrides are extremely toxic gases which are stored under high pressure (200-2000 psi). To reduce the safety hazards associated with these gases, alternative Group V precursors have been investigated. Organoarsenic and phosphorous compounds have received the most attention as replacements for AsH 3 and PH 3 because they are typically low vapor pressure liquids, and thus present significantly lower exposure risks than the hydrides. For AsH 3 these have included the methyl, ethyl and butyl-based derivatives RnAsH 3- n, with varying degrees ( n = 1-3) of hydrogen atom substitution. In this paper the growth properties, thermochemistry and toxicity of the various alkylarsine precursors are compared with arsine. Data are presented on the impact of the thermochemistry of these compounds on film electrical properties, and on the effects of precursor composition and purity on overall film quality. The suitability of alternative As-precursors for device applications is demonstrated, and selection criteria are presented for the most effective alkylarsine compound for a particular CVD growth process.

  16. Sol-gel precursors and products thereof

    Science.gov (United States)

    Warren, Scott C.; DiSalvo, Jr., Francis J.; Weisner, Ulrich B.

    2017-02-14

    The present invention provides a generalizable single-source sol-gel precursor capable of introducing a wide range of functionalities to metal oxides such as silica. The sol-gel precursor facilitates a one-molecule, one-step approach to the synthesis of metal-silica hybrids with combinations of biological, catalytic, magnetic, and optical functionalities. The single-source precursor also provides a flexible route for simultaneously incorporating functional species of many different types. The ligands employed for functionalizing the metal oxides are derived from a library of amino acids, hydroxy acids, or peptides and a silicon alkoxide, allowing many biological functionalities to be built into silica hybrids. The ligands can coordinate with a wide range of metals via a carboxylic acid, thereby allowing direct incorporation of inorganic functionalities from across the periodic table. Using the single-source precursor a wide range of functionalized nanostructures such as monolith structures, mesostructures, multiple metal gradient mesostructures and Stober-type nanoparticles can be synthesized. ##STR00001##

  17. Identified EM Earthquake Precursors

    Science.gov (United States)

    Jones, Kenneth, II; Saxton, Patrick

    2014-05-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After a number of custom rock experiments, two hypotheses were formed which could answer the EM wave model. The first hypothesis concerned a sufficient and continuous electron movement either by surface or penetrative flow, and the second regarded a novel approach to radio transmission. Electron flow along fracture surfaces was determined to be inadequate in creating strong EM fields, because rock has a very high electrical resistance making it a high quality insulator. Penetrative flow could not be corroborated as well, because it was discovered that rock was absorbing and confining electrons to a very thin skin depth. Radio wave transmission and detection worked with every single test administered. This hypothesis was reviewed for propagating, long-wave generation with sufficient amplitude, and the capability of penetrating solid rock. Additionally, fracture spaces, either air or ion-filled, can facilitate this concept from great depths and allow for surficial detection. A few propagating precursor signals have been detected in the field occurring with associated phases using custom-built loop antennae. Field testing was conducted in Southern California from 2006-2011, and outside the NE Texas town of Timpson in February, 2013. The antennae have mobility and observations were noted for

  18. Neural stem cell-like cells derived from autologous bone mesenchymal stem cells for the treatment of patients with cerebral palsy

    Directory of Open Access Journals (Sweden)

    Chen Guojun

    2013-01-01

    Full Text Available Abstract Background Stem cell therapy is a promising treatment for cerebral palsy, which refers to a category of brain diseases that are associated with chronic motor disability in children. Autologous MSCs may be a better cell source and have been studied for the treatment of cerebral palsy because of their functions in tissue repair and the regulation of immunological processes. Methods To assess neural stem cell–like (NSC-like cells derived from autologous marrow mesenchymal stem cells as a novel treatment for patients with moderate-to-severe cerebral palsy, a total of 60 cerebral palsy patients were enrolled in this open-label, non-randomised, observer-blinded controlled clinical study with a 6-months follow-up. For the transplantation group, a total of 30 cerebral palsy patients received an autologous NSC-like cells transplantation (1-2 × 107 cells into the subarachnoid cavity and rehabilitation treatments whereas 30 patients in the control group only received rehabilitation treatment. Results We recorded the gross motor function measurement scores, language quotients, and adverse events up to 6 months post-treatment. The gross motor function measurement scores in the transplantation group were significantly higher at month 3 (the score increase was 42.6, 95% CI: 9.8–75.3, P=.011 and month 6 (the score increase was 58.6, 95% CI: 25.8–91.4, P=.001 post-treatment compared with the baseline scores. The increase in the Gross Motor Function Measurement scores in the control group was not significant. The increases in the language quotients at months 1, 3, and 6 post-treatment were not statistically significant when compared with the baseline quotients in both groups. All the 60 patients survived, and none of the patients experienced serious adverse events or complications. Conclusion Our results indicated that NSC-like cells are safe and effective for the treatment of motor deficits related to cerebral palsy. Further randomised clinical

  19. Neural stem cell-like cells derived from autologous bone mesenchymal stem cells for the treatment of patients with cerebral palsy.

    Science.gov (United States)

    Chen, Guojun; Wang, Yali; Xu, Zhenyu; Fang, Feng; Xu, Renmei; Wang, Yue; Hu, Xiaoli; Fan, Lixing; Liu, Houqi

    2013-01-26

    Stem cell therapy is a promising treatment for cerebral palsy, which refers to a category of brain diseases that are associated with chronic motor disability in children. Autologous MSCs may be a better cell source and have been studied for the treatment of cerebral palsy because of their functions in tissue repair and the regulation of immunological processes. To assess neural stem cell-like (NSC-like) cells derived from autologous marrow mesenchymal stem cells as a novel treatment for patients with moderate-to-severe cerebral palsy, a total of 60 cerebral palsy patients were enrolled in this open-label, non-randomised, observer-blinded controlled clinical study with a 6-months follow-up. For the transplantation group, a total of 30 cerebral palsy patients received an autologous NSC-like cells transplantation (1-2 × 107 cells into the subarachnoid cavity) and rehabilitation treatments whereas 30 patients in the control group only received rehabilitation treatment. We recorded the gross motor function measurement scores, language quotients, and adverse events up to 6 months post-treatment. The gross motor function measurement scores in the transplantation group were significantly higher at month 3 (the score increase was 42.6, 95% CI: 9.8-75.3, P=.011) and month 6 (the score increase was 58.6, 95% CI: 25.8-91.4, P=.001) post-treatment compared with the baseline scores. The increase in the Gross Motor Function Measurement scores in the control group was not significant. The increases in the language quotients at months 1, 3, and 6 post-treatment were not statistically significant when compared with the baseline quotients in both groups. All the 60 patients survived, and none of the patients experienced serious adverse events or complications. Our results indicated that NSC-like cells are safe and effective for the treatment of motor deficits related to cerebral palsy. Further randomised clinical trials are necessary to establish the efficacy of this procedure.

  20. Report on Fukushima Daiichi NPP precursor events

    International Nuclear Information System (INIS)

    2014-01-01

    The main questions to be answered by this report were: The Fukushima Daiichi NPP accident, could it have been prevented? If there is a next severe accident, may it be prevented? To answer the first question, the report addressed several aspects. First, the report investigated whether precursors to the Fukushima Daiichi NPP accident existed in the operating experience; second, the reasons why these precursors did not evolve into a severe accident. Third, whether lessons learned from these precursor events were adequately considered by member countries; and finally, if the operating experience feedback system needs to be improved, based on the previous analysis. To address the second question which is much more challenging, the report considered precursor events identified through a search and analysis of the IRS database and also precursors events based on risk significance. Both methods can point out areas where further work may be needed, even if it depends heavily on design and site-specific factors. From the operating experience side, more efforts are needed to ensure timely and full implementation of lessons learnt from precursor events. Concerning risk considerations, a combined use of risk precursors and operating experience may drive to effective changes to plants to reduce risk. The report also contains a short description and evaluation of selected precursors that are related to the course of the Fukushima Daiichi NPP accident. The report addresses the question whether operating experience feedback can be effectively used to identify plant vulnerabilities and minimize potential for severe core damage accidents. Based on several of the precursor events national or international in-depth evaluations were started. The vulnerability of NPPs due to external and internal flooding has clearly been addressed. In addition to the IRS based investigation, the WGRISK was asked to identify important precursor events based on risk significance. These precursors have

  1. Steam Reforming of Bio-Ethanol to Produce Hydrogen over Co/CeO2 Catalysts Derived from Ce1−xCoxO2−y Precursors

    Directory of Open Access Journals (Sweden)

    Yanyong Liu

    2016-02-01

    Full Text Available A series of Ce1−xCoxO2−y precursors were prepared by homogeneous precipitation using urea as a precipitant. The Co/CeO2 catalysts obtained from the Ce1−xCoxO2−y precursors were used for the steam reforming of ethanol to produce hydrogen. Co ions could enter the CeO2 lattices to form Ce1−xCoxO2−y mixed oxides at x ≤ 0.2 using the homogeneous precipitation (hp method. CeO2 was an excellent support for Co metal in the steam reforming of ethanol because a strong interaction between support and metal (SISM exists in the Co/CeO2 catalysts. Because Co/CeO2 (hp prepared by homogeneous precipitation possessed a high BET surface area and small Co metal particles, Co/CeO2 (hp showed a higher ethanol conversion than the Co/CeO2 catalysts prepared using the co-precipitation (cp method and the impregnation (im method. The selectivity of CO2 over Co/CeO2 (hp increased with increasing reaction temperature at from 573 to 673 K, and decreased with increasing reaction temperature above 673 K due to the increase of CO formation. The carbonaceous deposits formed on the catalyst surface during the reaction caused a slow deactivation in the steam reforming of ethanol over Co/CeO2 (hp. The catalytic activity of the used catalysts could be regenerated by an oxidation-reduction treatment, calcined in air at 723 K and then reduced by H2 at 673 K.

  2. High-Throughput Screening to Identify Compounds That Increase Fragile X Mental Retardation Protein Expression in Neural Stem Cells Differentiated From Fragile X Syndrome Patient-Derived Induced Pluripotent Stem Cells.

    Science.gov (United States)

    Kumari, Daman; Swaroop, Manju; Southall, Noel; Huang, Wenwei; Zheng, Wei; Usdin, Karen

    2015-07-01

    : Fragile X syndrome (FXS), the most common form of inherited cognitive disability, is caused by a deficiency of the fragile X mental retardation protein (FMRP). In most patients, the absence of FMRP is due to an aberrant transcriptional silencing of the fragile X mental retardation 1 (FMR1) gene. FXS has no cure, and the available treatments only provide symptomatic relief. Given that FMR1 gene silencing in FXS patient cells can be partially reversed by treatment with compounds that target repressive epigenetic marks, restoring FMRP expression could be one approach for the treatment of FXS. We describe a homogeneous and highly sensitive time-resolved fluorescence resonance energy transfer assay for FMRP detection in a 1,536-well plate format. Using neural stem cells differentiated from an FXS patient-derived induced pluripotent stem cell (iPSC) line that does not express any FMRP, we screened a collection of approximately 5,000 known tool compounds and approved drugs using this FMRP assay and identified 6 compounds that modestly increase FMR1 gene expression in FXS patient cells. Although none of these compounds resulted in clinically relevant levels of FMR1 mRNA, our data provide proof of principle that this assay combined with FXS patient-derived neural stem cells can be used in a high-throughput format to identify better lead compounds for FXS drug development. In this study, a specific and sensitive fluorescence resonance energy transfer-based assay for fragile X mental retardation protein detection was developed and optimized for high-throughput screening (HTS) of compound libraries using fragile X syndrome (FXS) patient-derived neural stem cells. The data suggest that this HTS format will be useful for the identification of better lead compounds for developing new therapeutics for FXS. This assay can also be adapted for FMRP detection in clinical and research settings. ©AlphaMed Press.

  3. The neural cell adhesion molecule-derived peptide, FGL, attenuates lipopolysaccharide-induced changes in glia in a CD200-dependent manner

    DEFF Research Database (Denmark)

    Cox, F F; Berezin, V; Bock, E

    2013-01-01

    Fibroblast growth loop (FGL) is a neural cell adhesion molecule (NCAM)-mimetic peptide that mimics the interaction of NCAM with fibroblast growth factor receptor (FGFR). FGL increases neurite outgrowth and promotes neuronal survival in vitro, and it has also been shown to have neuroprotective eff...

  4. Dynamics of neural cryptography

    International Nuclear Information System (INIS)

    Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

    2007-01-01

    Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible

  5. Dynamics of neural cryptography.

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

    2007-05-01

    Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.

  6. Dynamics of neural cryptography

    Science.gov (United States)

    Ruttor, Andreas; Kinzel, Wolfgang; Kanter, Ido

    2007-05-01

    Synchronization of neural networks has been used for public channel protocols in cryptography. In the case of tree parity machines the dynamics of both bidirectional synchronization and unidirectional learning is driven by attractive and repulsive stochastic forces. Thus it can be described well by a random walk model for the overlap between participating neural networks. For that purpose transition probabilities and scaling laws for the step sizes are derived analytically. Both these calculations as well as numerical simulations show that bidirectional interaction leads to full synchronization on average. In contrast, successful learning is only possible by means of fluctuations. Consequently, synchronization is much faster than learning, which is essential for the security of the neural key-exchange protocol. However, this qualitative difference between bidirectional and unidirectional interaction vanishes if tree parity machines with more than three hidden units are used, so that those neural networks are not suitable for neural cryptography. In addition, the effective number of keys which can be generated by the neural key-exchange protocol is calculated using the entropy of the weight distribution. As this quantity increases exponentially with the system size, brute-force attacks on neural cryptography can easily be made unfeasible.

  7. Role of glial cell line-derived neurotrophic factor (GDNF)-neural cell adhesion molecule (NCAM) interactions in induction of neurite outgrowth and identification of a binding site for NCAM in the heel region of GDNF

    DEFF Research Database (Denmark)

    Nielsen, Janne; Gotfryd, Kamil; Li, Shizhong

    2009-01-01

    The formation of appropriate neuronal circuits is an essential part of nervous system development and relies heavily on the outgrowth of axons and dendrites and their guidance to their respective targets. This process is governed by a large array of molecules, including glial cell line......-derived neurotrophic factor (GDNF) and the neural cell adhesion molecule (NCAM), the interaction of which induce neurite outgrowth. In the present study the requirements for NCAM-mediated GDNF-induced neurite outgrowth were investigated in cultures of hippocampal neurons, which do not express Ret. We demonstrate...

  8. Sound Waves Induce Neural Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells via Ryanodine Receptor-Induced Calcium Release and Pyk2 Activation.

    Science.gov (United States)

    Choi, Yura; Park, Jeong-Eun; Jeong, Jong Seob; Park, Jung-Keug; Kim, Jongpil; Jeon, Songhee

    2016-10-01

    Mesenchymal stem cells (MSCs) have shown considerable promise as an adaptable cell source for use in tissue engineering and other therapeutic applications. The aims of this study were to develop methods to test the hypothesis that human MSCs could be differentiated using sound wave stimulation alone and to find the underlying mechanism. Human bone marrow (hBM)-MSCs were stimulated with sound waves (1 kHz, 81 dB) for 7 days and the expression of neural markers were analyzed. Sound waves induced neural differentiation of hBM-MSC at 1 kHz and 81 dB but not at 1 kHz and 100 dB. To determine the signaling pathways involved in the neural differentiation of hBM-MSCs by sound wave stimulation, we examined the Pyk2 and CREB phosphorylation. Sound wave induced an increase in the phosphorylation of Pyk2 and CREB at 45 min and 90 min, respectively, in hBM-MSCs. To find out the upstream activator of Pyk2, we examined the intracellular calcium source that was released by sound wave stimulation. When we used ryanodine as a ryanodine receptor antagonist, sound wave-induced calcium release was suppressed. Moreover, pre-treatment with a Pyk2 inhibitor, PF431396, prevented the phosphorylation of Pyk2 and suppressed sound wave-induced neural differentiation in hBM-MSCs. These results suggest that specific sound wave stimulation could be used as a neural differentiation inducer of hBM-MSCs.

  9. Intraspinal administration of human spinal cord-derived neural progenitor cells in the G93A-SOD1 mouse model of ALS delays symptom progression, prolongs survival and increases expression of endogenous neurotrophic factors.

    Science.gov (United States)

    Knippenberg, Sarah; Rath, Klaus Jan; Böselt, Sebastian; Thau-Habermann, Nadine; Schwarz, Sigrid C; Dengler, Reinhard; Wegner, Florian; Petri, Susanne

    2017-03-01

    Neural stem or progenitor cells are considered to be a novel therapeutic strategy for amyotrophic lateral sclerosis (ALS), based on their potential to generate a protective environment rather than to replace degenerating motor neurons. Following local injection to the spinal cord, neural progenitor cells may generate glial cells and release neurotrophic factors. In the present study, human spinal cord-derived neural progenitor cells (hscNPCs) were injected into the lumbar spinal cord of G93A-SOD1 ALS transgenic mice. We evaluated the potential effect of hscNPC treatment by survival analysis and behavioural/phenotypic assessments. Immunohistological and real-time PCR experiments were performed at a defined time point to study the underlying mechanisms. Symptom progression in hscNPC-injected mice was significantly delayed at the late stage of disease. On average, survival was only prolonged for 5 days. Animals treated with hscNPCs performed significantly better in motor function tests between weeks 18 and 19. Increased production of GDNF and IGF-1 mRNA was detectable in spinal cord tissue of hscNPC-treated mice. In summary, treatment with hscNPCs led to increased endogenous production of several growth factors and increased the preservation of innervated motor neurons but had only a small effect on overall survival. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Cerebellar granule cells are predominantly generated by terminal symmetric divisions of granule cell precursors.

    Science.gov (United States)

    Nakashima, Kie; Umeshima, Hiroki; Kengaku, Mineko

    2015-06-01

    Neurons in the central nervous system (CNS) are generated by symmetric and asymmetric cell division of neural stem cells and their derivative progenitor cells. Cerebellar granule cells are the most abundant neurons in the CNS, and are generated by intensive cell division of granule cell precursors (GCPs) during postnatal development. Dysregulation of GCP cell cycle is causal for some subtypes of medulloblastoma. However, the details and mechanisms underlying neurogenesis from GCPs are not well understood. Using long-term live-cell imaging of proliferating GCPs transfected with a fluorescent newborn-granule cell marker, we found that GCPs underwent predominantly symmetric divisions, generating two GCPs or two neurons, while asymmetric divisions generating a GCP and a neuron were only occasionally observed, in both dissociated culture and within tissues of isolated cerebellar lobules. We found no significant difference in cell cycle length between proliferative and neurogenic divisions, or any consistent changes in cell cycle length during repeated proliferative division. Unlike neural stem cells in the cerebral cortex and spinal cord, which generate many neurons by repeated asymmetric division, cerebellar GCPs produce neurons predominantly by terminal symmetric division. These results indicate diverse mechanisms of neurogenesis in the mammalian brain. © 2015 Wiley Periodicals, Inc.

  11. Cellular Kinetics of Perivascular MSC Precursors

    Directory of Open Access Journals (Sweden)

    William C. W. Chen

    2013-01-01

    Full Text Available Mesenchymal stem/stromal cells (MSCs and MSC-like multipotent stem/progenitor cells have been widely investigated for regenerative medicine and deemed promising in clinical applications. In order to further improve MSC-based stem cell therapeutics, it is important to understand the cellular kinetics and functional roles of MSCs in the dynamic regenerative processes. However, due to the heterogeneous nature of typical MSC cultures, their native identity and anatomical localization in the body have remained unclear, making it difficult to decipher the existence of distinct cell subsets within the MSC entity. Recent studies have shown that several blood-vessel-derived precursor cell populations, purified by flow cytometry from multiple human organs, give rise to bona fide MSCs, suggesting that the vasculature serves as a systemic reservoir of MSC-like stem/progenitor cells. Using individually purified MSC-like precursor cell subsets, we and other researchers have been able to investigate the differential phenotypes and regenerative capacities of these contributing cellular constituents in the MSC pool. In this review, we will discuss the identification and characterization of perivascular MSC precursors, including pericytes and adventitial cells, and focus on their cellular kinetics: cell adhesion, migration, engraftment, homing, and intercellular cross-talk during tissue repair and regeneration.

  12. Simple in vitro migration assay for neural crest cells and the opposite effects of all-trans-retinoic acid on cephalic- and trunk-derived cells.

    Science.gov (United States)

    Usami, Makoto; Mitsunaga, Katsuyoshi; Irie, Tomohiko; Miyajima, Atsuko; Doi, Osamu

    2014-08-01

    Here, we describe a simple in vitro neural crest cell (NCC) migration assay and the effects of all-trans-retinoic acid (RA) on NCCs. Neural tubes excised from the rhombencephalic or trunk region of day 10.5 rat embryos were cultured for 48 h to allow emigration and migration of NCCs. Migration of NCCs was measured as the change in the radius (radius ratio) calculated from the circular spread of NCCs between 24 and 48 h of culture. RA was added to the culture medium after 24 h at embryotoxic concentrations determined by rat whole embryo culture. RA (10 μM) reduced the migration of cephalic NCCs, whereas it enhanced the migration of trunk NCCs, indicating that RA has opposite effects on these two types of NCCs. © 2014 Japanese Teratology Society.

  13. Novel Precursor-Derived Meso-/Macroporous TiO2/SiOC Nanocomposites with Highly Stable Anatase Nanophase Providing Visible Light Photocatalytic Activity and Superior Adsorption of Organic Dyes

    Directory of Open Access Journals (Sweden)

    Eranezhuth Wasan Awin

    2018-03-01

    Full Text Available Titania (TiO2 is considered to have immense potential as a photocatalyst, the anatase phase in particular. There have been numerous attempts to push the limits of its catalytic activity to higher wavelengths to harness the visible electromagnetic radiation. Most of the investigations till date have been restricted to fine-tuning the bandgap by doping, control of defect chemistry at the surface and several to first principle simulations either with limited success or success at the cost of complexities in processing. Here, we report a simple and elegant way of preparing ceramics through precursor chemistry which involves synthesis of macroporous and mesoporous nanocomposites with in situ formation of TiO2 nanocrystals into a robust and protecting SiOC matrix. The in situ nanoscaled TiO2 is anatase of size 9–10 nm, which is uniformly distributed in an amorphous SiOC matrix forming a new generation of nanocomposites that combine the robustness, structural stability and durability of the SiOC matrix while achieving nanoscaled TiO2 functionalities. The stabilization of the anatase phase even at temperature as high as 1200 °C was evident. With an average pore size of 6.8 nm, surface area of 129 m2/g (BET and pore volume of 0.22 cm3/g (BET, mesoporosity was achieved in the nanocomposites. The composites exhibited visible light photocatalytic activity, which is attributed to the Ti–O–C/TiC bonds resulting in the reduction of band gap by 0.2 to 0.9 eV. Furthermore, the heterojunction formed between the amorphous SiOC and crystalline TiO2 is also expected to minimize the recombination rate of electron-hole pair, making these novel nanocomposites based on TiO2 extremely active in visible wavelength regime.

  14. Samba, a Xenopus hnRNP expressed in neural and neural crest tissues.

    Science.gov (United States)

    Yan, Chao Yun Irene; Skourides, Paris; Chang, Chenbei; Brivanlou, Ali

    2009-01-01

    RNA binding proteins regulate gene expression at the posttranscriptional level and play important roles in embryonic development. Here, we report the cloning and expression of Samba, a Xenopus hnRNP that is maternally expressed and persists at least until tail bud stages. During gastrula stages, Samba is enriched in the dorsal regions. Subsequently, its expression is elevated only in neural and neural crest tissues. In the latter, Samba expression overlaps with that of Slug in migratory neural crest cells. Thereafter, Samba is maintained in the neural crest derivatives, as well as other neural tissues, including the anterior and posterior neural tube and the eyes. Overexpression of Samba in the animal pole leads to defects in neural crest migration and cranial cartilage development. Thus, Samba encodes a Xenopus hnRNP that is expressed early in neural and neural crest derivatives and may regulate crest cells migratory behavior. Copyright (c) 2008 Wiley-Liss, Inc.

  15. Skeletal muscle neural progenitor cells exhibit properties of NG2-glia.

    Science.gov (United States)

    Birbrair, Alexander; Zhang, Tan; Wang, Zhong-Min; Messi, María Laura; Enikolopov, Grigori N; Mintz, Akiva; Delbono, Osvaldo

    2013-01-01

    Reversing brain degeneration and trauma lesions will depend on cell therapy. Our previous work identified neural precursor cells derived from the skeletal muscle of Nestin-GFP transgenic mice, but their identity, origin, and potential survival in the brain are only vaguely understood. In this work, we show that Nestin-GFP+ progenitor cells share morphological and molecular markers with NG2-glia, including NG2, PDGFRα, O4, NGF receptor (p75), glutamate receptor-1(AMPA), and A2B5 expression. Although these cells exhibit NG2, they do not express other pericyte markers, such as α-SMA or connexin-43, and do not differentiate into the muscle lineage. Patch-clamp studies displayed outward potassium currents, probably carried through Kir6.1 channels. Given their potential therapeutic application, we compared their abundance in tissues and concluded that skeletal muscle is the richest source of predifferentiated neural precursor cells. We found that these cells migrate toward the neurogenic subventricular zone displaying their typical morphology and nestin-GFP expression two weeks after brain injection. For translational purposes, we sought to identify these neural progenitor cells in wild-type species by developing a DsRed expression vector under Nestin-Intron II control. This approach revealed them in nonhuman primates and aging rodents throughout the lifespan. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Neural networks

    International Nuclear Information System (INIS)

    Denby, Bruce; Lindsey, Clark; Lyons, Louis

    1992-01-01

    The 1980s saw a tremendous renewal of interest in 'neural' information processing systems, or 'artificial neural networks', among computer scientists and computational biologists studying cognition. Since then, the growth of interest in neural networks in high energy physics, fueled by the need for new information processing technologies for the next generation of high energy proton colliders, can only be described as explosive

  17. Myelin plasticity, neural activity, and traumatic neural injury.

    Science.gov (United States)

    Kondiles, Bethany R; Horner, Philip J

    2018-02-01

    The possibility that adult organisms exhibit myelin plasticity has recently become a topic of great interest. Many researchers are exploring the role of myelin growth and adaptation in daily functions such as memory and motor learning. Here we consider evidence for three different potential categories of myelin plasticity: the myelination of previously bare axons, remodeling of existing sheaths, and the removal of a sheath with replacement by a new internode. We also review evidence that points to the importance of neural activity as a mechanism by which oligodendrocyte precursor cells (OPCs) are cued to differentiate into myelinating oligodendrocytes, which may potentially be an important component of myelin plasticity. Finally, we discuss demyelination in the context of traumatic neural injury and present an argument for altering neural activity as a potential therapeutic target for remyelination following injury. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 108-122, 2018. © 2017 Wiley Periodicals, Inc.

  18. Proteolytic Processing of the Human Immunodeficiency Virus Envelope Glycoprotein Precursor Decreases Conformational Flexibility

    OpenAIRE

    Haim, Hillel; Salas, Ignacio; Sodroski, Joseph

    2013-01-01

    The mature envelope glycoprotein (Env) spike on the surface of human immunodeficiency virus type 1 (HIV-1) virions is derived by proteolytic cleavage of a trimeric gp160 glycoprotein precursor. Remarkably, proteolytic processing of the HIV-1 Env precursor results in changes in Env antigenicity that resemble those associated with glutaraldehyde fixation. Apparently, proteolytic processing of the HIV-1 Env precursor decreases conformational flexibility of the Env trimeric complex, differentiall...

  19. Methionine as a Precursor of Ethylene—Commentary

    Science.gov (United States)

    Lieberman et al. showed in a 1966 publication of Plant Physiology that methionine is a precursor of ethylene. It was the first paper that showed ethylene carbons are derived from carbons 3 and 4 of methionine. This paper catalyzed remarkable interest among plant biologists to elucidate the biosynth...

  20. Identification of Phox2b-regulated genes by expression profiling of cranial motoneuron precursors

    Directory of Open Access Journals (Sweden)

    Reiprich Simone

    2008-06-01

    Full Text Available Abstract Background Branchiomotor neurons comprise an important class of cranial motor neurons that innervate the branchial-arch-derived muscles of the face, jaw and neck. They arise in the ventralmost progenitor domain of the rhombencephalon characterized by expression of the homeodomain transcription factors Nkx2.2 and Phox2b. Phox2b in particular plays a key role in the specification of branchiomotor neurons. In its absence, generic neuronal differentiation is defective in the progenitor domain and no branchiomotor neurons are produced. Conversely, ectopic expression of Phox2b in spinal regions of the neural tube promotes cell cycle exit and neuronal differentiation and, at the same time, induces genes and an axonal phenotype characteristic for branchiomotor neurons. How Phox2b exerts its pleiotropic functions, both as a proneural gene and a neuronal subtype determinant, has remained unknown. Results To gain further insights into the genetic program downstream of Phox2b, we searched for novel Phox2b-regulated genes by cDNA microarray analysis of facial branchiomotor neuron precursors from heterozygous and homozygous Phox2b mutant embryos. We selected for functional studies the genes encoding the axonal growth promoter Gap43, the Wnt antagonist Sfrp1 and the transcriptional regulator Sox13, which were not previously suspected to play roles downstream of Phox2b and whose expression was affected by Phox2b misexpression in the spinal cord. While Gap43 did not produce an obvious phenotype when overexpressed in the neural tube, Sfrp1 induced the interneuron marker Lhx1,5 and Sox13 inhibited neuronal differentiation. We then tested whether Sfrp1 and Sox13, which are down-regulated by Phox2b in the facial neuron precursors, would antagonize some aspects of Phox2b activity. Co-expression of Sfrp1 prevented Phox2b from repressing Lhx1,5 and alleviated the commissural axonal phenotype. When expressed together with Sox13, Phox2b was still able to promote

  1. Impaired neural differentiation of induced pluripotent stem cells generated from a mouse model of Sandhoff disease.

    Directory of Open Access Journals (Sweden)

    Yasuhiro Ogawa

    Full Text Available Sandhoff disease (SD is a glycosphingolipid storage disease that arises from mutations in the Hexb gene and the resultant deficiency in β-hexosaminidase activity. This deficiency results in aberrant lysosomal accumulation of the ganglioside GM2 and related glycolipids, and progressive deterioration of the central nervous system. Dysfunctional glycolipid storage causes severe neurodegeneration through a poorly understood pathogenic mechanism. Induced pluripotent stem cell (iPSC technology offers new opportunities for both elucidation of the pathogenesis of diseases and the development of stem cell-based therapies. Here, we report the generation of disease-specific iPSCs from a mouse model of SD. These mouse model-derived iPSCs (SD-iPSCs exhibited pluripotent stem cell properties and significant accumulation of GM2 ganglioside. In lineage-directed differentiation studies using the stromal cell-derived inducing activity method, SD-iPSCs showed an impaired ability to differentiate into early stage neural precursors. Moreover, fewer neurons differentiated from neural precursors in SD-iPSCs than in the case of the wild type. Recovery of the Hexb gene in SD-iPSCs improved this impairment of neuronal differentiation. These results provide new insights as to understanding the complex pathogenic mechanisms of SD.

  2. Cannabidiol Activates Neuronal Precursor Genes in Human Gingival Mesenchymal Stromal Cells.

    Science.gov (United States)

    Soundara Rajan, Thangavelu; Giacoppo, Sabrina; Scionti, Domenico; Diomede, Francesca; Grassi, Gianpaolo; Pollastro, Federica; Piattelli, Adriano; Bramanti, Placido; Mazzon, Emanuela; Trubiani, Oriana

    2017-06-01

    In the last years, mesenchymal stromal cells (MSCs) from oral tissues have received considerable interest in regenerative medicine since they can be obtained with minimal invasive procedure and exhibit immunomodulatory properties. This study was aimed to investigate whether in vitro pre-treatment of MSCs obtained from human gingiva (hGMSCs) with Cannabidiol (CBD), a cannabinoid component produced by the plant Cannabis sativa, may promote human gingiva derived MSCs to differentiate toward neuronal precursor cells. Specifically, we have treated the hGMSCs with CBD (5 µM) for 24 h in order to evaluate the expression of genes involved in cannabidiol signaling, cell proliferation, self-renewal and multipotency, and neural progenitor cells differentiation. Next generation sequencing (NGS) demonstrated that CBD activates genes associated with G protein coupled receptor signaling in hGMSCs. Genes involved in DNA replication, cell cycle, proliferation, and apoptosis were regulated. Moreover, genes associated with the biological process of neuronal progenitor cells (NCPs) proliferation, neuron differentiation, neurogenesis, and nervous system development were significantly modulated. From our results, we hypothesize that human gingiva-derived MSCs conditioned with CBD could represent a valid method for improving the hGMSCs phenotype and thus might be a potential therapeutic tool in the treatment of neurodegenerative diseases. J. Cell. Biochem. 118: 1531-1546, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Differentiation of retinal ganglion cells and photoreceptor precursors from mouse induced pluripotent stem cells carrying an Atoh7/Math5 lineage reporter.

    Directory of Open Access Journals (Sweden)

    Bin-Bin Xie

    Full Text Available The neural retina is a critical component of the visual system, which provides the majority of sensory input in humans. Various retinal degenerative diseases can result in the permanent loss of retinal neurons, especially the light-sensing photoreceptors and the centrally projecting retinal ganglion cells (RGCs. The replenishment of lost RGCs and the repair of optic nerve damage are particularly challenging, as both RGC specification and their subsequent axonal growth and projection involve complex and precise regulation. To explore the developmental potential of pluripotent stem cell-derived neural progenitors, we have established mouse iPS cells that allow cell lineage tracing of progenitors that have expressed Atoh7/Math5, a bHLH transcription factor required for RGC production. These Atoh7 lineage reporter iPS cells encode Cre to replace one copy of the endogenous Atoh7 gene and a Cre-dependent YFP reporter in the ROSA locus. In addition, they express pluripotent markers and are capable of generating teratomas in vivo. Under anterior neural induction and neurogenic conditions in vitro, the Atoh7-Cre/ROSA-YFP iPS cells differentiate into neurons that co-express various RGC markers and YFP, indicating that these neurons are derived from Atoh7-expressing progenitors. Consistent with previous in vivo cell lineage studies, the Atoh7-Cre/ROSA-YFP iPS cells also give rise to a subset of Crx-positive photoreceptor precursors. Furthermore, inhibition of Notch signaling in the iPSC cultures results in a significant increase of YFP-positive RGCs and photoreceptor precursors. Together, these results show that Atoh7-Cre/ROSA-YFP iPS cells can be used to monitor the development and survival of RGCs and photoreceptors from pluripotent stem cells.

  4. Unique Preservation of Neural Cells in Hutchinson- Gilford Progeria Syndrome Is Due to the Expression of the Neural-Specific miR-9 MicroRNA

    Directory of Open Access Journals (Sweden)

    Xavier Nissan

    2012-07-01

    Full Text Available One puzzling observation in patients affected with Hutchinson-Gilford progeria syndrome (HGPS, who overall exhibit systemic and dramatic premature aging, is the absence of any conspicuous cognitive impairment. Recent studies based on induced pluripotent stem cells derived from HGPS patient cells have revealed a lack of expression in neural derivatives of lamin A, a major isoform of LMNA that is initially produced as a precursor called prelamin A. In HGPS, defective maturation of a mutated prelamin A induces the accumulation of toxic progerin in patient cells. Here, we show that a microRNA, miR-9, negatively controls lamin A and progerin expression in neural cells. This may bear major functional correlates, as alleviation of nuclear blebbing is observed in nonneural cells after miR-9 overexpression. Our results support the hypothesis, recently proposed from analyses in mice, that protection of neural cells from progerin accumulation in HGPS is due to the physiologically restricted expression of miR-9 to that cell lineage.

  5. PSA-NCAM-Negative Neural Crest Cells Emerging during Neural Induction of Pluripotent Stem Cells Cause Mesodermal Tumors and Unwanted Grafts

    Science.gov (United States)

    Lee, Dongjin R.; Yoo, Jeong-Eun; Lee, Jae Souk; Park, Sanghyun; Lee, Junwon; Park, Chul-Yong; Ji, Eunhyun; Kim, Han-Soo; Hwang, Dong-Youn; Kim, Dae-Sung; Kim, Dong-Wook

    2015-01-01

    Summary Tumorigenic potential of human pluripotent stem cells (hPSCs) is an important issue in clinical applications. Despite many efforts, PSC-derived neural precursor cells (NPCs) have repeatedly induced tumors in animal models even though pluripotent cells were not detected. We found that polysialic acid-neural cell adhesion molecule (PSA-NCAM)− cells among the early NPCs caused tumors, whereas PSA-NCAM+ cells were nontumorigenic. Molecular profiling, global gene analysis, and multilineage differentiation of PSA-NCAM− cells confirm that they are multipotent neural crest stem cells (NCSCs) that could differentiate into both ectodermal and mesodermal lineages. Transplantation of PSA-NCAM− cells in a gradient manner mixed with PSA-NCAM+ cells proportionally increased mesodermal tumor formation and unwanted grafts such as PERIPHERIN+ cells or pigmented cells in the rat brain. Therefore, we suggest that NCSCs are a critical target for tumor prevention in hPSC-derived NPCs, and removal of PSA-NCAM− cells eliminates the tumorigenic potential originating from NCSCs after transplantation. PMID:25937368

  6. Differentiation of Mouse Embryonic Stem Cells into Ventral Foregut Precursors

    DEFF Research Database (Denmark)

    Rothová, Michaela; Hölzenspies, Jurriaan J; Livigni, Alessandra

    2016-01-01

    Anterior definitive endoderm (ADE), the ventral foregut precursor, is both an important embryonic signaling center and a unique multipotent precursor of liver, pancreas, and other organs. Here, a method is described for the differentiation of mouse embryonic stem cells (mESCs) to definitive...... endoderm with pronounced anterior character. ADE-containing cultures can be produced in vitro by suspension (embryoid body) culture or in a serum-free adherent monolayer culture. ESC-derived ADE cells are committed to endodermal fates and can undergo further differentiation in vitro towards ventral foregut...

  7. Preparation of superconductor precursor powders

    Science.gov (United States)

    Bhattacharya, Raghunath; Blaugher, Richard D.

    1995-01-01

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals, such as nitrate salts of thallium, barium, calcium, and copper, which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of thallium in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

  8. Trending analysis of precursor events

    International Nuclear Information System (INIS)

    Watanabe, Norio

    1998-01-01

    The Accident Sequence Precursor (ASP) Program of United States Nuclear Regulatory Commission (U.S.NRC) identifies and categorizes operational events at nuclear power plants in terms of the potential for core damage. The ASP analysis has been performed on yearly basis and the results have been published in the annual reports. This paper describes the trends in initiating events and dominant sequences for 459 precursors identified in the ASP Program during the 1969-94 period and also discusses a comparison with dominant sequences predicted in the past Probabilistic Risk Assessment (PRA) studies. These trends were examined for three time periods, 1969-81, 1984-87 and 1988-94. Although the different models had been used in the ASP analyses for these three periods, the distribution of precursors by dominant sequences show similar trends to each other. For example, the sequences involving loss of both main and auxiliary feedwater were identified in many PWR events and those involving loss of both high and low coolant injection were found in many BWR events. Also, it was found that these dominant sequences were comparable to those determined to be dominant in the predictions by the past PRAs. As well, a list of the 459 precursors identified are provided in Appendix, indicating initiating event types, unavailable systems, dominant sequences, conditional core damage probabilities, and so on. (author)

  9. Synthesis of labelled ecdysone precursors

    International Nuclear Information System (INIS)

    Haag, T.; Hetru, C.; Nakatani, Y.; Luu, B.; Meister, M.; Pichat, L.; Audinot, M.

    1985-01-01

    High specific activity tritiated 3β,14α-dihydroxy-5β-cholest-7-en-6-one, has been prepared using a precursor which permits rapid and easy labelling. This compound is converted to ecdysone under in vitro conditions by insect prothoracic glands, a well known site of ecdysone biosynthesis. (author)

  10. A neural cell adhesion molecule-derived fibroblast growth factor receptor agonist, the FGL-peptide, promotes early postnatal sensorimotor development and enhances social memory retention

    DEFF Research Database (Denmark)

    Secher, Thomas; Novitskaia, V; Berezin, Vladimir

    2006-01-01

    with the fibroblast growth factor receptor (FGFR). A 15-amino-acid long peptide, the FG loop (FGL) peptide, that is derived from the second F3 module of NCAM has been found to activate FGFR1. We here report that the FGL peptide, when administered intranasally to newborn rats, accelerated early postnatal development...

  11. Graphene oxide and reduced graphene oxide induced neural pheochromocytoma-derived PC12 cell lines apoptosis and cell cycle alterations via the ERK signaling pathways.

    Science.gov (United States)

    Kang, Yiyuan; Liu, Jia; Wu, Junrong; Yin, Qian; Liang, Huimin; Chen, Aijie; Shao, Longquan

    2017-01-01

    Given the novel applications of graphene materials in biomedical and electronics industry, the health hazards of these particles have attracted extensive worldwide attention. Although many studies have been performed on graphene material-induced toxic effects, toxicological data for the effect of graphene materials on the nervous system are lacking. In this study, we focused on the biological effects of graphene oxide (GO) and reduced graphene oxide (rGO) materials on PC12 cells, a type of traditional neural cell line. We found that GO and rGO exerted significant toxic effects on PC12 cells in a dose- and time-dependent manner. Moreover, apoptosis appeared to be a response to toxicity. A potent increase in the number of PC12 cells at G0/G1 phase after GO and rGO exposure was detected by cell cycle analysis. We found that phosphorylation levels of ERK signaling molecules, which are related to cell cycle regulation and apoptosis, were significantly altered after GO and rGO exposure. In conclusion, our results show that GO has more potent toxic effects than rGO and that apoptosis and cell cycle arrest are the main toxicity responses to GO and rGO treatments, which are likely due to ERK pathway regulation.

  12. Design of a decoupled AP1000 reactor core control system using digital proportional–integral–derivative (PID) control based on a quasi-diagonal recurrent neural network (QDRNN)

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Xinyu, E-mail: xyuwei@mail.xjtu.edu.cn; Wang, Pengfei, E-mail: pengfeixiaoli@yahoo.cn; Zhao, Fuyu, E-mail: fuyuzhao_xj@163.com

    2016-08-01

    Highlights: • We establish a disperse dynamic model for AP1000 reactor core. • A digital PID control based on QDRNN is used to design a decoupling control system. • The decoupling performance is verified and discussed. • The decoupling control system is simulated under the load following operation. - Abstract: The control system of the AP1000 reactor core uses the mechanical shim (MSHIM) strategy, which includes a power control subsystem and an axial power distribution control subsystem. To address the strong coupling between the two subsystems, an interlock between the two subsystems is used, which can only alleviate but not eliminate the coupling. Therefore, sometimes the axial offset (AO) cannot be controlled tightly, and the flexibility of load-following operation is limited. Thus, the decoupling of the original AP1000 reactor core control system is the focus of this paper. First, a two-node disperse dynamic model is established for the AP1000 reactor core to use PID control. Then, a digital PID control system based on a quasi-diagonal recurrent neural network (QDRNN) is designed to decouple the original system. Finally, the decoupling of the control system is verified by the step signal and load-following condition. The results show that the designed control system can decouple the original system as expected and the AO can be controlled much more tightly. Moreover, the flexibility of the load following is increased.

  13. Neural engineering

    CERN Document Server

    2013-01-01

    Neural Engineering, 2nd Edition, contains reviews and discussions of contemporary and relevant topics by leading investigators in the field. It is intended to serve as a textbook at the graduate and advanced undergraduate level in a bioengineering curriculum. This principles and applications approach to neural engineering is essential reading for all academics, biomedical engineers, neuroscientists, neurophysiologists, and industry professionals wishing to take advantage of the latest and greatest in this emerging field.

  14. Derivation of mesenchymal stromal cells from pluripotent stem cells through a neural crest lineage using small molecule compounds with defined media.

    Directory of Open Access Journals (Sweden)

    Makoto Fukuta

    Full Text Available Neural crest cells (NCCs are an embryonic migratory cell population with the ability to differentiate into a wide variety of cell types that contribute to the craniofacial skeleton, cornea, peripheral nervous system, and skin pigmentation. This ability suggests the promising role of NCCs as a source for cell-based therapy. Although several methods have been used to induce human NCCs (hNCCs from human pluripotent stem cells (hPSCs, such as embryonic stem cells (ESCs and induced pluripotent stem cells (iPSCs, further modifications are required to improve the robustness, efficacy, and simplicity of these methods. Chemically defined medium (CDM was used as the basal medium in the induction and maintenance steps. By optimizing the culture conditions, the combination of the GSK3β inhibitor and TGFβ inhibitor with a minimum growth factor (insulin very efficiently induced hNCCs (70-80% from hPSCs. The induced hNCCs expressed cranial NCC-related genes and stably proliferated in CDM supplemented with EGF and FGF2 up to at least 10 passages without changes being observed in the major gene expression profiles. Differentiation properties were confirmed for peripheral neurons, glia, melanocytes, and corneal endothelial cells. In addition, cells with differentiation characteristics similar to multipotent mesenchymal stromal cells (MSCs were induced from hNCCs using CDM specific for human MSCs. Our simple and robust induction protocol using small molecule compounds with defined media enabled the generation of hNCCs as an intermediate material producing terminally differentiated cells for cell-based innovative medicine.

  15. Precursor polymer compositions comprising polybenzimidazole

    Energy Technology Data Exchange (ETDEWEB)

    Klaehn, John R.; Peterson, Eric S.; Orme, Christopher J.

    2015-07-14

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  16. Boron nitride ceramics from molecular precursors: synthesis, properties and applications.

    Science.gov (United States)

    Bernard, Samuel; Salameh, Chrystelle; Miele, Philippe

    2016-01-21

    Hexagonal boron nitride (h-BN) attracts considerable interest because its structure is similar to that of carbon graphite while it displays different properties which are of interest for environmental and green technologies. The polar nature of the B-N bond in sp(2)-bonded BN makes it a wide band gap insulator with different chemistry on its surface and particular physical and chemical properties such as a high thermal conductivity, a high temperature stability, a high resistance to corrosion and oxidation and a strong UV emission. It is chemically inert and nontoxic and has good environmental compatibility. h-BN also has enhanced physisorption properties due to the dipolar fields near its surface. Such properties are closely dependent on the processing method. Bottom-up approaches consist of transforming molecular precursors into non-oxide ceramics with retention of the structural units inherent to the precursor molecule. The purpose of the present review is to give an up-to-date overview on the most recent achievements in the preparation of h-BN from borazine-based molecular single-source precursors including borazine and 2,4,6-trichloroborazine through both vapor phase syntheses and methods in the liquid/solid state involving polymeric intermediates, called the Polymer-Derived Ceramics (PDCs) route. In particular, the effect of the chemistry, composition and architecture of the borazine-based precursors and derived polymers on the shaping ability as well as the properties of h-BN is particularly highlighted.

  17. Comparative Study of Microtubule-associated Protein-2 and Glial Fibrillary Acidic Proteins during Neural Induction of Human Bone Marrow Mesenchymal Stem Cells and Adipose-Derived Stem Cells

    Directory of Open Access Journals (Sweden)

    Fatemeh Sadat Mostafavi

    2014-01-01

    Full Text Available Background: In recent years, adipose tissue, due to the stem cells contained within, has found a new special place in laboratory and clinical applications. These adipose-derived stem cells (ADSCs have the same characteristics of bone marrow mesenchymal stem cells (BMSCs. Although bone marrow (BM is not easily accessible and its procurements may be painful, most patients possess excess fat which can be obtained by less invasive methods; this makes adipose tissue ubiquitous, available and an ideal large-scale source for research on clinical applications. Methods: BMSCs and ADSCs were harvested from three healthy human and were characterized using flow-cytometry. After they were treated for neurosphere formation using basic fibroblast growth factor, epidermal growth factor, B 27 ; terminal differentiation was performed. In this study, we used immunocytochemistry, real time-polymerase chain reaction and western blotting techniques for detection and comparison of Nestin, microtubule-associated protein-2 (MAP-2 and glial fibrillary acidic protein (GFAP markers in human ADSCs and BMSCs. Results: Under appropriate conditions ADSCs can differentiate into neuron-like cells and express neural markers the same as BMSCs, also the expression of GFAP marker in differentiated cells derived from ADSCs was significantly lower than the cells derived from BMSCs (P < 0.05. While the expression of MAP-2 marker in both groups was the same. Conclusions: However, due to its advantages and according to our results based on the expression levels of GFAP and MAP-2, adipose tissue rather than BM could represent a more appropriate stem cell source for investigating the application of these cells in understanding the pathophysiology and in treatment of neurodegenerative disorders.

  18. Context-dependent autoprocessing of human immunodeficiency virus type 1 protease precursors.

    Directory of Open Access Journals (Sweden)

    ChihFeng Tien

    Full Text Available HIV-1 protease autoprocessing is responsible for liberation of free mature protease (PR from the Gag-Pol polyprotein precursor. A cell-based model system was previously developed to examine the autoprocessing mechanism of fusion precursors carrying the p6*-PR miniprecursor sandwiched between various proteins or epitopes. We here report that precursor autoprocessing is context-dependent as its activity and outcomes can be modulated by sequences upstream of p6*-PR. This was exemplified by the 26aa maltose binding protein (MBP signal peptide (SigP when placed at the N-terminus of a fusion precursor. The mature PRs released from SigP-carrying precursors are resistant to self-degradation whereas those released from SigP-lacking fusion precursors are prone to self-degradation. A H69D mutation in PR abolished autoprocessing of SigP-containing fusion precursors whereas it only partially suppressed autoprocessing of fusion precursors lacking SigP. An autoprocessing deficient GFP fusion precursor with SigP exhibited a subcellular distribution pattern distinct from the one without it in transfected HeLa cells. Furthermore, a SigP fusion precursor carrying a substitution at the P1 position released the mature PR and PR-containing fragments that were different from those released from the precursor carrying the same mutation but lacking SigP. We also examined autoprocessing outcomes in viral particles produced by a NL4-3 derived proviral construct and demonstrated the existence of several PR-containing fragments along with the mature PR. Some of these resembled the SigP precursor autoprocessing outcomes. This finding of context-dependent modulation reveals the complexity of precursor autoprocessing regulation that most likely accompanies sequence variation imposed by the evolution of the upstream Gag moiety.

  19. Application of Deep Learning to Detect Precursors of Tropical Cyclone

    Science.gov (United States)

    Matsuoka, D.; Nakano, M.; Sugiyama, D.; Uchida, S.

    2017-12-01

    Tropical cyclones (TCs) affect significant damage to human society. Predicting TC generation as soon as possible is important issue in both academic and social perspectives. In the present work, we investigate the probability of predicting TCs seven days prior using deep neural networks. The training data is produced from 30-year cloud resolving global atmospheric simulation (NICAM) with 14 km horizontal resolution (Kodama et al., 2015). We employed a TCs tracking algorithm (Sugi et al., 2002; Nakano et al., 2015) to NICAM simulation data in order to generate supervised cloud images (horizontal sizes are 800-1,000km). We generate approximately one million images of "TCs (include their precursors)" and "not TCs (low pressure clouds)". We generate ten types of image classifier based on 2-dimensional convolutional neural network, includes four convolutional layers, three pooling layers and two fully connected layers. The final predicted results are obtained by these ensemble mean values. Generated classifiers are applied to untrained global simulation data (four million test images). As a result, we succeeded in predicting the precursors of TCs seven and five days before their formation with a Recall of 88.6% and 89.6% (Precision is 11.4%), respectively.

  20. Dynamic transcriptional signature and cell fate analysis reveals plasticity of individual neural plate border cells.

    Science.gov (United States)

    Roellig, Daniela; Tan-Cabugao, Johanna; Esaian, Sevan; Bronner, Marianne E

    2017-03-29

    The 'neural plate border' of vertebrate embryos contains precursors of neural crest and placode cells, both defining vertebrate characteristics. How these lineages segregate from neural and epidermal fates has been a matter of debate. We address this by performing a fine-scale quantitative temporal analysis of transcription factor expression in the neural plate border of chick embryos. The results reveal significant overlap of transcription factors characteristic of multiple lineages in individual border cells from gastrula through neurula stages. Cell fate analysis using a Sox2 (neural) enhancer reveals that cells that are initially Sox2+ cells can contribute not only to neural tube but also to neural crest and epidermis. Moreover, modulating levels of Sox2 or Pax7 alters the apportionment of neural tube versus neural crest fates. Our results resolve a long-standing question and suggest that many individual border cells maintain ability to contribute to multiple ectodermal lineages until or beyond neural tube closure.

  1. Introduction to neural networks

    International Nuclear Information System (INIS)

    Pavlopoulos, P.

    1996-01-01

    This lecture is a presentation of today's research in neural computation. Neural computation is inspired by knowledge from neuro-science. It draws its methods in large degree from statistical physics and its potential applications lie mainly in computer science and engineering. Neural networks models are algorithms for cognitive tasks, such as learning and optimization, which are based on concepts derived from research into the nature of the brain. The lecture first gives an historical presentation of neural networks development and interest in performing complex tasks. Then, an exhaustive overview of data management and networks computation methods is given: the supervised learning and the associative memory problem, the capacity of networks, the Perceptron networks, the functional link networks, the Madaline (Multiple Adalines) networks, the back-propagation networks, the reduced coulomb energy (RCE) networks, the unsupervised learning and the competitive learning and vector quantization. An example of application in high energy physics is given with the trigger systems and track recognition system (track parametrization, event selection and particle identification) developed for the CPLEAR experiment detectors from the LEAR at CERN. (J.S.). 56 refs., 20 figs., 1 tab., 1 appendix

  2. SYNTHESIS OF 17-(ISOCYANOTOSYLMETHYLENE) STEROIDS - PRECURSORS TO PREGNANE DERIVATIVES

    NARCIS (Netherlands)

    VANLEUSEN, D; VANLEUSEN, AM

    1991-01-01

    The synthesis is described of a series of twenty 17-(isocyanotosylmethylene) steroids 5 from 17-oxo steroids and 4-tolysulfonylmethyl isocyanide (TosMIC). Furthermore, nine analogous 17-(isocyanosulfonylmethylene) steroids (15-21a) have been prepared using sulfonylmethyl isocyanides other than

  3. SLS-Derived Lab- Precursor to Deep Space Human Exploration

    Science.gov (United States)

    Griffin, Brand M.; Lewis, Ruthan; Eppler, Dean; Smitherman, David

    2015-01-01

    Plans to send humans to Mars are in the works and the launch system is being built. Are we ready? Transportation, entry, landing, and surface operations have been successfully demonstrated for robotic missions. However, for human missions, there are significant, potentially show-stopping issues. These issues, called Strategic Knowledge Gaps (SKGs), are the unanswered questions concerning long duration exploration Beyond low Earth Orbit (BEO). The gaps represent a risk of loss of life or mission and because they require extended exposure to the weightless environment outside of earth's protective geo-magnetic field, they cannot be resolved on Earth or on the International Space Station (ISS). Placing a laboratory at a relatively close and stable lunar Distant Retrograde Orbit (DRO) provides an accessible location with the requisite environmental conditions for conducting SKG research and testing mitigation solutions. Configurations comprised of multiple 3 m and 4.3 m diameter modules have been studied but the most attractive solution uses elements of the human Mars launch vehicle or Space Launch System (SLS) for a Mars proving ground laboratory. A shortened version of an SLS hydrogen propellant tank creates a Skylab-like pressure vessel that flies fully outfitted on a single launch. This not only offers significant savings by incorporating SLS pressure vessel development costs but avoids the expensive ISS approach using many launches with substantial on-orbit assembly before becoming operational. One of the most challenging SKGs is crew radiation protection; this is why SKG laboratory research is combined with Mars transit habitat systems development. Fundamentally, the two cannot be divorced because using the habitat systems for protection requires actual hardware geometry and material properties intended to contribute to shielding effectiveness. The SKGs are difficult problems. The solutions to these problems are not obvious; they require integrated, iterative, and multi-disciplinary development. A lunar DRO lab built from SLS elements enables an early and representative transit habitat test bed necessary for closing gaps before sending humans on a 1,000-day Mars mission.

  4. SLS-Derived Lab: Precursor to Deep Space Human Exploration

    Science.gov (United States)

    Griffin, Brand; Lewis, Ruthan; Eppler, Dean; Smitherman, David

    2014-01-01

    Plans to send humans to Mars are in work and the launch system is being built. Are we ready? Robotic missions have successfully demonstrated transportation, entry, landing and surface operations but for human missions there are significant, potentially show-stopping issues. These issues, called Strategic Knowledge Gaps (SKGs) are the unanswered questions concerning long-duration exploration beyond low-earth-orbit. The gaps represent a risk of loss of life or mission and because they require extended exposure to the weightless environment outside earth's protective geo-magnetic field they cannot be resolved on the earth or on the International Space Station (ISS). Placing a laboratory at the relatively close and stable lunar Distant Retrograde Orbit (DRO) provides an accessible location with the requisite environmental conditions for conducting SKG research and testing mitigation solutions. Configurations comprised of multiple 3 meter and 4.3 meter diameter modules have been studied but the most attractive solution uses elements of the human Mars launch vehicle or Space Launch System (SLS) for a Mars proving ground laboratory. A shortened version of an SLS hydrogen propellant tank creates a Skylab-like pressure vessel that flies fully outfitted on a single launch. This not only offers significant savings by incorporating SLS pressure vessel development costs but avoids the expensive ISS approach using many launches with substantial on-orbit assembly before becoming operational. One of the most challenging SKGs is crew radiation protection; this is why SKG laboratory research is combined with Mars transit Habitat systems development. Fundamentally, the two cannot be divorced because using the habitat systems for protection requires actual hardware geometry and material properties intended to contribute to shielding effectiveness. The SKGs are difficult problems, solutions are not obvious, and require integrated, iterative, and multi-disciplinary development. A lunar DRO lab built from the launch system elements enables an early and representative transit habitat test bed necessary for closing gaps before sending humans on a 1000 day Mars mission.

  5. Synthesis of novel vitamin K derivatives with alkylated phenyl groups introduced at the ω-terminal side chain and evaluation of their neural differentiation activities.

    Science.gov (United States)

    Sakane, Rie; Kimura, Kimito; Hirota, Yoshihisa; Ishizawa, Michiyasu; Takagi, Yuta; Wada, Akimori; Kuwahara, Shigefumi; Makishima, Makoto; Suhara, Yoshitomo

    2017-11-01

    Vitamin K is an essential cofactor of γ-glutamylcarboxylase as related to blood coagulation and bone formation. Menaquinone-4, one of the vitamin K homologues, is biosynthesized in the body and has various biological activities such as being a ligand for steroid and xenobiotic receptors, protection of neuronal cells from oxidative stress, and so on. From this background, we focused on the role of menaquinone in the differentiation activity of progenitor cells into neuronal cells and we synthesized novel vitamin K derivatives with modification of the ω-terminal side chain. We report here new vitamin K analogues, which introduced an alkylated phenyl group at the ω-terminal side chain. These compounds exhibited potent differentiation activity as compared to control. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  6. Environmental factors unveil dormant developmental capacities in multipotent progenitors of the trunk neural crest.

    Science.gov (United States)

    Coelho-Aguiar, Juliana M; Le Douarin, Nicole M; Dupin, Elisabeth

    2013-12-01

    The neural crest (NC), an ectoderm-derived structure of the vertebrate embryo, gives rise to the melanocytes, most of the peripheral nervous system and the craniofacial mesenchymal tissues (i.e., connective, bone, cartilage and fat cells). In the trunk of Amniotes, no mesenchymal tissues are derived from the NC. In certain in vitro conditions however, avian and murine trunk NC cells (TNCCs) displayed a limited mesenchymal differentiation capacity. Whether this capacity originates from committed precursors or from multipotent TNCCs was unknown. Here, we further investigated the potential of TNCCs to develop into mesenchymal cell types in vitro. We found that, in fact, quail TNCCs exhibit a high ability to differentiate into myofibroblasts, chondrocytes, lipid-laden adipocytes and mineralizing osteoblasts. In single cell cultures, both mesenchymal and neural cell types coexisted in TNCC clonal progeny: 78% of single cells yielded osteoblasts together with glial cells and neurons; moreover, TNCCs generated heterogenous clones with adipocytes, myofibroblasts, melanocytes and/or glial cells. Therefore, alike cephalic NCCs, early migratory TNCCs comprised multipotent progenitors able to generate both mesenchymal and melanocytic/neural derivatives, suggesting a continuum in NC developmental potentials along the neural axis. The skeletogenic capacity of the TNC, which was present in the exoskeletal armor of the extinct basal forms of Vertebrates and which persisted in the distal fin rays of extant teleost fish, thus did not totally disappear during vertebrate evolution. Mesenchymal potentials of the TNC, although not fulfilled during development, are still present in a dormant state in Amniotes and can be disclosed in in vitro culture. Whether these potentials are not expressed in vivo due to the presence of inhibitory cues or to the lack of permissive factors in the trunk environment remains to be understood. © 2013 Published by Elsevier Inc.

  7. The operational cloud retrieval algorithms from TROPOMI on board Sentinel-5 Precursor

    Directory of Open Access Journals (Sweden)

    D. G. Loyola

    2018-01-01

    Full Text Available This paper presents the operational cloud retrieval algorithms for the TROPOspheric Monitoring Instrument (TROPOMI on board the European Space Agency Sentinel-5 Precursor (S5P mission scheduled for launch in 2017. Two algorithms working in tandem are used for retrieving cloud properties: OCRA (Optical Cloud Recognition Algorithm and ROCINN (Retrieval of Cloud Information using Neural Networks. OCRA retrieves the cloud fraction using TROPOMI measurements in the ultraviolet (UV and visible (VIS spectral regions, and ROCINN retrieves the cloud top height (pressure and optical thickness (albedo using TROPOMI measurements in and around the oxygen A-band in the near infrared (NIR. Cloud parameters from TROPOMI/S5P will be used not only for enhancing the accuracy of trace gas retrievals but also for extending the satellite data record of cloud information derived from oxygen A-band measurements, a record initiated with the Global Ozone Monitoring Experiment (GOME on board the second European Remote-Sensing Satellite (ERS-2 over 20 years ago. The OCRA and ROCINN algorithms are integrated in the S5P operational processor UPAS (Universal Processor for UV/VIS/NIR Atmospheric Spectrometers, and we present here UPAS cloud results using the Ozone Monitoring Instrument (OMI and GOME-2 measurements. In addition, we examine anticipated challenges for the TROPOMI/S5P cloud retrieval algorithms, and we discuss the future validation needs for OCRA and ROCINN.

  8. The operational cloud retrieval algorithms from TROPOMI on board Sentinel-5 Precursor

    Science.gov (United States)

    Loyola, Diego G.; Gimeno García, Sebastián; Lutz, Ronny; Argyrouli, Athina; Romahn, Fabian; Spurr, Robert J. D.; Pedergnana, Mattia; Doicu, Adrian; Molina García, Víctor; Schüssler, Olena

    2018-01-01

    This paper presents the operational cloud retrieval algorithms for the TROPOspheric Monitoring Instrument (TROPOMI) on board the European Space Agency Sentinel-5 Precursor (S5P) mission scheduled for launch in 2017. Two algorithms working in tandem are used for retrieving cloud properties: OCRA (Optical Cloud Recognition Algorithm) and ROCINN (Retrieval of Cloud Information using Neural Networks). OCRA retrieves the cloud fraction using TROPOMI measurements in the ultraviolet (UV) and visible (VIS) spectral regions, and ROCINN retrieves the cloud top height (pressure) and optical thickness (albedo) using TROPOMI measurements in and around the oxygen A-band in the near infrared (NIR). Cloud parameters from TROPOMI/S5P will be used not only for enhancing the accuracy of trace gas retrievals but also for extending the satellite data record of cloud information derived from oxygen A-band measurements, a record initiated with the Global Ozone Monitoring Experiment (GOME) on board the second European Remote-Sensing Satellite (ERS-2) over 20 years ago. The OCRA and ROCINN algorithms are integrated in the S5P operational processor UPAS (Universal Processor for UV/VIS/NIR Atmospheric Spectrometers), and we present here UPAS cloud results using the Ozone Monitoring Instrument (OMI) and GOME-2 measurements. In addition, we examine anticipated challenges for the TROPOMI/S5P cloud retrieval algorithms, and we discuss the future validation needs for OCRA and ROCINN.

  9. Fate of grape flavor precursors during storage on yeast lees.

    Science.gov (United States)

    Loscos, Natalia; Hernández-Orte, Purificación; Cacho, Juan; Ferreira, Vicente

    2009-06-24

    The effect of the addition of a grape flavor precursor extract to a grape juice, before or after fermentation with three different Saccharomyces cerevisiae yeast strains, on the evolution of the wine aroma composition during a 9-month aging period on yeast lees has been studied. Wine aroma compounds were determined by gas chromatography-mass spectrometry after alcoholic fermentation and after 3 and 9 months of storage. The aging of wine on lees caused important changes in the aroma profiles of wines, making the concentrations of three terpenes, norisoprenoids (except beta-damascenone and beta-ionone), 4-allyl-2,6-dimethoxyphenol, ethyl vanillate, syringaldehyde, and ethyl cinnamate increase, whereas the concentrations of most of the rest of compounds tended to decrease. Lees are responsible for the observed increasing trends, except for linalool and alpha-terpineol, and also for a large part of the observed decrements. As expected, the addition of precursors brings about an increment in the levels of most terpenes, norisoprenoids, vanillins, and ethyl cinnamate, and it is after an aging time when differences linked to the level of precursors in the must become more evident. The timing of the addition of precursors has a minor influence, except for beta-damascenone, vanillin, and syringaldehyde, for which supplementation after fermentation is more effective. It has also been observed that the precursor fraction makes the levels of vinylphenols decrease. Finally, it has also been found that lees from different yeast strains may have a slightly different abilities to release volatile compounds derived from precursors.

  10. Neural Progenitor-Like Cells Induced from Human Gingiva-Derived Mesenchymal Stem Cells Regulate Myelination of Schwann Cells in Rat Sciatic Nerve Regeneration.

    Science.gov (United States)

    Zhang, Qunzhou; Nguyen, Phuong; Xu, Qilin; Park, Wonse; Lee, Sumin; Furuhashi, Akihiro; Le, Anh D

    2017-02-01

    Regeneration of peripheral nerve injury remains a major clinical challenge. Recently, mesenchymal stem cells (MSCs) have been considered as potential candidates for peripheral nerve regeneration; however, the underlying mechanisms remain elusive. Here, we show that human gingiva-derived MSCs (GMSCs) could be directly induced into multipotent NPCs (iNPCs) under minimally manipulated conditions without the introduction of exogenous genes. Using a crush-injury model of rat sciatic nerve, we demonstrate that GMSCs transplanted to the injury site could differentiate into neuronal cells, whereas iNPCs could differentiate into both neuronal and Schwann cells. After crush injury, iNPCs, compared with GMSCs, displayed superior therapeutic effects on axonal regeneration at both the injury site and the distal segment of the injured sciatic nerve. Mechanistically, transplantation of GMSCs, especially iNPCs, significantly attenuated injury-triggered increase in the expression of c-Jun, a transcription factor that functions as a major negative regulator of myelination and plays a central role in dedifferentiation/reprogramming of Schwann cells into a progenitor-like state. Meanwhile, our results also demonstrate that transplantation of GMSCs and iNPCs consistently increased the expression of Krox-20/EGR2, a transcription factor that governs the expression of myelin proteins and facilitates myelination. Altogether, our findings suggest that transplantation of GMSCs and iNPCs promotes peripheral nerve repair/regeneration, possibly by promoting remyelination of Schwann cells mediated via the regulation of the antagonistic myelination regulators, c-Jun and Krox-20/EGR2. Stem Cells Translational Medicine 2017;6:458-470. © 2016 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  11. Ataxin-1 Poly(Q)-induced Proteotoxic Stress and Apoptosis Are Attenuated in Neural Cells by Docosahexaenoic Acid-derived Neuroprotectin D1*

    Science.gov (United States)

    Calandria, Jorgelina M.; Mukherjee, Pranab K.; de Rivero Vaccari, Juan Carlos; Zhu, Min; Petasis, Nicos A.; Bazan, Nicolas G.

    2012-01-01

    Neurodegenerative diseases share two common features: enhanced oxidative stress and cellular inability to scavenge structurally damaged abnormal proteins. Pathogenesis of polyglutamine (poly(Q)) diseases involves increased protein misfolding, along with ubiquitin and chaperon protein-containing nuclear aggregates. In spinocerebellar ataxia, the brain and retina undergo degeneration. Neuroprotectin D1 (NPD1) is made on-demand in the nervous system and retinal pigment epithelial (RPE) cells in response to oxidative stress, which activates prosurvival signaling via regulation of gene expression and other processes. We hypothesized that protein misfolding-induced proteotoxic stress triggers NPD1 synthesis. We used ARPE-19 cells as a cellular model to assess stress due to ataxin-1 82Q protein expression and determine whether NPD1 prevents apoptosis. Ectopic ataxin-1 expression induced RPE cell apoptosis, which was abrogated by 100 nm docosahexaenoic acid, 10 ng/ml pigment epithelium-derived factor, or NPD1. Similarly, NPD1 was protective in neurons and primary human RPE cells. Furthermore, when ataxin-1 82Q was expressed in 15-lipoxygenase-1-deficient cells, apoptosis was greatly enhanced, and only NPD1 (50 nm) rescued cells from death. NPD1 reduced misfolded ataxin-1-induced accumulation of proapoptotic Bax in the cytoplasm, suggesting that NPD1 acts by preventing proapoptotic signaling pathways from occurring. Finally, NPD1 signaling interfered with ataxin-1/capicua repression of gene expression and decreased phosphorylated ataxin-1 in an Akt-independent manner, suggesting that NPD1 signaling modulates formation or stabilization of ataxin-1 complexes. These data suggest that 1) NPD1 synthesis is an early response induced by proteotoxic stress due to abnormally folded ataxin-1, and 2) NPD1 promotes cell survival through modulating stabilization of ataxin-1 functional complexes and pro-/antiapoptotic and inflammatory pathways. PMID:22511762

  12. Ataxin-1 poly(Q)-induced proteotoxic stress and apoptosis are attenuated in neural cells by docosahexaenoic acid-derived neuroprotectin D1.

    Science.gov (United States)

    Calandria, Jorgelina M; Mukherjee, Pranab K; de Rivero Vaccari, Juan Carlos; Zhu, Min; Petasis, Nicos A; Bazan, Nicolas G

    2012-07-06

    Neurodegenerative diseases share two common features: enhanced oxidative stress and cellular inability to scavenge structurally damaged abnormal proteins. Pathogenesis of polyglutamine (poly(Q)) diseases involves increased protein misfolding, along with ubiquitin and chaperon protein-containing nuclear aggregates. In spinocerebellar ataxia, the brain and retina undergo degeneration. Neuroprotectin D1 (NPD1) is made on-demand in the nervous system and retinal pigment epithelial (RPE) cells in response to oxidative stress, which activates prosurvival signaling via regulation of gene expression and other processes. We hypothesized that protein misfolding-induced proteotoxic stress triggers NPD1 synthesis. We used ARPE-19 cells as a cellular model to assess stress due to ataxin-1 82Q protein expression and determine whether NPD1 prevents apoptosis. Ectopic ataxin-1 expression induced RPE cell apoptosis, which was abrogated by 100 nm docosahexaenoic acid, 10 ng/ml pigment epithelium-derived factor, or NPD1. Similarly, NPD1 was protective in neurons and primary human RPE cells. Furthermore, when ataxin-1 82Q was expressed in 15-lipoxygenase-1-deficient cells, apoptosis was greatly enhanced, and only NPD1 (50 nm) rescued cells from death. NPD1 reduced misfolded ataxin-1-induced accumulation of proapoptotic Bax in the cytoplasm, suggesting that NPD1 acts by preventing proapoptotic signaling pathways from occurring. Finally, NPD1 signaling interfered with ataxin-1/capicua repression of gene expression and decreased phosphorylated ataxin-1 in an Akt-independent manner, suggesting that NPD1 signaling modulates formation or stabilization of ataxin-1 complexes. These data suggest that 1) NPD1 synthesis is an early response induced by proteotoxic stress due to abnormally folded ataxin-1, and 2) NPD1 promotes cell survival through modulating stabilization of ataxin-1 functional complexes and pro-/antiapoptotic and inflammatory pathways.

  13. Stable Neural Control of Uncertain Multivariable Systems

    National Research Council Canada - National Science Library

    Mears, Mark

    2001-01-01

    ... that the trajectories remain bonded. Lyapunov analysis is used to derive equations for the sliding mode control, neural network training, and to show uniform ultimate boundedness of the closed loop systems...

  14. The neural crest and neural crest cells: discovery and significance ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    ). Le Douarin N M 1986 Cell line segregation during peripheral nervous system ontogeny; Science 231 1515–1522. Le Douarin N M, Dupin E, Baroffio A and Dulac C 1992 New insights into the development of neural crest derivatives; Int. Rev.

  15. Artificial Neural Networks·

    Indian Academy of Sciences (India)

    cial intelligence. However to understand the basics of ANNs, a knowledge of neurobiology is not necessary. Yet, it is a good idea to understand how ANNs have been derived from real biological neural systems (see Figures 1,2 and the accompanying boxes). The soma of the cell body receives inputs from other neurons via.

  16. Artificial Neural Networks·

    Indian Academy of Sciences (India)

    works. They have the ability to learn from empirical datal information. They find use in computer science and control engineering fields. In recent years artificial ... However there are vast differences between biological neural networks (BNNs) of the brain and ANN s. A thorough understanding of biologically derived NNs ...

  17. Manganite perovskite ceramics, their precursors and methods for forming

    Science.gov (United States)

    Payne, David Alan; Clothier, Brent Allen

    2015-03-10

    Disclosed are a variety of ceramics having the formula Ln.sub.1-xM.sub.xMnO.sub.3, where 0.Itoreq.x.Itoreq.1 and where Ln is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or Y; M is Ca, Sr, Ba, Cd, or Pb; manganite precursors for preparing the ceramics; a method for preparing the precursors; and a method for transforming the precursors into uniform, defect-free ceramics having magnetoresistance properties. The manganite precursors contain a sol and are derived from the metal alkoxides: Ln(OR).sub.3, M(OR).sub.2 and Mn(OR).sub.2, where R is C.sub.2 to C.sub.6 alkyl or C.sub.3 to C.sub.9 alkoxyalkyl, or C.sub.6 to C.sub.9 aryl. The preferred ceramics are films prepared by a spin coating method and are particularly suited for incorporation into a device such as an integrated circuit device.

  18. Premarital precursors of marital infidelity.

    Science.gov (United States)

    Allen, Elizabeth S; Rhoades, Galena Kline; Stanley, Scott M; Markman, Howard J; Williams, Tamara; Melton, Jessica; Clements, Mari L

    2008-06-01

    Premarital precursors of infidelity were evaluated in a sample of 72 couples (N = 144) who were taking part in a longitudinal study of marriage. Premarital self-report and observational data were compared for couples who experienced infidelity and those who did not experience infidelity in the first years of marriage. Couples in which the male engaged in marital infidelity were characterized, premaritally, by significantly lower male sexual satisfaction, lower male positive communication, and higher female invalidation, whereas couples in which the female went on to engage in infidelity were characterized, premaritally, by significantly lower levels of female positive communication, higher levels of male and female negative communication, and higher levels of male and female invalidation. Implications of the findings for future research on the prediction and prevention of infidelity are discussed.

  19. Fluorescence-Activated Cell Sorting of EGFP-Labeled Neural Crest Cells From Murine Embryonic Craniofacial Tissue

    Directory of Open Access Journals (Sweden)

    Saurabh Singh

    2005-01-01

    Full Text Available During the early stages of embryogenesis, pluripotent neural crest cells (NCC are known to migrate from the neural folds to populate multiple target sites in the embryo where they differentiate into various derivatives, including cartilage, bone, connective tissue, melanocytes, glia, and neurons of the peripheral nervous system. The ability to obtain pure NCC populations is essential to enable molecular analyses of neural crest induction, migration, and/or differentiation. Crossing Wnt1-Cre and Z/EG transgenic mouse lines resulted in offspring in which the Wnt1-Cre transgene activated permanent EGFP expression only in NCC. The present report demonstrates a flow cytometric method to sort and isolate populations of EGFP-labeled NCC. The identity of the sorted neural crest cells was confirmed by assaying expression of known marker genes by TaqMan Quantitative Real-Time Polymerase Chain Reaction (QRT-PCR. The molecular strategy described in this report provides a means to extract intact RNA from a pure population of NCC thus enabling analysis of gene expression in a defined population of embryonic precursor cells critical to development.

  20. Neural Networks

    Directory of Open Access Journals (Sweden)

    Schwindling Jerome

    2010-04-01

    Full Text Available This course presents an overview of the concepts of the neural networks and their aplication in the framework of High energy physics analyses. After a brief introduction on the concept of neural networks, the concept is explained in the frame of neuro-biology, introducing the concept of multi-layer perceptron, learning and their use as data classifer. The concept is then presented in a second part using in more details the mathematical approach focussing on typical use cases faced in particle physics. Finally, the last part presents the best way to use such statistical tools in view of event classifers, putting the emphasis on the setup of the multi-layer perceptron. The full article (15 p. corresponding to this lecture is written in french and is provided in the proceedings of the book SOS 2008.

  1. Non-Linear Systems Identification Using Neural Networks

    OpenAIRE

    Chen, S.; Billings, S.A.; Grant, P.M.

    1989-01-01

    Multi-layered neural networks offer an exciting alternative for modelling complex non-linear systems. This paper investigates the identification of discrete-time non-linear systems using neural networks with a single hidden layer. New parameter estimation algorithms are derived for the neural network model based on a prediction error formulation and the application to both simulated and real data is included to demonstrate the effectiveness of the neural network approach.

  2. Recurrent Neural Network Identification and Adaptive Neural Control of Hydrocarbon Biodegradation Processes

    OpenAIRE

    Baruch, Ieroham; Mariaca-Gaspar, Carlos; Barrera-Cortes, Josefina

    2008-01-01

    The chapter proposes a new Kalman filter closed loop topology of recurrent neural network for identification and modeling of an unknown hydrocarbon degradation process carried out in a biopile system and a rotating drum. The proposed KF RNN contained a recurrent neural plant model, a recurrent neural output plant filter and posses global and local feedbacks. The learning algorithm is a modified version of the dynamic Backpropagation one derived using the adjoint KF RNN topology by means of th...

  3. Auraptene induces oligodendrocyte lineage precursor cells in a cuprizone-induced animal model of demyelination.

    Science.gov (United States)

    Nakajima, Mitsunari; Shimizu, Risei; Furuta, Kohei; Sugino, Mami; Watanabe, Takashi; Aoki, Rui; Okuyama, Satoshi; Furukawa, Yoshiko

    2016-05-15

    We investigated the effects of auraptene on mouse oligodendroglial cell lineage in an animal model of demyelination induced by cuprizone. Auraptene, a citrus coumarin, was intraperitoneally administered to mice fed the demyelinating agent cuprizone. Immunohistochemical analysis of the corpus callosum and/or Western blotting analysis of brain extracts revealed that cuprizone reduced immunoreactivity for myelin-basic protein, a marker of myelin, whereas it increased immunoreactivity to platelet derived-growth factor receptor-α, a marker of oligodendrocyte precursor cells. Administration of auraptene enhanced the immunoreactivity to oligodendrocyte transcription factor 2, a marker of oligodendrocyte precursor cells and oligodendrocyte lineage precursor cells, but had no effect on immunoreactivity to myelin-basic protein or platelet-derived growth factor receptor-α. These findings suggest that auraptene promotes the production of oligodendrocyte lineage precursor cells in an animal model of demyelination and may be useful for individuals with demyelinating diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. 1994 Accident sequence precursor program results

    International Nuclear Information System (INIS)

    Belles, R.J.; Cletcher, J.W.; Copinger, D.A.

    1996-01-01

    The Accident Sequence Precursor (ASP) Program involves the systematic review and evaluation of operational events that have occurred at light-water reactors to identify and categorize precursors to potential severe core damage accident sequences. The results of the ASP Program are published in an annual report. The most recent report, which contains the analyses of the precursors for 1994, is NUREG/CR-4674, Vols. 21 and 22, Precursors to Potential Severe Core Damage Accidents: 1994, A Status Report, published in December 1995. This article provides an overview of the ASP review and evaluation process and a summary of the results for 1994. 12 refs., 2 figs., 4 tabs

  5. Ezh2 Expression in Astrocytes Induces Their Dedifferentiation Toward Neural Stem Cells

    NARCIS (Netherlands)

    Sher, Falak; Boddeke, Erik; Copray, Sjef

    Recently, we have demonstrated the expression of the polycomb group protein Ezh2 in embryonic and adult neural stem cells. Although Ezh2 remained highly expressed when neural stem cells differentiate into oligodendrocyte precursor cells, it is downregulated during the differentiation into neurons or

  6. FGF Signaling Transforms Non-neural Ectoderm into Neural Crest

    OpenAIRE

    Yardley, Nathan; García-Castro, Martín I.

    2012-01-01

    The neural crest arises at the border between the neural plate and the adjacent non-neural ectoderm. It has been suggested that both neural and non-neural ectoderm can contribute to the neural crest. Several studies have examined the molecular mechanisms that regulate neural crest induction in neuralized tissues or the neural plate border. Here, using the chick as a model system, we address the molecular mechanisms by which non-neural ectoderm generates neural crest. We report that in respons...

  7. Biodegradable mesoporous delivery system for biomineralization precursors.

    Science.gov (United States)

    Yang, Hong-Ye; Niu, Li-Na; Sun, Jin-Long; Huang, Xue-Qing; Pei, Dan-Dan; Huang, Cui; Tay, Franklin R

    2017-01-01

    Scaffold supplements such as nanoparticles, components of the extracellular matrix, or growth factors have been incorporated in conventional scaffold materials to produce smart scaffolds for tissue engineering of damaged hard tissues. Due to increasing concerns on the clinical side effects of using large doses of recombinant bone-morphogenetic protein-2 in bone surgery, it is desirable to develop an alternative nanoscale scaffold supplement that is not only osteoinductive, but is also multifunctional in that it can perform other significant bone regenerative roles apart from stimulation of osteogenic differentiation. Because both amorphous calcium phosphate (ACP) and silica are osteoinductive, a biodegradable, nonfunctionalized, expanded-pore mesoporous silica nanoparticle carrier was developed for loading, storage, and sustained release of a novel, biosilicification-inspired, polyamine-stabilized liquid precursor phase of ACP for collagen biomineralization and for release of orthosilicic acid, both of which are conducive to bone growth. Positively charged poly(allylamine)-stabilized ACP (PAH-ACP) could be effectively loaded and released from nonfunctionalized expanded-pore mesoporous silica nanoparticles (pMSN). The PAH-ACP released from loaded pMSN still retained its ability to infiltrate and mineralize collagen fibrils. Complete degradation of pMSN occurred following unloading of their PAH-ACP cargo. Because PAH-ACP loaded pMSN possesses relatively low cytotoxicity to human bone marrow-derived mesenchymal stem cells, these nanoparticles may be blended with any osteoconductive scaffold with macro- and microporosities as a versatile scaffold supplement to enhance bone regeneration.

  8. Leukemia inhibitory factor favours neurogenic differentiation of long-term propagated human midbrain precursor cells

    DEFF Research Database (Denmark)

    Andersen, Rikke K; Widmer, Hans R; Zimmer, Jens

    2009-01-01

    There is a lot of excitement about the potential use of multipotent neural stem cells for the treatment of neurodegenerative diseases. However, the strategy is compromised by the general loss of multipotency and ability to generate neurons after long-term in vitro propagation. In the present study......-term propagated, our study also suggests that LIF favours neurogenic differentiation of human VM precursor cells....

  9. Targeted Inhibition of the miR-199a/214 Cluster by CRISPR Interference Augments the Tumor Tropism of Human Induced Pluripotent Stem Cell-Derived Neural Stem Cells under Hypoxic Condition

    Directory of Open Access Journals (Sweden)

    Yumei Luo

    2016-01-01

    Full Text Available The human induced pluripotent stem cell (hiPSC provides a breakthrough approach that helps overcoming ethical and allergenic challenges posed in application of neural stem cells (NSCs in targeted cancer gene therapy. However, the tumor-tropic capacity of hiPSC-derived NSCs (hiPS-NSCs still has much room to improve. Here we attempted to promote the tumor tropism of hiPS-NSCs by manipulating the activity of endogenous miR-199a/214 cluster that is involved in regulation of hypoxia-stimulated cell migration. We first developed a baculovirus-delivered CRISPR interference (CRISPRi system that sterically blocked the E-box element in the promoter of the miR-199a/214 cluster with an RNA-guided catalytically dead Cas9 (dCas9. We then applied this CRISPRi system to hiPS-NSCs and successfully suppressed the expression of miR-199a-5p, miR-199a-3p, and miR-214 in the microRNA gene cluster. Meanwhile, the expression levels of their targets related to regulation of hypoxia-stimulated cell migration, such as HIF1A, MET, and MAPK1, were upregulated. Further migration assays demonstrated that the targeted inhibition of the miR-199a/214 cluster significantly enhanced the tumor tropism of hiPS-NSCs both in vitro and in vivo. These findings suggest a novel application of CRISPRi in NSC-based tumor-targeted gene therapy.

  10. Glutamate Increases In Vitro Survival and Proliferation and Attenuates Oxidative Stress-Induced Cell Death in Adult Spinal Cord-Derived Neural Stem/Progenitor Cells via Non-NMDA Ionotropic Glutamate Receptors.

    Science.gov (United States)

    Hachem, Laureen D; Mothe, Andrea J; Tator, Charles H

    2016-08-15

    Traumatic spinal cord injury (SCI) leads to a cascade of secondary chemical insults, including oxidative stress and glutamate excitotoxicity, which damage host neurons and glia. Transplantation of exogenous neural stem/progenitor cells (NSPCs) has shown promise in enhancing regeneration after SCI, although survival of transplanted cells remains poor. Understanding the response of NSPCs to the chemical mediators of secondary injury is essential in finding therapies to enhance survival. We examined the in vitro effects of glutamate and glutamate receptor agonists on adult rat spinal cord-derived NSPCs. NSPCs isolated from the periventricular region of the adult rat spinal cord were exposed to various concentrations of glutamate for 96 h. We found that glutamate treatment (500 μM) for 96 h significantly increased live cell numbers, reduced cell death, and increased proliferation, but did not significantly alter cell phenotype. Concurrent glutamate treatment (500 μM) in the setting of H2O2 exposure (500 μM) for 10 h increased NSPC survival compared to H2O2 exposure alone. The effects of glutamate on NSPCs were blocked by the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptor antagonist GYKI-52466, but not by the N-methyl-D-aspartic acid receptor antagonist MK-801 or DL-AP5, or the mGluR3 antagonist LY-341495. Furthermore, treatment of NSPCs with AMPA, kainic acid, or the kainate receptor-specific agonist (RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid mimicked the responses seen with glutamate both alone and in the setting of oxidative stress. These findings offer important insights into potential mechanisms to enhance NSPC survival and implicate a potential role for glutamate in promoting NSPC survival and proliferation after traumatic SCI.

  11. Chicken trunk neural crest migration visualized with HNK1

    OpenAIRE

    Giovannone, Dion; Ortega, Blanca; Reyes, Michelle; El-Ghali, Nancy; Rabadi, Maes; Sao, Sothy; de Bellard, Maria Elena

    2015-01-01

    The development of the nervous system involves cells remaining within the neural tube (CNS) and a group of cells that delaminate from the dorsal neural tube and migrate extensively throughout the developing embryo called neural crest cells (NCC). These cells are a mesenchymal highly migratory group of cells that give rise to a wide variety of cell derivatives: melanocytes, sensory neurons, bone, Schwann cells, etc. But not all NCC can give rise to all derivatives, they have fate restrictions ...

  12. Role of SDF1/CXCR4 Interaction in Experimental Hemiplegic Models with Neural Cell Transplantation

    Directory of Open Access Journals (Sweden)

    Noboru Suzuki

    2012-02-01

    Full Text Available Much attention has been focused on neural cell transplantation because of its promising clinical applications. We have reported that embryonic stem (ES cell derived neural stem/progenitor cell transplantation significantly improved motor functions in a hemiplegic mouse model. It is important to understand the molecular mechanisms governing neural regeneration of the damaged motor cortex after the transplantation. Recent investigations disclosed that chemokines participated in the regulation of migration and maturation of neural cell grafts. In this review, we summarize the involvement of inflammatory chemokines including stromal cell derived factor 1 (SDF1 in neural regeneration after ES cell derived neural stem/progenitor cell transplantation in mouse stroke models.

  13. Iron nanoparticles prepared from natural ferrihydrite precursors: kinetics and properties

    International Nuclear Information System (INIS)

    Natural ferrihydrite was used as the precursors for the preparation of the nanocrystalline alpha-Fe powder using heat treatment in hydrogen atmosphere. Transformation temperatures were estimated from the temperature dependences of magnetic moment. Structure and phase composition of the precursors and the final powders were characterized by X-ray diffraction and Mössbauer spectroscopy. Magnetic properties were characterized according to hysteresis loop parameters. The kinetics of the transformation was described using Avrami relation applied on the data of the isothermal time dependence of magnetic moment measurements and subsequently the activation enthalpy of transformation was estimated using Arrhenius plots of their parameters. Comparison of the changes of activation enthalpies derived from a different temperature ranges indicates effects of different processes on formation of alpha-Fe nanoparticles.

  14. Behaviour in O of the Neural Networks Training Cost

    DEFF Research Database (Denmark)

    Goutte, Cyril

    1998-01-01

    We study the behaviour in zero of the derivatives of the cost function used when training non-linear neural networks. It is shown that a fair number offirst, second and higher order derivatives vanish in zero, validating the belief that 0 is a peculiar and potentially harmful location....... These calculations arerelated to practical and theoretical aspects of neural networks training....

  15. Methylprednisolone inhibits the proliferation and affects the differentiation of rat spinal cord-derived neural progenitor cells cultured in low oxygen conditions by inhibiting HIF-1α and Hes1 in vitro.

    Science.gov (United States)

    Wang, Wenhao; Wang, Peng; Li, Shiyuan; Yang, Jiewen; Liang, Xinjun; Tang, Yong; Li, Yuxi; Yang, Rui; Wu, Yanfeng; Shen, Huiyong

    2014-09-01

    Although there is much controversy over the use of methylprednisolone (MP), it is one of the main drugs used in the treatment of acute spinal cord injury (SCI). The induction of the proliferation and differentiation of endogenous neural progenitor cells (NPCs) is considered a promising mode of treatment for SCI. However, the effects of MP on spinal cord-derived endogenous NPCs in a low oxygen enviroment remain to be delineated. Thus, the aim of this study was to investigate the potential effects of MP on NPCs cultured under low oxygen conditions in vitro and to elucidate the molecular mechanisms involved. Fetal rat spinal cord-derived NPCs were harvested and divided into 4 groups: 2 groups of cells cultured under normal oxygen conditions and treated with or without MP, and 2 groups incubated in 3% O2 (low oxygen) treated in a similar manner. We found that MP induced suppressive effects on NPC proliferation even under low oxygen conditions (3% O2). The proportion of nestin-positive NPCs decreased from 51.8±2.46% to 36.17±3.55% following the addition of MP and decreased more significantly to 27.20±2.68% in the cells cultured in 3% O2. In addition, a smaller number of glial fibrillary acidic protein (GFAP)-positive cells and a greater number of microtubule-associated protein 2 (MAP2)-positive cells was observed following the addition of MP under both normal (normoxic) and low oxygen (hypoxic) conditions. In response to MP treatment, hypoxia-inducible factor-1α (HIF-1α) and the Notch signaling pathway downstream protein, Hes1, but not the upstream Notch-1 intracelluar domain (NICD), were inhibited. After blocking NICD with a γ-secretase inhibitor (DAPT) MP still inhibited the expression of Hes1. Our results provide insight into the molecular mechanisms responsible for the MP-induced inhibition of proliferation and its effects on differentiation and suggest that HIF-1α and Hes1 play an important role in this effect.

  16. nanoparticles synthesized by citrate precursor m

    African Journals Online (AJOL)

    user

    Abstract. Ni0.5M0.5Fe2O4 (M = Co, Cu) ferrite nanoparticles were synthesized using citrate precursor method. The citrate precursor was annealed at temperatures 400oC, 450oC, 500oC and 550oC. The annealed powders were characterized using X-ray diffractometer. (XRD) and vibrating sample magnetometer (VSM).

  17. Rapid synthesis of macrocycles from diol precursors

    DEFF Research Database (Denmark)

    Wingstrand, Magnus; Madsen, Charlotte Marie; Clausen, Mads Hartvig

    2009-01-01

    A method for the formation of synthetic macrocycles with different ring sizes from diols is presented. Reacting a simple diol precursor with electrophilic reagents leads to a cyclic carbonate, sulfite or phosphate in a single step in 25-60% yield. Converting the cyclization precursor to a bis-ele...

  18. Operational experience feedback with precursor analysis

    International Nuclear Information System (INIS)

    Koncar, M.; Ferjancic, M.; Muehleisen, A.; Vojnovic, D.

    2003-01-01

    Experience of practical operation is a valuable source of information for improving the safety and reliability of nuclear power plants. Operational experience feedback (Olef) system manages this aspect of NPP operation. The traditional ways of investigating operational events, such as the root cause analysis (RCA), are predominantly qualitative. RCA as a part of the Olef system provides technical guidance and management expectations in the conduct of assessing the root cause to prevent recurrence, covering the following areas: conditions preceding the event, sequence of events, equipment performance and system response, human performance considerations, equipment failures, precursors to the event, plant response and follow-up, radiological considerations, regulatory process considerations and safety significance. The root cause of event is recognized when there is no known answer on question 'why has it happened?' regarding relevant condition that may have affected the event. At that point the Olef is proceeding by actions taken in response to events, utilization, dissemination and exchange of operating experience information and at the end reviewing the effectiveness of the Olef. Analysis of the event and the selection of recommended corrective/preventive actions for implementation and prioritization can be enhanced by taking into account the information and insights derived from Pasa-based analysis. A Pasa based method, called probabilistic precursor event analysis (PPE A) provides a complement to the RCA approach by focusing on how an event might have developed adversely, and implies the mapping of an operational event on a probabilistic risk model of the plant in order to obtain a quantitative assessment of the safety significance of the event PSA based event analysis provides, due to its quantitative nature, appropriate prioritization of corrective actions. PPEA defines requirements for PSA model and code, identifies input requirements and elaborates following

  19. Transcription factor Runx1 is pro-neurogenic in adult hippocampal precursor cells.

    Directory of Open Acces