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Sample records for adult schwann cells

  1. A new protocol for cultivation of predegenerated adult rat Schwann cells.

    PubMed

    Pietrucha-Dutczakv, Marita; Marcol, Wiesław; Francuz, Tomasz; Gołka, Dariusz; Lewin-Kowalik, Joanna

    2014-09-01

    The purpose of this study was to optimize the methodology of cultivation of predegenerated Schwann cells (SCs). SCs were isolated from 7-day-predegenerated sciatic nerves of adult rats. We applied commercially available culture medium for cultivation of endothelial cells endothelial cell culture medium (EBM-2) instead of Dulbecco's Modified Eagle's Medium commonly used to culture adult Schwann cells. Additionally, cell culture medium was supplemented with factors specifically supporting SCs growth as: bovine pituitary extract (5 μg/ml), heregulin (40 ng/ml) and insulin (2.5 ng/ml). Similarly to the reports of others authors, we did not observe any beneficial effects of Forskolin application, so we didn't supplement our medium with it. Cell culture purity was determined by counting the ratio of GFAP, N-Cadherin and NGFR p75-positive cells to total number of cells. About 94-97 % of cells were confirmed as Schwann cells. As a result, we obtained sufficient number and purity of Schwann cells to be applied in different experimental models in rats. EBM-2 medium coated with fibronectin was the best for cultivation of adult rat Schwann cells.

  2. Distinct cell tropism of canine distemper virus strains to adult olfactory ensheathing cells and Schwann cells in vitro.

    PubMed

    Techangamsuwan, Somporn; Haas, Ludwig; Rohn, Karl; Baumgärtner, Wolfgang; Wewetzer, Konstantin

    2009-09-01

    Canine distemper virus (CDV) can enter the brain via infection of olfactory neurons. Whether olfactory ensheathing cells (OECs) are also infected by CDV, and if yes, how they respond to the virus has remained enigmatic. Here, we exposed adult canine OECs in vitro to several attenuated (CDV-2544, CDV-R252, CDV-Ond, CDV-OndeGFP) and one virulent CDV strain (CDV-5804PeGFP) and studied their susceptibility compared to Schwann cells, a closely related cell type sharing the phagocytizing activity. We show that OECs and Schwann cells were infected by CDV strains albeit to different levels. Ten days post-infection (dpi), a mild to severe cytopathic effect ranging from single cell necrosis to layer detachment was noted. The percentage of infection increased during 10 dpi and viral progenies were detected in each culture using virus titration. Interestingly, CDV-2544, CDV-OndeGFP, and CDV-5804PeGFP predominantly infected OECs, while CDV-Ond targeted Schwann cells. No significant differences were found between the virulent and attenuated CDV strains. The observation of a CDV strain-specific cell tropism is evidence for significant molecular differences between OECs and Schwann cells. Whether these differences are either related to strain-specific distemper pathogenesis or support a role of OECs during CDV infection and virus spread needs to be addressed in future studies.

  3. Toxic effects of bortezomib on primary sensory neurons and Schwann cells of adult mice.

    PubMed

    Alé, Albert; Bruna, Jordi; Herrando, Mireia; Navarro, Xavier; Udina, Esther

    2015-05-01

    The proteasome inhibitor bortezomib is nowadays first line treatment for multiple myeloma. One of the most significant adverse events is peripheral neuropathy, mainly involving sensory nerve fibers that can lead to withdrawal of treatment. Here we develop an in vitro model to compare the effects of bortezomib on primary sensory neurons and Schwann cells of adult mice. We observed that sensory neurons were more susceptible to bortezomib, and their viability was reduced at a concentration of 6 nM, that only affected Schwann cell proliferation but not survival. At concentration higher than 8 nM Schwann cell viability was also compromised. Already at low concentrations, surviving neurons presented alterations in neurite outgrowth. Neurites were shorter and had dystrophic appearance, with alterations in neurofilament staining. However, neurites were able to regrow after removing bortezomib from the medium, thus indicating reversibility of the neurotoxicity. We confirmed in vivo that bortezomib produced alterations in neurofilaments at early stages of the treatment. After an accumulated dose of 2 mg/kg bortezomib, dorsal root ganglia neurons of treated animals showed accumulation of neurofilament in the soma. To evaluate if this accumulation was related with alterations in axonal transport, we tested the ability of sensory neurons to retrogradely transport a retrotracer applied at the distal nerve. Treated animals showed a lower amount of retrotracer in the soma 24 h after its application to the tibial nerve, therefore suggesting that axonal transport was affected by bortezomib.

  4. A new type of Schwann cell graft transplantation to promote optic nerve regeneration in adult rats.

    PubMed

    Fang, Yuan; Mo, Xiaofen; Guo, Wenyi; Zhang, Meng; Zhang, Peihua; Wang, Yan; Rong, Xianfang; Tian, Jie; Sun, Xinghuai

    2010-12-01

    Like other parts of the central nervous system, the adult mammalian optic nerve is difficult to regenerate after injury. Transplantation of the peripheral nerve or a Schwann cell (SC) graft can promote injured axonal regrowth. We tried to develop a new type of tissue-engineered SC graft that consisted of SCs seeded onto a poly(lactic-co-glycolic acid)/chitosan conduit. Meanwhile, SCs were transfected along the ciliary neurotrophic factor (CNTF) gene in vitro by electroporation to increase their neurotrophic effect. Four weeks after transplantation, GAP-43 labelled regenerating axons were found in the SC grafts, and axons in the CNTF-SC graft were longer than those in the SC graft. Tissue-engineered SC grafts can provide a feasible environment for optic nerve regeneration and may become an alternative for bridging damaged nerves and repairing nerve defects in the future.

  5. Adult skin-derived precursor Schwann cells exhibit superior myelination and regeneration supportive properties compared to chronically denervated nerve-derived Schwann cells.

    PubMed

    Kumar, Ranjan; Sinha, Sarthak; Hagner, Andrew; Stykel, Morgan; Raharjo, Eko; Singh, Karun K; Midha, Rajiv; Biernaskie, Jeff

    2016-04-01

    Functional outcomes following delayed peripheral nerve repair are poor. Schwann cells (SCs) play key roles in supporting axonal regeneration and remyelination following nerve injury, thus understanding the impact of chronic denervation on SC function is critical toward developing therapies to enhance regeneration. To improve our understanding of SC function following acute versus chronic-denervation, we performed functional assays of SCs from adult rodent sciatic nerve with acute- (Day 5 post) or chronic-denervation (Day 56 post), versus embryonic nerves. We also compared Schwann cells derived from adult skin-derived precursors (aSKP-SCs) as an accessible, autologous alternative to supplement the distal (denervated) nerve. We found that acutely-injured SCs and aSKP-SCs exhibited superior proliferative capacity, promotion of neurite outgrowth and myelination of axons, both in vitro and following transplant into a sciatic nerve crush injury model, while chronically-denervated SCs were severely impaired. Acute injury caused re-activation of transcription factors associated with an immature and pro-myelinating SC state (Oct-6, cJun, Sox2, AP2α, cadherin-19), but was diminished with prolonged denervation in vivo and could not be rescued following expansion in vitro suggesting that this is a permanent deficiency. Interestingly, aSKP-SCs closely resembled acutely injured and embryonic SCs, exhibiting elevated expression of these same transcription factors. In summary, prolonged denervation resulted in SC deficiency in several functional parameters that may contribute to impaired regeneration. In contrast, aSKP-SCs closely resemble the regenerative attributes ascribed to acutely-denervated or embryonic SCs emphasizing their potential as an accessible and autologous source of glia cells to enhance nerve regeneration, particularly following delays to surgical repair.

  6. Schwann Cell Expressed Nogo-B Modulates Axonal Branching of Adult Sensory Neurons Through the Nogo-B Receptor NgBR

    PubMed Central

    Eckharter, Christoph; Junker, Nina; Winter, Lilli; Fischer, Irmgard; Fogli, Barbara; Kistner, Steffen; Pfaller, Kristian; Zheng, Binhai; Wiche, Gerhard; Klimaschewski, Lars; Schweigreiter, Rüdiger

    2015-01-01

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

  7. New Insights on Schwann Cell Development

    PubMed Central

    Monk, Kelly R.; Feltri, M. Laura; Taveggia, Carla

    2015-01-01

    In the peripheral nervous system, Schwann cells are glial cells that are in intimate contact with axons throughout development. Schwann cells generate the insulating myelin sheath and provide vital trophic support to the neurons that they ensheathe. Schwann cell precursors arise from neural crest progenitor cells, and a highly ordered developmental sequence controls the progression of these cells to become mature myelinating or non-myelinating Schwann cells. Here, we discuss both seminal discoveries and recent advances in our understanding of the molecular mechanisms that drive Schwann cell development and myelination with a focus on cell-cell and cell-matrix signaling events. PMID:25921593

  8. Sodium channels in the cytoplasm of Schwann cells

    SciTech Connect

    Ritchie, J.M. ); Black, J.A.; Waxman, S.G. Veterans Affairs Medical Center, West Haven, CT ); Angelides, K.J. )

    1990-12-01

    Immunoblotting, ultrastructural immunocytochemistry, and tritiated saxitoxin (({sup 3}H)STX) binding experiments were used to study sodium channel localization in Schwann cells. Polyclonal antibody 7493, which is directed against purifed sodium channels from rat brain, specifically recognized a 260-kDa protein corresponding to the {alpha} subunit of the sodium channel in immunoblots of crude glycoproteins from rat sciatic nerve. Electron microscopic localization of sodium channel immunoreactivity within adult rat sciatic nerves reveals heavy staining of the axon membrane at the node of Ranvier, in contrast to the internodal axon membrane, which does not stain. Schwann cells including perinodal processes also exhibit antibody 7493 immunoreactivity, localized within both the cytoplasm and the plasmalemma of the Schwann cell. To examine further the possibility that sodium channels are localized within Schwann cell cytoplasm, ({sup 3}H)STX binding was studied in cultured rabbit Schwann cells, both intact and after homogenization. Saturable binding of STX was singificantly higher in homogenized Schwann cells than in intact Schwann cells. Moreover, the equilibrium dissociation constant was higher for homogenized preparations (1.77 {plus minus} 0.37 nM) than for intact Schwann cells (1.06 {plus minus} 0.29 nM). These data suggest the presence of an intracellular pool of sodium channels or channel presursors in Schwann cells.

  9. A rapid and versatile method for the isolation, purification and cryogenic storage of Schwann cells from adult rodent nerves

    PubMed Central

    Andersen, Natalia D.; Srinivas, Shruthi; Piñero, Gonzalo; Monje, Paula V.

    2016-01-01

    We herein developed a protocol for the rapid procurement of adult nerve-derived Schwann cells (SCs) that was optimized to implement an immediate enzymatic dissociation of fresh nerve tissue while maintaining high cell viability, improving yields and minimizing fibroblast and myelin contamination. This protocol introduces: (1) an efficient method for enzymatic cell release immediately after removal of the epineurium and extensive teasing of the nerve fibers; (2) an adaptable drop-plating method for selective cell attachment, removal of myelin debris, and expansion of the initial SC population in chemically defined medium; (3) a magnetic-activated cell sorting purification protocol for rapid and effective fibroblast elimination; and (4) an optional step of cryopreservation for the storage of the excess of cells. Highly proliferative SC cultures devoid of myelin and fibroblast growth were obtained within three days of nerve processing. Characterization of the initial, expanded, and cryopreserved cell products confirmed maintenance of SC identity, viability and growth rates throughout the process. Most importantly, SCs retained their sensitivity to mitogens and potential for differentiation even after cryopreservation. To conclude, this easy-to-implement and clinically relevant protocol allows for the preparation of expandable homogeneous SC cultures while minimizing time, manipulation of the cells, and exposure to culture variables. PMID:27549422

  10. A rapid and versatile method for the isolation, purification and cryogenic storage of Schwann cells from adult rodent nerves.

    PubMed

    Andersen, Natalia D; Srinivas, Shruthi; Piñero, Gonzalo; Monje, Paula V

    2016-08-23

    We herein developed a protocol for the rapid procurement of adult nerve-derived Schwann cells (SCs) that was optimized to implement an immediate enzymatic dissociation of fresh nerve tissue while maintaining high cell viability, improving yields and minimizing fibroblast and myelin contamination. This protocol introduces: (1) an efficient method for enzymatic cell release immediately after removal of the epineurium and extensive teasing of the nerve fibers; (2) an adaptable drop-plating method for selective cell attachment, removal of myelin debris, and expansion of the initial SC population in chemically defined medium; (3) a magnetic-activated cell sorting purification protocol for rapid and effective fibroblast elimination; and (4) an optional step of cryopreservation for the storage of the excess of cells. Highly proliferative SC cultures devoid of myelin and fibroblast growth were obtained within three days of nerve processing. Characterization of the initial, expanded, and cryopreserved cell products confirmed maintenance of SC identity, viability and growth rates throughout the process. Most importantly, SCs retained their sensitivity to mitogens and potential for differentiation even after cryopreservation. To conclude, this easy-to-implement and clinically relevant protocol allows for the preparation of expandable homogeneous SC cultures while minimizing time, manipulation of the cells, and exposure to culture variables.

  11. Bone marrow-derived Schwann cells achieve fate commitment--a prerequisite for remyelination therapy.

    PubMed

    Shea, Graham K H; Tsui, Alex Y P; Chan, Ying Shing; Shum, Daisy K Y

    2010-08-01

    Schwann cell transplantation improves post-traumatic nerve regeneration in both PNS and CNS but sufficient numbers of immunocompatible cells are required for clinical application. Currently, Schwann cell-like cells derived from the bone marrow lack fate commitment and revert to a fibroblast-like phenotype upon withdrawal of differentiation-inducing factors. In recapitulation of embryonic events leading to Schwann cell maturation, we hypothesize that the Schwann cell-like cells acquire the switch to fate commitment through contact-dependent cues from incipient neurons of the developing dorsal root ganglia. To address this, Schwann cell-like cells derived from adult rat bone marrow were cocultured with neurons purified from embryonic dorsal root ganglia. A cell-intrinsic switch to the Schwann cell fate was achieved consistently and the cell progeny maintained expression of the markers S100 beta, p75(NTR) , GFAP, P0 and Sox 10 even without exogenous differentiation-inducing factors or neurons. In vitro formation of MBP-positive segments under myelinating conditions by the cell progeny was comparable to that by sciatic nerve-derived Schwann cells. Controls in which Schwann cell-like cells were barred from direct contact with neurons in coculture reverted to SMA/CD90-expressing myofibroblasts. We demonstrate therefore for the first time fate commitment among bone marrow-derived Schwann cells. The therapeutic potential of these cells may be tested in future transplantation studies. (206 words).

  12. Neuritin is expressed in Schwann cells and down-regulated in apoptotic Schwann cells under hyperglycemia.

    PubMed

    Min, Shi; Jian-bo, Li; Hong-man, Zhang; Ling-fei, Yan; Min, Xie; Jia-wei, Chen

    2012-11-01

    We aimed to explore neuritin expression in Schwann cells under different glucose conditions. Expression of neuritin at the levels of transcription and translation in purified Schwann cells was detected and measured using reverse transcriptase (RT) (quantitative) polymerase chain reaction (PCR) and western blot. Apoptosis of Schwann cells was measured by flow cytometry using Fluorescence Activated Cell Sorter (FACS) analysis and caspase fluorometric assay. Neuritin mRNA and protein were detected in cultured primary Schwann cells. Neuritin was identified as cell membrane form of protein and predominately as secreted or solube form of protein. Neuritin was significantly lower in 150 mM glucose condition, and more significantly lower in 300 mM glucose, than 5.6 mM glucose condition at 36 hours and especially at 48 hours of the culture, respectively (P < 0.05-0.01). In contrast to 5.6 mM glucose, obvious apoptosis of Schwann cells was demonstrated at 42 hours in 300 mM glucose condition and at 48 hours in 150 mM glucose, respectively (P < 0.05-0.01). Neuritin and apoptosis were correlated in a power regression (P < 0.01). 5.6 mM glucose cultured cells did not show these obvious changes during the experiment. It is concluded that neuritin mRNA and protein were expressed and down-regulated in Schwann cells under high-glucose concentration and the down-regulation may contribute to apopotosis of Schwann cells. PMID:22782233

  13. Biological Role of Dystroglycan in Schwann Cell Function and Its Implications in Peripheral Nervous System Diseases

    PubMed Central

    Masaki, Toshihiro; Matsumura, Kiichiro

    2010-01-01

    Dystroglycan is a central component of the dystrophin-glycoprotein complex (DGC) that links extracellular matrix with cytoskeleton, expressed in a variety of fetal and adult tissues. Dystroglycan plays diverse roles in development and homeostasis including basement membrane formation, epithelial morphogenesis, membrane stability, cell polarization, and cell migration. In this paper, we will focus on biological role of dystroglycan in Schwann cell function, especially myelination. First, we review the molecular architecture of DGC in Schwann cell abaxonal membrane. Then, we will review the loss-of-function studies using targeted mutagenesis, which have revealed biological functions of each component of DGC in Schwann cells. Based on these findings, roles of dystroglycan in Schwann cell function, in myelination in particular, and its implications in diseases will be discussed in detail. Finally, in view of the fact that understanding the role of dystroglycan in Schwann cells is just beginning, future perspectives will be discussed. PMID:20625412

  14. Schwann cells induce cancer cell dispersion and invasion

    PubMed Central

    Deborde, Sylvie; Lyubchik, Anna; Zhou, Yi; He, Shizhi; McNamara, William F.; Chernichenko, Natalya; Lee, Sei-Young; Barajas, Fernando; Chen, Chun-Hao; Bakst, Richard L.; Vakiani, Efsevia; He, Shuangba; Hall, Alan; Wong, Richard J.

    2016-01-01

    Nerves enable cancer progression, as cancers have been shown to extend along nerves through the process of perineural invasion, which carries a poor prognosis. Furthermore, the innervation of some cancers promotes growth and metastases. It remains unclear, however, how nerves mechanistically contribute to cancer progression. Here, we demonstrated that Schwann cells promote cancer invasion through direct cancer cell contact. Histological evaluation of murine and human cancer specimens with perineural invasion uncovered a subpopulation of Schwann cells that associates with cancer cells. Coculture of cancer cells with dorsal root ganglion extracts revealed that Schwann cells direct cancer cells to migrate toward nerves and promote invasion in a contact-dependent manner. Upon contact, Schwann cells induced the formation of cancer cell protrusions in their direction and intercalated between the cancer cells, leading to cancer cell dispersion. The formation of these processes was dependent on Schwann cell expression of neural cell adhesion molecule 1 (NCAM1) and ultimately promoted perineural invasion. Moreover, NCAM1-deficient mice showed decreased neural invasion and less paralysis. Such Schwann cell behavior reflects normal Schwann cell programs that are typically activated in nerve repair but are instead exploited by cancer cells to promote perineural invasion and cancer progression. PMID:26999607

  15. Schwann cells induce cancer cell dispersion and invasion.

    PubMed

    Deborde, Sylvie; Omelchenko, Tatiana; Lyubchik, Anna; Zhou, Yi; He, Shizhi; McNamara, William F; Chernichenko, Natalya; Lee, Sei-Young; Barajas, Fernando; Chen, Chun-Hao; Bakst, Richard L; Vakiani, Efsevia; He, Shuangba; Hall, Alan; Wong, Richard J

    2016-04-01

    Nerves enable cancer progression, as cancers have been shown to extend along nerves through the process of perineural invasion, which carries a poor prognosis. Furthermore, the innervation of some cancers promotes growth and metastases. It remains unclear, however, how nerves mechanistically contribute to cancer progression. Here, we demonstrated that Schwann cells promote cancer invasion through direct cancer cell contact. Histological evaluation of murine and human cancer specimens with perineural invasion uncovered a subpopulation of Schwann cells that associates with cancer cells. Coculture of cancer cells with dorsal root ganglion extracts revealed that Schwann cells direct cancer cells to migrate toward nerves and promote invasion in a contact-dependent manner. Upon contact, Schwann cells induced the formation of cancer cell protrusions in their direction and intercalated between the cancer cells, leading to cancer cell dispersion. The formation of these processes was dependent on Schwann cell expression of neural cell adhesion molecule 1 (NCAM1) and ultimately promoted perineural invasion. Moreover, NCAM1-deficient mice showed decreased neural invasion and less paralysis. Such Schwann cell behavior reflects normal Schwann cell programs that are typically activated in nerve repair but are instead exploited by cancer cells to promote perineural invasion and cancer progression.

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

    PubMed

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

    2015-07-01

    Although Schwann cell myelin breakdown is the universal outcome of a remarkably wide range of conditions that cause disease or injury to peripheral nerves, the cellular and molecular mechanisms that make Schwann cell-mediated myelin digestion possible have not been established. We report that Schwann cells degrade myelin after injury by a novel form of selective autophagy, myelinophagy. Autophagy was up-regulated by myelinating Schwann cells after nerve injury, myelin debris was present in autophagosomes, and pharmacological and genetic inhibition of autophagy impaired myelin clearance. Myelinophagy was positively regulated by the Schwann cell JNK/c-Jun pathway, a central regulator of the Schwann cell reprogramming induced by nerve injury. We also present evidence that myelinophagy is defective in the injured central nervous system. These results reveal an important role for inductive autophagy during Wallerian degeneration, and point to potential mechanistic targets for accelerating myelin clearance and improving demyelinating disease.

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

    PubMed Central

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

    2015-01-01

    Although Schwann cell myelin breakdown is the universal outcome of a remarkably wide range of conditions that cause disease or injury to peripheral nerves, the cellular and molecular mechanisms that make Schwann cell–mediated myelin digestion possible have not been established. We report that Schwann cells degrade myelin after injury by a novel form of selective autophagy, myelinophagy. Autophagy was up-regulated by myelinating Schwann cells after nerve injury, myelin debris was present in autophagosomes, and pharmacological and genetic inhibition of autophagy impaired myelin clearance. Myelinophagy was positively regulated by the Schwann cell JNK/c-Jun pathway, a central regulator of the Schwann cell reprogramming induced by nerve injury. We also present evidence that myelinophagy is defective in the injured central nervous system. These results reveal an important role for inductive autophagy during Wallerian degeneration, and point to potential mechanistic targets for accelerating myelin clearance and improving demyelinating disease. PMID:26150392

  18. Schwann cells promote endothelial cell migration

    PubMed Central

    Ramos, Tiago; Ahmed, Maqsood; Wieringa, Paul; Moroni, Lorenzo

    2015-01-01

    Directed cell migration is a crucial orchestrated process in embryonic development, wound healing, and immune response. The underlying substrate can provide physical and/or chemical cues that promote directed cell migration. Here, using electrospinning we developed substrates of aligned poly(lactic-co-glycolic acid) nanofibres to study the influence of glial cells on endothelial cells (ECs) in a 3-dimensional (3D) co-culture model. ECs build blood vessels and regulate their plasticity in coordination with neurons. Likewise, neurons construct nerves and regulate their circuits in coordination with ECs. In our model, the neuro-vascular cross-talk was assessed using a direct co-culture model of human umbilical vein endothelial cells (HUVECs) and rat Schwann cells (rSCs). The effect of rSCs on ECs behavior was demonstrated by earlier and higher velocity values and genetic expression profiles different of those of HUVECs when seeded alone. We observed 2 different gene expression trends in the co-culture models: (i) a later gene expression of angiogenic factors, such as interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF), and (ii) an higher gene expression of genes involved in actin filaments rearrangement, such as focal adhesion kinase (FAK), Mitogen-activated protein kinase-activated protein kinase 13 (MAPKAPK13), Vinculin (VCL), and Profilin (PROF). These results suggested that the higher ECs migration is mainly due to proteins involved in the actin filaments rearrangement and in the directed cell migration rather than the effect of angiogenic factors. This co-culture model provides an approach to enlighten the neurovascular interactions, with particular focus on endothelial cell migration. PMID:26491999

  19. Neuronal Neuregulin 1 type III directs Schwann cell migration

    PubMed Central

    Perlin, Julie R.; Lush, Mark E.; Stephens, W. Zac; Piotrowski, Tatjana; Talbot, William S.

    2011-01-01

    During peripheral nerve development, each segment of a myelinated axon is matched with a single Schwann cell. Tight regulation of Schwann cell movement, proliferation and differentiation is essential to ensure that these glial cells properly associate with axons. ErbB receptors are required for Schwann cell migration, but the operative ligand and its mechanism of action have remained unknown. We demonstrate that zebrafish Neuregulin 1 (Nrg1) type III, which signals through ErbB receptors, controls Schwann cell migration in addition to its previously known roles in proliferation and myelination. Chimera analyses indicate that ErbB receptors are required in all migrating Schwann cells, and that Nrg1 type III is required in neurons for migration. Surprisingly, expression of the ligand in a few axons is sufficient to induce migration along a chimeric nerve constituted largely of nrg1 type III mutant axons. These studies also reveal a mechanism that allows Schwann cells to fasciculate axons regardless of nrg1 type III expression. Time-lapse imaging of transgenic embryos demonstrated that misexpression of human NRG1 type III results in ectopic Schwann cell migration, allowing them to aberrantly enter the central nervous system. These results demonstrate that Nrg1 type III is an essential signal that controls Schwann cell migration to ensure that these glia are present in the correct numbers and positions in developing nerves. PMID:21965611

  20. Changes in Schwann cells and vessels in lead neuropathy

    SciTech Connect

    Powell, H.C.; Myers, R.R.; Lampert, P.W.

    1982-11-01

    Transmission electron microscopy (TEM) of peripheral nerve in rats receiving 6% lead carbonate for 4-10 weeks provided evidence of a specific Schwann cell injury, associated with demyelination. Intranuclear inclusions in Schwann cells appeared within 2 weeks of administration of a lead-containing diet. Swelling of Schwann cells and disintegration of their cytoplasm was evident at 4 weeks. Distinctive electron-dense inclusions appeared in both Schwann and endothelial cells during the period of intoxication and were ultrastructurally identical to pathognomonic inclusions of lead poisoning seen in renal tubular epithelial cells. Scanning microscopy (SEM) with electron-probe microanalysis was used to identify the lead-containing deposits. In addition to Schwann cell changes, vessels revealed endothelial cell injury and alteread permeability to macromolecules. Since morphologic changes of Schwann cells precede the development of altered vascular permeability and endoneurial edema, it appears that lead gains access to the endoneurium prior to the development of altered vascular permeability, suggesting that edema and altered endoneurial fluid pressure are epiphenomena that supervene after demyelination occurs. Remyelination, Schwann cell proliferation and formation of onion bulbs are manifestations of persistent toxic injury to myelin-sustaining cells, resulting in chronic demyelination.

  1. Changes in Schwann cells and vessels in lead neuropathy.

    PubMed

    Powell, H C; Myers, R R; Lampert, P W

    1982-11-01

    Transmission electron microscopy (TEM) of peripheral nerve in rats receiving 6% lead carbonate for 4-10 weeks provided evidence of a specific Schwann cell injury, associated with demyelination. Intranuclear inclusions in Schwann cells appeared within 2 weeks of administration of a lead-containing diet. Swelling of Schwann cells and disintegration of their cytoplasm was evident at 4 weeks. Distinctive electron-dense inclusions appeared in both Schwann and endothelial cells during the period of intoxication and were ultrastructurally identical to pathognomonic inclusions of lead poisoning seen in renal tubular epithelial cells. Scanning microscopy (SEM) with electron-probe microanalysis was used to identify the lead-containing deposits. In addition to Schwann cell changes, vessels revealed endothelial cell injury and alteread permeability to macromolecules. Since morphologic changes of Schwann cells precede the development of altered vascular permeability and endoneurial edema, it appears that lead gains access to the endoneurium prior to the development of altered vascular permeability, suggesting that edema and altered endoneurial fluid pressure are epiphenomena that supervene after demyelination occurs. Remyelination, Schwann cell proliferation and formation of onion bulbs are manifestations of persistent toxic injury to myelin-sustaining cells, resulting in chronic demyelination. PMID:6291397

  2. The repair Schwann cell and its function in regenerating nerves

    PubMed Central

    Mirsky, R.

    2016-01-01

    Abstract Nerve injury triggers the conversion of myelin and non‐myelin (Remak) Schwann cells to a cell phenotype specialized to promote repair. Distal to damage, these repair Schwann cells provide the necessary signals and spatial cues for the survival of injured neurons, axonal regeneration and target reinnervation. The conversion to repair Schwann cells involves de‐differentiation together with alternative differentiation, or activation, a combination that is typical of cell type conversions often referred to as (direct or lineage) reprogramming. Thus, injury‐induced Schwann cell reprogramming involves down‐regulation of myelin genes combined with activation of a set of repair‐supportive features, including up‐regulation of trophic factors, elevation of cytokines as part of the innate immune response, myelin clearance by activation of myelin autophagy in Schwann cells and macrophage recruitment, and the formation of regeneration tracks, Bungner's bands, for directing axons to their targets. This repair programme is controlled transcriptionally by mechanisms involving the transcription factor c‐Jun, which is rapidly up‐regulated in Schwann cells after injury. In the absence of c‐Jun, damage results in the formation of a dysfunctional repair cell, neuronal death and failure of functional recovery. c‐Jun, although not required for Schwann cell development, is therefore central to the reprogramming of myelin and non‐myelin (Remak) Schwann cells to repair cells after injury. In future, the signalling that specifies this cell requires further analysis so that pharmacological tools that boost and maintain the repair Schwann cell phenotype can be developed. PMID:26864683

  3. Immortalization of human normal and NF1 neurofibroma Schwann cells.

    PubMed

    Li, Hua; Chang, Lung-Ji; Neubauer, Debbie R; Muir, David F; Wallace, Margaret R

    2016-10-01

    Neurofibromas, which are benign Schwann cell tumors, are the hallmark feature in the autosomal dominant condition neurofibromatosis 1 (NF1) and are associated with biallelic loss of NF1 gene function. There is a need for effective therapies for neurofibromas, particularly the larger, plexiform neurofibromas. Tissue culture is an important tool for research. However, it is difficult to derive enriched human Schwann cell cultures, and most enter replicative senescence after 6-10 passages, impeding cell-based research in NF1. Through exogenous expression of human telomerase reverse transcriptase and murine cyclin-dependent kinase (mCdk4), normal (NF1 wild-type), neurofibroma-derived Schwann cells heterozygous for NF1 mutation, and neurofibroma-derived Schwann cells homozygous for NF1 mutation were immortalized, including some matched samples from the same NF1 patient. Initial experiments employed retroviral vectors, while subsequent work utilized lentiviral vectors carrying these genes because of improved efficiency. Expression of both transgenes was required for immortalization. Molecular and immunohistochemical analysis indicated that these cell lines are of Schwann cell lineage and have a range of phenotypes, many of which are consistent with their primary cultures. This is the first report of immortalization and detailed characterization of multiple human NF1 normal nerve and neurofibroma-derived Schwann cell lines, which will be highly useful research tools to study NF1 and other Schwann tumor biology and conditions. PMID:27617404

  4. Arf6 mediates Schwann cell differentiation and myelination.

    PubMed

    Torii, Tomohiro; Miyamoto, Yuki; Yamamoto, Masahiro; Ohbuchi, Katsuya; Tsumura, Hideki; Kawahara, Kazuko; Tanoue, Akito; Sakagami, Hiroyuki; Yamauchi, Junji

    2015-09-25

    During development of the peripheral nervous system (PNS), Schwann cells wrap neuronal axons, becoming the myelin sheaths that help axonal functions. While the intercellular signals controlling the myelination process between Schwann cells and peripheral neurons are well studied, the transduction of these signals in Schwann cells still remains elusive. Here, we show that Arf6, an Arf protein of the small GTPase family, is involved in promoting the myelination process. Knockdown of Arf6 with the small-interfering (si)RNA in primary Schwann cells markedly decreases dibutyl-cyclic AMP-induced myelin marker protein expression, indicating that Arf6 plays a role in differentiation-like phenotypic changes. To obtain in vivo evidence, we generated small-hairpin (sh)RNA transgenic mice targeting Arf6 for Schwann cells. Transgenic mice exhibited reduced myelin thickness compared to littermate controls, consistent with the defective myelin formation observed in the transgenic mouse-derived Schwann cell and neuronal culture system. Transgenic mice also exhibited decreased phosphorylation of myelination-related signaling molecules such as Akt kinase cascade proteins as well as downregulation of myelin marker proteins. These results suggest that signaling through Arf6 is required for Schwann cell myelination, adding Arf6 to the list of intracellular signaling molecules involved in the myelination process.

  5. Zeb2 is essential for Schwann cell differentiation, myelination and nerve repair.

    PubMed

    Quintes, Susanne; Brinkmann, Bastian G; Ebert, Madlen; Fröb, Franziska; Kungl, Theresa; Arlt, Friederike A; Tarabykin, Victor; Huylebroeck, Danny; Meijer, Dies; Suter, Ueli; Wegner, Michael; Sereda, Michael W; Nave, Klaus-Armin

    2016-08-01

    Schwann cell development and peripheral nerve myelination require the serial expression of transcriptional activators, such as Sox10, Oct6 (also called Scip or Pou3f1) and Krox20 (also called Egr2). Here we show that transcriptional repression, mediated by the zinc-finger protein Zeb2 (also known as Sip1), is essential for differentiation and myelination. Mice lacking Zeb2 in Schwann cells develop a severe peripheral neuropathy, caused by failure of axonal sorting and virtual absence of myelin membranes. Zeb2-deficient Schwann cells continuously express repressors of lineage progression. Moreover, genes for negative regulators of maturation such as Sox2 and Ednrb emerge as Zeb2 target genes, supporting its function as an 'inhibitor of inhibitors' in myelination control. When Zeb2 is deleted in adult mice, Schwann cells readily dedifferentiate following peripheral nerve injury and become repair cells. However, nerve regeneration and remyelination are both perturbed, demonstrating that Zeb2, although undetectable in adult Schwann cells, has a latent function throughout life.

  6. Interaction between Schwann Cells and Osteoblasts In Vitro

    PubMed Central

    Cai, Xiao-xiao; Luo, En; Yuan, Quan

    2010-01-01

    Aim Given the well-known properties of Schwann cells in promoting nerve regeneration, transplanting Schwann cells into implant sockets might be an effective method to promote sensory responses of osseointegrated implants. The aim of this study was to evaluate the interaction between Schwann cells and osteoblasts. Methodology Schwann cells derived from the sciatic nerves of neonatal rat were co-culured with osteoblasts using Transwell inserts. The proliferation of Schwann cells in the co-culture system was evaluated using methylthiazol tetrazolium (MTT) colorimetric method. Moreover, the secretions and mRNA levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were measured by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR, respectively. In order to test the effect of Schwann cells on osteoblasts, alkaline phosphatase (ALP) staining and Alizerin red staining were performed as well. Results Schwann cells, which were co-cultured with the osteoblasts, showed an intact proliferation during the observation period. Moreover, the gene expression and synthesis of BDNF and NGF were not impaired by the osteoblasts. Meanwhile, co-cultured osteoblasts exhibited a significant increase in the proliferation on day 3 and 6 (P< 0.05). Co-culture of these two types of cells also led to a more intense staining of ALP and an elevated number of calcified nodules. Conclusion These findings demonstrate that, in the in vitro indirect co-culture environment, Schwann cells can maintain their normal ability to synthesize neurotrophins, which then enhance the proliferation and differentiation of osteoblasts. PMID:20737933

  7. Axon-schwann cell interaction in the squid nerve fibre

    PubMed Central

    Villegas, Jorge

    1972-01-01

    The electrical properties of Schwann cells and the effects of neuronal impulses on their membrane potential have been studied in the giant nerve fibre of the squid. 1. The behaviour of the Schwann cell membrane to current injection into the cell was ohmic. No impulse-like responses were observed with displacements of 35 mV in the membrane potential. The resistance of the Schwann cell membrane was found to be approximately 103 Ω cm2. 2. A long-lasting hyperpolarization is observed in the Schwann cells following the conduction of impulse trains by the axon. Whereas the propagation of a single impulse had little effect, prolonged stimulation of the fibre at 250 impulses/sec was followed by a hyperpolarization of the Schwann cell that gradually declined over a period of several minutes. 3. The prolonged effects of nerve impulse trains on the Schwann cell were similar to those produced by depolarizing current pulses applied to the axon by the voltage-clamp technique. Thus, a series of depolarizing pulses in the axon was followed by a long-lasting hyperpolarization of the Schwann cells. In contrast, the application of a series of hyperpolarizing 100 mV pulses at a frequency of 1/sec had no apparent effects. 4. Changes in the external potassium concentration did not reproduce the long-lasting effects of nerve excitation. 5. The hyperpolarizing effects of impulse trains were abolished by the incubation of the nerve fibre in a sea-water solution containing trypsin. 6. These findings are discussed in relation to the possible mechanisms that might be responsible for the long-lasting hyperpolarizations of the Schwann cells. PMID:5074387

  8. TACE (ADAM17) inhibits Schwann cell myelination.

    PubMed

    La Marca, Rosa; Cerri, Federica; Horiuchi, Keisuke; Bachi, Angela; Feltri, M Laura; Wrabetz, Lawrence; Blobel, Carl P; Quattrini, Angelo; Salzer, James L; Taveggia, Carla

    2011-06-12

    Tumor necrosis factor-α-converting enzyme (TACE; also known as ADAM17) is a proteolytic sheddase that is responsible for the cleavage of several membrane-bound molecules. We report that TACE cleaves neuregulin-1 (NRG1) type III in the epidermal growth factor domain, probably inactivating it (as assessed by deficient activation of the phosphatidylinositol-3-OH kinase pathway), and thereby negatively regulating peripheral nervous system (PNS) myelination. Lentivirus-mediated knockdown of TACE in vitro in dorsal root ganglia neurons accelerates the onset of myelination and results in hypermyelination. In agreement, motor neurons of conditional knockout mice lacking TACE specifically in these cells are significantly hypermyelinated, and small-caliber fibers are aberrantly myelinated. Further, reduced TACE activity rescues hypomyelination in NRG1 type III haploinsufficient mice in vivo. We also show that the inhibitory effect of TACE is neuron-autonomous, as Schwann cells lacking TACE elaborate myelin of normal thickness. Thus, TACE is a modulator of NRG1 type III activity and is a negative regulator of myelination in the PNS.

  9. Schwann Cell Myelination Requires Timely and Precise Targeting of P0 Protein

    PubMed Central

    Yin, X.; Kidd, G.J.; Wrabetz, L.; Feltri, M.L.; Messing, A.; Trapp, B.D.

    2000-01-01

    This report investigated mechanisms responsible for failed Schwann cell myelination in mice that overexpress P0 (P0tg), the major structural protein of PNS myelin. Quantitative ultrastructural immunocytochemistry established that P0 protein was mistargeted to abaxonal, periaxonal, and mesaxon membranes in P0tg Schwann cells with arrested myelination. The extracellular leaflets of P0-containing mesaxon membranes were closely apposed with periodicities of compact myelin. The myelin-associated glycoprotein was appropriately sorted in the Golgi apparatus and targeted to periaxonal membranes. In adult mice, occasional Schwann cells myelinated axons possibly with the aid of endocytic removal of mistargeted P0. These results indicate that P0 gene multiplication causes P0 mistargeting to mesaxon membranes, and through obligate P0 homophilic adhesion, renders these dynamic membranes inert and halts myelination. PMID:10704450

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

    SciTech Connect

    Ota, Kimiko; Nakamura, Jiro; Li, Weiguo; Kozakae, Mika; Watarai, Atsuko; Nakamura, Nobuhisa; Yasuda, Yutaka; Nakashima, Eirtaro; Naruse, Keiko; Watabe, Kazuhiko; Kato, Koichi; Oiso, Yutaka; Hamada, Yoji . E-mail: yhama@med.nagoya-u.ac.jp

    2007-05-25

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

  11. Induction of adipose-derived stem cells into Schwann-like cells and observation of Schwann-like cell proliferation

    PubMed Central

    Fu, Xiumei; Tong, Zhaoxue; Li, Qi; Niu, Qingfei; Zhang, Zhe; Tong, Xiaojie; Tong, Lei; Zhang, Xu

    2016-01-01

    The peripheral nervous system has the potential for full regeneration following injury and recovery, predominantly controlled by Schwann cells (SCs). Therefore, obtaining a sufficient number of SCs in a short duration is crucial. In the present study, rat adipose-derived stem cells (ADSCs) were isolated and cultured, following which characterization of the ADSCs was performed using flow cytometry. The results showed that the cells were positive for the CD29 and CD44 markers, and negative for the CD31, CD45, CD49 and CD106 markers. The multilineage differentiation potential of the ADSCs was assayed by determining the ability of the cells to differentiate into osteoblasts and adipocytes. Following this, the ADSCs were treated with a specific medium and differentiated into Schwann-like cells. Immunofluorescence, western blot and reverse transcription-quantitative polymerase chain reaction analyses showed that ~95% of the differentiated cells expressed glial fibrillary acidic protein, S100 and p75. In addition, the present study found that a substantial number of SCs can be produced in a short duration via the mitotic feature of Schwann-like cells. These data indicated that Schwann-like cells derived from ADSCs can undergo mitotic proliferation, which may be beneficial for the treatment of peripheral nerve injury in the future. PMID:27279556

  12. Glial versus melanocyte cell fate choice: Schwann cell precursors as a cellular origin of melanocytes.

    PubMed

    Adameyko, Igor; Lallemend, Francois

    2010-09-01

    Melanocytes and Schwann cells are derived from the multipotent population of neural crest cells. Although both cell types were thought to be generated through completely distinct pathways and molecular processes, a recent study has revealed that these different cell types are intimately interconnected far beyond previously postulated limits in that they share a common post-neural crest progenitor, i.e. the Schwann cell precursor. This finding raises interesting questions about the lineage relationships of hitherto unrelated cell types such as melanocytes and Schwann cells, and may provide clinical insights into mechanisms of pigmentation disorders and for cancer involving Schwann cells and melanocytes.

  13. Mesenchymal stem cells as a source of Schwann cells: their anticipated use in peripheral nerve regeneration.

    PubMed

    Wakao, Shohei; Matsuse, Dai; Dezawa, Mari

    2014-01-01

    Schwann cells form myelin, sustain axons and provide the microenvironment for nerve fibers, thereby playing a key role in the peripheral nervous system (PNS). Schwann cells also provide support for the damaged PNS by producing factors that strongly promote axonal regrowth and contribute to remyelination, which is crucial for the recovery of neural function. These advantages are not confined to the PNS and also apply to the central nervous system. Many diseases, including peripheral nerve injury, neuropathy, multiple sclerosis and spinal cord injury, are targets for Schwann cell therapy. The collection of Schwann cells, however, causes new damage to other peripheral nerve segments. Furthermore, the doubling time of Schwann cells is not very fast, and thus adequate amounts of Schwann cells for clinical use cannot be collected within a reasonable amount of time. Mesenchymal stem cells, which are highly proliferative, are easily accessible from various types of mesenchymal tissues, such as the bone marrow, umbilical cord and fat tissue. Because these cells have the ability to cross oligolineage boundaries between mesodermal to ectodermal lineages, they are capable of differentiating into Schwann cells with step-by-step cytokine stimulation. In this review, we summarize the properties of mesenchymal stem cell-derived Schwann cells, which are comparable to authentic Schwann cells, and discuss future perspectives.

  14. Generation of pure cultures of autologous Schwann cells by use of biopsy specimens of the dorsal cutaneous branches of the cervical nerves of young adult dogs.

    PubMed

    Lim, Ji-Hey; Olby, Natasha J

    2016-10-01

    OBJECTIVE To identify an optimal technique for isolation, purification, and amplification of Schwann cells (SCs) from biopsy specimens of the dorsal cutaneous branches of the cervical nerves of dogs. SAMPLE Biopsy specimens of dorsal cervical cutaneous nerves from the cadavers of three 1- to 2-year-old dogs. PROCEDURES Nerve specimens were dissected, predegenerated, and dissociated to isolate single cells. After culture to enhance SC growth, cells were immunopurified by use of magnetic beads. Cell purity was evaluated by assessing expression of cell surface antigens p75 (to detect SCs) and CD90 (to detect fibroblasts). Effects of various concentrations of recombinant human glial growth factor 2 (rhGGF2) on SC proliferation were tested. Cell doubling time was assessed in SC cultures with selected concentrations of rhGGF2. RESULTS Mean ± SD wet weight of nerve fascicles obtained from the biopsy specimens was 16.8 ± 2.8 mg. A mean predegeneration period of 8.6 days yielded approximately 6,000 cells/mg of nerve tissue, and primary culture yielded 43,000 cells/mg of nerve tissue in a mean of 11 days, of which 39.9 ± 9.1% expressed p75. Immunopurification with magnetic beads yielded a mean of 85.4 ± 1.9% p75-positive cells. Two passages of subculture with 10μM cytosine arabinoside further enhanced SC purity to a mean of 97.8 ± 1.2% p75-positive cells. Finally, rhGGF2 supplementation at a range of 40 to 100 ng/mL increased the SC proliferation rate up to 3-fold. CONCLUSIONS AND CLINICAL RELEVANCE SCs could be cultured from biopsy specimens of dorsal cervical cutaneous nerves and purified and expanded to generate adequate numbers for autologous transplants to treat dogs with spinal cord and peripheral nerve injuries. PMID:27668589

  15. Sox4 participates in the modulation of Schwann cell myelination.

    PubMed

    Bartesaghi, Luca; Arnaud Gouttenoire, Estelle; Prunotto, Andrea; Médard, Jean-Jacques; Bergmann, Sven; Chrast, Roman

    2015-07-01

    In order to identify new regulators of Schwann cell myelination potentially playing a role in peripheral nervous system (PNS) pathologies, we analysed gene expression profiling data from three mouse models of demyelinating neuropathies and from the developing PNS. This analysis revealed that Sox4, which encodes a member of the Sry-related high-mobility group box protein family, was consistently upregulated in all three analysed models of neuropathy. Moreover, Sox4 showed a peak in its expression during development that corresponded with the onset of myelination. To gain further insights into the role of Sox4 in PNS development, we generated a transgenic mouse that specifically overexpresses Sox4 in Schwann cells. Sox4 overexpression led to a temporary delay in PNS myelination without affecting axonal sorting. Importantly, we observed that, whereas Sox4 mRNA could be efficiently overexpressed, Sox4 protein expression in Schwann cells was strictly regulated. Finally, our data showed that enforced expression of Sox4 in the mouse model for Charcot-Marie-Tooth 4C aggravated its neuropathic phenotype. Together, these observations reveal that Sox4 contributes to the regulation of Schwann cell myelination, and also indicates its involvement in the pathophysiology of peripheral neuropathies.

  16. Human epidermal neural crest stem cells as a source of Schwann cells

    PubMed Central

    Sakaue, Motoharu; Sieber-Blum, Maya

    2015-01-01

    We show that highly pure populations of human Schwann cells can be derived rapidly and in a straightforward way, without the need for genetic manipulation, from human epidermal neural crest stem cells [hEPI-NCSC(s)] present in the bulge of hair follicles. These human Schwann cells promise to be a useful tool for cell-based therapies, disease modelling and drug discovery. Schwann cells are glia that support axons of peripheral nerves and are direct descendants of the embryonic neural crest. Peripheral nerves are damaged in various conditions, including through trauma or tumour-related surgery, and Schwann cells are required for their repair and regeneration. Schwann cells also promise to be useful for treating spinal cord injuries. Ex vivo expansion of hEPI-NCSC isolated from hair bulge explants, manipulating the WNT, sonic hedgehog and TGFβ signalling pathways, and exposure of the cells to pertinent growth factors led to the expression of the Schwann cell markers SOX10, KROX20 (EGR2), p75NTR (NGFR), MBP and S100B by day 4 in virtually all cells, and maturation was completed by 2 weeks of differentiation. Gene expression profiling demonstrated expression of transcripts for neurotrophic and angiogenic factors, as well as JUN, all of which are essential for nerve regeneration. Co-culture of hEPI-NCSC-derived human Schwann cells with rodent dorsal root ganglia showed interaction of the Schwann cells with axons, providing evidence of Schwann cell functionality. We conclude that hEPI-NCSCs are a biologically relevant source for generating large and highly pure populations of human Schwann cells. PMID:26251357

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

    PubMed

    Gupta, Ranjan; Steward, Oswald

    2003-06-23

    Chronic nerve compression (CNC), as in carpal tunnel syndrome, is a common cause of peripheral nerve dysfunction in humans. Previous studies using animal models have demonstrated progressive demyelination and a slowing of nerve conduction velocity. To characterize the Schwann cell response to CNC, we evaluated total Schwann cell number, apoptosis, and proliferation in an animal model of CNC. Design-based stereologic techniques revealed a striking transient increase in Schwann cell number following CNC. Schwann cell number increased sixfold relative to the normal nerve at the site of compression at 1 month and then slowly declined toward control levels. Nevertheless, assays of apoptosis (TUNEL and an antipoly-ADP-ribose polymerase labeling assays) revealed extensive Schwann cell apoptosis at 2 weeks postcompression, which is during the time when Schwann cell number was increasing. Electron microscopic analysis confirmed that these dramatic changes in Schwann cells occurred in the absence of axon degeneration and axonal swelling and before there were any detectable alterations in nerve conduction velocity. Counts of bromodeoxyuridine-labeled Schwann cells revealed that proliferation occurred concurrently with ongoing apoptosis. To define further the possible mitogenic properties of mechanical stimuli on Schwann cells, we used an in-vitro model to deliver shear stress in the form of laminar fluid flow to pure populations of Schwann cells and confirmed that mechanical stimuli induce Schwann cell proliferation. Our findings indicate that chronic nerve compression induces Schwann cell turnover with minimal axonal injury and support the idea that mechanical stimuli have a direct mitogenic effect on Schwann cells. PMID:12724836

  18. Signals regulating myelination in peripheral nerves and the Schwann cell response to injury

    PubMed Central

    Glenn, Thomas D.; Talbot, William S.

    2013-01-01

    In peripheral nerves, Schwann cells form myelin, which facilitates the rapid conduction of action potentials along axons in the vertebrate nervous system. Myelinating Schwann cells are derived from neural crest progenitors in a step-wise process that is regulated by extracellular signals and transcription factors. In addition to forming the myelin sheath, Schwann cells orchestrate much of the regenerative response that occurs after injury to peripheral nerves. In response to injury, myelinating Schwann cells dedifferentiate into repair cells that are essential for axonal regeneration, and then redifferentiate into myelinating Schwann cells to restore nerve function. Although this remarkable plasticity has long been recognized, many questions remain unanswered regarding the signaling pathways regulating both myelination and the Schwann cell response to injury. PMID:23896313

  19. Blocking mitochondrial calcium release in Schwann cells prevents demyelinating neuropathies.

    PubMed

    Gonzalez, Sergio; Berthelot, Jade; Jiner, Jennifer; Perrin-Tricaud, Claire; Fernando, Ruani; Chrast, Roman; Lenaers, Guy; Tricaud, Nicolas

    2016-03-01

    Schwann cells produce myelin sheath around peripheral nerve axons. Myelination is critical for rapid propagation of action potentials, as illustrated by the large number of acquired and hereditary peripheral neuropathies, such as diabetic neuropathy or Charcot-Marie-Tooth diseases, that are commonly associated with a process of demyelination. However, the early molecular events that trigger the demyelination program in these diseases remain unknown. Here, we used virally delivered fluorescent probes and in vivo time-lapse imaging in a mouse model of demyelination to investigate the underlying mechanisms of the demyelination process. We demonstrated that mitochondrial calcium released by voltage-dependent anion channel 1 (VDAC1) after sciatic nerve injury triggers Schwann cell demyelination via ERK1/2, p38, JNK, and c-JUN activation. In diabetic mice, VDAC1 activity was altered, resulting in a mitochondrial calcium leak in Schwann cell cytoplasm, thereby priming the cell for demyelination. Moreover, reduction of mitochondrial calcium release, either by shRNA-mediated VDAC1 silencing or pharmacological inhibition, prevented demyelination, leading to nerve conduction and neuromuscular performance recovery in rodent models of diabetic neuropathy and Charcot-Marie-Tooth diseases. Therefore, this study identifies mitochondria as the early key factor in the molecular mechanism of peripheral demyelination and opens a potential opportunity for the treatment of demyelinating peripheral neuropathies. PMID:26878172

  20. Peripheral nervous system plasmalogens regulate Schwann cell differentiation and myelination

    PubMed Central

    da Silva, Tiago Ferreira; Eira, Jessica; Lopes, André T.; Malheiro, Ana R.; Sousa, Vera; Luoma, Adrienne; Avila, Robin L.; Wanders, Ronald J.A.; Just, Wilhelm W.; Kirschner, Daniel A.; Sousa, Mónica M.; Brites, Pedro

    2014-01-01

    Rhizomelic chondrodysplasia punctata (RCDP) is a developmental disorder characterized by hypotonia, cataracts, abnormal ossification, impaired motor development, and intellectual disability. The underlying etiology of RCDP is a deficiency in the biosynthesis of ether phospholipids, of which plasmalogens are the most abundant form in nervous tissue and myelin; however, the role of plasmalogens in the peripheral nervous system is poorly defined. Here, we used mouse models of RCDP and analyzed the consequence of plasmalogen deficiency in peripheral nerves. We determined that plasmalogens are crucial for Schwann cell development and differentiation and that plasmalogen defects impaired radial sorting, myelination, and myelin structure. Plasmalogen insufficiency resulted in defective protein kinase B (AKT) phosphorylation and subsequent signaling, causing overt activation of glycogen synthase kinase 3β (GSK3β) in nerves of mutant mice. Treatment with GSK3β inhibitors, lithium, or 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione (TDZD-8) restored Schwann cell defects, effectively bypassing plasmalogen deficiency. Our results demonstrate the requirement of plasmalogens for the correct and timely differentiation of Schwann cells and for the process of myelination. In addition, these studies identify a mechanism by which the lack of a membrane phospholipid causes neuropathology, implicating plasmalogens as regulators of membrane and cell signaling. PMID:24762439

  1. Blocking mitochondrial calcium release in Schwann cells prevents demyelinating neuropathies

    PubMed Central

    Berthelot, Jade; Jiner, Jennifer; Perrin-Tricaud, Claire; Fernando, Ruani; Chrast, Roman; Lenaers, Guy

    2016-01-01

    Schwann cells produce myelin sheath around peripheral nerve axons. Myelination is critical for rapid propagation of action potentials, as illustrated by the large number of acquired and hereditary peripheral neuropathies, such as diabetic neuropathy or Charcot-Marie-Tooth diseases, that are commonly associated with a process of demyelination. However, the early molecular events that trigger the demyelination program in these diseases remain unknown. Here, we used virally delivered fluorescent probes and in vivo time-lapse imaging in a mouse model of demyelination to investigate the underlying mechanisms of the demyelination process. We demonstrated that mitochondrial calcium released by voltage-dependent anion channel 1 (VDAC1) after sciatic nerve injury triggers Schwann cell demyelination via ERK1/2, p38, JNK, and c-JUN activation. In diabetic mice, VDAC1 activity was altered, resulting in a mitochondrial calcium leak in Schwann cell cytoplasm, thereby priming the cell for demyelination. Moreover, reduction of mitochondrial calcium release, either by shRNA-mediated VDAC1 silencing or pharmacological inhibition, prevented demyelination, leading to nerve conduction and neuromuscular performance recovery in rodent models of diabetic neuropathy and Charcot-Marie-Tooth diseases. Therefore, this study identifies mitochondria as the early key factor in the molecular mechanism of peripheral demyelination and opens a potential opportunity for the treatment of demyelinating peripheral neuropathies. PMID:26878172

  2. Dynamic Regulation of Schwann Cell Enhancers after Peripheral Nerve Injury*

    PubMed Central

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

    2015-01-01

    Myelination of the peripheral nervous system is required for axonal function and long term stability. After peripheral nerve injury, Schwann cells transition from axon myelination to a demyelinated state that supports neuronal survival and ultimately remyelination of axons. Reprogramming of gene expression patterns during development and injury responses is shaped by the actions of distal regulatory elements that integrate the actions of multiple transcription factors. We used ChIP-seq to measure changes in histone H3K27 acetylation, a mark of active enhancers, to identify enhancers in myelinating rat peripheral nerve and their dynamics after demyelinating nerve injury. Analysis of injury-induced enhancers identified enriched motifs for c-Jun, a transcription factor required for Schwann cells to support nerve regeneration. We identify a c-Jun-bound enhancer in the gene for Runx2, a transcription factor induced after nerve injury, and we show that Runx2 is required for activation of other induced genes. In contrast, enhancers that lose H3K27ac after nerve injury are enriched for binding sites of the Sox10 and early growth response 2 (Egr2/Krox20) transcription factors, which are critical determinants of Schwann cell differentiation. Egr2 expression is lost after nerve injury, and many Egr2-binding sites lose H3K27ac after nerve injury. However, the majority of Egr2-bound enhancers retain H3K27ac, indicating that other transcription factors maintain active enhancer status after nerve injury. The global epigenomic changes in H3K27ac deposition pinpoint dynamic changes in enhancers that mediate the effects of transcription factors that control Schwann cell myelination and peripheral nervous system responses to nerve injury. PMID:25614629

  3. ProBDNF inhibits collective migration and chemotaxis of rat Schwann cells.

    PubMed

    Ding, You-Quan; Li, Xuan-Yang; Xia, Guan-Nan; Ren, Hong-Yi; Zhou, Xin-Fu; Su, Bing-Yin; Qi, Jian-Guo

    2016-10-01

    Schwann cell migration, including collective migration and chemotaxis, is essential for the formation of coordinate interactions between Schwann cells and axons during peripheral nerve development and regeneration. Moreover, limited migration of Schwann cells imposed a serious obstacle on Schwann cell-astrocytes intermingling and spinal cord repair after Schwann cell transplantation into injured spinal cords. Recent studies have shown that mature brain-derived neurotrophic factor, a member of the neurotrophin family, inhibits Schwann cell migration. The precursor form of brain-derived neurotrophic factor, proBDNF, was expressed in the developing or degenerating peripheral nerves and the injured spinal cords. Since "the yin and yang of neurotrophin action" has been established as a common sense, proBDNF would be expected to promote Schwann cell migration. However, we found, in the present study, that exogenous proBDNF also inhibited in vitro collective migration and chemotaxis of RSC 96 cells, a spontaneously immortalized rat Schwann cell line. Moreover, proBDNF suppressed adhesion and spreading of those cells. At molecular level, proBDNF inhibits F-actin polymerization and focal adhesion dynamics in cultured RSC 96 cells. Therefore, our results suggested a special case against the classical opinion of "the yin and yang of neurotrophin action" and implied that proBDNF might modulate peripheral nerve development or regeneration and spinal cord repair through perturbing native or transplanted Schwann cell migration.

  4. E-cadherin enhances neuregulin signaling and promotes Schwann cell myelination.

    PubMed

    Basak, Sayantani; Desai, Darshan J; Rho, Esther H; Ramos, Roselle; Maurel, Patrice; Kim, Haesun A

    2015-09-01

    In myelinating Schwann cells, E-cadherin is a component of the adherens junctions that stabilize the architecture of the noncompact myelin region. In other cell types, E-cadherin has been considered as a signaling receptor that modulates intracellular signal transduction and cellular responses. To determine whether E-cadherin plays a regulatory role during Schwann cell myelination, we investigated the effects of E-cadherin deletion and over-expression in Schwann cells. In vivo, Schwann cell-specific E-cadherin ablation results in an early myelination delay. In Schwann cell-dorsal root ganglia neuron co-cultures, E-cadherin deletion attenuates myelin formation and shortens the myelin segment length. When over-expressed in Schwann cells, E-cadherin improves myelination on Nrg1 type III(+/-) neurons and induces myelination on normally non-myelinated axons of sympathetic neurons. The pro-myelinating effect of E-cadherin is associated with an enhanced Nrg1-erbB receptor signaling, including activation of the downstream Akt and Rac. Accordingly, in the absence of E-cadherin, Nrg1-signaling is diminished in Schwann cells. Our data also show that E-cadherin expression in Schwann cell is induced by axonal Nrg1 type III, indicating a reciprocal interaction between E-cadherin and the Nrg1 signaling. Altogether, our data suggest a regulatory function of E-cadherin that modulates Nrg1 signaling and promotes Schwann cell myelin formation.

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

    SciTech Connect

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

    2013-01-11

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

  6. Nerve growth factor and its low-affinity receptor promote Schwann cell migration.

    PubMed Central

    Anton, E S; Weskamp, G; Reichardt, L F; Matthew, W D

    1994-01-01

    Migrating Schwann cells in developing or regenerating peripheral nerves are known to express dramatically increased levels of nerve growth factor (NGF) and the low-affinity NGF receptor (LNGFR). Schwann cells do not express detectable pp140trk, the NGF-activated receptor tyrosine kinase which is essential for neuronal responses to NGF. The temporal correlation observed in Schwann cells between migration and the enhanced expression of NGF and LNGFR suggests that NGF and LNGFR may promote Schwann cell migration. To test this possibility, we examined the effects of NGF on Schwann cell migration on cryostat sections of biologically relevant NGF-poor and NGF-rich substrates--normal or denervated peripheral (sciatic) nerve, untreated or pretreated with NGF. Results show that Schwann cells migrate more rapidly on denervated than on normal sciatic nerve. Antibodies to NGF or to LNGFR strongly, but incompletely, inhibit enhanced migration on denervated nerves. Pretreatment of denervated nerve sections with NGF increases further the rate of Schwann cell migration. The same antibodies to NGF or to LNGFR abolish this response. These results suggest that one function of the elevated levels of NGF known to be present in embryonic and regenerating peripheral nerves is to promote the migration of Schwann cells. In contrast to neurons, where pp140trk appears to be the functionally critical NGF receptor, NGF responses in Schwann cells depend on LNGFR. Images PMID:8146193

  7. Ras-mediated cell cycle arrest is altered by nuclear oncogenes to induce Schwann cell transformation.

    PubMed Central

    Ridley, A J; Paterson, H F; Noble, M; Land, H

    1988-01-01

    The cellular responses to ras and nuclear oncogenes were investigated in purified populations of rat Schwann cells. v-Ha-ras and SV40 large T cooperate to transform Schwann cells, inducing growth in soft agar and allowing proliferation in the absence of added mitogens. Expression of large T alone reduces their growth factor requirements but is insufficient to induce full transformation. In contrast, expression of v-Ha-ras leads to proliferation arrest in Schwann cells expressing a temperature-sensitive mutant of large T at the restrictive temperature. Cells arrest in either the G1 or G2/M phases of the cell cycle, and can re-enter cell division at the permissive temperature even after prolonged periods at the restrictive conditions. Oncogenic ras proteins also inhibit DNA synthesis when microinjected into Schwann cells. Adenovirus E1a and c-myc oncogenes behave similarly to SV40 large T. They cooperate with Ha-ras oncogenes to transform Schwann cells, and prevent ras-induced growth arrest. Thus nuclear oncogenes fundamentally alter the response of Schwann cells to a ras oncogene from cell cycle arrest to transformation. Images PMID:3049071

  8. Collagen synthesis in axotomized peripheral nerve: evidence against Schwann cell involvement.

    PubMed

    Eather, T F; Pollock, M

    1987-04-01

    To explore the role of Schwann cells in nerve collagen formation, fascicular collagen was measured in axotomized rat sciatic nerve after regeneration or permanent axotomy. The same increase in fascicular collagen was seen in both paradigms. Thus there is no evidence that Schwann cells unassociated with axons make an important contribution to nerve collagen synthesis after transection.

  9. Involvement of the Tyro3 receptor and its intracellular partner Fyn signaling in Schwann cell myelination.

    PubMed

    Miyamoto, Yuki; Torii, Tomohiro; Takada, Shuji; Ohno, Nobuhiko; Saitoh, Yurika; Nakamura, Kazuaki; Ito, Akihito; Ogata, Toru; Terada, Nobuo; Tanoue, Akito; Yamauchi, Junji

    2015-10-01

    During early development of the peripheral nervous system, Schwann cell precursors proliferate, migrate, and differentiate into premyelinating Schwann cells. After birth, Schwann cells envelop neuronal axons with myelin sheaths. Although some molecular mechanisms underlying myelination by Schwann cells have been identified, the whole picture remains unclear. Here we show that signaling through Tyro3 receptor tyrosine kinase and its binding partner, Fyn nonreceptor cytoplasmic tyrosine kinase, is involved in myelination by Schwann cells. Impaired formation of myelin segments is observed in Schwann cell neuronal cultures established from Tyro3-knockout mouse dorsal root ganglia (DRG). Indeed, Tyro3-knockout mice exhibit reduced myelin thickness. By affinity chromatography, Fyn was identified as the binding partner of the Tyro3 intracellular domain, and activity of Fyn is down-regulated in Tyro3-knockout mice, suggesting that Tyro3, acting through Fyn, regulates myelination. Ablating Fyn in mice results in reduced myelin thickness. Decreased myelin formation is observed in cultures established from Fyn-knockout mouse DRG. Furthermore, decreased kinase activity levels and altered expression of myelination-associated transcription factors are observed in these knockout mice. These results suggest the involvement of Tyro3 receptor and its binding partner Fyn in Schwann cell myelination. This constitutes a newly recognized receptor-linked signaling mechanism that can control Schwann cell myelination.

  10. YAP and TAZ control peripheral myelination and the expression of laminin receptors in Schwann cells.

    PubMed

    Poitelon, Yannick; Lopez-Anido, Camila; Catignas, Kathleen; Berti, Caterina; Palmisano, Marilena; Williamson, Courtney; Ameroso, Dominique; Abiko, Kansho; Hwang, Yoonchan; Gregorieff, Alex; Wrana, Jeffrey L; Asmani, Mohammadnabi; Zhao, Ruogang; Sim, Fraser James; Wrabetz, Lawrence; Svaren, John; Feltri, Maria Laura

    2016-07-01

    Myelination is essential for nervous system function. Schwann cells interact with neurons and the basal lamina to myelinate axons using known receptors, signals and transcription factors. In contrast, the transcriptional control of axonal sorting and the role of mechanotransduction in myelination are largely unknown. Yap and Taz are effectors of the Hippo pathway that integrate chemical and mechanical signals in cells. We describe a previously unknown role for the Hippo pathway in myelination. Using conditional mutagenesis in mice, we show that Taz is required in Schwann cells for radial sorting and myelination and that Yap is redundant with Taz. Yap and Taz are activated in Schwann cells by mechanical stimuli and regulate Schwann cell proliferation and transcription of basal lamina receptor genes, both necessary for radial sorting of axons and subsequent myelination. These data link transcriptional effectors of the Hippo pathway and of mechanotransduction to myelin formation in Schwann cells.

  11. Neurotrophins regulate Schwann cell migration by activating divergent signaling pathways dependent on Rho GTPases

    PubMed Central

    Yamauchi, Junji; Chan, Jonah R.; Shooter, Eric M.

    2004-01-01

    Neurotrophins are recognized widely as essential factors in the developing nervous system. Previously, we demonstrated that neurotrophin 3 activation of TrkC inhibits Schwann cell myelination and enhances the migration of primary Schwann cells through the signaling pathway regulated by the Rho GTPases Rac1 and Cdc42. Here, we show that neurotrophins activate divergent signaling pathways to promote or inhibit Schwann cell migration. Endogenous brain-derived neurotrophic factor acting through p75NTR inhibits Schwann cell migration dramatically by Src kinase-dependent activation of the guanine-nucleotide exchange factor Vav2 and RhoA. Together, these results suggest that neurotrophins and their receptors differentially regulate Schwann cell migration through the signaling pathways that depend on Rho GTPases. PMID:15161978

  12. ATP Released by Injured Neurons Activates Schwann Cells

    PubMed Central

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

    2016-01-01

    Injured nerve terminals of neuromuscular junctions (NMJs) can regenerate. This remarkable and complex response is governed by molecular signals that are exchanged among the cellular components of this synapse: motor axon nerve terminal (MAT), perisynaptic Schwann cells (PSCs), and muscle fiber. The nature of signals that govern MAT regeneration is ill-known. In the present study the spider toxin α-latrotoxin has been used as tool to investigate the mechanisms underlying peripheral neuroregeneration. Indeed this neurotoxin induces an acute, specific, localized and fully reversible damage of the presynaptic nerve terminal, and its action mimics the cascade of events that leads to nerve terminal degeneration in injured patients and in many neurodegenerative conditions. Here we provide evidence of an early release by degenerating neurons of adenosine triphosphate as alarm messenger, that contributes to the activation of a series of intracellular pathways within Schwann cells that are crucial for nerve regeneration: Ca2+, cAMP, ERK1/2, and CREB. These results contribute to define the cross-talk taking place among degenerating nerve terminals and PSCs, involved in the functional recovery of the NMJ. PMID:27242443

  13. Jab1 regulates Schwann cell proliferation and axonal sorting through p27

    PubMed Central

    Porrello, Emanuela; Rivellini, Cristina; Dina, Giorgia; Triolo, Daniela; Del Carro, Ubaldo; Ungaro, Daniela; Panattoni, Martina; Feltri, Maria Laura; Wrabetz, Lawrence; Pardi, Ruggero; Quattrini, Angelo

    2014-01-01

    Axonal sorting is a crucial event in nerve formation and requires proper Schwann cell proliferation, differentiation, and contact with axons. Any defect in axonal sorting results in dysmyelinating peripheral neuropathies. Evidence from mouse models shows that axonal sorting is regulated by laminin211– and, possibly, neuregulin 1 (Nrg1)–derived signals. However, how these signals are integrated in Schwann cells is largely unknown. We now report that the nuclear Jun activation domain–binding protein 1 (Jab1) may transduce laminin211 signals to regulate Schwann cell number and differentiation during axonal sorting. Mice with inactivation of Jab1 in Schwann cells develop a dysmyelinating neuropathy with axonal sorting defects. Loss of Jab1 increases p27 levels in Schwann cells, which causes defective cell cycle progression and aberrant differentiation. Genetic down-regulation of p27 levels in Jab1-null mice restores Schwann cell number, differentiation, and axonal sorting and rescues the dysmyelinating neuropathy. Thus, Jab1 constitutes a regulatory molecule that integrates laminin211 signals in Schwann cells to govern cell cycle, cell number, and differentiation. Finally, Jab1 may constitute a key molecule in the pathogenesis of dysmyelinating neuropathies. PMID:24344238

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

    PubMed

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

    2016-10-15

    Transplanted Schwann cells have the potential to serve as a support for regenerating neurites after spinal cord injury. However, implanted Schwann cells die off rapidly once transplanted partly owing to the absence of a proper matrix support, with a glia scar and a cavity being present instead at the injury site. For this report, we evaluated aligned electrospun poly(methyl methacrylate) nanofibers as a Schwann cell-loading scaffold in vitro. By monitoring the fluorescence of green fluorescence protein-containing Schwann cells cultured on nanofibers, we found that aligned nanofibers provided better support for the cells than did non-aligned nanofibers. The cells elongated along the long axes of the aligned nanofibers and formed longer cell processes than when the substrate was non-aligned nanofibers. By coculturing Schwann cells with dorsal root ganglion neurons, it was also found that Schwann cells and neurites of dorsal root ganglion neurons could share and both elongate along the orientation of aligned nanofibers and thus they had a higher chance of colocalization than cocultured on film and non-aligned fibers, which might be beneficial to the ensuring process of myelination. The results of the study indicate that aligned electrospun nanofibers may serve as a Schwann cell-loading scaffold for future implantation research. PMID:27653871

  15. Long-term effect of vital labelling on mixed Schwann cell cultures.

    PubMed

    Mosahebi, A; Woodward, B; Green, C; Martin, R; Terenghi, G

    2000-06-01

    Schwann cell transplantation following neuronal injury could encourage regeneration of spinal cord as well as improving peripheral nerve gap repair. In order to gain a better understanding of the role of transplanted Schwann cells in vivo, it is essential to be able to follow their behaviour after transplantation. Our aim was to evaluate the suitability of two vital fluorescent labels on the proliferation rate and phenotypic stability of Schwann cells, in either pure culture or mixed co-culture. Primary cultures of Schwann cells were obtained from Dark Agouti and Lewis neonatal rats and labelled with H33342 and PKH26, respectively. In mixed cultures, a 50: 50 mixture of Dark Agouti and Lewis Schwann cells was present. Labelled cultured cells were examined at 1, 2 and 4 weeks for viability and phenotypic marker expression of S100, GFAP, p75, MHC I, MHC II and compared with corresponding unlabelled cells. The results showed that although there was no deleterious interaction in the mixed cultures, the viability was reduced by the labelling after 2 weeks. Labelled cells could be distinguished up to 4 weeks, but there was leakage of H33342 label after 2 weeks. Labelled Schwann cells showed reduced expression of phenotypic markers, especially p75 when labelled with H33342. In conclusion, H33342 and PKH26 can be used as fluorescent markers of Schwann cells for short-term studies, for a maximum of 2 weeks, but different markers may be needed for longer experiments.

  16. Molecular mechanisms promoting the pathogenesis of Schwann cell neoplasms.

    PubMed

    Carroll, Steven L

    2012-03-01

    Neurofibromas, schwannomas and malignant peripheral nerve sheath tumors (MPNSTs) all arise from the Schwann cell lineage. Despite their common origin, these tumor types have distinct pathologies and clinical behaviors; a growing body of evidence indicates that they also arise via distinct pathogenic mechanisms. Identification of the genes that are mutated in genetic diseases characterized by the development of either neurofibromas and MPNSTs [neurofibromatosis type 1 (NF1)] or schwannomas [neurofibromatosis type 2 (NF2), schwannomatosis and Carney complex type 1] has greatly advanced our understanding of these mechanisms. The development of genetically engineered mice with ablation of NF1, NF2, SMARCB1/INI1 or PRKAR1A has confirmed the key role these genes play in peripheral nerve sheath tumorigenesis. Establishing the functions of the NF1, NF2, SMARCB1/INI1 and PRKAR1A gene products has led to the identification of key cytoplasmic signaling pathways promoting Schwann cell neoplasia and identified new therapeutic targets. Analyses of human neoplasms and genetically engineered mouse models have established that interactions with other tumor suppressors such as TP53 and CDKN2A promote neurofibroma-MPNST progression and indicate that intratumoral interactions between neoplastic and non-neoplastic cell types play an essential role in peripheral nerve sheath tumorigenesis. Recent advances have also provided new insights into the identity of the neural crest-derived populations that give rise to different types of peripheral nerve sheath tumors. Based on these findings, we now have an initial outline of the molecular mechanisms driving the pathogenesis of neurofibromas, MPNSTs and schwannomas. However, this improved understanding in turn raises a host of intriguing new questions. PMID:22160322

  17. Nerve Allografts Supplemented with Schwann Cells Overexpressing GDNF

    PubMed Central

    Santosa, Katherine B.; Jesuraj, Nithya J.; Viader, Andreu; MacEwan, Matthew; Newton, Piyaraj; Hunter, Daniel A.; Mackinnon, Susan E.; Johnson, Philip J.

    2012-01-01

    Introduction We sought to determine if supplementation of acellular nerve allografts (ANAs) with Schwann Cells overexpressing GDNF (G-SCs) would enhance functional recovery following peripheral nerve injury. Methods SCs expanded in vitro were infected with a lentiviral vector to induce GDNF overexpression. Wild type-SCs (WT-SCs) and G-SCs were seeded into ANAs used to repair a 14mm nerve gap defect. Animals were harvested after 6 and 12 weeks for histomorphometric and muscle force analysis. Results At 6 weeks, histomorphometry revealed that ANAs supplemented with G-SCs promoted similar regeneration compared to the isograft at midgraft. However, G-SCs failed to promote regeneration into the distal stump. At 12 weeks, ANAs with G-SCs had lower maximum and specific force production compared to controls. Discussion The combined results suggest that consistent overexpression of GDNF by G-SCs trapped axons in the graft and prevented functional regeneration. PMID:23169341

  18. Detection, Distribution and Amount of Posttranslational α-Tubulin Modifications in Immortalized Rat Schwann Cells.

    PubMed

    Gadau, S D

    2015-12-01

    Microtubules (MTs), heterodimers of α- and β-tubulin, are involved in different cellular processes including mitosis, cell motility, intracellular transport, cell shape and polarization. In most eukaryotes tubulins, especially the α, are subjected to several post-translational modifications (PTMs) which include acetylation, tyrosination, detyrosination, Δ2 modification, polyglutamylation, that characterize different type of MTs and regulate the interactions between MTs and certain MAPs or motor proteins. Despite neurons, in which presence and distributions of tubulin PTMs are well evaluated, in glial cells like Schwann cells, little is known about the diverse tubulin PTMs amount, distribution and their functional role. So that, the purpose of the present work was to deepen the knowledge about the diverse tubulin PTMs in a commonly used immortalized Schwann cell line. By Western blot analysis we found a higher amount of polyglutamylated and tyrosinated α-tubulin, whereas acetylated, Δ2 and detyrosinated α-tubulin were less expressed.  Immunofluorescence staining, highlighted the distribution of acetylated and detyrosinated α-tubulin along the Schwann cells prolongations. In contrast, polyglutamylated α-tubulin was more detectable close to the cell body of Schwann cells, whereas the Δ2-modification was mainly distributed round the nuclear profile. Summing up, our investigation offers insight on several tubulin PTMs amount and distribution in Schwann cells. This could be a further contribution to better understand the role played by different MTs in Schwann cells biology and during the onset of certain disorders of peripheral nervous system.

  19. Detection, Distribution and Amount of Posttranslational α-Tubulin Modifications in Immortalized Rat Schwann Cells.

    PubMed

    Gadau, S D

    2015-12-01

    Microtubules (MTs), heterodimers of α- and β-tubulin, are involved in different cellular processes including mitosis, cell motility, intracellular transport, cell shape and polarization. In most eukaryotes tubulins, especially the α, are subjected to several post-translational modifications (PTMs) which include acetylation, tyrosination, detyrosination, Δ2 modification, polyglutamylation, that characterize different type of MTs and regulate the interactions between MTs and certain MAPs or motor proteins. Despite neurons, in which presence and distributions of tubulin PTMs are well evaluated, in glial cells like Schwann cells, little is known about the diverse tubulin PTMs amount, distribution and their functional role. So that, the purpose of the present work was to deepen the knowledge about the diverse tubulin PTMs in a commonly used immortalized Schwann cell line. By Western blot analysis we found a higher amount of polyglutamylated and tyrosinated α-tubulin, whereas acetylated, Δ2 and detyrosinated α-tubulin were less expressed.  Immunofluorescence staining, highlighted the distribution of acetylated and detyrosinated α-tubulin along the Schwann cells prolongations. In contrast, polyglutamylated α-tubulin was more detectable close to the cell body of Schwann cells, whereas the Δ2-modification was mainly distributed round the nuclear profile. Summing up, our investigation offers insight on several tubulin PTMs amount and distribution in Schwann cells. This could be a further contribution to better understand the role played by different MTs in Schwann cells biology and during the onset of certain disorders of peripheral nervous system. PMID:27168411

  20. Differential clustering of Caspr by oligodendrocytes and Schwann cells.

    PubMed

    Eisenbach, Menahem; Kartvelishvily, Elena; Eshed-Eisenbach, Yael; Watkins, Trent; Sorensen, Annette; Thomson, Christine; Ranscht, Barbara; Barnett, Susan C; Brophy, Peter; Peles, Elior

    2009-11-15

    Formation of the paranodal axoglial junction (PNJ) requires the presence of three cell adhesion molecules: the 155-kDa isoform of neurofascin (NF155) on the glial membrane and a complex of Caspr and contactin found on the axolemma. Here we report that the clustering of Caspr along myelinated axons during development differs fundamentally between the central (CNS) and peripheral (PNS) nervous systems. In cultures of Schwann cells (SC) and dorsal root ganglion (DRG) neurons, membrane accumulation of Caspr was detected only after myelination. In contrast, in oligodendrocytes (OL)/DRG neurons cocultures, Caspr was clustered upon initial glial cell contact already before myelination had begun. Premyelination clustering of Caspr was detected in cultures of oligodendrocytes and retinal ganglion cells, motor neurons, and DRG neurons as well as in mixed cell cultures of rat forebrain and spinal cords. Cocultures of oligodendrocyte precursor cells isolated from contactin- or neurofascin-deficient mice with wild-type DRG neurons showed that clustering of Caspr at initial contact sites between OL processes and the axon requires glial expression of NF155 but not of contactin. These results demonstrate that the expression of membrane proteins along the axolemma is determined by the type of the contacting glial cells and is not an intrinsic characteristic of the axon. PMID:19565653

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

    PubMed

    Kegler, Kristel; Spitzbarth, Ingo; Imbschweiler, Ilka; Wewetzer, Konstantin; Baumgärtner, Wolfgang; Seehusen, Frauke

    2015-01-01

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

  2. Synergistic effects of micropatterned biodegradable conduits and Schwann cells on sciatic nerve regeneration

    NASA Astrophysics Data System (ADS)

    Rutkowski, Gregory E.; Miller, Cheryl A.; Jeftinija, Srdija; Mallapragada, Surya K.

    2004-09-01

    This paper describes a novel biodegradable conduit that provides a combination of physical, chemical and biological cues at the cellular level to facilitate peripheral nerve regeneration. The conduit consists of a porous poly(D,L-lactic acid) (PDLLA) tubular support structure with a micropatterned inner lumen. Schwann cells were pre-seeded into the lumen to provide additional trophic support. Conduits with micropatterned inner lumens pre-seeded with Schwann cells (MS) were fabricated and compared with three types of conduits used as controls: M (conduits with micropatterned inner lumens without pre-seeded Schwann cells), NS (conduits without micropatterned inner lumens pre-seeded with Schwann cells) and N (conduits without micropatterned inner lumens, without pre-seeded Schwann cells). The conduits were implanted in rats with 1 cm sciatic nerve transections and the regeneration and functional recovery were compared in the four different cases. The number or size of regenerated axons did not vary significantly among the different conduits. The time of recovery, and the sciatic function index, however, were significantly enhanced using the MS conduits, based on qualitative observations as well as quantitative measurements using walking track analysis. This demonstrates that biodegradable micropatterned conduits pre-seeded with Schwann cells that provide a combination of physical, chemical and biological guidance cues for regenerating axons at the cellular level offer a better alternative for repairing sciatic nerve transactions than conventional biodegradable conduits.

  3. Nuclear Factor-κB Activation in Schwann Cells Regulates Regeneration and Re-myelination

    PubMed Central

    Morton, Paul D.; Johnstone, Joshua T.; Ramos, Angel Y.; Liebl, Daniel J.; Bunge, Mary B.; Bethea, John R.

    2014-01-01

    Schwann cells (SCs) are crucial for peripheral nerve development and regeneration; however, the intrinsic regulatory mechanisms governing post-injury responses are poorly understood. Activation and deacetylation of nuclear factor-κB (NF- κB) in SCs have been implicated as prerequisites for peripheral nerve myelination. Using GFAP-IκBα-dn mice in which NF- κB transcriptional activation is inhibited in SCs we found no discernable differences in the quantity or structure of myelinated axons in adult facial nerves. Following crush injury, axonal regeneration was impaired at 31 days and significantly enhanced at 65 days in transgenic animals. Compact re-myelination and Remak bundle organization were significantly compromised at 31 days and restored by 65 days post injury. Together, these data indicate that inhibition of NF- κB activation in SCs transiently delays axonal regeneration and compact re-myelination. Manipulating the temporal activation of nuclear factor-κB in Schwann cells may offer new therapeutic avenues for PNS and CNS regeneration. PMID:22275133

  4. Effects of cerebrolysin on rat Schwann cells in vitro.

    PubMed

    Lucas, Benjamin; Pinkernelle, Josephine; Fansa, Hisham; Keilhoff, Gerburg

    2014-06-01

    Although the peripheral nervous system (PNS) is capable of regeneration, these processes are limited. As a potential means to augment PNS regeneration, the effects of cerebrolysin (CL), a proteolytic peptide fraction, were tested in vitro on Schwann cell (SC) proliferation, stress resistance, phagocytic and cluster-forming capacity. Primary SC/fibrocyte co-cultures were prepared from dorsal root ganglia of 5-7-day-old rats. SCs were subjected to mechanical stress by media change and metabolic stress by serum glucose deprivation (SGD). Cell survival was assessed using MTT test. SC proliferation was determined by counting BrdU-labeled cells. SC clustering was studied by ImageJ analysis of S100 immunostaining. Wallerian degeneration (WD) was evaluated by measuring acetylcholine-esterase staining within sciatic nerves in vitro. It was found that CL caused no effect on MTT turnover in the tested doses. CL inhibited SC proliferation in a dose-dependent manner. Media change and additional SGD stress inhibited SC clustering. CL enhanced the reorganization of SC clusters and was able to counteract SGD-induced cluster defects. Moreover, CL accelerated WD in vitro. CL was able to enhance the functions of SCs that are relevant to nerve regeneration. Thus, our findings suggest that CL may be suitable for therapeutic usage to enhance PNS regeneration/reconstruction.

  5. c-Jun activation in Schwann cells protects against loss of sensory axons in inherited neuropathy

    PubMed Central

    Hantke, Janina; Carty, Lucy; Wagstaff, Laura J.; Turmaine, Mark; Wilton, Daniel K.; Quintes, Susanne; Koltzenburg, Martin; Baas, Frank; Mirsky, Rhona

    2014-01-01

    Charcot–Marie–Tooth disease type 1A is the most frequent inherited peripheral neuropathy. It is generally due to heterozygous inheritance of a partial chromosomal duplication resulting in over-expression of PMP22. A key feature of Charcot–Marie–Tooth disease type 1A is secondary death of axons. Prevention of axonal loss is therefore an important target of clinical intervention. We have previously identified a signalling mechanism that promotes axon survival and prevents neuron death in mechanically injured peripheral nerves. This work suggested that Schwann cells respond to injury by activating/enhancing trophic support for axons through a mechanism that depends on upregulation of the transcription factor c-Jun in Schwann cells, resulting in the sparing of axons that would otherwise die. As c-Jun orchestrates Schwann cell support for distressed neurons after mechanical injury, we have now asked: do Schwann cells also activate a c-Jun dependent neuron-supportive programme in inherited demyelinating disease? We tested this by using the C3 mouse model of Charcot–Marie–Tooth disease type 1A. In line with our previous findings in humans with Charcot–Marie–Tooth disease type 1A, we found that Schwann cell c-Jun was elevated in (uninjured) nerves of C3 mice. We determined the impact of this c-Jun activation by comparing C3 mice with double mutant mice, namely C3 mice in which c-Jun had been conditionally inactivated in Schwann cells (C3/Schwann cell-c-Jun−/− mice), using sensory-motor tests and electrophysiological measurements, and by counting axons in proximal and distal nerves. The results indicate that c-Jun elevation in the Schwann cells of C3 nerves serves to prevent loss of myelinated sensory axons, particularly in distal nerves, improve behavioural symptoms, and preserve F-wave persistence. This suggests that Schwann cells have two contrasting functions in Charcot–Marie–Tooth disease type 1A: on the one hand they are the genetic source of

  6. Topographic Cue from Electrospun Scaffolds Regulate Myelin-Related Gene Expressions in Schwann Cells.

    PubMed

    Radhakrishnan, Janani; Kuppuswamy, Ashok Ayyappa; Sethuraman, Swaminathan; Subramanian, Anuradha

    2015-03-01

    Matured Schwann cells play a vital role in promoting regeneration and restoration of functional peripheral nervous tissue. In the present study, two dimensional film, three dimensional random and longitudinally aligned electrospun fibers of poly(lactide-co-glycolide) were used to evaluate the effect of topography on expressions of myelin related genes. The aligned nanofibrous scaffold demonstrated significant increase in Schwann cell adhesion using after 3, 6 and 12 hours of culture compared to the film and random fibers. Cell morphology, degree of orientation and elongation factor evaluated using a scanning electron microscope revealed that cells on aligned scaffold have spindle morphology, whereas cells on random and two dimensional films favor spherical morphology confirming the effect of topography. Significant increase in elongation factor was observed in aligned scaffold as compared to film and random fibers (p < 0.05). The gene expression analysis revealed that aligned scaffold significantly up-regulated the expression of early myelination markers: myelin-associated glycoprotein and myelin protein zero, cell adhesion molecule: neural cadherin, extracellular matrix molecule: neurocan, as well the down-regulation of non-myelinating Schwann cell marker: neural cell adhesion molecule when compared to random and film (p < 0.05). The gene expression patterns of aligned fibers favor myelination of Schwann cells when compared to film and random fibers. Thus, our results demonstrate that the aligned topography of the scaffold promotes maturation of Schwann cells and thereby its myelination to maintain its functionality. PMID:26307833

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

    PubMed

    Love, James M; Shah, Sameer B

    2015-01-01

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

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

    PubMed Central

    Love, James M.; Shah, Sameer B.

    2015-01-01

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

  9. Peptidergic modulation of the membrane potential of the Schwann cell of the squid giant nerve fibre.

    PubMed Central

    Evans, P D; Reale, V; Villegas, J

    1986-01-01

    The effects of a range of neuropeptides were investigated on the membrane potential of the Schwann cells of the giant nerve fibre of the tropical squid. Vasoactive intestinal peptide (VIP) produced a dose-dependent, long-lasting hyperpolarization of the Schwann-cell membrane potential. Among peptides structurally related to VIP, similar effects were produced by peptide histidine isoleucine (PHI) but not by secretin and glucagon. Substance P and somatostatin also hyperpolarized the Schwann-cell membrane potential but via receptor systems distinct from those activated by VIP. Methionine enkephalin ([Met]-enkephalin) blocked the actions of all the above peptides as well as the effects of DL-octopamine and carbachol. The actions of [Met]-enkephalin upon the VIP responses were antagonized by naloxone. VIP produces its effects on the Schwann-cell membrane potential via a receptor system that is independent from those described previously which mediate the effects of carbachol and DL-octopamine. However, VIP can potentiate the effects of the latter systems. The actions of VIP on the Schwann cell are unlikely to be mediated via changes in adenosine 3',5'-cyclic monophosphate (cyclic AMP) levels and are insensitive to changes in the level of extracellular calcium in the superfusate. The actions of VIP are, however, potentiated in the presence of low concentrations of lithium ions suggesting that the VIP receptor may mediate its effects by inducing the hydrolysis of polyphosphatidylinositols in the Schwann-cell membrane. Evidence is presented for the existence of an endogenous VIP-like component in the normal hyperpolarizing action of giant-axon activity on the membrane potential of the Schwann cell. PMID:2435897

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

    SciTech Connect

    Thomas, Stacey L.; Deadwyler, Gail D.; Tang, Jun; Stubbs, Evan B.; Muir, David; Hiatt, Kelly K. . E-mail: George.Devries@med.va.gov

    2006-09-29

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

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

    PubMed Central

    Schulz, Alexander; Kyselyova, Anna; Baader, Stephan L.; Jung, Marie Juliane; Zoch, Ansgar; Mautner, Victor-Felix

    2014-01-01

    Axonal surface proteins encompass a group of heterogeneous molecules, which exert a variety of different functions in the highly interdependent relationship between axons and Schwann cells. We recently revealed that the tumour suppressor protein merlin, mutated in the hereditary tumour syndrome neurofibromatosis type 2, impacts significantly on axon structure maintenance in the peripheral nervous system. We now report on a role of neuronal merlin in the regulation of the axonal surface protein neuregulin 1 important for modulating Schwann cell differentiation and myelination. Specifically, neuregulin 1 type III expression is reduced in sciatic nerve tissue of neuron-specific knockout animals as well as in biopsies from seven patients with neurofibromatosis type 2. In vitro experiments performed on both the P19 neuronal cell line and primary dorsal root ganglion cells demonstrate the influence of merlin on neuregulin 1 type III expression. Moreover, expression of ERBB2, a Schwann cell receptor for neuregulin 1 ligands is increased in nerve tissue of both neuron-specific merlin knockout animals and patients with neurofibromatosis type 2, demonstrating for the first time that axonal merlin indirectly regulates Schwann cell behaviour. Collectively, we have identified that neuronally expressed merlin can influence Schwann cell activity in a cell-extrinsic manner. PMID:24309211

  12. S-100 protein in soft-tissue tumors derived from Schwann cells and melanocytes.

    PubMed Central

    Stefansson, K.; Wollmann, R.; Jerkovic, M.

    1982-01-01

    In soft tissues outside the central nervous system, S-100 protein is found normally only in Schwann cells. Using the peroxidase-antiperoxidase immunohistochemical method S-100 was also found in tumors derived from Schwann cells and melanocytes, including neurofibromas, neurilemomas, granular cell myoblastomas, cutaneous nevi, and malignant melanomas. S-100 was not detected in malignant Schwannomas, neuroblastomas, oat cell carcinomas, medullary carcinomas of the thyroid, paragangliomas, or meningiomas. S-100 was also absent from neoplasms of soft tissues not usually considered to arise from cells of neural crest origin. S-100 appears to be a useful marker for identifying neoplasms derived from Schwann cells and melanocytes. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:6278936

  13. SncRNA715 Inhibits Schwann Cell Myelin Basic Protein Synthesis

    PubMed Central

    Müller, Christina; Hochhaus, Nina M.; Fontana, Xavier; Luhmann, Heiko J.; White, Robin

    2015-01-01

    Myelin basic proteins (MBP) are major constituents of the myelin sheath in the central nervous system (CNS) and the peripheral nervous system (PNS). In the CNS Mbp translation occurs locally at the axon-glial contact site in a neuronal activity-dependent manner. Recently we identified the small non-coding RNA 715 (sncRNA715) as a key inhibitor of Mbp translation during transport in oligodendrocytes. Mbp mRNA localization in Schwann cells has been observed, but has not been investigated in much detail. Here we could confirm translational repression of Mbp mRNA in Schwann cells. We show that sncRNA715 is expressed and its levels correlate inversely with MBP in cultured Schwann cells and in the sciatic nerve in vivo. Furthermore we could reduce MBP protein levels in cultured Schwann cells by increasing the levels of the inhibitory sncRNA715. Our findings suggest similarities in sncRNA715-mediated translational repression of Mbp mRNA in oligodendrocytes and Schwann cells. PMID:26317513

  14. SncRNA715 Inhibits Schwann Cell Myelin Basic Protein Synthesis.

    PubMed

    Müller, Christina; Hochhaus, Nina M; Fontana, Xavier; Luhmann, Heiko J; White, Robin

    2015-01-01

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

  15. Survival, proliferation and morphological specialization of mouse Schwann cells in a serum-free, fully defined medium.

    PubMed

    Skaper, S D; Manthorpe, M; Adler, R; Varon, S

    1980-10-01

    Neonatal mouse dorsal root ganglionic (DRG) cell dissociates were cultured in a synthetic medium with horse serum or the serum-free supplement N1 (insulin, transferrin, progesterone, putrescine, selenium). Serum-supplemented cultures with added nerve growth factor (NGF) yielded neurons, small flat and spindle cells (Schwann) and large flat cells (fibroblastic elements). However, in serum-free, N1-supplemented medium plus exogenous NGF, neurons and Schwann cells predominated, with very few large flat cells. In the N1 medium most Schwann cells assumed a typical spindle shape and were associated with neuritic processes when neurons were present. Upon addition of serum, virtually all of the Schwann cells appeared to abandon physical contact with the neurites and develop a more flattened morphology. In N1 medium without NGF (no neurites), most Schwann cells still assumed a spindle shape and formed characteristic chain-like associations. Autoradiographic techniques, as well as numerical analyses, demonstrated that in N1 medium Schwann cells were able to proliferate when associated with neurites but only slightly so in their absence. These Schwann cells showed a marked increase in proliferation when serum was added regardless of the presence or absence of neurites. The above observations may provide a basis for the preparation of purified Schwann cells, alone or in combination with their neurons.

  16. Gliomedin mediates Schwann cell-axon interaction and the molecular assembly of the nodes of Ranvier.

    PubMed

    Eshed, Yael; Feinberg, Konstantin; Poliak, Sebastian; Sabanay, Helena; Sarig-Nadir, Offra; Spiegel, Ivo; Bermingham, John R; Peles, Elior

    2005-07-21

    Accumulation of Na(+) channels at the nodes of Ranvier is a prerequisite for saltatory conduction. In peripheral nerves, clustering of these channels along the axolemma is regulated by myelinating Schwann cells through a yet unknown mechanism. We report the identification of gliomedin, a glial ligand for neurofascin and NrCAM, two axonal immunoglobulin cell adhesion molecules that are associated with Na+ channels at the nodes of Ranvier. Gliomedin is expressed by myelinating Schwann cells and accumulates at the edges of each myelin segment during development, where it aligns with the forming nodes. Eliminating the expression of gliomedin by RNAi, or the addition of a soluble extracellular domain of neurofascin to myelinating cultures, which caused the redistribution of gliomedin along the internodes, abolished node formation. Furthermore, a soluble gliomedin induced nodal-like clusters of Na+ channels in the absence of Schwann cells. We propose that gliomedin provides a glial cue for the formation of peripheral nodes of Ranvier. PMID:16039564

  17. Data supporting Arf6 regulation of Schwann cell differentiation and myelination.

    PubMed

    Torii, Tomohiro; Miyamoto, Yuki; Yamamoto, Masahiro; Ohbuchi, Katsuya; Tsumura, Hideki; Kawahara, Kazuko; Tanoue, Akito; Sakagami, Hiroyuki; Yamauchi, Junji

    2015-12-01

    The data is related to the research article entitled "Arf6 mediates Schwann cell differentiation and myelination" [1]. To further investigate the role of Arf6 in promoting myelination by Schwann cells in vivo, we have characterized an another line (#2) of small-hairpin (sh)RNA transgenic mice targeting Arf6. The number of transgenes per one allele in this line was very low (2 transgenes), comparing with high copies in the previous line (#1, 20 transgenes) [1]. In 4 days of neonatal age, transgenic mice exhibited decreased myelin thickness; however, decreased levels were not as much as those in the line #1, likely depending on transgene copy number. In 60-day-old mice, the difference became smaller. On the other hand, transgene׳s effect was not related to cell proliferation and apoptosis. These data support the key role of Arf6 in Schwann cell myelination, especially in the initiation.

  18. Transplantation of human telomerase reverse transcriptase gene-transfected Schwann cells for repairing spinal cord injury

    PubMed Central

    Zhang, Shu-quan; Wu, Min-fei; Liu, Jia-bei; Li, Ye; Zhu, Qing-san; Gu, Rui

    2015-01-01

    Transfection of the human telomerase reverse transcriptase (hTERT) gene has been shown to increase cell proliferation and enhance tissue repair. In the present study, hTERT was transfected into rat Schwann cells. A rat model of acute spinal cord injury was established by the modified free-falling method. Retrovirus PLXSN was injected at the site of spinal cord injury as a vector to mediate hTERT gene-transfected Schwann cells (1 × 1010/L; 10 μL) or Schwann cells (1 × 1010/L; 10 μL) without hTERT gene transfection. Between 1 and 4 weeks after model establishment, motor function of the lower limb improved in the hTERT-transfected group compared with the group with non-transfected Schwann cells. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and reverse transcription-polymerase chain reaction results revealed that the number of apoptotic cells, and gene expression of aquaporin 4/9 and matrix metalloproteinase 9/2 decreased at the site of injury in both groups; however, the effect improved in the hTERT-transfected group compared with the Schwann cells without hTERT transfection group. Hematoxylin and eosin staining, PKH26 fluorescent labeling, and electrophysiological testing demonstrated that compared with the non-transfected group, spinal cord cavity and motor and sensory evoked potential latencies were reduced, while the number of PKH26-positive cells and the motor and sensory evoked potential amplitude increased at the site of injury in the hTERT-transfected group. These findings suggest that transplantation of hTERT gene-transfected Schwann cells repairs the structure and function of the injured spinal cord. PMID:26889196

  19. From the cell of Schwann to schwannoma--a century's fruition.

    PubMed

    Sonig, Ashish; Gandhi, Viraj; Nanda, Anil

    2014-11-01

    The word "schwannoma" is pervasive throughout the neurosurgical community. However, little is known about the origin of the cell of "Schwann cell," the manifestation of the tumor's nomenclature, or the prominent physicians who studied its etiopathogenesis. Schwann was a founding father of cellular theory and one of the greatest scientists of the 19th century. He not only proposed cell theory but also discovered the "secondary" nerve cell and hypothesized its possible function in myelination. It took a century to confirm Schwann's hypothesis. In 1954, Geren, aided by the electron microscope, demonstrated that the cell of Schwann is responsible for nerve myelination. Concurrently, researchers worked to understand the etiology and pathogenesis of peripheral nerve neoplasms. Several attempts were made; Older, Virchow, and von Recklinghausen were the first pioneers who worked on the classification of these neoplasms. However, Masson first used the word "schwannoma" to describe peripheral nerve neoplasms other than neuromas. His French colleague Nageotte used the term "peripheral-glioma" to denote these tumors. These schwannomas were considered to have a malignant course. In 1932, Penfield attempted to classify peripheral nerve neoplasms into 3 categories: peripheral fibroblastoma, peripheral glioma, and neurofibroma of von Recklinghausen. He classified "Verocay's neurinoma," "Masson's schwannoma," and "cerebellopontine angle" tumors as perineural fibroblastoma. He believed that these tumors have a non-nerve cell, non-Schwann cell origin. He classified the tumors arising from the Schwann cell sheath as peripheral gliomas and articulated, "If any tumors are to be called schwannomas, these should be." The neurofibroma of von Recklinghausen was recognized as a separate entity, as described by von Recklinghausen himself. Murray and Stout proposed that schwannomas are essentially benign in nature clarifying the abstruseness of the benign or malignant nature of schwannoma

  20. From the cell of Schwann to schwannoma--a century's fruition.

    PubMed

    Sonig, Ashish; Gandhi, Viraj; Nanda, Anil

    2014-11-01

    The word "schwannoma" is pervasive throughout the neurosurgical community. However, little is known about the origin of the cell of "Schwann cell," the manifestation of the tumor's nomenclature, or the prominent physicians who studied its etiopathogenesis. Schwann was a founding father of cellular theory and one of the greatest scientists of the 19th century. He not only proposed cell theory but also discovered the "secondary" nerve cell and hypothesized its possible function in myelination. It took a century to confirm Schwann's hypothesis. In 1954, Geren, aided by the electron microscope, demonstrated that the cell of Schwann is responsible for nerve myelination. Concurrently, researchers worked to understand the etiology and pathogenesis of peripheral nerve neoplasms. Several attempts were made; Older, Virchow, and von Recklinghausen were the first pioneers who worked on the classification of these neoplasms. However, Masson first used the word "schwannoma" to describe peripheral nerve neoplasms other than neuromas. His French colleague Nageotte used the term "peripheral-glioma" to denote these tumors. These schwannomas were considered to have a malignant course. In 1932, Penfield attempted to classify peripheral nerve neoplasms into 3 categories: peripheral fibroblastoma, peripheral glioma, and neurofibroma of von Recklinghausen. He classified "Verocay's neurinoma," "Masson's schwannoma," and "cerebellopontine angle" tumors as perineural fibroblastoma. He believed that these tumors have a non-nerve cell, non-Schwann cell origin. He classified the tumors arising from the Schwann cell sheath as peripheral gliomas and articulated, "If any tumors are to be called schwannomas, these should be." The neurofibroma of von Recklinghausen was recognized as a separate entity, as described by von Recklinghausen himself. Murray and Stout proposed that schwannomas are essentially benign in nature clarifying the abstruseness of the benign or malignant nature of schwannoma.

  1. Immortalized Human Schwann Cell Lines Derived From Tumors of Schwannomatosis Patients

    PubMed Central

    Ostrow, Kimberly Laskie; Donaldson, Katelyn; Blakeley, Jaishri; Belzberg, Allan; Hoke, Ahmet

    2015-01-01

    Schwannomatosis, a rare form of neurofibromatosis, is characterized predominantly by multiple, often painful, schwannomas throughout the peripheral nervous system. The current standard of care for schwannomatosis is surgical resection. A major obstacle to schwannomatosis research is the lack of robust tumor cell lines. There is a great need for mechanistic and drug discovery studies of schwannomatosis, yet appropriate tools are not currently available. Schwannomatosis tumors are difficult to grow in culture as they survive only a few passages before senescence. Our lab has extensive experience in establishing primary and immortalized human Schwann cell cultures from normal tissue that retain their phenotypes after immortalization. Therefore we took on the challenge of creating immortalized human Schwann cell lines derived from tumors from schwannomatosis patients. We have established and fully characterized 2 schwannomatosis cell lines from 2 separate patients using SV40 virus large T antigen. One patient reported pain and the other did not. The schwannomatosis cell lines were stained with S100B antibodies to confirm Schwann cell identity. The schwannomatosis cells also expressed the Schwann cell markers, p75NTR, S100B, and NGF after multiple passages. Cell morphology was retained following multiple passaging and freeze/ thaw cycles. Gene expression microarray analysis was used to compare the cell lines with their respective parent tumors. No differences in key genes were detected, with the exception that several cell cycle regulators were upregulated in the schwannomatosis cell lines when compared to their parent tumors. This upregulation was apparently a product of cell culturing, as the schwannomatosis cells exhibited the same expression pattern of cell cycle regulatory genes as normal primary human Schwann cells. Cell growth was also similar between normal primary and immortalized tumor cells in culture. Accurate cell lines derived directly from human tumors

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

    PubMed Central

    Peng, Chuan-gang; Zhang, Shu-quan; Wu, Min-fei; Lv, Yang; Wu, Dan-kai; Yang, Qi; Gu, Rui

    2015-01-01

    Schwann cell transplantation and hyperbaric oxygen therapy each promote recovery from spinal cord injury, but it remains unclear whether their combination improves therapeutic results more than monotherapy. To investigate this, we used Schwann cell transplantation via the tail vein, hyperbaric oxygen therapy, or their combination, in rat models of spinal cord contusion injury. The combined treatment was more effective in improving hindlimb motor function than either treatment alone; injured spinal tissue showed a greater number of neurite-like structures in the injured spinal tissue, somatosensory and motor evoked potential latencies were notably shorter, and their amplitudes greater, after combination therapy than after monotherapy. These findings indicate that Schwann cell transplantation combined with hyperbaric oxygen therapy is more effective than either treatment alone in promoting the recovery of spinal cord in rats after injury. PMID:26604910

  3. Specific inhibition of secreted NRG1 types I-II by heparin enhances Schwann Cell myelination.

    PubMed

    Eshed-Eisenbach, Yael; Gordon, Aaron; Sukhanov, Natalya; Peles, Elior

    2016-07-01

    Primary cultures of mixed neuron and Schwann cells prepared from dorsal root ganglia (DRG) are extensively used as a model to study myelination. These dissociated DRG cultures have the particular advantage of bypassing the difficulty in purifying mouse Schwann cells, which is often required when using mutant mice. However, the drawback of this experimental system is that it yields low amounts of myelin. Here we report a simple and efficient method to enhance myelination in vitro. We show that the addition of heparin or low molecular weight heparin to mixed DRG cultures markedly increases Schwann cells myelination. The myelin promoting activity of heparin results from specific inhibition of the soluble immunoglobulin (Ig)-containing isoforms of neuregulin 1 (i.e., NRG1 types I and II) that negatively regulates myelination. Heparin supplement provides a robust and reproducible method to increase myelination in a simple and commonly used culture system. GLIA 2016;64:1227-1234.

  4. The role of cyclic nucleotides in modulation of the membrane potential of the Schwann cell of squid giant nerve fibre.

    PubMed Central

    Evans, P D; Reale, V; Villegas, J

    1985-01-01

    The role of cyclic nucleotides in mediating the effects of nicotine cholinergic receptors has been investigated in Schwann cells of the giant nerve fibre of the squid. Elevation of cyclic AMP levels in this preparation by means of the phosphodiesterase inhibitor, theophylline, by the diterpene adenylate cyclase activator, forskolin, and by cyclic nucleotide analogues mimics the action of activating the nicotinic cholinergic receptors in producing a long-lasting hyperpolarization of the membrane potential of the Schwann cell. Theophylline and forskolin also potentiate the effects of carbachol and of neural stimulation on the Schwann cell. The results suggest that the nicotinic receptor of the squid Schwann cell is likely to mediate its effects via a mechanism that activates adenylate cyclase. The results are discussed in terms of the role of cyclic AMP in the complex multistep interaction between the giant axon of the squid and its surrounding Schwann-cell layer. PMID:2991504

  5. The role of cyclic nucleotides in modulation of the membrane potential of the Schwann cell of squid giant nerve fibre.

    PubMed

    Evans, P D; Reale, V; Villegas, J

    1985-06-01

    The role of cyclic nucleotides in mediating the effects of nicotine cholinergic receptors has been investigated in Schwann cells of the giant nerve fibre of the squid. Elevation of cyclic AMP levels in this preparation by means of the phosphodiesterase inhibitor, theophylline, by the diterpene adenylate cyclase activator, forskolin, and by cyclic nucleotide analogues mimics the action of activating the nicotinic cholinergic receptors in producing a long-lasting hyperpolarization of the membrane potential of the Schwann cell. Theophylline and forskolin also potentiate the effects of carbachol and of neural stimulation on the Schwann cell. The results suggest that the nicotinic receptor of the squid Schwann cell is likely to mediate its effects via a mechanism that activates adenylate cyclase. The results are discussed in terms of the role of cyclic AMP in the complex multistep interaction between the giant axon of the squid and its surrounding Schwann-cell layer.

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

    PubMed

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

    2012-10-15

    Bone marrow mesenchymal stem cells were isolated from New Zealand white rabbits, culture-expanded and differentiated into Schwann cell-like cells. Autologous platelet-rich plasma and Schwann cell-like cells were mixed in suspension at a density of 1 × 10(6) cells/mL, prior to introduction into a poly (lactic-co-glycolic acid) conduit. Fabricated tissue-engineered nerves were implanted into rabbits to bridge 10 mm sciatic nerve defects (platelet-rich plasma group). Controls were established using fibrin as the seeding matrix for Schwann cell-like cells at identical density to construct tissue-engineered nerves (fibrin group). Twelve weeks after implantation, toluidine blue staining and scanning electron microscopy were used to demonstrate an increase in the number of regenerating nerve fibers and thickness of the myelin sheath in the platelet-rich plasma group compared with the fibrin group. Fluoro-gold retrograde labeling revealed that the number of Fluoro-gold-positive neurons in the dorsal root ganglion and the spinal cord anterior horn was greater in the platelet-rich plasma group than in the fibrin group. Electrophysiological examination confirmed that compound muscle action potential and nerve conduction velocity were superior in the platelet-rich plasma group compared with the fibrin group. These results indicate that autologous platelet-rich plasma gel can effectively serve as a seeding matrix for Schwann cell-like cells to construct tissue-engineered nerves to promote peripheral nerve regeneration. PMID:25538751

  7. Production of Plasminogen Activator in Cultures of Superior Cervical Ganglia and Isolated Schwann Cells

    NASA Astrophysics Data System (ADS)

    Alvarez-Buylla, Arturo; Valinsky, Jay E.

    1985-05-01

    Plasminogen activator has been implicated in tissue remodeling and cell migration during embryogenesis. In the developing nervous system, these processes are evident in the migration of neurons, axonal extension, Schwann cell migration, and the ensheathment and myelination of nerves. We have studied the production of plasminogen activator in cultures of superior cervical ganglia under conditions in which both neurons and glia are present. We have found that a principal source of the enzyme in these cultures is the glial cells and that the enzyme could not be detected at the growing tips of neurites. Plasminogen activator is also produced by Schwann cells isolated from neonatal rat sciatic nerve. The production of the enzyme by these cells is stimulated 6- to 10-fold by cholera toxin. Isolated Schwann cells and glial cells in the ganglion explant cultures produce the tissue form of plasminogen activator, a form of the enzyme not often found in nonmalignant cells. Preliminary experiments suggest that neuronal-glial interactions may regulate enzyme production by Schwann cells.

  8. Schwann cell myelination of the myelin deficient rat spinal cord following X-irradiation

    SciTech Connect

    Duncan, I.D.; Hammang, J.P.; Gilmore, S.A.

    1988-01-01

    The myelin-deficient (md) rat is an X-linked myelin mutant that has an abnormality of oligodendrocytes and a severe paucity of myelin throughout the CNS. This lack of myelin makes it an ideal model in which to study the cellular interactions that occur when foreign myelinating cells are induced in the milieu of this nonmyelinated CNS. In this study, Schwann cells were induced in the lumbosacral spinal cord by exposing it to radiation, a technique demonstrated repeatedly in other nonmutant strains of rats. Md rats and their age-matched littermates were irradiated (3,000 to 4,000 R) at 3 days of age and perfused 16-22 days later after pulse labeling with tritiated thymidine. In the md rat, Schwann cell invasion progressed from the area of the spinal cord-nerve root junction and extended into the dorsal columns and adjacent gray matter. Autoradiographic evidence revealed that many of these cells incorporated 3H-thymidine, indicating that they were undergoing proliferation. Ultrastructural observations showed that there was an integration of these intraspinal Schwann cells with the cells normally occurring in this environment, i.e., oligodendrocytes and astrocytes. The extent of migration and division of Schwann cells, as well as their interactions with glial cells, were similar to those seen in the nonmutant irradiated littermates. These studies provide conclusive evidence that md rat axons are normal with respect to their ability to provide trophic and mitogenic signals to myelinating cells.

  9. M2 muscarinic receptor activation regulates Schwann cell differentiation and myelin organization.

    PubMed

    Uggenti, Carolina; De Stefano, M Egle; Costantino, Michele; Loreti, Simona; Pisano, Annalinda; Avallone, Bice; Talora, Claudio; Magnaghi, Valerio; Tata, Ada Maria

    2014-07-01

    Glial cells express acetylcholine receptors. In particular, rat Schwann cells express different muscarinic receptor subtypes, the most abundant of which is the M2 subtype. M2 receptor activation causes a reversible arrest of the cell cycle. This negative effect on Schwann cell proliferation suggests that these cells may possibly progress into a differentiating program. In this study we analyzed the in vitro modulation, by the M2 agonist arecaidine, of transcription factors and specific signaling pathways involved in Schwann cell differentiation. The arecaidine-induced M2 receptor activation significantly upregulates transcription factors involved in the promyelinating phase (e.g., Sox10 and Krox20) and downregulates proteins involved in the maintenance of the undifferentiated state (e.g., c-jun, Notch-1, and Jagged-1). Furthermore, arecaidine stimulation significantly increases the expression of myelin proteins, which is accompanied by evident changes in cell morphology, as indicated by electron microscopy analysis, and by substantial cellular re-distribution of actin and cell adhesion molecules. Moreover, ultrastructural and morphometric analyses on sciatic nerves of M2/M4 knockout mice show numerous degenerating axons and clear alterations in myelin organization compared with wild-type mice. Therefore, our data demonstrate that acetylcholine mediates axon-glia cross talk, favoring Schwann cell progression into a differentiated myelinating phenotype and contributing to compact myelin organization.

  10. Specific asparagine-linked oligosaccharides are not required for certain neuron-neuron and neuron-Schwann cell interactions

    PubMed Central

    1986-01-01

    To determine whether specific asparagine-linked (N-linked) oligosaccharides present in cell surface glycoproteins are required for cell-cell interactions within the peripheral nervous system, we have used castanospermine to inhibit maturation of N-linked sugars in cell cultures of neurons or neurons plus Schwann cells. Maximally 10-15% of the N-linked oligosaccharides on neuronal proteins have normal structure when cells are cultured in the presence of 250 micrograms/ml castanospermine; the remaining oligosaccharides are present as immature carbohydrate chains not normally found in these glycoproteins. Although cultures were treated for 2 wk with castanospermine, cells always remained viable and appeared healthy. We have analyzed several biological responses of embryonic dorsal root ganglion neurons, with or without added purified populations of Schwann cells, in the presence of castanospermine. We have observed that a normal complement of mature, N- linked sugars are not required for neurite outgrowth, neuron-Schwann cell adhesion, neuron-induced Schwann cell proliferation, or ensheathment of neurites by Schwann cells. Treatment of neuronal cultures with castanospermine increases the propensity of neurites to fasciculate. Extracellular matrix deposition by Schwann cells and myelination of neurons by Schwann cells are greatly diminished in the presence of castanospermine as assayed by electron microscopy and immunocytochemistry, suggesting that specific N-linked oligosaccharides are required for the expression of these cellular functions. PMID:3522602

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

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

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

  14. The NMDA receptor functions independently and as an LRP1 co-receptor to promote Schwann cell survival and migration.

    PubMed

    Mantuano, Elisabetta; Lam, Michael S; Shibayama, Masataka; Campana, W Marie; Gonias, Steven L

    2015-09-15

    NMDA receptors (NMDA-Rs) are ionotropic glutamate receptors, which associate with LDL-receptor-related protein-1 (LRP1) to trigger cell signaling in response to protein ligands in neurons. Here, we demonstrate for the first time that the NMDA-R is expressed by rat Schwann cells and functions independently and with LRP1 to regulate Schwann cell physiology. The NR1 (encoded by GRIN1) and NR2b (encoded by GRIN2B) NMDA-R subunits were expressed by cultured Schwann cells and upregulated in sciatic nerves following crush injury. The ability of LRP1 ligands to activate ERK1/2 (also known as MAPK3 and MAPK1, respectively) and promote Schwann cell migration required the NMDA-R. NR1 gene silencing compromised Schwann cell survival. Injection of the LRP1 ligands tissue-type plasminogen activator (tPA, also known as PLAT) or MMP9-PEX into crush-injured sciatic nerves activated ERK1/2 in Schwann cells in vivo, and the response was blocked by systemic treatment with the NMDA-R inhibitor MK801. tPA was unique among the LRP1 ligands examined because tPA activated cell signaling and promoted Schwann cell migration by interacting with the NMDA-R independently of LRP1, albeit with delayed kinetics. These results define the NMDA-R as a Schwann cell signaling receptor for protein ligands and a major regulator of Schwann cell physiology, which may be particularly important in peripheral nervous system (PNS) injury. PMID:26272917

  15. The NMDA receptor functions independently and as an LRP1 co-receptor to promote Schwann cell survival and migration

    PubMed Central

    Mantuano, Elisabetta; Lam, Michael S.; Shibayama, Masataka; Campana, W. Marie; Gonias, Steven L.

    2015-01-01

    ABSTRACT NMDA receptors (NMDA-Rs) are ionotropic glutamate receptors, which associate with LDL-receptor-related protein-1 (LRP1) to trigger cell signaling in response to protein ligands in neurons. Here, we demonstrate for the first time that the NMDA-R is expressed by rat Schwann cells and functions independently and with LRP1 to regulate Schwann cell physiology. The NR1 (encoded by GRIN1) and NR2b (encoded by GRIN2B) NMDA-R subunits were expressed by cultured Schwann cells and upregulated in sciatic nerves following crush injury. The ability of LRP1 ligands to activate ERK1/2 (also known as MAPK3 and MAPK1, respectively) and promote Schwann cell migration required the NMDA-R. NR1 gene silencing compromised Schwann cell survival. Injection of the LRP1 ligands tissue-type plasminogen activator (tPA, also known as PLAT) or MMP9-PEX into crush-injured sciatic nerves activated ERK1/2 in Schwann cells in vivo, and the response was blocked by systemic treatment with the NMDA-R inhibitor MK801. tPA was unique among the LRP1 ligands examined because tPA activated cell signaling and promoted Schwann cell migration by interacting with the NMDA-R independently of LRP1, albeit with delayed kinetics. These results define the NMDA-R as a Schwann cell signaling receptor for protein ligands and a major regulator of Schwann cell physiology, which may be particularly important in peripheral nervous system (PNS) injury. PMID:26272917

  16. Nrg1/ErbB signaling networks in Schwann cell development and myelination

    PubMed Central

    Newbern, Jason; Birchmeier, Carmen

    2010-01-01

    Neuregulin-1 (Nrg1) provides a key axonal signal that regulates Schwann cell proliferation, migration and myelination through binding to ErbB2/3 receptors. The analysis of a number of genetic models has unmasked fundamental mechanisms underlying the specificity of the Nrg1/ErbB signaling axis. Differential expression of Nrg1 isoforms, Nrg1 processing, and ErbB receptor localization and trafficking represent important regulatory themes in the control of Nrg1/ErbB function. Nrg1 binding to ErbB2/3 receptors results in the activation of intracellular signal transduction pathways that initiate changes in Schwann cell behavior. Here, we review data that has defined the role of key Nrg1/ErbB signaling components like Shp2, ERK1/2, FAK, Rac1/Cdc42 and calcineurin in development of the Schwann cell lineage in vivo. Many of these regulators receive converging signals from other cues that are provided by Notch, integrin or G-protein coupled receptors. Signaling by multiple extracellular factors may act as key modifiers and allow Schwann cells at different developmental stages to respond in distinct manners to the Nrg1/ErbB signal. PMID:20832498

  17. Differentiation of adipose-derived stem cells into Schwann-like cells: fetal bovine serum or human serum?

    PubMed Central

    Younesi, Elham; Hashemitabar, Mahmoud; Azandeh, Seyyed Saeed; Bijannejad, Dariush; Bahreini, Amin

    2015-01-01

    Access to autologous Schwann cells is limited due to lack of donor site and its difficult isolation and culture. Therefore, one of the possible ways to obtain to Schwann cells is to differentiate mesenchymal stem cells into glial pathway using various materials and protocols. The aim of this study was to compare the effects of fetal bovine serum and human serum on Schwann cell differentiation of adipose-derived stem cells to choose the best serum for use in future research. For this purpose, after isolation of human adipose-derived stem cells, it was characterized and differentiated into Schwann cell lineage using two protocols which one of them contained fetal bovine serum and the other human serum. At the end, morphological evaluation declared an increased detachment of cells in response to human serum. On the other side, immunocytochemistry showed that there was a significant increase in the number of cells expressing glial fibrillary acidic proteins and S100 in fetal bovine serum-treated group when compared to human serum-treated one (P<0.05). It was concluded that fetal bovine serum was more effective than allogeneic human serum in Schwann cell differentiation of adipose-derived stem cells. PMID:26417476

  18. Schwann Cells Metabolize Extracellular 2',3'-cAMP to 2'-AMP.

    PubMed

    Verrier, Jonathan D; Kochanek, Patrick M; Jackson, Edwin K

    2015-08-01

    The 3',5'-cAMP-adenosine pathway (3',5'-cAMP→5'-AMP→adenosine) and the 2',3'-cAMP-adenosine pathway (2',3'-cAMP→2'-AMP/3'-AMP→adenosine) are active in the brain. Oligodendrocytes participate in the brain 2',3'-cAMP-adenosine pathway via their robust expression of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase; converts 2',3'-cAMP to 2'-AMP). Because Schwann cells also express CNPase, it is conceivable that the 2',3'-cAMP-adenosine pathway exists in the peripheral nervous system. To test this and to compare the 2',3'-cAMP-adenosine pathway to the 3',5'-cAMP-adenosine pathway in Schwann cells, we examined the metabolism of 2',3'-cAMP, 2'-AMP, 3'-AMP, 3',5'-cAMP, and 5'-AMP in primary rat Schwann cells in culture. Addition of 2',3'-cAMP (3, 10, and 30 µM) to Schwann cells increased levels of 2'-AMP in the medium from 0.006 ± 0.002 to 21 ± 2, 70 ± 3, and 187 ± 10 nM/µg protein, respectively; in contrast, Schwann cells had little ability to convert 2',3'-cAMP to 3'-AMP or 3',5'-cAMP to either 3'-AMP or 5'-AMP. Although Schwann cells slightly converted 2',3'-cAMP and 2'-AMP to adenosine, they did so at very modest rates (e.g., 5- and 3-fold, respectively, more slowly compared with our previously reported studies in oligodendrocytes). Using transected myelinated rat sciatic nerves in culture medium, we observed a time-related increase in endogenous intracellular 2',3'-cAMP and extracellular 2'-AMP. These findings indicate that Schwann cells do not have a robust 3',5'-cAMP-adenosine pathway but do have a 2',3'-cAMP-adenosine pathway; however, because the pathway mostly involves 2'-AMP formation rather than 3'-AMP, and because the conversion of 2'-AMP to adenosine is slow, metabolism of 2',3'-cAMP mostly results in the accumulation of 2'-AMP. Accumulation of 2'-AMP in peripheral nerves postinjury could have pathophysiological consequences. PMID:25998049

  19. [Theodor Schwann and reductionism].

    PubMed

    Hayashi, M

    1992-01-01

    In this article I have examined the cell theory of T. Schwann and considered whether Schwann is to be called a reductionist. Schwann paid more attention to the development of cells rather than to the structure of them. That was because he intended to establish the unified theory of organisms which can be used to explain the regularity of the development. Schwann assumed the unteleological force of cell development, regarded physical method as the ideal method of science, and used the analogy between cell development and crystal development. But he did not identify organic forces with unorganic forces and intended to certify the unity of organic world. So it is true that Schwann introduced physical method to life science, but reduction of biological theory to physico-chemical theory has little to do with him. PMID:11639601

  20. [Theodor Schwann and reductionism].

    PubMed

    Hayashi, M

    1992-01-01

    In this article I have examined the cell theory of T. Schwann and considered whether Schwann is to be called a reductionist. Schwann paid more attention to the development of cells rather than to the structure of them. That was because he intended to establish the unified theory of organisms which can be used to explain the regularity of the development. Schwann assumed the unteleological force of cell development, regarded physical method as the ideal method of science, and used the analogy between cell development and crystal development. But he did not identify organic forces with unorganic forces and intended to certify the unity of organic world. So it is true that Schwann introduced physical method to life science, but reduction of biological theory to physico-chemical theory has little to do with him.

  1. Axon-Schwann cell interaction in degenerating and regenerating peripheral nerve

    SciTech Connect

    Pellegrino, R.G.

    1984-01-01

    Severance of a peripheral nerve stimulates a characteristic sequence of events in the distal stump, including the dissolution of axons and myelin and the proliferation of Schwann cells within their basal lamina. The first part of this thesis employs the cat tibial nerve to examine the relationship between the spatio-temporal pattern of Schwann cell mitosis, loss of the structural and functional properties of axolemma, synthesis of P/sub 0/, the major myelin glycoprotein, and the clearance of morphological myelin. Induction of S phase was measured by determining the uptake of /sup 3/H thymidine into trichloroacetic acid (TCA) precipitates following a 3 hour in vitro incubation in Krebs-Ringers buffer containing /sup 3/H thymidine. Nerve transection stimulated a monophasic increase in /sup 3/H thymidine uptake that peaked at 4 days post-transection throughout an 80 mm length of distal stump. Light microscope autoradiography revealed prominent incorporation into Schwann cells of myelinated fibers. Nerve transection also produced dramatic changes in the intrafascicular binding of /sup 3/H STX which binds to voltage-sensitive sodium channels STX binding fell precipitously to 20% of normal at 4 days post-transection, concurrent with the peak of /sup 3/H thymidine uptake. In conclusion, these studies suggest: (a) Schwann cells divide more or less contemporaneously throughout the distal stump; (b) changes in axons rather than myelin are likely to stimulate the Schwann cell to divide; (c) mitosis regulates other events during Wallerian degeneration, including myelin degeneration and the clearance of sodium channels from nodal axolemma.

  2. Hydrogen sulfide is essential for Schwann cell responses to peripheral nerve injury.

    PubMed

    Park, Byung Sun; Kim, Hyun-Wook; Rhyu, Im Joo; Park, Chan; Yeo, Seung Geun; Huh, Youngbuhm; Jeong, Na Young; Jung, Junyang

    2015-01-01

    Hydrogen sulfide (H2 S) functions as a physiological gas transmitter in both normal and pathophysiological cellular events. H2 S is produced from substances by three enzymes: cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (MST). In human tissues, these enzymes are involved in tissue-specific biochemical pathways for H2 S production. For example, CBS and cysteine aminotransferase/MST are present in the brain, but CSE is not. Thus, we examined the expression of H2 S production-related enzymes in peripheral nerves. Here, we found that CSE and MST/cysteine aminotransferase, but not CBS, were present in normal peripheral nerves. In addition, injured sciatic nerves in vivo up-regulated CSE in Schwann cells during Wallerian degeneration (WD); however, CSE was not up-regulated in peripheral axons. Using an ex vivo sciatic nerve explant culture, we found that the inhibition of H2 S production broadly prevented the process of nerve degeneration, including myelin fragmentation, axonal degradation, Schwann cell dedifferentiation, and Schwann cell proliferation in vitro and in vivo. Thus, these results indicate that H2 S signaling is essential for Schwann cell responses to peripheral nerve injury. Hydrogen sulfide (H2 S) functions as a physiological gas transmitter in both normal and pathophysiological cellular events. H2 S is produced from cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE), and 3-mercaptopyruvate sulfur transferase (MST). Here, we found that CSE and MST/CAT were present in normal peripheral nerves. Injured static nerves in vivo up-regulated CSE in Schwann cells during Wallerian degeneration, but CSE was not up-regulated in peripheral axons.

  3. Cytotoxic effects of ZnO hierarchical architectures on RSC96 Schwann cells

    NASA Astrophysics Data System (ADS)

    Yin, Yixia; Lin, Qiang; Sun, Haiming; Chen, Dan; Wu, Qingzhi; Chen, Xiaohui; Li, Shipu

    2012-08-01

    The alteration in intracellular Zn2+ homeostasis is attributed to the generation of intracellular reactive oxygen species, which subsequently results in oxidative damage of organelles and cell apoptosis. In this work, the neurotoxic effects of ZnO hierarchical architectures (nanoparticles and microspheres, the prism-like and flower-like structures) were evaluated through the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay using RSC96 Schwann cells as the model. Cell apoptosis and cell cycle were detected using flow cytometry. The concentration of Zn2+ in the culture media was monitored using atomic absorption spectrometry. The results show that ZnO nanoparticles and microspheres displayed significant cytotoxic effects on RSC96 Schwann cells in dose- and time-dependent manners, whereas no or low cytotoxic effect was observed when the cells were treated with the prism-like and flower-like ZnO. A remarkable cell apoptosis and G2/M cell cycle arrest were observed when RSC96 Schwann cells were exposed to ZnO nanoparticles and microspheres at a dose of 80 μg/mL for 12 h. The time-dependent increase of Zn2+ concentration in the culture media suggests that the cytotoxic effects were associated with the decomposition of ZnO hierarchical architecture and the subsequent release of Zn2+. These results provide new insights into the cytotoxic effects of complex ZnO architectures, which could be prominently dominated by nanoscale building blocks.

  4. Cytotoxic effects of ZnO hierarchical architectures on RSC96 Schwann cells

    PubMed Central

    2012-01-01

    The alteration in intracellular Zn2+ homeostasis is attributed to the generation of intracellular reactive oxygen species, which subsequently results in oxidative damage of organelles and cell apoptosis. In this work, the neurotoxic effects of ZnO hierarchical architectures (nanoparticles and microspheres, the prism-like and flower-like structures) were evaluated through the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay using RSC96 Schwann cells as the model. Cell apoptosis and cell cycle were detected using flow cytometry. The concentration of Zn2+ in the culture media was monitored using atomic absorption spectrometry. The results show that ZnO nanoparticles and microspheres displayed significant cytotoxic effects on RSC96 Schwann cells in dose- and time-dependent manners, whereas no or low cytotoxic effect was observed when the cells were treated with the prism-like and flower-like ZnO. A remarkable cell apoptosis and G2/M cell cycle arrest were observed when RSC96 Schwann cells were exposed to ZnO nanoparticles and microspheres at a dose of 80 μg/mL for 12 h. The time-dependent increase of Zn2+ concentration in the culture media suggests that the cytotoxic effects were associated with the decomposition of ZnO hierarchical architecture and the subsequent release of Zn2+. These results provide new insights into the cytotoxic effects of complex ZnO architectures, which could be prominently dominated by nanoscale building blocks. PMID:22873432

  5. Up-regulation of NF45 correlates with Schwann cell proliferation after sciatic nerve crush.

    PubMed

    Wang, Youhua; Zhou, Shiran; Xu, Hua; Yan, Shixian; Xu, Dawei; Zhang, Yi

    2015-05-01

    Nuclear factor (NF)45 (also known as interleukin enhancer-binding factor (ILF)2), is a transcription factor that interacts with NF90 to regulate gene expression. It has long been implicated in the regulation of cell proliferation. However, the role of NF45 in the process of peripheral nervous system regeneration after injury remains poorly understood. Herein, we investigated the spatiotemporal expression of NF45 in a rat sciatic nerve crush model. We detected the up-regulated expression of NF45 in Schwann cell after sciatic nerve crush. What's more, the expression of the cell proliferation marker proliferating cell nuclear antigen (PCNA) exhibited a similar tendency with that of NF45. In cell cultures, we observed increased expression of NF45 during the process of TNF-α-induced Schwann cell proliferation, whereas the protein level of p21 was down-regulated. Interference of NF45 led to enhanced expression of p21 and also impaired proliferation of Schwan cells. Taken together, our data implicated that NF45 was up-regulated in the sciatic nerve after crush, which was associated with proliferation of Schwann cell.

  6. Schwann cell coculture improves the therapeutic effect of bone marrow stromal cells on recovery in spinal cord-injured mice.

    PubMed

    Xu, Xiaoyun; Geremia, Nicole; Bao, Feng; Pniak, Anna; Rossoni, Melissa; Brown, Arthur

    2011-01-01

    Studies of bone marrow stromal cells (MSCs) transplanted into the spinal cord-injured rat give mixed results: some groups report improved locomotor recovery while others only demonstrate improved histological appearance of the lesion. These studies show no clear correlation between neurological improvements and MSC survival. We examined whether MSC survival in the injured spinal cord could be enhanced by closely matching donor and recipient mice for genetic background and marker gene expression and whether exposure of MSCs to a neural environment (Schwann cells) prior to transplantation would improve their survival or therapeutic effects. Mice underwent a clip compression spinal cord injury at the fourth thoracic level and cell transplantation 7 days later. Despite genetic matching of donors and recipients, MSC survival in the injured spinal cord was very poor (∼1%). However, we noted improved locomotor recovery accompanied by improved histopathological appearance of the lesion in mice receiving MSC grafts. These mice had more white and gray matter sparing, laminin expression, Schwann cell infiltration, and preservation of neurofilament and 5-HT-positive fibers at and below the lesion. There was also decreased collagen and chondroitin sulphate proteoglycan deposition in the scar and macrophage activation in mice that received the MSC grafts. The Schwann cell cocultured MSCs had greater effects than untreated MSCs on all these indices of recovery. Analyses of chemokine and cytokine expression revealed that MSC/Schwann cell cocultures produced far less MCP-1 and IL-6 than MSCs or Schwann cells cultured alone. Thus, transplanted MSCs may improve recovery in spinal cord-injured mice through immunosuppressive effects that can be enhanced by a Schwann cell coculturing step. These results indicate that the temporary presence of MSCs in the injured cord is sufficient to alter the cascade of pathological events that normally occurs after spinal cord injury, generating a

  7. Retinoic acid regulates Schwann cell migration via NEDD9 induction by transcriptional and post-translational mechanisms.

    PubMed

    Latasa, Maria-Jesus; Jiménez-Lara, Ana María; Cosgaya, Jose Miguel

    2016-07-01

    Schwann cell migration is essential during the regenerative response to nerve injury, however, the factors that regulate this phenomenon are not yet clear. Here we describe that retinoic acid (RA), whose production and signaling activity are greatly enhanced during nerve regeneration, increases Schwann cell migration. This is accompanied by the up-regulation of NEDD9, a member of the CAS family of scaffold proteins previously implicated in migratory and invasive behavior in gliomas, melanomas and the neural crest cells from which Schwann cells derive. This RA-induced NEDD9 accumulation is due to augmented mRNA levels, as well as an increase of NEDD9 protein stability. Although all NEDD9 phospho-isoforms present in Schwann cells are induced by the retinoid, the hormone also changes its phosphorylation status, thus altering the ratio between the different isoforms. Silencing NEDD9 in Schwann cells had no effect on basal migratory ability, but completely abrogated RA-induced enhanced migration. Collectively, our results indicate that RA could be a major regulator of Schwann cell migration after nerve injury, thus offering a new insight into peripheral nerve repair. PMID:27085739

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

    PubMed

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

    2014-10-01

    We have developed a biodegradable polymer scaffold made of a polycaprolactone/polylactic acid (PCL/PLA) film. Surface properties such as topography and chemistry have a vital influence on cell-material interactions. Surface modifications of PCL/PLA films were performed using topographical cues and UV-ozone treatment to improve Schwann cell organisation and behaviour. Schwann cell attachment, alignment and proliferation were evaluated on the grooved UV-ozone treated and non-treated films. Solvent casting of the polymer solution on patterned silicon substrates resulted in films with different groove shapes: V (V), sloped (SL) and square (SQ) shapes. Pitted films, with no grooves, were prepared as a negative control. The UV-ozone treatment was performed to increase hydrophilicity. The process specifications for UV-ozone treatment were evaluated and 5 min radiation time and 6 cm distance to the UV source were suggested as the optimal practise. When cultured on grooved films, Schwann cells elongated on the V and SL shape grooves without crossing over, and grew in the direction of the grooves. However, there was less elongation with more crossing over on the SQ shape grooves. The maximum cell length (511 μm) was observed on the treated V-grooved films. The cells cultured on pitted UV-ozone treated surfaces showed random arrangements with no increase in length. We have demonstrated that the synergic effects of physical cues combined with UV-ozone treatment have the potential to enhance Schwann cell morphology and alignment. PMID:25167538

  9. Ras activation of a Rac1 exchange factor, Tiam1, mediates neurotrophin-3-induced Schwann cell migration

    PubMed Central

    Yamauchi, Junji; Miyamoto, Yuki; Tanoue, Akito; Shooter, Eric M.; Chan, Jonah R.

    2005-01-01

    Endogenous neurotrophins positively and negatively regulate migration of premyelinating Schwann cells before the initiation of myelination. Neurotrophin-3 (NT3) acting through the TrkC receptor tyrosine kinase stimulates Schwann cell migration via the Rho GTPases Rac1 and Cdc42. We previously demonstrated that TrkC directly phosphorylates and activates Dbs, the guanine-nucleotide exchange factor (GEF) for Cdc42, to partially mediate Schwann cell migration. Here, we identify T lymphoma invasion and metastasis (Tiam) 1 as the Rac1-specific guanine-nucleotide exchange factor involved in NT3-induced Schwann cell migration. Furthermore, the interaction between the small GTPase Ras and Tiam1 plays an essential role in the activation of Rac1. Taken together, these results suggest that NT3 activation of TrkC stimulates Schwann cell migration through two parallel signaling units, Ras/Tiam1/Rac1 and Dbs/Cdc42, and that Schwann cell migration is uniquely regulated in the case of Ras and Rac1, by two different types of small GTPases. PMID:16203995

  10. Myelin basic protein gene contains separate enhancers for oligodendrocyte and Schwann cell expression

    PubMed Central

    1992-01-01

    The DNA sequence between position +36 and -1907 of the murine myelin basic protein gene contains the enhancer and promoter elements necessary for abundant and cell specific expression in transgenic mice. Surprisingly, the pattern of expression promoted by this DNA fragment is a subset of that exhibited by the endogenous myelin basic protein (MBP) gene. Fusion genes prepared with this promoter/enhancer and a Lac Z reporter gene are expressed only in oligodendrocytes and not in Schwann cells, whereas the endogenous MBP gene is expressed in both cell types. The level of transgene expression measured by nuclear run- on experiments is very substantial and rivals that of the endogenous MBP gene. Furthermore, this 1.9-kb DNA fragment directs transcription on the same (or very similar) developmental schedule as the endogenous gene. These results indicate that the MBP promoter/enhancer sequences are at least tripartite: a core promoter, the oligodendrocyte enhancer elements, and a third component that either expands the specificity of the oligodendrocyte enhancer to include Schwann cells or acts independently to specifically stimulate transcription in Schwann cells. PMID:1383235

  11. Schwann cells expressing dismutase active mutant SOD1 unexpectedly slow disease progression in ALS mice

    PubMed Central

    Lobsiger, Christian S.; Boillee, Severine; McAlonis-Downes, Melissa; Khan, Amir M.; Feltri, M. Laura; Yamanaka, Koji; Cleveland, Don W.

    2009-01-01

    Neurodegeneration in an inherited form of ALS is non-cell-autonomous, with ALS-causing mutant SOD1 damage developed within multiple cell types. Selective inactivation within motor neurons of an ubiquitously expressed mutant SOD1 gene has demonstrated that mutant damage within motor neurons is a determinant of disease initiation, whereas mutant synthesis within neighboring astrocytes or microglia accelerates disease progression. We now report the surprising finding that diminished synthesis (by 70%) within Schwann cells of a fully dismutase active ALS-linked mutant (SOD1G37R) significantly accelerates disease progression, accompanied by reduction of insulin-like growth factor 1 (IGF-1) in nerves. Coupled with shorter disease duration in mouse models caused by dismutase inactive versus dismutase active SOD1 mutants, our findings implicate an oxidative cascade during disease progression that is triggered within axon ensheathing Schwann cells and that can be ameliorated by elevated dismutase activity. Thus, therapeutic down-regulation of dismutase active mutant SOD1 in familial forms of ALS should be targeted away from Schwann cells. PMID:19251638

  12. Canonical Wnt/β-catenin Signaling Drives Human Schwann Cell Transformation, Progression, and Tumor Maintenance

    PubMed Central

    Watson, Adrienne L.; Rahrmann, Eric P.; Moriarity, Branden S.; Choi, Kwangmin; Conboy, Caitlin B.; Greeley, Andrew D.; Halfond, Amanda L.; Anderson, Leah K.; Wahl, Brian R.; Keng, Vincent W.; Rizzardi, Anthony E.; Forster, Colleen L.; Collins, Margaret H.; Sarver, Aaron L.; Wallace, Margaret R.; Schmechel, Stephen C.; Ratner, Nancy; Largaespada, David A.

    2013-01-01

    Genetic changes required for the formation and progression of human Schwann cell tumors remain elusive. Using a Sleeping Beauty forward genetic screen, we identified several genes involved in canonical Wnt signaling as potential drivers of benign neurofibromas and malignant peripheral nerve sheath tumors (MPNSTs). In human neurofibromas and MPNSTs, activation of Wnt signaling increased with tumor grade and was associated with down-regulation of β-catenin destruction complex members or overexpression of a ligand that potentiates Wnt signaling, R-spondin 2 (RSPO2). Induction of Wnt signaling was sufficient to induce transformed properties to immortalized human Schwann cells, and down-regulation of this pathway was sufficient to reduce the tumorigenic phenotype of human MPNST cell lines. Small molecule inhibition of Wnt signaling effectively reduced viability of MPNST cell lines, and synergistically induced apoptosis when combined with an mTOR inhibitor, RAD-001, suggesting that Wnt inhibition represents a novel target for therapeutic intervention in Schwann cell tumors. PMID:23535903

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

    PubMed

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

    2014-03-01

    The cell adhesion molecule L1 regulates cellular responses in the developing and adult nervous system. Here, we show that stimulation of cultured mouse cerebellar neurons by a function-triggering L1 antibody leads to cathepsin E-mediated generation of a sumoylated 30 kDa L1 fragment (L1-30) and to import of L1-30 into the nucleus. Mutation of the sumoylation site at K1172 or the cathepsin E cleavage site at E1167 abolishes generation of L1-30, while mutation of the nuclear localization signal at K1147 prevents nuclear import of L1-30. Moreover, the aspartyl protease inhibitor pepstatin impairs the generation of L1-30 and inhibits L1-induced migration of cerebellar neurons and Schwann cells as well as L1-dependent in vitro myelination on axons of dorsal root ganglion neurons by Schwann cells. L1-stimulated migration of HEK293 cells expressing L1 with mutated cathepsin E cleavage site is diminished in comparison to migration of cells expressing non-mutated L1. In addition, L1-stimulated migration of HEK293 cells expressing non-mutated L1 is also abolished upon knock-down of cathepsin E expression and enhanced by over-expression of cathepsin E. The findings of the present study indicate that generation and nuclear import of L1-30 regulate neuronal and Schwann cell migration as well as myelination. Cell adhesion molecule L1 regulates cellular responses in the developing and adult nervous system. L1 stimulation triggers sumoylation and cleavage of L1, thus generating the L1-70 fragment (1) which is cleaved by cathepsin E (2) yielding the L1-30 fragment that is imported to the nucleus (3), may bind to DNA and/or nuclear proteins (4), to regulate diverse cellular functions. PMID:24118054

  14. Diminished Schwann cell repair responses underlie age-associated impaired axonal regeneration.

    PubMed

    Painter, Michio W; Brosius Lutz, Amanda; Cheng, Yung-Chih; Latremoliere, Alban; Duong, Kelly; Miller, Christine M; Posada, Sean; Cobos, Enrique J; Zhang, Alice X; Wagers, Amy J; Havton, Leif A; Barres, Ben; Omura, Takao; Woolf, Clifford J

    2014-07-16

    The regenerative capacity of the peripheral nervous system declines with age. Why this occurs, however, is unknown. We demonstrate that 24-month-old mice exhibit an impairment of functional recovery after nerve injury compared to 2-month-old animals. We find no difference in the intrinsic growth capacity between aged and young sensory neurons in vitro or in their ability to activate growth-associated transcriptional programs after injury. Instead, using age-mismatched nerve transplants in vivo, we show that the extent of functional recovery depends on the age of the nerve graft, and not the age of the host. Molecular interrogation of the sciatic nerve reveals that aged Schwann cells (SCs) fail to rapidly activate a transcriptional repair program after injury. Functionally, aged SCs exhibit impaired dedifferentiation, myelin clearance, and macrophage recruitment. These results suggest that the age-associated decline in axonal regeneration results from diminished Schwann cell plasticity, leading to slower myelin clearance.

  15. Mitochondrial alarmins released by degenerating motor axon terminals activate perisynaptic Schwann cells

    PubMed Central

    Duregotti, Elisa; Negro, Samuele; Scorzeto, Michele; Zornetta, Irene; Dickinson, Bryan C.; Chang, Christopher J.; Montecucco, Cesare; Rigoni, Michela

    2015-01-01

    An acute and highly reproducible motor axon terminal degeneration followed by complete regeneration is induced by some animal presynaptic neurotoxins, representing an appropriate and controlled system to dissect the molecular mechanisms underlying degeneration and regeneration of peripheral nerve terminals. We have previously shown that nerve terminals exposed to spider or snake presynaptic neurotoxins degenerate as a result of calcium overload and mitochondrial failure. Here we show that toxin-treated primary neurons release signaling molecules derived from mitochondria: hydrogen peroxide, mitochondrial DNA, and cytochrome c. These molecules activate isolated primary Schwann cells, Schwann cells cocultured with neurons and at neuromuscular junction in vivo through the MAPK pathway. We propose that this inter- and intracellular signaling is involved in triggering the regeneration of peripheral nerve terminals affected by other forms of neurodegenerative diseases. PMID:25605902

  16. Protein zero is necessary for E-cadherin-mediated adherens junction formation in Schwann cells.

    PubMed

    Menichella, D M; Arroyo, E J; Awatramani, R; Xu, T; Baron, P; Vallat, J M; Balsamo, J; Lilien, J; Scarlato, G; Kamholz, J; Scherer, S S; Shy, M E

    2001-12-01

    Protein Zero (P0), the major structural protein in the peripheral nervous system (PNS) myelin, acts as a homotypic adhesion molecule and is thought to mediate compaction of adjacent wraps of myelin membrane. E-Cadherin, a calcium-dependent adhesion molecule, is also expressed in myelinating Schwann cells in the PNS and is involved in forming adherens junctions between adjacent loops of membrane at the paranode. To determine the relationship, if any, between P0-mediated and cadherin-mediated adhesion during myelination, we investigated the expression of E-cadherin and its binding partner, beta-catenin, in sciatic nerve of mice lacking P0 (P0(-/-)). We find that in P0(-/-) peripheral myelin neither E-cadherin nor beta-catenin are localized to paranodes, but are instead found in small puncta throughout the Schwann cell. In addition, only occasional, often rudimentary, adherens junctions are formed. Analysis of E-cadherin and beta-catenin expression during nerve development demonstrates that E-cadherin and beta-catenin are localized to the paranodal region after the onset of myelin compaction. Interestingly, axoglial junction formation is normal in P0(-/-) nerve. Taken together, these data demonstrate that P0 is necessary for the formation of adherens junctions but not axoglial junctions in myelinating Schwann cells. PMID:11749037

  17. Biphasic bisperoxovanadium administration and Schwann cell transplantation for repair after cervical contusive spinal cord injury

    PubMed Central

    Walker, Chandler L.; Wang, Xiaofei; Bullis, Carli; Liu, Nai-Kui; Lu, Qingbo; Fry, Colin; Deng, Lingxiao; Xu, Xiao-Ming

    2014-01-01

    Schwann cells (SCs) hold promise for spinal cord injury (SCI) repair; however, there are limitations for use as a lone treatment. We showed acute inhibition of the phosphatase and tensin homologue (PTEN) by bisperoxovanadium (bpV) was neuroprotective and enhanced function following cervical hemicontusion SCI. We hypothesized that combining acute bpV therapy and delayed SC engraftment would further improve neuroprotection and recovery after cervical SCI. Adult female Sprague Dawley (SD) rats were randomly sorted into 5 groups: sham, vehicle, bpV, SC transplantation, and bpV + SC transplantation. SCs were isolated from adult green fluorescent protein (GFP)-expressing SD rats (GFP-SCs). 200 g/kg bpV(pic) was administered intraperitoneally (i.p.) twice daily for 7 days post-SCI in bpV-treated groups. GFP-SCs (1 × 106 in 5 μl medium) were transplanted into the lesion epicenter at the 8th day post-SCI. Forelimb function was tested for 10 weeks and histology was assessed. bpV alone significantly reduced lesion (by 40%, p<0.05) and cavitation (by 65%, p<0.05) and improved functional recovery (p <0.05) compared to injury alone. The combination promoted similar neuroprotection (p<0.01 vs. injury); however, GFP-SCs alone did not. Both SC-transplanted groups exhibited remarkable long-term SC survival, SMI-31+ axon ingrowth and RECA-1+ vasculature presence in the SC graft; however, bpV + SCs promoted an 89% greater axon-to-lesion ratio than SCs only. We concluded that bpV likely contributed largely to the neuroprotective and functional benefits while SCs facilitated considerable host-tissue interaction and modification. The combination of the two shows promise as an attractive strategy to enhance recovery after SCI. PMID:25510318

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

    PubMed Central

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

    2016-01-01

    Background Radical prostatectomy (RP) carries the risk of erectile dysfunction (ED) due to cavernous nerve (CN) injury. Schwann cells are essential for the maintenance of integrity and function of peripheral nerves such as the CNs. We hypothesize that brain-derived neurotrophic factor (BDNF) activates the Janus kinase (JAK)/(signal transducer and activator of transcription) STAT pathway in Schwann cells, not in neuronal axonal fibers, with the resultant secretion of cytokines from Schwann cells to facilitate nerve recovery. Methods Using four different cell lines—human neuroblastoma BE(2)-C and SH-SY5Y, human Schwann cell (HSC), and rat Schwann cell (RSC) RT4-D6P2T—we assessed the effect of BDNF application on the activation of the JAK/STAT pathway. We also assessed the time response of JAK/STAT pathway activation in RSCs and HSCs after BDNF treatment. We then assayed cytokine release from HSCs as a response to BDNF treatment using oncostatin M and IL6 as markers. Results We showed extensive phosphorylation of STAT3/STAT1 by BDNF at high dose (100 pM) in RSCs, with no JAK/STAT pathway activation in human neuroblastoma cell lines. The time response of JAK/STAT pathway activation in RSCs and HSCs after BDNF treatment showed an initial peak at shortly after treatment and then a second higher peak at 24–48 hours. Cytokine release from HSCs increased progressively after BDNF application, reaching statistical significance for IL6. Conclusions We demonstrated for the first time the indirect mechanism of BDNF enhancement of nerve regeneration through the activation of JAK/STAT pathway in Schwann cells, rather than directly on neurons. As a result of BDNF application, Schwann cells produce cytokines that promote nerve regeneration. PMID:27141442

  19. Oriented growth and transdifferentiation of mesenchymal stem cells towards a Schwann cell fate on micropatterned substrates.

    PubMed

    Sharma, Anup D; Zbarska, Svitlana; Petersen, Emma M; Marti, Mustafa E; Mallapragada, Surya K; Sakaguchi, Donald S

    2016-03-01

    While Schwann cells (SCs) have a significant role in peripheral nerve regeneration, their use in treatments has been limited because of lack of a readily available source. To address this issue, this study focused on the effect of guidance cues by employing micropatterned polymeric films to influence the alignment, morphology and transdifferentiation of bone marrow-derived rat mesenchymal stem cells (MSCs) towards a Schwann cell-like fate. Two different types of polymers, biocompatible polystyrene (PS) and biodegradable poly(lactic acid) (PLA) were used to fabricate patterned films. Percentages of transdifferentiated MSCs (tMSCs) immunolabeled with SC markers (α-S100β and α-p75(NTR)) were found to be similar on patterned versus smooth PS and PLA substrates. However, patterning had a significant effect on the alignment and elongation of the tMSCs. More than 80% of the tMSCs were oriented in the direction of microgrooves (0°-20°), while cells on the smooth substrates were randomly oriented. The aspect ratio [AR, ratio of length (in direction of microgrooves) and breadth (in direction perpendicular to microgrooves)] of the tMSCs on patterned substrates had a value of approximately five, as compared to cells on smooth substrates where the AR was one. Understanding responses to these cues in vitro helps us in understanding the behavior and interaction of the cells with the 3D environment of the scaffolds, facilitating the application of these concepts to designing effective nerve guidance conduits for peripheral nerve regeneration.

  20. Tuning the Mechanical Properties of Poly(Ethylene Glycol) Microgel-Based Scaffolds to Increase 3D Schwann Cell Proliferation.

    PubMed

    Zhou, Wenda; Stukel, Jessica M; Cebull, Hannah L; Willits, Rebecca Kuntz

    2016-04-01

    2D in vitro studies have demonstrated that Schwann cells prefer scaffolds with mechanical modulus approximately 10× higher than the modulus preferred by nerves, limiting the ability of many scaffolds to promote both neuron extension and Schwann cell proliferation. Therefore, the goals of this work are to develop and characterize microgel-based scaffolds that are tuned over the stiffness range relevant to neural tissue engineering and investigate Schwann cell morphology, viability, and proliferation within 3D scaffolds. Using thiol-ene reaction, microgels with surface thiols are produced and crosslinked into hydrogels using a multiarm vinylsulfone (VS). By varying the concentration of VS, scaffold stiffness ranges from 0.13 to 0.76 kPa. Cell morphology in all groups demonstrates that cells are able to spread and interact with the scaffold through day 5. Although the viability in all groups is high, proliferation of Schwann cells within the scaffold of G* = 0.53 kPa is significantly higher than other groups. This result is ≈ 5× lower than previously reported optimal stiffnesses on 2D surfaces, demonstrating the need for correlation of 3D cell response to mechanical modulus. As proliferation is the first step in Schwann cell integration into peripheral nerve conduits, these scaffolds demonstrate that the stiffness is a critical parameter to optimizing the regenerative process.

  1. Perisynaptic Schwann Cells at the Neuromuscular Synapse: Adaptable, Multitasking Glial Cells.

    PubMed

    Ko, Chien-Ping; Robitaille, Richard

    2015-10-01

    The neuromuscular junction (NMJ) is engineered to be a highly reliable synapse to carry the control of the motor commands of the nervous system over the muscles. Its development, organization, and synaptic properties are highly structured and regulated to support such reliability and efficacy. Yet, the NMJ is also highly plastic, able to react to injury and adapt to changes. This balance between structural stability and synaptic efficacy on one hand and structural plasticity and repair on another hand is made possible by the intricate regulation of perisynaptic Schwann cells, glial cells at this synapse. They regulate both the efficacy and structural plasticity of the NMJ in a dynamic, bidirectional manner owing to their ability to decode synaptic transmission and by their interactions via trophic-related factors.

  2. Perisynaptic Schwann Cells at the Neuromuscular Synapse: Adaptable, Multitasking Glial Cells.

    PubMed

    Ko, Chien-Ping; Robitaille, Richard

    2015-10-01

    The neuromuscular junction (NMJ) is engineered to be a highly reliable synapse to carry the control of the motor commands of the nervous system over the muscles. Its development, organization, and synaptic properties are highly structured and regulated to support such reliability and efficacy. Yet, the NMJ is also highly plastic, able to react to injury and adapt to changes. This balance between structural stability and synaptic efficacy on one hand and structural plasticity and repair on another hand is made possible by the intricate regulation of perisynaptic Schwann cells, glial cells at this synapse. They regulate both the efficacy and structural plasticity of the NMJ in a dynamic, bidirectional manner owing to their ability to decode synaptic transmission and by their interactions via trophic-related factors. PMID:26430218

  3. Matrix RGD ligand density and L1CAM-mediated Schwann cell interactions synergistically enhance neurite outgrowth.

    PubMed

    Romano, Nicole H; Madl, Christopher M; Heilshorn, Sarah C

    2015-01-01

    The innate biological response to peripheral nerve injury involves a complex interplay of multiple molecular cues to guide neurites across the injury gap. Many current strategies to stimulate regeneration take inspiration from this biological response. However, little is known about the balance of cell-matrix and Schwann cell-neurite dynamics required for regeneration of neural architectures. We present an engineered extracellular matrix (eECM) microenvironment with tailored cell-matrix and cell-cell interactions to study their individual and combined effects on neurite outgrowth. This eECM regulates cell-matrix interactions by presenting integrin-binding RGD (Arg-Gly-Asp) ligands at specified densities. Simultaneously, the addition or exclusion of nerve growth factor (NGF) is used to modulate L1CAM-mediated Schwann cell-neurite interactions. Individually, increasing the RGD ligand density from 0.16 to 3.2mM resulted in increasing neurite lengths. In matrices presenting higher RGD ligand densities, neurite outgrowth was synergistically enhanced in the presence of soluble NGF. Analysis of Schwann cell migration and co-localization with neurites revealed that NGF enhanced cooperative outgrowth between the two cell types. Interestingly, neurites in NGF-supplemented conditions were unable to extend on the surrounding eECM without the assistance of Schwann cells. Blocking studies revealed that L1CAM is primarily responsible for these Schwann cell-neurite interactions. Without NGF supplementation, neurite outgrowth was unaffected by L1CAM blocking or the depletion of Schwann cells. These results underscore the synergistic interplay between cell-matrix and cell-cell interactions in enhancing neurite outgrowth for peripheral nerve regeneration. PMID:25308870

  4. Inkjet printing Schwann cells and neuronal analogue NG108-15 cells.

    PubMed

    Tse, Christopher; Whiteley, Robert; Yu, Tong; Stringer, Jonathan; MacNeil, Sheila; Haycock, John W; Smith, Patrick J

    2016-03-01

    Porcine Schwann cells and neuronal analogue NG108-15 cells were printed using a piezoelectric-inkjet-printer with a nozzle diameter of 60 μm, within the range of 70-230 V, with analysis of viability and quality after printing. Neuronal and glial cell viabilities of >86% and >90% were detected immediately after printing and no correlation between voltage applied and cell viability could be seen. Printed neuronal cells were shown to produce neurites earlier compared to controls, and over several days, produced longer neurites which become most evident by day 7. The number of neurites becomes similar by day 7 also, and cells proliferate with a similar viability to that of non-printed cells (controls). This method of inkjet printing cells provides a technical platform for investigating neuron-glial cell interactions with no significant difference to cell viability than standard cell seeding. Such techniques can be utilized for lab-on-a-chip technologies and to create printed neural networks for neuroscience applications. PMID:26930268

  5. TRANSDUCED SCHWANN CELLS PROMOTE AXON GROWTH AND MYELINATION AFTER SPINAL CORD INJURY

    PubMed Central

    Golden, Kevin L.; Pearse, Damien D.; Blits, Bas; Garg, Maneesh S.; Oudega, Martin; Wood, Patrick M.; Bunge, Mary Bartlett

    2007-01-01

    We sought to directly compare growth and myelination of local and supraspinal axons by implanting into the injured spinal cord Schwann cells (SCs) transduced ex vivo with adenoviral (AdV) or lentiviral (LV) vectors encoding a bifunctional neurotrophin molecule (D15A). D15A mimics actions of both neurotrophin-3 and brain-derived neurotrophic factor. Transduced SCs were injected into the injury center one week after a moderate thoracic (T8) adult rat spinal cord contusion. D15A expression and bioactivity in vitro; D15A levels in vivo; and graft volume, SC number, implant axon number and cortico-, reticulo-, raphe-, coerulo-spinal and sensory axon growth were determined for both types of vectors employed to transduce SCs. ELISAs revealed that D15A-secreting SC implants contained significantly higher levels of neurotrophin than non-transduced SC and AdV/GFP and LV/GFP SC controls early after implantation. At 6 wk post-implantation, D15A-secreting SC grafts exhibited 5-fold increases in graft volume, SC number and myelinated axon counts and a 3-fold increase in myelinated to unmyelinated (ensheathed) axon ratios. The total number of axons within grafts of LV/GFP/D15A SCs was estimated to be over 70,000. Also 5-HT, DβH, and CGRP axon length was increased up to 5-fold within D15A grafts. In sum, despite qualitative differences using the two vectors, increased neurotrophin secretion by the implanted D15A SCs led to the presence of a significantly increased number of axons in the contusion site. These results demonstrate the therapeutic potential for utilizing neurotrophin-transduced SCs to repair the injured spinal cord. PMID:17719577

  6. Transfection of neonatal rat Schwann cells with SV-40 large T antigen gene under control of the metallothionein promoter

    PubMed Central

    1987-01-01

    Secondary cultures of Schwann cells were transfected with a plasmid containing the SV-40 T antigen gene expressed under the control of the mouse metallothionein-I promoter. We used the calcium phosphate method for transfection and obtained a transfection efficiency of 0.01%. The colonies were cloned by limited dilution, and these cloned cell lines were carried in medium containing zinc chloride (100 microM). One cloned cell line, which has now been carried for 180 doublings, appears to have a transformed phenotype with a doubling time of 20 h. These cells express SV-40 T antigen while maintaining established Schwann cell properties (positive staining for 217c, Ran-2, A5E3, glial fibrillary acidic protein, presence of 2',3'-cyclic nucleotide phosphohydrolase [CNPase] activity, and the ability to synthesize sulfogalactosylceramide and mRNA for the myelin protein, P0). Removal of zinc chloride from the medium resulted in reduced expression of T antigen and a change in the appearance of the cells to a more bipolar shape, although they still did not exhibit contact inhibition and maintained a doubling time of 20 h. These cells now became Ran-2- negative and showed increases in CNPase activity and in their ability to synthesize sulfogalactosylceramide. The amount of P0 mRNA remained unchanged. Transfected Schwann cells, however, stopped dividing when they contacted either basal lamina or neurites and became bipolar in appearance. The Schwann cells in contact with the neurites then extended processes to wrap around bundles of neurites. Transfection with the SV-40 T antigen gene therefore provides a method for obtaining Schwann cell lines that continue to express properties associated with untransfected cells in culture and may be used to study axon-Schwann cell interaction. PMID:2824529

  7. Neuropathologic characterization of INF2-related Charcot-Marie-Tooth disease: evidence for a Schwann cell actinopathy.

    PubMed

    Mathis, Stéphane; Funalot, Benoît; Boyer, Olivia; Lacroix, Catherine; Marcorelles, Pascale; Magy, Laurent; Richard, Laurence; Antignac, Corinne; Vallat, Jean-Michel

    2014-03-01

    The association of Charcot-Marie-Tooth (CMT) disease with renal dysfunction is uncommon but has long been recognized in several families. Recently, mutations in the INF2 gene, which encodes inverted formin-2, were identified in patients with focal segmental glomerulosclerosis and a dominant intermediate form of CMT (CMTDIE, OMIM #614455). We describe the pathologic lesions of nerve biopsies from 6 patients with INF2-related CMTDIE. There were 4 females and 2 males; ages were from 12 to 47 years; durations between neuropathy onset and biopsy were from 2 to 37 years. Clinical phenotypes were similar to those seen in other forms of CMT disease, but there was always an associated proteinuria (and later renal failure). Motor median nerve conduction velocities were in the range of intermediate CMT disease. Pathologic lesions suggested chronic demyelination and remyelination associated with progressive axonal loss. By electron microscopy, we observed unusual whorl-like proliferations of flattened Schwann cell cytoplasm and anomalies of unmyelinating Schwann cell cytoplasm with supernumerary elongated extensions similar to those described in CMT4C. We also observed abnormal accumulation of β-actin in the cytoplasm of Schwann cells. Our results suggest that these lesions reflect a global disorder of the actin cytoskeleton in Schwann cells and that CMTDIE is the first peripheral nerve disorder associated with a Schwann cell actinopathy. PMID:24487800

  8. Drp2 and Periaxin form Cajal Bands with Dystroglycan but have Distinct Roles in Schwann Cell Growth

    PubMed Central

    Sherman, Diane L.; Wu, Lai Man N.; Grove, Matthew; Gillespie, C. Stewart; Brophy, Peter J.

    2012-01-01

    Cajal bands are cytoplasmic channels flanked by appositions where the abaxonal surface of Schwann cell myelin apposes and adheres to the overlying plasma membrane. These appositions contain a dystroglycan complex that includes periaxin and dystrophin-related protein 2 (Drp2). Loss of periaxin disrupts appositions and Cajal bands in Schwann cells and causes a severe demyelinating neuropathy in mouse and man. Here we have investigated the role of mouse Drp2 in apposition assembly and Cajal band function and compared it to periaxin. We show that Periaxin and Drp2 are not only both required to form appositions, but they must also interact. Periaxin-Drp2 interaction is also required for Drp2 phosphorylation but phosphorylation is not required for the assembly of appositions. Drp2 loss causes corresponding increases in Dystrophin family members, utrophin and dystrophin Dp116 though dystroglycan remains unchanged. We also show that all dystroglycan complexes in Schwann cells utilise the uncleaved form of β-dystroglycan. Drp2-null Schwann cells have disrupted appositions and Cajal bands, and they undergoe focal hypermyelination and concomitant demyelination. Nevertheless, they do not have the short internodal lengths and associated reduced nerve conduction velocity seen in the absence of periaxin, showing that periaxin regulates Schwann cell elongation independent of its role in the dystroglycan complex. We conclude that the primary role of the dystroglycan complex in appositions is to stabilize and limit the radial growth of myelin. PMID:22764250

  9. Myelin is dependent on the Charcot–Marie–Tooth Type 4H disease culprit protein FRABIN/FGD4 in Schwann cells

    PubMed Central

    Horn, Michael; Baumann, Reto; Pereira, Jorge A.; Sidiropoulos, Páris N. M.; Somandin, Christian; Welzl, Hans; Stendel, Claudia; Lühmann, Tessa; Wessig, Carsten; Toyka, Klaus V.; Relvas, João B.; Senderek, Jan

    2012-01-01

    Studying the function and malfunction of genes and proteins associated with inherited forms of peripheral neuropathies has provided multiple clues to our understanding of myelinated nerves in health and disease. Here, we have generated a mouse model for the peripheral neuropathy Charcot–Marie–Tooth disease type 4H by constitutively disrupting the mouse orthologue of the suspected culprit gene FGD4 that encodes the small RhoGTPase Cdc42-guanine nucleotide exchange factor Frabin. Lack of Frabin/Fgd4 causes dysmyelination in mice in early peripheral nerve development, followed by profound myelin abnormalities and demyelination at later stages. At the age of 60 weeks, this was accompanied by electrophysiological deficits. By crossing mice carrying alleles of Frabin/Fgd4 flanked by loxP sequences with animals expressing Cre recombinase in a cell type-specific manner, we show that Schwann cell-autonomous Frabin/Fgd4 function is essential for proper myelination without detectable primary contributions from neurons. Deletion of Frabin/Fgd4 in Schwann cells of fully myelinated nerve fibres revealed that this protein is not only required for correct nerve development but also for accurate myelin maintenance. Moreover, we established that correct activation of Cdc42 is dependent on Frabin/Fgd4 function in healthy peripheral nerves. Genetic disruption of Cdc42 in Schwann cells of adult myelinated nerves resulted in myelin alterations similar to those observed in Frabin/Fgd4-deficient mice, indicating that Cdc42 and the Frabin/Fgd4–Cdc42 axis are critical for myelin homeostasis. In line with known regulatory roles of Cdc42, we found that Frabin/Fgd4 regulates Schwann cell endocytosis, a process that is increasingly recognized as a relevant mechanism in peripheral nerve pathophysiology. Taken together, our results indicate that regulation of Cdc42 by Frabin/Fgd4 in Schwann cells is critical for the structure and function of the peripheral nervous system. In particular

  10. Myelin is dependent on the Charcot-Marie-Tooth Type 4H disease culprit protein FRABIN/FGD4 in Schwann cells.

    PubMed

    Horn, Michael; Baumann, Reto; Pereira, Jorge A; Sidiropoulos, Páris N M; Somandin, Christian; Welzl, Hans; Stendel, Claudia; Lühmann, Tessa; Wessig, Carsten; Toyka, Klaus V; Relvas, João B; Senderek, Jan; Suter, Ueli

    2012-12-01

    Studying the function and malfunction of genes and proteins associated with inherited forms of peripheral neuropathies has provided multiple clues to our understanding of myelinated nerves in health and disease. Here, we have generated a mouse model for the peripheral neuropathy Charcot-Marie-Tooth disease type 4H by constitutively disrupting the mouse orthologue of the suspected culprit gene FGD4 that encodes the small RhoGTPase Cdc42-guanine nucleotide exchange factor Frabin. Lack of Frabin/Fgd4 causes dysmyelination in mice in early peripheral nerve development, followed by profound myelin abnormalities and demyelination at later stages. At the age of 60 weeks, this was accompanied by electrophysiological deficits. By crossing mice carrying alleles of Frabin/Fgd4 flanked by loxP sequences with animals expressing Cre recombinase in a cell type-specific manner, we show that Schwann cell-autonomous Frabin/Fgd4 function is essential for proper myelination without detectable primary contributions from neurons. Deletion of Frabin/Fgd4 in Schwann cells of fully myelinated nerve fibres revealed that this protein is not only required for correct nerve development but also for accurate myelin maintenance. Moreover, we established that correct activation of Cdc42 is dependent on Frabin/Fgd4 function in healthy peripheral nerves. Genetic disruption of Cdc42 in Schwann cells of adult myelinated nerves resulted in myelin alterations similar to those observed in Frabin/Fgd4-deficient mice, indicating that Cdc42 and the Frabin/Fgd4-Cdc42 axis are critical for myelin homeostasis. In line with known regulatory roles of Cdc42, we found that Frabin/Fgd4 regulates Schwann cell endocytosis, a process that is increasingly recognized as a relevant mechanism in peripheral nerve pathophysiology. Taken together, our results indicate that regulation of Cdc42 by Frabin/Fgd4 in Schwann cells is critical for the structure and function of the peripheral nervous system. In particular, this

  11. Inter-microcarrier transfer and phenotypic stability of stem cell-derived Schwann cells in stirred suspension bioreactor culture.

    PubMed

    Shakhbazau, Antos; Mirfeizi, Leila; Walsh, Tylor; Wobma, Holly M; Kumar, Ranjan; Singh, Bhagat; Kallos, Michael S; Midha, Rajiv

    2016-02-01

    Emerging bioreactor technologies offer an effective way for scaled-up production of large numbers of cells for cell therapy applications. One of the clinical paradigms where cell therapy can be an asset is restorative neurosciences. Nerve repair can benefit from the injections of stem cells and/or Schwann cells, acting as a source for axon myelination, myelin debris clearance, and trophic support. We have adapted microcarrier-based suspension bioreactor culture for Schwann cells (SCs) differentiated from a new stem cell source - skin-derived precursors (SKPs). SKP-derived SCs attach and grow on different types of microcarriers in both static and stirred culture, with Cytodex 3 and CultiSpher-S found most effective. Inter-microcarrier migration of SKP-SCs represents a key mechanism for rapid expansion and colonization in stirred suspension culture. We have shown that microcarrier-expanded SKP-SCs cells express Schwann cell markers p75-NTR, GFAP and S100 and retain their key ability to myelinate axons both in vitro and in vivo. Scaled-up microcarrier-based production of SKP-SCs in suspension bioreactors appears feasible for timely generation of sufficient cell numbers for nerve repair strategies.

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

    PubMed Central

    Liu, Weimin; Markman, John D.; Gelbard, Harris A.; Huang, Jason H.

    2015-01-01

    Objective In this study, the functional recoveries of Sprague-Dawley rats following repair of a complete sciatic nerve transection using allotransplanted dorsal root ganglion (DRG) neurons or Schwann cells were examined using a number of outcome measures. Methods Four groups were compared: (1) repair with a nerve guide conduit seeded with allotransplanted Schwann cells harvested from Wistar rats, (2) repair with a nerve guide conduit seeded with DRG neurons, (3) repair with solely a nerve guide conduit, and (4) sham-surgery animals where the sciatic nerve was left intact. The results corroborated our previous reported histology findings and measures of immunogenicity. Results The Wistar-DRG-treated group achieved the best recovery, significantly outperforming both the Wistar-Schwann group and the nerve guide conduit group in the Von Frey assay of touch response (P < 0.05). Additionally, Wistar-DRG and Wistar-Schwann seeded repairs showed lower frequency and severity in an autotomy measure of the self-mutilation of the injured leg because of neuralgia. Conclusion These results suggest that in complete peripheral nerve transections, surgical repair using nerve guide conduits with allotransplanted DRG and Schwann cells may improve recovery, especially DRG neurons, which elicit less of an immune response. PMID:24836462

  13. Schwann cell proliferation and differentiation that is induced by ferulic acid through MEK1/ERK1/2 signalling promotes peripheral nerve remyelination following crush injury in rats

    PubMed Central

    Zhu, Xiaoyan; Li, Kun; Guo, Xin; Wang, Jian; Xiang, Yang

    2016-01-01

    Schwann cell proliferation and differentiation is critical for the remyelination of injured peripheral nerves. Ferulic acid (FA) is a widely used antioxidant agent with neuroprotective properties. However, the potentially beneficial effects of FA on Schwann cells are unknown. Therefore, the present study was designed to examine the effects of FA on Schwann cell proliferation and differentiation. By using the cultured primary Schwann cells and proliferation assay, the results identified that FA was capable of increasing Schwann cell proliferation and expression of myelin-associated glycoprotein (MAG) and myelin basic protein (MBP) in vitro. It was also observed that the beneficial effect of FA treatment on Schwann cells was mainly dependent on the activation of MEK1/ERK1/2 signalling. Furthermore, FA was intraperitoneally administered to rats with sciatic nerve crush injury, and the results revealed an increase in Schwann cell proliferation and differentiation, while the MAG and MBP expression levels in sciatic nerves were markedly upregulated following FA administration. In conclusion, the current results demonstrate that Schwann cell proliferation and differentiation is induced by FA through MEK1/ERK1/2 signalling and that FA may accelerate injured peripheral nerve remyelination. PMID:27588110

  14. Multiple kinetic components of sodium channel inactivation in rabbit Schwann cells.

    PubMed Central

    Howe, J R; Ritchie, J M

    1992-01-01

    1. We have studied the kinetics of inactivation of sodium currents evoked in Schwann cells from neonatal and adult rabbits with patch-clamp recording techniques. The decay both of whole-cell currents and of ensemble currents obtained from outside-out patches was reasonably well-described by single exponential fits which gave values for the time constant, tau h, similar to those found for such currents in nerve (about 0.5 ms at 0 mV). Although inclusion of an additional exponential component usually improved the fits to the decay of these currents, the relative amplitude of the slower component (time constant 3-6 ms) was always small. 2. The time course of recovery from steady-state inactivation clearly consisted of two exponential components. At -120 mV, recovery from steady-state inactivation at -50 mV consisted of a fast component with a time constant of 2.2 +/- 0.2 ms and a much slower component with a time constant of 1.2 +/- 0.2 s (n = 9). The relative amplitude of the slow component (expressed as a fraction of the sodium current when inactivation was removed completely) was 0.56 +/- 0.03. The corresponding amplitudes of the slow component when similar experiments were done from holding potentials of 0 and -70 mV were 0.80 +/- 0.04 and 0.36 +/- 0.03, respectively (n = 5 and 8). 3. The onset of steady-state inactivation also followed a bi-exponential time course. The time constant of the slower component was similar at each potential examined (0, -50 and -70 mV), being 6-7 s. The relative amplitude of the slow component of onset depended on membrane potential, and it was similar (at each potential examined) to the corresponding amplitude of the slow component of recovery. 4. The inclusion of 40 mM-iodate ions in the pipette solution slowed the decay of whole-cell sodium currents, as did the extracellular application of venom (10 micrograms ml-1) from the scorpion Leiurus quinquestriatus. Prolonged exposure of the cells to Leiurus venom appeared to increase the

  15. Differentiation of axon-related Schwann cells in vitro. I. Ascorbic acid regulates basal lamina assembly and myelin formation

    PubMed Central

    1987-01-01

    Rat Schwann cells cultured with dorsal root ganglion neurons in a serum- free defined medium fail to ensheathe or myelinate axons or assemble basal laminae. Replacement of defined medium with medium that contains human placental serum (HPS) and chick embryo extract (EE) results in both basal lamina and myelin formation. In the present study, the individual effects of HPS and EE on basal lamina assembly and on myelin formation by Schwann cells cultured with neurons have been examined. Some batches of HPS were unable to promote myelin formation in the absence of EE, as assessed by quantitative evaluation of cultures stained with Sudan black; such HPS also failed to promote basal lamina assembly, as assessed by immunofluorescence using antibodies against laminin, type IV collagen, and heparan sulfate proteoglycan. The addition of EE or L-ascorbic acid with such HPS led to the formation of large quantities of myelin and to the assembly of basal laminae. Pretreatment of EE with ascorbic acid oxidase abolished the EE activity, whereas trypsin did not. Other batches of HPS were found to promote both basal lamina and myelin formation in the absence of either EE or ascorbic acid. Ascorbic acid oxidase treatment or dialysis of these batches of HPS abolished their ability to promote Schwann cell differentiation, whereas the subsequent addition of ascorbic acid restored that ability. Ascorbic acid in the absence of serum was relatively ineffective in promoting either basal lamina or myelin formation. Fetal bovine serum was as effective as HPS in allowing ascorbic acid (and several analogs but not other reducing agents) to manifest its ability to promote Schwann cell differentiation. We suggest that ascorbic acid promotes Schwann cell myelin formation by enabling the Schwann cell to assemble a basal lamina, which is required for complete differentiation. PMID:3624305

  16. Label-free imaging of Schwann cell myelination by third harmonic generation microscopy

    PubMed Central

    Lim, Hyungsik; Sharoukhov, Denis; Kassim, Imran; Zhang, Yanqing; Salzer, James L.; Melendez-Vasquez, Carmen V.

    2014-01-01

    Understanding the dynamic axon–glial cell interaction underlying myelination is hampered by the lack of suitable imaging techniques. Here we demonstrate third harmonic generation microscopy (THGM) for label-free imaging of myelinating Schwann cells in live culture and ex vivo and in vivo tissue. A 3D structure was acquired for a variety of compact and noncompact myelin domains, including juxtaparanodes, Schmidt–Lanterman incisures, and Cajal bands. Other subcellular features of Schwann cells that escape traditional optical microscopies were also visualized. We tested THGM for morphometry of compact myelin. Unlike current methods based on electron microscopy, g-ratio could be determined along an extended length of myelinated fiber in the physiological condition. The precision of THGM-based g-ratio estimation was corroborated in mouse models of hypomyelination. Finally, we demonstrated the feasibility of THGM to monitor morphological changes of myelin during postnatal development and degeneration. The outstanding capabilities of THGM may be useful for elucidation of the mechanism of myelin formation and pathogenesis. PMID:25453108

  17. Self-aligned Schwann cell monolayers demonstrate an inherent ability to direct neurite outgrowth

    NASA Astrophysics Data System (ADS)

    Seggio, A. M.; Narayanaswamy, A.; Roysam, B.; Thompson, D. M.

    2010-08-01

    In vivo nerve guidance channel studies have identified Schwann cell (SC) presence as an integral factor in axonal number and extension in an injury site, and in vitro studies have provided evidence that oriented SCs can direct neurite outgrowth. However, traditional methods used to create oriented SC monolayers (e.g. micropatterns/microtopography) potentially introduce secondary guidance cues to the neurons that are difficult to de-couple. Although SCs expanded on uniform laminin-coated coverslips lack a global orientation, the monolayers contain naturally formed regions of locally oriented cells that can be used to investigate SC-mediated neurite guidance. In this work, novel image analysis techniques have been developed to quantitatively assess local neurite orientation with respect to the underlying regional orientation of the Schwann cell monolayer. Results confirm that, in the absence of any secondary guidance cues, a positive correlation exists between neurite outgrowth and regional orientation of the SC monolayer. Thus, SCs alone possess an inherent ability to direct neurite outgrowth, and expansion of the co-culture-based quantitative method described can be used to further deconstruct specific biomolecular mechanisms of neurite guidance.

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

    PubMed

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

    2003-09-01

    Terminal Schwann cells (TSCs) that cover motor neuron terminals are known to play important roles in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. We have established a method of selectively and efficiently collecting TSCs so that cDNA analysis can be done properly. The expression of 1-2% of whole mRNAs was compared between myelinating Schwann cells (MSCs) and TSCs, and it turned out that approximately one-third of the bands could be categorized as cell-type-specific bands. TSCs thus constitute a distinct entity from the viewpoint of gene expression. As one of the cDNA clones belonging to TSC-specific bands was identified homocysteine-responsive ER-resident protein (Herp), and in situ hybridization confirmed that Herp mRNA is expressed in TSCs on motor nerve terminals but not in MSCs, both in developing and adult rats. In conclusion, we have been able to identify Herp as a novel molecular marker for TSCs. PMID:12927800

  19. Conditional Inactivation of Pten with EGFR Overexpression in Schwann Cells Models Sporadic MPNST

    PubMed Central

    Keng, Vincent W.; Watson, Adrienne L.; Rahrmann, Eric P.; Li, Hua; Tschida, Barbara R.; Moriarity, Branden S.; Choi, Kwangmin; Rizvi, Tilat A.; Collins, Margaret H.; Wallace, Margaret R.; Ratner, Nancy; Largaespada, David A.

    2012-01-01

    The genetic mechanisms involved in the transformation from a benign neurofibroma to a malignant sarcoma in patients with neurofibromatosis-type-1- (NF1-)associated or sporadic malignant peripheral nerve sheath tumors (MPNSTs) remain unclear. It is hypothesized that many genetic changes are involved in transformation. Recently, it has been shown that both phosphatase and tensin homolog (PTEN) and epidermal growth factor receptor (EGFR) play important roles in the initiation of peripheral nerve sheath tumors (PNSTs). In human MPNSTs, PTEN expression is often reduced, while EGFR expression is often induced. We tested if these two genes cooperate in the evolution of PNSTs. Transgenic mice were generated carrying conditional floxed alleles of Pten, and EGFR was expressed under the control of the 2′,3′-cyclic nucleotide 3′phosphodiesterase (Cnp) promoter and a desert hedgehog (Dhh) regulatory element driving Cre recombinase transgenic mice (Dhh-Cre). Complete loss of Pten and EGFR overexpression in Schwann cells led to the development of high-grade PNSTs. In vitro experiments using immortalized human Schwann cells demonstrated that loss of PTEN and overexpression of EGFR cooperate to increase cellular proliferation and anchorage-independent colony formation. This mouse model can rapidly recapitulate PNST onset and progression to high-grade PNSTs, as seen in sporadic MPNST patients. PMID:23319880

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

    PubMed

    Zenker, Jennifer; Stettner, Mark; Ruskamo, Salla; Domènech-Estévez, Enric; Baloui, Hasna; Médard, Jean-Jacques; Verheijen, Mark H G; Brouwers, Jos F; Kursula, Petri; Kieseier, Bernd C; Chrast, Roman

    2014-09-01

    Peripheral myelin protein 2 (Pmp2, P2 or Fabp8), a member of the fatty acid binding protein family, was originally described together with myelin basic protein (Mbp or P1) and myelin protein zero (Mpz or P0) as one of the most abundant myelin proteins in the peripheral nervous system (PNS). Although Pmp2 is predominantly expressed in myelinated Schwann cells, its role in glia is currently unknown. To study its function in PNS biology, we have generated a complete Pmp2 knockout mouse (Pmp2(-/-) ). Comprehensive characterization of Pmp2(-/-) mice revealed a temporary reduction in their motor nerve conduction velocity (MNCV). While this change was not accompanied by any defects in general myelin structure, we detected transitory alterations in the myelin lipid profile of Pmp2(-/-) mice. It was previously proposed that Pmp2 and Mbp have comparable functions in the PNS suggesting that the presence of Mbp can partially mask the Pmp2(-/-) phenotype. Indeed, we found that Mbp lacking Shi(-/-) mice, similar to Pmp2(-/-) animals, have preserved myelin structure and reduced MNCV, but this phenotype was not aggravated in Pmp2(-/-) /Shi(-/-) mutants indicating that Pmp2 and Mbp do not substitute each other's functions in the PNS. These data, together with our observation that Pmp2 binds and transports fatty acids to membranes, uncover a role for Pmp2 in lipid homeostasis of myelinating Schwann cells.

  1. Silencing of the Charcot-Marie-Tooth associated MTMR2 gene decreases proliferation and enhances cell death in primary cultures of Schwann cells.

    PubMed

    Chojnowski, Alexandre; Ravisé, Nicole; Bachelin, Corinne; Depienne, Christel; Ruberg, Merle; Brugg, Bernard; Laporte, Jocelyn; Baron-Van Evercooren, Anne; LeGuern, Eric

    2007-05-01

    Loss of function of the myotubularin (MTM)-related protein 2 (MTMR2) in Schwann cells causes Charcot-Marie-Tooth disease type 4B1, a severe demyelinating neuropathy, but the consequences of MTMR2 disruption in Schwann cells are unknown. We established the expression profile of MTMR2 by real-time RT-PCR during rat myelination and showed it to be preferentially expressed at the onset of the myelination period. We developed a model in which MTMR2 loss of function was reproduced in primary cultures of Schwann cells by RNA interference. We found that depletion of MTMR2 in Schwann cells decreased their rate of proliferation. Furthermore, when cultivated in serum-free medium, MTMR2 depletion increased the number of Schwann cells that died by a caspase-dependent process. These results support the hypothesis that loss of MTMR2 in patients, by decreasing Schwann cells proliferation and survival, may impair the first stages of myelination of the peripheral nervous system.

  2. Deficiency in the mRNA export mediator Gle1 impairs Schwann cell development in the zebrafish embryo.

    PubMed

    Seytanoglu, A; Alsomali, N I; Valori, C F; McGown, A; Kim, H R; Ning, K; Ramesh, T; Sharrack, B; Wood, J D; Azzouz, M

    2016-05-13

    GLE1 mutations cause lethal congenital contracture syndrome 1 (LCCS1), a severe autosomal recessive fetal motor neuron disease, and more recently have been associated with amyotrophic lateral sclerosis (ALS). The gene encodes a highly conserved protein with an essential role in mRNA export. The mechanism linking Gle1 function to motor neuron degeneration in humans has not been elucidated, but increasing evidence implicates abnormal RNA processing as a key event in the pathogenesis of several motor neuron diseases. Homozygous gle1(-/-) mutant zebrafish display various aspects of LCCS, showing severe developmental abnormalities including motor neuron arborization defects and embryonic lethality. A previous gene expression study on spinal cord from LCCS fetuses indicated that oligodendrocyte dysfunction may be an important factor in LCCS. We therefore set out to investigate the development of myelinating glia in gle1(-/-) mutant zebrafish embryos. While expression of myelin basic protein (mbp) in hindbrain oligodendrocytes appeared relatively normal, our studies revealed a prominent defect in Schwann cell precursor proliferation and differentiation in the posterior lateral line nerve. Other genes mutated in LCCS have important roles in Schwann cell development, thereby suggesting that Schwann cell deficits may be a common factor in LCCS pathogenesis. These findings illustrate the potential importance of glial cells such as myelinating Schwann cells in motor neuron diseases linked to RNA processing defects. PMID:26921650

  3. Dorsal root ganglion-derived Schwann cells combined with poly(lactic-co-glycolic acid)/chitosan conduits for the repair of sciatic nerve defects in rats.

    PubMed

    Zhao, Li; Qu, Wei; Wu, Yuxuan; Ma, Hao; Jiang, Huajun

    2014-11-15

    Schwann cells, nerve regeneration promoters in peripheral nerve tissue engineering, can be used to repair both the peripheral and central nervous systems. However, isolation and purification of Schwann cells are complicated by contamination with fibroblasts. Current reported measures are mainly limited by either high cost or complicated procedures with low cell yields or purity. In this study, we collected dorsal root ganglia from neonatal rats from which we obtained highly purified Schwann cells using serum-free melanocyte culture medium. The purity of Schwann cells (> 95%) using our method was higher than that using standard medium containing fetal bovine serum. The obtained Schwann cells were implanted into poly(lactic-co-glycolic acid)/chitosan conduits to repair 10-mm sciatic nerve defects in rats. Results showed that axonal diameter and area were significantly increased and motor functions were obviously improved in the rat sciatic nerve tissue. Experimental findings suggest that serum-free melanocyte culture medium is conducive to purify Schwann cells and poly(lactic-co-glycolic acid)/chitosan nerve conduits combined with Schwann cells contribute to restore sciatic nerve defects.

  4. miR-148b-3p promotes migration of Schwann cells by targeting cullin-associated and neddylation-dissociated 1

    PubMed Central

    Qian, Tian-mei; Zhao, Li-li; Wang, Jing; Li, Ping; Qin, Jing; Liu, Yi-sheng; Yu, Bin; Ding, Fei; Gu, Xiao-song; Zhou, Song-lin

    2016-01-01

    MicroRNAs (miRNAs) are small, non-coding RNAs that negatively adjust gene expression in multifarious biological processes. However, the regulatory effects of miRNAs on Schwann cells remain poorly understood. Previous microarray analysis results have shown that miRNA expression is altered following sciatic nerve transaction, thereby affecting proliferation and migration of Schwann cells. This study investigated whether miR-148b-3p could regulate migration of Schwann cells by directly targeting cullin-associated and neddylation-dissociated 1 (Cand1). Up-regulated expression of miR-148b-3p promoted Schwann cell migration, whereas silencing of miR-148b-3p inhibited Schwann cell migration in vitro. Further experiments confirmed that Cand1 was a direct target of miR-148b-3p, and Cand1 knockdown reversed suppression of the miR-148b-3p inhibitor on Schwann cell migration. These results suggested that miR-148b-3p promoted migration of Schwann cells by directly targeting Cand1 in vitro. PMID:27482232

  5. Neoplasms with schwannian differentiation express transcription factors known to regulate normal schwann cell development.

    PubMed

    Pytel, Peter; Karrison, Theodore; Can Gong; Tonsgard, James H; Krausz, Thomas; Montag, Anthony G

    2010-12-01

    A number of transcription factors have been identified as important in guiding normal Schwann cell development. This study used immunohistochemistry on tissue arrays to assess the expression of some of these transcription factors (Sox5, Sox9, Sox10, AP-2α, Pax7, and FoxD3) on 76 schwannomas, 105 neurofibromas, and 34 malignant peripheral nerve sheath tumors (MPNSTs). Sox9 and Sox10 were found to be widely expressed in all tumor types. FoxD3 reactivity was stronger and more frequently found in schwannomas and MPNSTs than neurofibromas. AP-2α was positive in 31% to 49% of all tumors, but strong reactivity was limited to MPNSTs and schwannomas. Pax7 and Sox5 expression was restricted to subsets of MPNSTs. Statistical analysis showed significant differences between the 3 tumor types in the expression of these markers. No differences were found in the analyzed tumor subgroups, including schwannomas of different sites, schwannomas with or without NF2 association, neurofibromas of different types, or sporadic versus NF1-associated MPNSTs. These results suggest that the transcription factors that guide normal Schwann cell development also play a role in the biology of neoplastic cells with Schwannian differentiation. FoxD3, AP-2α, Pax7, and Sox5 are upregulated in MPNSTs compared with neurofibromas and may be markers of malignant transformation. Screening the expression of FoxD3, Sox9, and Sox10 on 23 cases of other spindle-cell proliferations that may be considered in the differential diagnosis of MPNST, including synovial sarcoma and spindle cell melanoma, suggests that these 3 are helpful markers of Schwannian differentiation in the context of diagnosing MPNSTs.

  6. Effects of cis-4-hydroxy-L-proline, an inhibitor of Schwann cell differentiation, on the secretion of collagenous and noncollagenous proteins by Schwann cells

    SciTech Connect

    Eldridge, C.F.; Bunge, R.P.; Bunge, M.B. )

    1988-02-01

    The proline analog cis-4-hydroxy-L-proline (CHP) was previously shown to inhibit both Schwann cell (SC) differentiation and extracellular matrix (ECM) formation in cultures of rat SCs and dorsal root ganglion neurons. The authors confirmed that CHP inhibits basal lamina formation by immunofluorescence with antibodies to laminin, type IV collagen, and heparan sulfate proteoglycan. In order to test the hypothesis that CHP inhibits SC differentiation by specifically inhibiting the secretion of collagen. Cultures grown in the presence or absence of CHP were metabolically labeled with ({sup 3}H)leucine and the media were analyzed for relative amounts of (a) collagenous and noncollagenous proteins by assay with bacterial collagenase and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), or (b) triple-helical collagen by pepsin digestion followed by SDS-PAGE. The results indicate that although CHP inhibited the accumulation of secreted collagen in the culture medium and disrupted collagen triple-helix formation, it also significantly inhibited the accumulation of secreted noncollagenous proteins in the medium. They conclude that CHP does not act as a specific inhibitor of collagen secretion in this system, and thus data from these experiments cannot be used to relate SC collagen production to other aspects of SC differentiation. They discuss the evidence for and against specificity of CHP action in other systems.

  7. Schwann Cell Transplantation and Descending Propriospinal Regeneration after Spinal Cord Injury

    PubMed Central

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

    2014-01-01

    After spinal cord injury (SCI), poor ability of damaged axons of the central nervous system (CNS) to regenerate causes very limited functional recovery. Schwann cells (SCs) have been widely explored as promising donors for transplantation to promote axonal regeneration in the CNS including the spinal cord. Compared with other CNS axonal pathways, injured propriospinal tracts display the strongest regenerative response to SC transplantation. Even without providing additional neurotrophic factors, propriospinal axons can grow into the SC environment which is rarely seen in supraspinal tracts. Propriospinal tract has been found to respond to several important neurotrophic factors secreted by SCs. Therefore, the SC is considered to be one of the most promising candidates for cell-based therapies for SCI. Since many reviews have already appeared on topics of SC transplantation in SCI repair, this review will focus particularly on the rationale of SC transplantation in mediating descending propriospinal axonal regeneration as well as optimizing such regeneration by using different combinatorial strategies. PMID:25257034

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

    PubMed

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

    2016-01-26

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

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

    PubMed Central

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

    2016-01-01

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

  10. Protocatechuic Acid from Alpinia oxyphylla Induces Schwann Cell Migration via ERK1/2, JNK and p38 Activation.

    PubMed

    Ju, Da-Tong; Kuo, Wei-Wen; Ho, Tsung-Jung; Paul, Catherine Reena; Kuo, Chia-Hua; Viswanadha, Vijaya Padma; Lin, Chien-Chung; Chen, Yueh-Sheng; Chang, Yung-Ming; Huang, Chih-Yang

    2015-01-01

    Alpinia oxyphylla MIQ (Alpinate Oxyphyllae Fructus, AOF) is an important traditional Chinese medicinal herb whose fruits is widely used to prepare tonics and is used as an aphrodisiac, anti salivary, anti diuretic and nerve-protective agent. Protocatechuic acid (PCA), a simple phenolic compound was isolated from the kernels of AOF. This study investigated the role of PCA in promoting neural regeneration and the underlying molecular mechanisms. Nerve regeneration is a complex physiological response that takes place after injury. Schwann cells play a crucial role in the endogenous repair of peripheral nerves due to their ability to proliferate and migrate. The role of PCA in Schwann cell migration was determined by assessing the induced migration potential of RSC96 Schwann cells. PCA induced changes in the expression of proteins of three MAPK pathways, as determined using Western blot analysis. In order to determine the roles of MAPK (ERK1/2, JNK, and p38) pathways in PCA-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production, the expression of several MAPK-associated proteins was analyzed after siRNA-mediated inhibition assays. Treatment with PCA-induced ERK1/2, JNK, and p38 phosphorylation that activated the downstream expression of PAs and MMPs. PCA-stimulated ERK1/2, JNK and p38 phosphorylation was attenuated by individual pretreatment with siRNAs or MAPK inhibitors (U0126, SP600125, and SB203580), resulting in the inhibition of migration and the uPA-related signal pathway. Taken together, our data suggest that PCA extract regulate the MAPK (ERK1/2, JNK, and p38)/PA (uPA, tPA)/MMP (MMP2, MMP9) mediated regeneration and migration signaling pathways in Schwann cells. Therefore, PCA plays a major role in Schwann cell migration and the regeneration of damaged peripheral nerve.

  11. Influence of mechanical properties of alginate-based substrates on the performance of Schwann cells in culture.

    PubMed

    Ning, Liqun; Xu, Yitong; Chen, Xiongbiao; Schreyer, David J

    2016-06-01

    In tissue engineering, artificial tissue scaffolds containing living cells have been studied for tissue repair and regeneration. Notably, the performance of these encapsulated-in-scaffolds cells in terms of cell viability, proliferation, and expression of function during and after the scaffold fabrication process, has not been well documented because of the influence of mechanical, chemical, and physical properties of the scaffold substrate materials. This paper presents our study on the influence of mechanical properties of alginate-based substrates on the performance of Schwann cells, which are the major glial cells of peripheral nervous system. Given the fact that alginate polysaccharide hydrogel has poor cell adhesion properties, in this study, we examined several types of cell-adhesion supplements and found that alginate covalently modified with RGD peptide provided improved cell proliferation and adhesion. We prepared alginate-based substrates for cell culture using varying alginate concentrations for altering their mechanical properties, which were confirmed by compression testing. Then, we examined the viability, proliferation, morphology, and expression of the extracellular matrix protein laminin of Schwann cells that were seeded on the surface of alginate-based substrates (or 2D culture) or encapsulated within alginate-based substrates (3D cultures), and correlated the examined cell performance to the alginate concentration (or mechanical properties) of hydrogel substrates. Our findings suggest that covalent attachment of RGD peptide can improve the success of Schwann cell encapsulation within alginate-based scaffolds, and provide guidance for regulating the mechanical properties of alginate-based scaffolds containing Schwann cells for applications in peripheral nervous system regeneration and repair. PMID:27012482

  12. Influence of mechanical properties of alginate-based substrates on the performance of Schwann cells in culture.

    PubMed

    Ning, Liqun; Xu, Yitong; Chen, Xiongbiao; Schreyer, David J

    2016-06-01

    In tissue engineering, artificial tissue scaffolds containing living cells have been studied for tissue repair and regeneration. Notably, the performance of these encapsulated-in-scaffolds cells in terms of cell viability, proliferation, and expression of function during and after the scaffold fabrication process, has not been well documented because of the influence of mechanical, chemical, and physical properties of the scaffold substrate materials. This paper presents our study on the influence of mechanical properties of alginate-based substrates on the performance of Schwann cells, which are the major glial cells of peripheral nervous system. Given the fact that alginate polysaccharide hydrogel has poor cell adhesion properties, in this study, we examined several types of cell-adhesion supplements and found that alginate covalently modified with RGD peptide provided improved cell proliferation and adhesion. We prepared alginate-based substrates for cell culture using varying alginate concentrations for altering their mechanical properties, which were confirmed by compression testing. Then, we examined the viability, proliferation, morphology, and expression of the extracellular matrix protein laminin of Schwann cells that were seeded on the surface of alginate-based substrates (or 2D culture) or encapsulated within alginate-based substrates (3D cultures), and correlated the examined cell performance to the alginate concentration (or mechanical properties) of hydrogel substrates. Our findings suggest that covalent attachment of RGD peptide can improve the success of Schwann cell encapsulation within alginate-based scaffolds, and provide guidance for regulating the mechanical properties of alginate-based scaffolds containing Schwann cells for applications in peripheral nervous system regeneration and repair.

  13. Electromagnetic induction between axons and their schwann cell myelin-protein sheaths.

    PubMed

    Goodman, G; Bercovich, D

    2013-12-01

    Two concepts have long dominated vertebrate nerve electrophysiology: (a) Schwann cell-formed myelin sheaths separated by minute non-myelinated nodal gaps and spiraling around axons of peripheral motor nerves reduce current leakage during propagation of trains of axon action potentials; (b) "jumping" by action potentials between successive nodes greatly increases signal conduction velocity. Long-held and more recent assumptions and issues underlying those concepts have been obscured by research emphasis on axon-sheath biochemical symbiosis and nerve regeneration. We hypothesize: mutual electromagnetic induction in the axon-glial sheath association, is fundamental in signal conduction in peripheral and central myelinated axons, explains the g-ratio and is relevant to animal navigation.

  14. Coculture of Primary Motor Neurons and Schwann Cells as a Model for In Vitro Myelination

    PubMed Central

    Hyung, Sujin; Yoon Lee, Bo; Park, Jong-Chul; Kim, Jinseok; Hur, Eun-Mi; Francis Suh, Jun-Kyo

    2015-01-01

    A culture system that can recapitulate myelination in vitro will not only help us better understand the mechanism of myelination and demyelination, but also find out possible therapeutic interventions for treating demyelinating diseases. Here, we introduce a simple and reproducible myelination culture system using mouse motor neurons (MNs) and Schwann cells (SCs). Dissociated motor neurons are plated on a feeder layer of SCs, which interact with and wrap around the axons of MNs as they differentiate in culture. In our MN-SC coculture system, MNs survived over 3 weeks and extended long axons. Both viability and axon growth of MNs in the coculture were markedly enhanced as compared to those of MN monoculture. Co-labeling of myelin basic proteins (MBPs) and neuronal microtubules revealed that SC formed myelin sheaths by wrapping around the axons of MNs. Furthermore, using the coculture system we found that treatment of an antioxidant substance coenzyme Q10 (Co-Q10) markedly facilitated myelination. PMID:26456300

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

    PubMed Central

    Verdiyan, Ekaterina E.; Allakhverdiev, Elvin S.; Maksimov, Georgy V.

    2016-01-01

    In the present paper we consider a new type of mechanism by which neurotransmitter acetylcholine (ACh) regulates the properties of peripheral nerve fibers myelin. Our data show the importance of the relationship between the changes in the number of Schwann cell (SC) acetylcholine receptors (AChRs) and the axon excitation (different intervals between action potentials (APs)). Using Raman spectroscopy, an effect of activation of SC AChRs on the myelin membrane fluidity was investigated. It was found, that ACh stimulates an increase in lipid ordering degree of the myelin lipids, thus providing evidence for specific role of the “axon-SC” interactions at the axon excitation. It was proposed, that during the axon excitation, the SC membrane K+- depolarization and the Ca2+—influx led to phospholipase activation or exocytosis of intracellular membrane vesicles and myelin structure reorganization. PMID:27455410

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

    PubMed

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

    2015-09-29

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

  17. Coculture of Primary Motor Neurons and Schwann Cells as a Model for In Vitro Myelination.

    PubMed

    Hyung, Sujin; Yoon Lee, Bo; Park, Jong-Chul; Kim, Jinseok; Hur, Eun-Mi; Francis Suh, Jun-Kyo

    2015-10-12

    A culture system that can recapitulate myelination in vitro will not only help us better understand the mechanism of myelination and demyelination, but also find out possible therapeutic interventions for treating demyelinating diseases. Here, we introduce a simple and reproducible myelination culture system using mouse motor neurons (MNs) and Schwann cells (SCs). Dissociated motor neurons are plated on a feeder layer of SCs, which interact with and wrap around the axons of MNs as they differentiate in culture. In our MN-SC coculture system, MNs survived over 3 weeks and extended long axons. Both viability and axon growth of MNs in the coculture were markedly enhanced as compared to those of MN monoculture. Co-labeling of myelin basic proteins (MBPs) and neuronal microtubules revealed that SC formed myelin sheaths by wrapping around the axons of MNs. Furthermore, using the coculture system we found that treatment of an antioxidant substance coenzyme Q10 (Co-Q10) markedly facilitated myelination.

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

    PubMed

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

    2015-07-10

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

  19. Distribution and role in regeneration of N-CAM in the basal laminae of muscle and Schwann cells.

    PubMed

    Rieger, F; Nicolet, M; Pinçon-Raymond, M; Murawsky, M; Levi, G; Edelman, G M

    1988-08-01

    The neural cell adhesion molecule (N-CAM) is a membrane glycoprotein involved in neuron-neuron and neuron-muscle adhesion. It can be synthesized in various forms by both nerve and muscle and it becomes concentrated at the motor endplate. Biochemical analysis of a frog muscle extract enriched in basal lamina revealed the presence of a polydisperse, polysialylated form of N-CAM with an average Mr of approximately 160,000 as determined by SDS-PAGE, which was converted to a form of 125,000 Mr by treatment with neuraminidase. To define further the role of N-CAM in neuromuscular junction organization, we studied the distribution of N-CAM in an in vivo preparation of frog basal lamina sheaths obtained by inducing the degeneration of both nerve and muscle fibers. Immunoreactive material could be readily detected by anti-N-CAM antibodies in such basal lamina sheaths. Ultrastructural analysis using immunogold techniques revealed N-CAM in close association with the basal lamina sheaths, present in dense accumulation at places that presumably correspond to synaptic regions. N-CAM epitopes were also associated with collagen fibrils in the extracellular matrix. The ability of anti-N-CAM antibodies to perturb nerve regeneration and reinnervation of the remaining basal lamina sheaths was then examined. In control animals, myelinating Schwann cells wrapped around the regenerated axon and reinnervation occurred only at the old synaptic areas; new contacts between nerve and basal lamina had a terminal Schwann cell capping the nerve terminal. In the presence of anti-N-CAM antibodies, three major abnormalities were observed in the regeneration and reinnervation processes: (a) regenerated axons in nerve trunks that had grown back into the old Schwann cell basal lamina were rarely associated with myelinating Schwann cell processes, (b) ectopic synapses were often present, and (c) many of the axon terminals lacked a terminal Schwann cell capping the nerve-basal lamina contact area. These

  20. The neurotrophin-3 receptor TrkC directly phosphorylates and activates the nucleotide exchange factor Dbs to enhance Schwann cell migration

    PubMed Central

    Yamauchi, Junji; Chan, Jonah R.; Miyamoto, Yuki; Tsujimoto, Gozoh; Shooter, Eric M.

    2005-01-01

    During the development of the peripheral nervous system, Schwann cells, the myelin-forming glia, migrate along axons before initiating myelination. We previously demonstrated that endogenous neurotrophin-3 (NT3) acting through the TrkC tyrosine kinase receptor enhances migration of premyelinating Schwann cells. This signaling pathway is mediated by the c-Jun N-terminal kinase (JNK) cascade regulated by the Rho GTPases Rac1 and Cdc42. However, missing is the link between TrkC and the GTPases. Here, we show that a guanine-nucleotide exchange factor (GEF), Dbl's big sister (Dbs), couples with TrkC to activate Cdc42 in Schwann cells. Furthermore, TrkC directly phosphorylates Dbs, thereby inducing the Cdc42-GEF activity. Taken together, activation of TrkC triggers Schwann cell migration by regulating Dbs upon direct tyrosine phosphorylation, providing a mechanism whereby a membrane receptor tyrosine kinase can induce the activation of Rho GTPase-GEFs. PMID:15758069

  1. A novel alternative splicing isoform of NF2 identified in human Schwann cells

    PubMed Central

    Su, Fang; Zhou, Zhengguang; Su, Wen; Wang, Zishu; Wu, Qiong

    2016-01-01

    Vestibular schwannoma (VS) is a benign, slow-growing cranial tumor that originates from the hypertrophy of Schwann cells. The majority of sporadic VS are unilateral, and the mechanisms underlying VS tumorigenesis are not fully understood. The human neurofibromin 2 (NF2) gene encodes the tumor suppressor protein merlin and the NF2 transcript can be alternatively spliced to form numerous isoforms. The present study investigated human Schwann cells (HSCs) at the mRNA and protein level to understand the function of the alternative splicing (AS) isoform of NF2. The total RNA of HSCs was isolated and the full-length coding sequence of NF2 was amplified. The amplified products were excised from agarose gels, purified and sequenced. NF2 at a protein level was assayed by immunoprecipitation and western blot analysis. The full-length and spliced NF2 forms were amplified by polymerase chain reaction (PCR) from the HSC complementary DNA and ligated into eukaryotic expression vector pcDNA3.1(+). The plasmids were transfected into the HSC HEI-193 cell line and cell proliferation assays were performed using Cell Counting Kit-8. PCR analysis using HSC total RNA as a template revealed the presence of a shortened NF2 transcript, which was due to splicing at the 3′-end of the NF2 mRNA. Sequence analysis confirmed that this AS isoform omitted exons 11, 12, 13, 14, 15 and 16. Immunoprecipitation and western blot analysis demonstrated that the AS isoform was highly expressed in the HSCs at 38 kDa, while the wild-type (WT) isoform, which was expected at 66 kDa, was undetectable. Transfection and cell proliferation assays revealed that the WT isoform exhibited significant growth inhibition, while the AS isoform did not suppress cell growth. In conclusion, the present study detected AS NF2 isoforms in HSC for the first time, and investigated the function of the principle AS isoform. The present study suggests that although HSCs have an undetectable level of WT isoform of the NF2 protein

  2. Integration of engrafted Schwann cells into injured peripheral nerve: axonal association and nodal formation on regenerated axons.

    PubMed

    Radtke, Christine; Akiyama, Yukinori; Lankford, Karen L; Vogt, Peter M; Krause, Diane S; Kocsis, Jeffery D

    2005-10-21

    Transplantation of myelin-forming cells can remyelinate axons, but little is known of the sodium channel organization of axons myelinated by donor cells. Sciatic nerve axons of female wild type mice were transected by a crush injury and Schwann cells (SCs) from green fluorescence protein (GFP)-expressing male mice were transplanted adjacent to the crush site. The male donor cells were identified by GFP fluorescence and fluorescence in situ hybridization (FISH) for Y chromosome. In nerves of GFP-expressing mice, GFP was observed in the axoplasm and in the cytoplasmic compartments of the Schwann cells, but not in the myelin. Following transplantation of GFP-SCs into crushed nerve of wild type mice, immuno-electron microscopic analysis indicated that GFP was observed in the cytoplasmic compartments of engrafted Schwann cells which formed myelin. Nodal and paranodal regions of the axons myelinated by the GFP-SCs were identified by Na(v)1.6 sodium channel and Caspr immunostaining, respectively. Nuclear identification of the Y chromosome by FISH confirmed the donor origin of the myelin-forming cells. These results indicate that engrafted GFP-SCs participate in myelination of regenerated peripheral nerve fibers and that Na(v)1.6 sodium channel, which is the dominant sodium channel at normal nodes, is reconstituted on the regenerated axons. PMID:16084645

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

    PubMed

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

    2013-11-01

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

  4. Predegenerated Schwann cells–a novel prospect for cell therapy for glaucoma: neuroprotection, neuroregeneration and neuroplasticity

    PubMed Central

    Smedowski, Adrian; Liu, Xiaonan; Pietrucha-Dutczak, Marita; Matuszek, Iwona; Varjosalo, Markku; Lewin-Kowalik, Joanna

    2016-01-01

    Glaucoma is an optic neuropathy that leads to irreversible blindness. Because the current therapies are not sufficient to protect against glaucoma-induced visual impairment, new treatment approaches are necessary to prevent disease progression. Cell transplantation techniques are currently considered to be among the most promising opportunities for nervous system damage treatment. The beneficial effects of undifferentiated cells have been investigated in experimental models of glaucoma, however experiments were accompanied by various barriers, which would make putative treatment difficult or even impossible to apply in a clinical setting. The novel therapy proposed in our study creates conditions to eliminate some of the identified barriers described for precursor cells transplantation and allows us to observe direct neuroprotective and pro-regenerative effects in ongoing optic neuropathy without additional modifications to the transplanted cells. We demonstrated that the proposed novel Schwann cell therapy might be promising, effective and easy to apply, and is safer than the alternative cell therapies for the treatment of glaucoma. PMID:27034151

  5. Pulsed magnetic field promotes proliferation and neurotrophic genes expression in Schwann cells in vitro

    PubMed Central

    Liu, Liang; Liu, Zhongyang; Huang, Liangliang; Sun, Zhen; Ma, Teng; Zhu, Shu; Quan, Xin; Yang, Yafeng; Huang, Jinghui; Luo, Zhuojing

    2015-01-01

    As one of the most classic supportive cells, Schwann cells (SCs) have been considered as potential candidates for nerve regeneration. However, SCs cultured in vitro are found with attenuated biological activities, which limits their application. Pulsed magnetic field (PMF) has been demonstrated to be safe and efficient to regulate several cells activities. However, it is still unclear the effect of PMF on proliferation and expression of neurotrophic factors in SCs. Therefore, the present study was designed to examine such possible effects. The tolerance of SCs to PMF was examined by flow cytometry and scanning electron microscopy (SEM). The proliferation of cells was detected by an EdU labeling assay and a Prestoblue assay. The expression and secretion of neurotrophic factors in SCs was assayed by RT-PCR and ELISA. We found that 2.0 mT was the optimal intensity that caused relatively little apoptosis with profound proliferation in SCs. The gene expression and protein level of brain-derived neurotrophic factor (BDNF), glial cell derived neurotrophic factor (GDNF), vascular endothelial growth factor (VEGF) were up-regulated following PMF stimulation, additionally, the gene expression and protein level of neurotrophin-3 (NT-3) was not enhanced by PMF. Our results suggested that PMF could improve SC proliferation and biological function, which might shed a light on the potential utilization of PMF in nerve regeneration via SC activation. PMID:26045741

  6. An integrated approach to characterize transcription factor and microRNA regulatory networks involved in Schwann cell response to peripheral nerve injury

    PubMed Central

    2013-01-01

    Background The regenerative response of Schwann cells after peripheral nerve injury is a critical process directly related to the pathophysiology of a number of neurodegenerative diseases. This SC injury response is dependent on an intricate gene regulatory program coordinated by a number of transcription factors and microRNAs, but the interactions among them remain largely unknown. Uncovering the transcriptional and post-transcriptional regulatory networks governing the Schwann cell injury response is a key step towards a better understanding of Schwann cell biology and may help develop novel therapies for related diseases. Performing such comprehensive network analysis requires systematic bioinformatics methods to integrate multiple genomic datasets. Results In this study we present a computational pipeline to infer transcription factor and microRNA regulatory networks. Our approach combined mRNA and microRNA expression profiling data, ChIP-Seq data of transcription factors, and computational transcription factor and microRNA target prediction. Using mRNA and microRNA expression data collected in a Schwann cell injury model, we constructed a regulatory network and studied regulatory pathways involved in Schwann cell response to injury. Furthermore, we analyzed network motifs and obtained insights on cooperative regulation of transcription factors and microRNAs in Schwann cell injury recovery. Conclusions This work demonstrates a systematic method for gene regulatory network inference that may be used to gain new information on gene regulation by transcription factors and microRNAs. PMID:23387820

  7. Neuregulin Facilitates Nerve Regeneration by Speeding Schwann Cell Migration via ErbB2/3-Dependent FAK Pathway

    PubMed Central

    Chang, Hung-Ming; Shyu, Ming-Kwang; Tseng, Guo-Fang; Liu, Chiung-Hui; Chang, Hung-Shuo; Lan, Chyn-Tair; Hsu, Wen-Ming; Liao, Wen-Chieh

    2013-01-01

    Background Adequate migration of Schwann cells (Sc) is crucial for axon-guidance in the regenerative process after peripheral nerve injury (PNI). Considering neuregulin-erbB-FAK signaling is an essential pathway participating in the regulation of Sc migration during development, the present study is aimed to examine whether neuregulin would exert its beneficial effects on adult following PNI and further determine the potential changes of downstream pathway engaged in neuro-regeneration by both in vitro and in vivo approaches. Methodology and Principal Findings Cultured RSC96 cells treated with neuregulin were processed for erbB2/3 immunofluorescence and FAK immunoblotings. The potential effects of neuregulin on Sc were assessed by cell adherence, spreading, and migration assays. In order to evaluate the functional significance of neuregulin on neuro-regeneration, the in vivo model of PNI was performed by chronic end-to-side neurorrhaphy (ESN). In vitro studies indicated that after neuregulin incubation, erbB2/3 were not only expressed in cell membranes, but also distributed throughout the cytoplasm and nucleus of RSC96 cells. Activation of erbB2/3 was positively correlated with FAK phosphorylation. Neuregulin also increases Sc adherence, spreading, and migration by 127.2±5.0%, 336.8±3.0%, and 80.0±5.7%, respectively. As for in vivo study, neuregulin significantly accelerates the speed of Sc migration and increases Sc expression in the distal stump of injured nerves. Retrograde labeling and compound muscle action potential recordings (CMAP) also showed that neuregulin successfully facilitates nerve regeneration by eliciting noticeably larger CMAP and promoting quick re-innervation of target muscles. Conclusions As neuregulin successfully improves axo-glial interaction by speeding Sc migration via the erbB2/3-FAK pathway, therapeutic use of neuregulin may thus serve as a promising strategy to facilitate the progress of nerve regeneration after PNI. PMID:23301073

  8. Schwann cell remyelination and recurrent demyelination in the central nervous system of mice infected with attenuated Theiler's virus.

    PubMed

    Dal Canto, M C; Lipton, H L

    1980-01-01

    Theiler's murine encephalomyelitis virus (TMEV) infection produces a chronic demyelinating disease in mice, and myelin breakdown appears to be immune-mediated. By using an attenuated TMEC strain, WW virus, to infect mice, the course of the disease was slowed and the severity of the inflammatory and glial responses were reduced. In this circumstance, most of the demyelinating lesions showed extensive remyelination, predominantly by Schwann cells. In addition, it was demonstrated that there was recurrent demyelinating activity in the central nervous system (CNS) of infected animals. It is suggested that the rapidity and intensity of demyelinating lesions may influence the potential for remyelination and that Schwann cell participation may be a more important mechanism of myelin repair than it is now thought to be. The fact that there is a recurrent demyelination in TMEV infection increases its relevance as an experimental animal model for multiple sclerosis.

  9. MiR-204 promotes apoptosis in oxidative stress-induced rat Schwann cells by suppressing neuritin expression.

    PubMed

    Gao, Rui; Wang, Liming; Sun, Jun; Nie, Kun; Jian, Huiling; Gao, Lei; Liao, Xinhua; Zhang, Haiyuan; Huang, Jin; Gan, Shangquan

    2014-08-25

    Neuritin (Nrn1) is a neurotrophin that plays an important role in nervous system plasticity and repair following nerve injury. MicroRNAs (miRNAs) are a type of small non-coding RNA that regulate nearly all aspects of nerve development and survival, including apoptosis. Here it was found that miR-204 negatively regulates Nrn1 protein expression through direct interaction with Nrn1 transcript. Moreover, miR-204 activates cleaved caspase-3, enhancing the sensitivity of RSC96 Schwann cells to H2O2-induced oxidative stress and apoptosis. Thus, miR-204 expressed at a low level may create a microenvironment suitable for the repair of injured nerves by relieving the inhibition of Nrn1 transcription and stimulating the anti-apoptotic function of Schwann cells. These results provide novel insights into the roles of miR-204 in nerve injury and repair. PMID:25036738

  10. Transcription factors Sox10 and Sox2 functionally interact with positive transcription elongation factor b in Schwann cells.

    PubMed

    Arter, Juliane; Wegner, Michael

    2015-02-01

    Sox proteins are mechanistically versatile regulators with established relevance to different developmental processes and crucial impact on chromatin structure, DNA conformation, and transcriptional initiation. Here, we show that Sox2 and Sox10, two Sox proteins important for Schwann cell development, also have the capability to activate transcriptional elongation in a Schwann cell line by recruiting the positive transcription elongation factor b. Recruitment is mediated by physical interaction between the carboxyterminal transactivation domains of the two Sox proteins and the Cyclin T1 subunit of positive transcription elongation factor b, with interaction interfaces for the two Sox proteins being mapped to adjacent regions of the central part of Cyclin T1. Supporting the relevance of this interaction to Schwann cell development, transcription of myelin genes appears regulated at the level of elongation. Our results thus add a new facet to the activity of Sox proteins and expand the functional repertoire of this important group of developmental regulators. Sox transcription factors are important regulators of nervous system development. While they are known to regulate transcription by recruiting and stabilizing the RNA polymerase II preinitiation complex directly or with help of the Mediator complex, this study provides evidence that Sox10 and Sox2 additionally influence transcription in glial cells at the elongation stage by recruiting P-TEFb. Cdk9, cyclin-dependent kinase 9; P-TEFb, positive transcription elongation factor b; Pol II, RNA polymerase II; Sox, Sox2 or Sox10 protein.

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

    PubMed

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

    2015-12-31

    Peripheral nerve injuries, caused by accidental trauma, acute compression or surgery, often result in temporary or life-long neuronal dysfunctions and inflict great economic or social burdens on the patients. Nerve cell proliferation is an essential process to restore injured nerves of adults. Schwann cells play a crucial role in endogenous repair of peripheral nerves due to their ability to proliferate, migrate and provide trophic support to axons via expression of various neurotrophic factors, such as the nerve growth factor (NGF), especially after nerve injury. Protocatechuic acid (PCA) is a dihydroxybenzoic acid, a type of phenolic acid, isolated from the kernels of Alpinia oxyphylla Miq (AOF), a traditional Chinese herbal medicine the fruits of which are widely used as a tonic, aphrodisiac, anti-salivation and anti-diarrheatic. This study investigated the molecular mechanisms by which PCA induces Schwann cell proliferation by activating IGF-IR-PI3K-Akt pathway. Treatment with PCA induces phosphorylation of the insulin-like growth factor-I (IGF-I)-mediated phosphatidylinositol 3 kinase/serine - threonine kinase (PI3K/Akt) pathway, and activates expression of cell nuclear antigen (PCNA) in a dose-dependent manner. Cell cycle analysis after 18 h of treatment showed that proliferation of the RSC96 cells was enhanced by PCA treatment. The PCA induced proliferation was accompanied by modulation in the expressions of cell cycle proteins cyclin D1, cyclin E and cyclin A. Knockdown of PI3K using small interfering RNA (siRNA) and inhibition of IGF-IR receptor resulted in the reduction in cell survival proteins. The results collectively showed that PCA treatment promoted cell proliferation and cell survival via IGF-I signaling. PMID:26717920

  12. Uptake of locally applied deoxyglucose, glucose and lactate by axons and Schwann cells of rat vagus nerve

    PubMed Central

    Véga, Céline; Martiel, Jean-Louis; Drouhault, Delphine; Burckhart, Marie-France; Coles, Jonathan A

    2003-01-01

    We asked whether, in a steady state, neurons and glial cells both take up glucose sufficient for their energy requirements, or whether glial cells take up a disproportionate amount and transfer metabolic substrate to neurons. A desheathed rat vagus nerve was held crossways in a laminar flow perfusion chamber and stimulated at 2 Hz. 14C-labelled substrate was applied from a micropipette for 5 min over a < 0.6 mm band of the surface of the nerve. After 10-55 min incubation, the nerve was lyophilized and the longitudinal distribution of radioactivity measured. When the weakly metabolizable analogue of glucose, 2-deoxy-[U-14C]d-glucose (*DG), was applied, the profiles of the radioactivity broadened with time, reaching distances several times the mean length of the Schwann cells (0.32 mm; most of the Schwann cells are non-myelinating). The profiles were well fitted by curves calculated for diffusion in a single compartment, the mean diffusion coefficient being 463 ± 34 μm2 s−1 (± s.e.m., n = 16). Applications of *DG were repeated in the presence of the gap junction blocker, carbenoxolone (100 μm). The profiles were now narrower and better fitted with two compartments. One compartment had a coefficient not significantly different from that in the absence of the gap junction blocker (axons), the other compartment had a coefficient of 204 ± 24 μm2 s−1, n = 4. Addition of the gap junction blocker 18-α-glycyrrhetinic acid, or blocking electrical activity with TTX, also reduced longitudinal diffusion. Ascribing the compartment in which diffusion was reduced by these treatments to non-myelinating Schwann cells, we conclude that 78.0 ± 3.6 % (n = 9) of the uptake of *DG was into Schwann cells. This suggests that there was transfer of metabolic substrate from Schwann cells to axons. Local application of [14C]glucose or [14C]lactate led to variable labelling along the length of the nerve, but with both substrates narrow peaks were often present at the application site

  13. A Fibrin Matrix Promotes the Differentiation of EMSCs Isolated from Nasal Respiratory Mucosa to Myelinating Phenotypical Schwann-Like Cells

    PubMed Central

    Chen, Qian; Zhang, Zhijian; Liu, Jinbo; He, Qinghua; Zhou, Yuepeng; Shao, Genbao; Sun, Xianglan; Cao, Xudong; Gong, Aihua; Jiang, Ping

    2015-01-01

    Because Schwann cells perform the triple tasks of myelination, axon guidance and neurotrophin synthesis, they are candidates for cell transplantation that might cure some types of nervous-system degenerative diseases or injuries. However, Schwann cells are difficult to obtain. As another option, ectomesenchymal stem cells (EMSCs) can be easily harvested from the nasal respiratory mucosa. Whether fibrin, an important transplantation vehicle, can improve the differentiation of EMSCs into Schwann-like cells (SLCs) deserves further research. EMSCs were isolated from rat nasal respiratory mucosa and were purified using anti-CD133 magnetic cell sorting. The purified cells strongly expressed HNK-1, nestin, p75NTR, S-100, and vimentin. Using nuclear staining, the MTT assay and Western blotting analysis of the expression of cell-cycle markers, the proliferation rate of EMSCs on a fibrin matrix was found to be significantly higher than that of cells grown on a plastic surface but insignificantly lower than that of cells grown on fibronectin. Additionally, the EMSCs grown on the fibrin matrix expressed myelination-related molecules, including myelin basic protein (MBP), 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) and galactocerebrosides (GalCer), more strongly than did those grown on fibronectin or a plastic surface. Furthermore, the EMSCs grown on the fibrin matrix synthesized more neurotrophins compared with those grown on fibronectin or a plastic surface. The expression level of integrin in EMSCs grown on fibrin was similar to that of cells grown on fibronectin but was higher than that of cells grown on a plastic surface. These results demonstrated that fibrin not only promoted EMSC proliferation but also the differentiation of EMSCs into the SLCs. Our findings suggested that fibrin has great promise as a cell transplantation vehicle for the treatment of some types of nervous system diseases or injuries. PMID:25666351

  14. A fibrin matrix promotes the differentiation of EMSCs isolated from nasal respiratory mucosa to myelinating phenotypical Schwann-like cells.

    PubMed

    Chen, Qian; Zhang, Zhijian; Liu, Jinbo; He, Qinghua; Zhou, Yuepeng; Shao, Genbao; Sun, Xianglan; Cao, Xudong; Gong, Aihua; Jiang, Ping

    2015-03-01

    Because Schwann cells perform the triple tasks of myelination, axon guidance and neurotrophin synthesis, they are candidates for cell transplantation that might cure some types of nervous-system degenerative diseases or injuries. However, Schwann cells are difficult to obtain. As another option, ectomesenchymal stem cells (EMSCs) can be easily harvested from the nasal respiratory mucosa. Whether fibrin, an important transplantation vehicle, can improve the differentiation of EMSCs into Schwann-like cells (SLCs) deserves further research. EMSCs were isolated from rat nasal respiratory mucosa and were purified using anti-CD133 magnetic cell sorting. The purified cells strongly expressed HNK-1, nestin, p75(NTR), S-100, and vimentin. Using nuclear staining, the MTT assay and Western blotting analysis of the expression of cell-cycle markers, the proliferation rate of EMSCs on a fibrin matrix was found to be significantly higher than that of cells grown on a plastic surface but insignificantly lower than that of cells grown on fibronectin. Additionally, the EMSCs grown on the fibrin matrix expressed myelination-related molecules, including myelin basic protein (MBP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) and galactocerebrosides (GalCer), more strongly than did those grown on fibronectin or a plastic surface. Furthermore, the EMSCs grown on the fibrin matrix synthesized more neurotrophins compared with those grown on fibronectin or a plastic surface. The expression level of integrin in EMSCs grown on fibrin was similar to that of cells grown on fibronectin but was higher than that of cells grown on a plastic surface. These results demonstrated that fibrin not only promoted EMSC proliferation but also the differentiation of EMSCs into the SLCs. Our findings suggested that fibrin has great promise as a cell transplantation vehicle for the treatment of some types of nervous system diseases or injuries.

  15. Human dental pulp stem cells can differentiate into Schwann cells and promote and guide neurite outgrowth in an aligned tissue-engineered collagen construct in vitro

    PubMed Central

    Martens, Wendy; Sanen, Kathleen; Georgiou, Melanie; Struys, Tom; Bronckaers, Annelies; Ameloot, Marcel; Phillips, James; Lambrichts, Ivo

    2014-01-01

    In the present study, we evaluated the differentiation potential of human dental pulp stem cells (hDPSCs) toward Schwann cells, together with their functional capacity with regard to myelination and support of neurite outgrowth in vitro. Successful Schwann cell differentiation was confirmed at the morphological and ultrastructural level by transmission electron microscopy. Furthermore, compared to undifferentiated hDPSCs, immunocytochemistry and ELISA tests revealed increased glial marker expression and neurotrophic factor secretion of differentiated hDPSCs (d-hDPSCs), which promoted survival and neurite outgrowth in 2-dimensional dorsal root ganglia cultures. In addition, neurites were myelinated by d-hDPSCs in a 3-dimensional collagen type I hydrogel neural tissue construct. This engineered construct contained aligned columns of d-hDPSCs that supported and guided neurite outgrowth. Taken together, these findings provide the first evidence that hDPSCs are able to undergo Schwann cell differentiation and support neural outgrowth in vitro, proposing them to be good candidates for cell-based therapies as treatment for peripheral nerve injury.—Martens, W., Sanen, K., Georgiou, M., Struys, T., Bronckaers, A., Ameloot, M., Phillips, J., Lambrichts, I. Human dental pulp stem cells can differentiate into Schwann cells and promote and guide neurite outgrowth in an aligned tissue-engineered collagen construct in vitro. PMID:24352035

  16. PDGF, NT-3 and IGF-2 in Combination Induced Transdifferentiation of Muscle-Derived Stem Cells into Schwann Cell-Like Cells

    PubMed Central

    Song, Yanling; Ding, Weijin; Zhang, Yingfan; Zhang, Wenhao; Zhang, Jie; Peng, Heng; Jiang, Hua

    2014-01-01

    Muscle-derived stem cells (MDSCs) are multipotent stem cells with a remarkable long-term self-renewal and regeneration capacity. Here, we show that postnatal MDSCs could be transdifferentiated into Schwann cell-like cells upon the combined treatment of three neurotrophic factors (PDGF, NT-3 and IGF-2). The transdifferentiation of MDSCs was initially induced by Schwann cell (SC) conditioned medium. MDSCs adopted a spindle-like morphology similar to SCs after the transdifferentiation. Immunocytochemistry and immunoblot showed clearly that the SC markers S100, GFAP and p75 were expressed highly only after the transdifferentiation. Flow cytometry assay showed that the portion of S100 expressed cells was more than 60 percent and over one fourth of the transdifferentiated cells expressed all the three SC markers, indicating an efficient transdifferentiation. We then tested neurotrophic factors in the conditioned medium and found it was PDGF, NT-3 and IGF-2 in combination that conducted the transdifferentiation. Our findings demonstrate that it is possible to use specific neurotrophic factors to transdifferentiate MDSCs into Schwann cell-like cells, which might be therapeutically useful for clinical applications. PMID:24454677

  17. Nerve compression activates selective nociceptive pathways and upregulates peripheral sodium channel expression in Schwann cells.

    PubMed

    Frieboes, Laura Rummler; Palispis, Winnie Anne; Gupta, Ranjan

    2010-06-01

    Chronic nerve compression (CNC) injuries, such as carpal tunnel syndrome, are common musculoskeletal conditions that affect patients with debilitating loss of sensory function and pain. Although early detection and treatment are important, our understanding of pain-related molecular mechanisms remains largely unclear. Here we investigate these mechanisms using an animal model for CNC injury. To confirm that CNC injury induces pain, we assessed expression of c-fos, a gene that is rapidly expressed in spinal sensory afferents in response to painful peripheral stimuli, and TNF-alpha and IL-6, two proinflammatory cytokines that are crucial to development of inflammatory-mediated pain. Results show c-fos upregulation 1-2 weeks postinjury in the absence of TNF-alpha or IL-6 expression, indicating increased neural sensitivity without an inflammatory response. This is consistent with previous studies that showed no morphologic evidence of inflammation in the CNC model. Surprisingly, we also found de novo expression of Na(V)1.8, a sodium channel linked to the development of neuropathic pain, in endoneurial Schwann cells following injury. Until now, Na(V)1.8 expression was thought to be restricted to sensory neurons. CNC injury appears to be a unique model of noninflammatory neuropathic pain. Further investigation of the underlying molecular basis could yield promising targets for early diagnosis and treatment.

  18. BMP7 retards peripheral myelination by activating p38 MAPK in Schwann cells

    PubMed Central

    Liu, Xiaoyu; Zhao, Yahong; Peng, Su; Zhang, Shuqiang; Wang, Meihong; Chen, Yeyue; Zhang, Shan; Yang, Yumin; Sun, Cheng

    2016-01-01

    Schwann cell (SC) myelination is pivotal for the proper physiological functioning of the nervous system, but the underlying molecular mechanism remains less well understood. Here, we showed that the expression of bone morphogenetic protein 7 (BMP7) inversely correlates with myelin gene expression during peripheral myelination, which suggests that BMP7 is likely a negative regulator for myelin gene expression. Our experiments further showed that the application of BMP7 attenuates the cAMP induced myelin gene expression in SCs. Downstream pathway analysis suggested that both p38 MAPK and SMAD are activated by exogenous BMP7 in SCs. The pharmacological intervention and gene silence studies revealed that p38 MAPK, not SMAD, is responsible for BMP7-mediated suppression of myelin gene expression. In addition, c-Jun, a potential negative regulator for peripheral myelination, was up-regulated by BMP7. In vivo experiments showed that BMP7 treatment greatly impaired peripheral myelination in newborn rats. Together, our results established that BMP7 is a negative regulator for peripheral myelin gene expression and that p38 MAPK/c-Jun axis might be the main downstream target of BMP7 in this process. PMID:27491681

  19. Glutamate signals through mGluR2 to control Schwann cell differentiation and proliferation.

    PubMed

    Saitoh, Fuminori; Wakatsuki, Shuji; Tokunaga, Shinji; Fujieda, Hiroki; Araki, Toshiyuki

    2016-01-01

    Rapid saltatory nerve conduction is facilitated by myelin structure, which is produced by Schwann cells (SC) in the peripheral nervous system (PNS). Proper development and degeneration/regeneration after injury requires regulated phenotypic changes of SC. We have previously shown that glutamate can induce SC proliferation in culture. Here we show that glutamate signals through metabotropic glutamate receptor 2 (mGluR2) to induce Erk phosphorylation in SC. mGluR2-elicited Erk phosphorylation requires ErbB2/3 receptor tyrosine kinase phosphorylation to limit the signaling cascade that promotes phosphorylation of Erk, but not Akt. We found that Gβγ and Src are involved in subcellular signaling downstream of mGluR2. We also found that glutamate can transform myelinating SC to proliferating SC, while inhibition of mGluR2 signaling can inhibit demyelination of injured nerves in vivo. These data suggest pathophysiological significance of mGluR2 signaling in PNS and its possible therapeutic importance to combat demyelinating disorders including Charcot-Marie-Tooth disease. PMID:27432639

  20. Bioactive poly(L-lactic acid) conduits seeded with Schwann cells for peripheral nerve regeneration.

    PubMed

    Evans, Gregory R D; Brandt, Keith; Katz, Steven; Chauvin, Priscilla; Otto, Lisa; Bogle, Melissa; Wang, Bao; Meszlenyi, Rudolph K; Lu, Lichun; Mikos, Antonios G; Patrick, Charles W

    2002-02-01

    This study attempted to enhance the efficacy of peripheral nerve regeneration using our previously tested poly(L-lactic acid) (PLLA) conduits by incorporating them with allogeneic Schwann cells (SCs). The SCs were harvested, cultured to obtain confluent monolayers and two concentrations (1 x 10(4) and 1 x 10(6) SC/ml) were combined with a collagen matrix (Vitrogen) and injected into the PLLA conduits. The conduits were then implanted into a 12 mm right sciatic nerve defect in rats. Three control groups were used: isografts, PLLA conduits filled with collagen alone and empty silicone tubes. The sciatic functional index (SFI) was calculated monthly through four months. At the end of second and fourth months, the gastrocnemius muscle was harvested and weighed for comparison and the graft conduit and distal nerve were harvested for histomorphologic analysis. The mean SFI demonstrated no group differences from isograft control. By four months, there was no significant difference in gastrocnemius muscle weight between the experimental groups compared to isograft controls. At four months, the distal nerve demonstrated a statistically lower number of axons mm2 for the high and low SC density groups and collagen control. The nerve fiber density was significantly lower in all of the groups compared to isograft controls by four months. The development of a "bioactive" nerve conduit using tissue engineering to replace autogenous nerve grafts offers a potential approach to improved patient care. Although equivalent nerve regeneration to autografts was not achieved, this study provides promising results for further investigation.

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

    PubMed

    Vasil, Indra K

    2008-09-01

    Plant biotechnology is founded on the principles of cellular totipotency and genetic transformation, which can be traced back to the Cell Theory of Matthias Jakob Schleiden and Theodor Schwann, and the discovery of genetic transformation in bacteria by Frederick Griffith, respectively. On the 25th anniversary of the genetic transformation of plants, this review provides a historical account of the evolution of the theoretical concepts and experimental strategies that led to the production and commercialization of biotech (transformed or transgenic) plants expressing many useful genes, and emphasizes the beneficial effects of plant biotechnology on food security, human health, the environment, and conservation of biodiversity. In so doing, it celebrates and pays tribute to the contributions of scores of scientists who laid the foundation of modern plant biotechnology by their bold and unconventional thinking and experimentation. It highlights also the many important lessons to be learnt from the fascinating history of plant biotechnology, the significance of history in science teaching and research, and warns against the danger of the growing trends of ignoring history and historical illiteracy. PMID:18612644

  2. Glutamate signals through mGluR2 to control Schwann cell differentiation and proliferation

    PubMed Central

    Saitoh, Fuminori; Wakatsuki, Shuji; Tokunaga, Shinji; Fujieda, Hiroki; Araki, Toshiyuki

    2016-01-01

    Rapid saltatory nerve conduction is facilitated by myelin structure, which is produced by Schwann cells (SC) in the peripheral nervous system (PNS). Proper development and degeneration/regeneration after injury requires regulated phenotypic changes of SC. We have previously shown that glutamate can induce SC proliferation in culture. Here we show that glutamate signals through metabotropic glutamate receptor 2 (mGluR2) to induce Erk phosphorylation in SC. mGluR2-elicited Erk phosphorylation requires ErbB2/3 receptor tyrosine kinase phosphorylation to limit the signaling cascade that promotes phosphorylation of Erk, but not Akt. We found that Gβγ and Src are involved in subcellular signaling downstream of mGluR2. We also found that glutamate can transform myelinating SC to proliferating SC, while inhibition of mGluR2 signaling can inhibit demyelination of injured nerves in vivo. These data suggest pathophysiological significance of mGluR2 signaling in PNS and its possible therapeutic importance to combat demyelinating disorders including Charcot-Marie-Tooth disease. PMID:27432639

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

    PubMed

    Vasil, Indra K

    2008-09-01

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

  4. BMP7 retards peripheral myelination by activating p38 MAPK in Schwann cells.

    PubMed

    Liu, Xiaoyu; Zhao, Yahong; Peng, Su; Zhang, Shuqiang; Wang, Meihong; Chen, Yeyue; Zhang, Shan; Yang, Yumin; Sun, Cheng

    2016-08-05

    Schwann cell (SC) myelination is pivotal for the proper physiological functioning of the nervous system, but the underlying molecular mechanism remains less well understood. Here, we showed that the expression of bone morphogenetic protein 7 (BMP7) inversely correlates with myelin gene expression during peripheral myelination, which suggests that BMP7 is likely a negative regulator for myelin gene expression. Our experiments further showed that the application of BMP7 attenuates the cAMP induced myelin gene expression in SCs. Downstream pathway analysis suggested that both p38 MAPK and SMAD are activated by exogenous BMP7 in SCs. The pharmacological intervention and gene silence studies revealed that p38 MAPK, not SMAD, is responsible for BMP7-mediated suppression of myelin gene expression. In addition, c-Jun, a potential negative regulator for peripheral myelination, was up-regulated by BMP7. In vivo experiments showed that BMP7 treatment greatly impaired peripheral myelination in newborn rats. Together, our results established that BMP7 is a negative regulator for peripheral myelin gene expression and that p38 MAPK/c-Jun axis might be the main downstream target of BMP7 in this process.

  5. In Vivo Gene Transfer to Schwann Cells in the Rodent Sciatic Nerve by Electroporation.

    PubMed

    Ino, Daisuke; Iino, Masamitsu

    2016-01-01

    The formation of the myelin sheath by Schwann cells (SCs) is essential for rapid conduction of nerve impulses along axons in the peripheral nervous system. SC-selective genetic manipulation in living animals is a powerful technique for studying the molecular and cellular mechanisms of SC myelination and demyelination in vivo. While knockout/knockin and transgenic mice are powerful tools for studying SC biology, these methods are costly and time consuming. Viral vector-mediated transgene introduction into the sciatic nerve is a simpler and less laborious method. However, viral methods have limitations, such as toxicity, transgene size constraints, and infectivity restricted to certain developmental stages. Here, we describe a new method that allows selective transfection of myelinating SCs in the rodent sciatic nerve using electroporation. By applying electric pulses to the sciatic nerve at the site of plasmid DNA injection, genes of interest can be easily silenced or overexpressed in SCs in both neonatal and more mature animals. Furthermore, this in vivo electroporation method allows for highly efficient simultaneous expression of multiple transgenes. Our novel technique should enable researchers to efficiently manipulate SC gene expression, and facilitate studies on SC development and function. PMID:27683960

  6. Culturing Schwann Cells from Neonatal Rats by Improved Enzyme Digestion Combined with Explants-culture Method.

    PubMed

    Liu, Di; Liang, Xiao-Chun; Zhang, Hong

    2016-08-01

    Objective To develop an improved method for culturing Schwann cells(SCs) by using both enzyme digestion and explants-culture approaches and compared with traditional explants-culture method and general hemi-explants-culture method. Methods Bilaterally sciatic nerves and brachial plexus nerves were dissected from 3 to 5-day-old neonatal SD rats and explants-culture method,general hemi-explants-culture method,and improved enzyme digestion combined with explants-culture method were adopted to culture SCs,respectively. SCs were digested and passaged after 7 days in culture and counted under the microscope. The purity of SCs was identified by S-100 immunofluorescence staining. Results The SCs of improved method group grew fastest and the total number of cells obtained was(1.85±0.13)×10(6);the SCs of the hemi-explants-culture method group grew slower than the improved method group and the total number of cells obtained was (1.10±0.10)×10(6);the SCs of the explants-culture method group grew slowest and the total number of cells obtained was (0.77±0.03)×10(6).The total number of cells obtained showed significant difference among the three groups(P<0.01). Immunofluorescence staining showed that the SCs purity was (95.73±1.51)% in the improved method group,(84.66±2.68)% in the hemi-explants-culture method group,and (74.50±4.23)% in the explants-culture method group(P<0.01). Conclusion The improved enzyme digestion combined with explants-culture method can obtain sufficient amount of high-purity SCs in a short time and thus may be applied in further research on peripheral nerve regeneration.

  7. Culturing Schwann Cells from Neonatal Rats by Improved Enzyme Digestion Combined with Explants-culture Method.

    PubMed

    Liu, Di; Liang, Xiao-Chun; Zhang, Hong

    2016-08-01

    Objective To develop an improved method for culturing Schwann cells(SCs) by using both enzyme digestion and explants-culture approaches and compared with traditional explants-culture method and general hemi-explants-culture method. Methods Bilaterally sciatic nerves and brachial plexus nerves were dissected from 3 to 5-day-old neonatal SD rats and explants-culture method,general hemi-explants-culture method,and improved enzyme digestion combined with explants-culture method were adopted to culture SCs,respectively. SCs were digested and passaged after 7 days in culture and counted under the microscope. The purity of SCs was identified by S-100 immunofluorescence staining. Results The SCs of improved method group grew fastest and the total number of cells obtained was(1.85±0.13)×10(6);the SCs of the hemi-explants-culture method group grew slower than the improved method group and the total number of cells obtained was (1.10±0.10)×10(6);the SCs of the explants-culture method group grew slowest and the total number of cells obtained was (0.77±0.03)×10(6).The total number of cells obtained showed significant difference among the three groups(P<0.01). Immunofluorescence staining showed that the SCs purity was (95.73±1.51)% in the improved method group,(84.66±2.68)% in the hemi-explants-culture method group,and (74.50±4.23)% in the explants-culture method group(P<0.01). Conclusion The improved enzyme digestion combined with explants-culture method can obtain sufficient amount of high-purity SCs in a short time and thus may be applied in further research on peripheral nerve regeneration. PMID:27594149

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

    PubMed Central

    Czisch, Christopher; Witek, Lukasz; Shi, Yang; Smay, Jim; Plant, Giles W.; Yang, Yunzhi

    2015-01-01

    Numerous studies have demonstrated that Schwann cells (SCs) play a role in nerve regeneration; however, their role in innervating a bioceramic scaffold for potential application in bone regeneration is still unknown. Here we report the cell growth and functional behavior of SCs on β-tricalcium phosphate (β-TCP) scaffolds arranged in 3D printed-lattice (P-β-TCP) and randomly-porous, template-casted (N-β-TCP) structures. Our results indicate that SCs proliferated well and expressed the phenotypic markers p75LNGFR and the S100-β subunit of SCs as well as displayed growth morphology on both scaffolds, but SCs showed spindle-shaped morphology with a significant degree of SCs alignment on the P-β-TCP scaffolds, seen to a lesser degree in the N-β-TCP scaffold. The gene expressions of nerve growth factor (β-ngf), neutrophin–3 (nt–3), platelet-derived growth factor (pdgf-bb), and vascular endothelial growth factor (vegf-a) were higher at day 7 than at day 14. While no significant differences in protein secretion were measured between these last two time points, the scaffolds promoted the protein secretion at day 3 compared to that on the cell culture plates. These results together imply that the β-TCP scaffolds can support SC cell growth and that the 3D-printed scaffold appeared to significantly promote the alignment of SCs along the struts. Further studies are needed to investigate the early and late stage relationship between gene expression and protein secretion of SCs on the scaffolds with refined characteristics, thus better exploring the potential of SCs to support vascularization and innervation in synthetic bone grafts. PMID:26444999

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

    SciTech Connect

    Lv, Jianwei; Sun, Xiaolei; Ma, Jianxiong; Ma, Xinlong; Zhang, Yang; Li, Fengbo; Li, Yanjun; Zhao, Zhihu

    2015-08-14

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

  10. Photopolymerized microfeatures for directed spiral ganglion neurite and Schwann cell growth

    PubMed Central

    Tuft, Bradley W.; Li, Shufeng; Xu, Linjing; Clarke, Joseph C.; White, Scott P.; Guymon, Bradley A.; Perez, Krystian X.; Hansen, Marlan R.; Guymon, C. Allan

    2015-01-01

    Cochlear implants (CIs) provide auditory perception to individuals with severe hearing impairment. However, their ability to encode complex auditory stimuli is limited due, in part, to poor spatial resolution caused by electrical current spread in the inner ear. Directing nerve cell processes towards target electrodes may reduce the problematic current spread and improve stimulatory specificity. In this work, photopolymerization was used to fabricate micro- and nano-patterned methacrylate polymers to probe the extent of spiral ganglion neuron (SGN) neurite and Schwann cell (SGSC) contact guidance based on variations in substrate topographical cues. Micropatterned substrates are formed in a rapid, single-step reaction by selectively blocking light with photomasks which have parallel line-space gratings with periodicities of 10 – 100 μm. Channel amplitudes of 250 nm – 10 μm are generated by modulating UV exposure time, light intensity, and photoinitiator concentration. Gradual transitions are observed between ridges and grooves using scanning electron and atomic force microscopy. The transitions stand in contrast to vertical features generated via etching lithographic techniques. Alignment of neural elements increases significantly with increasing feature amplitude and constant periodicity, as well as with decreasing periodicity and constant amplitude. SGN neurite alignment strongly correlates (r = 0.93) with maximum feature slope. Multiple neuronal and glial types orient to the patterns with varying degrees of alignment. This work presents a method to fabricate gradually-sloping micropatterns for cellular contact guidance studies and demonstrates spatial control of inner ear neural elements in response to micro- and nano-scale surface topography. PMID:23069708

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

    PubMed

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

    2014-07-01

    Regulating the production of brain-derived neurotrophic factor (BDNF) in Schwann cells (SCs) is critical for their application in traumatic nerve injury, neurodegenerative disorders, and demyelination disease in both central and peripheral nervous systems. The present study investigated the possibility of using electrical stimulation (ES) to activate SCs to release BDNF. We found that short-term ES was capable of promoting BDNF production from SCs, and the maximal BDNF release was achieved by ES at 6 V (3 Hz, 30 min). We further examined the involvement of intracellular calcium ions ([Ca2+]i) in the ES-induced BDNF production in SCs by pharmacological studies. We found that the ES-induced BDNF release required calcium influx through T-type voltage-gated calcium channel (VGCC) and calcium mobilization from internal calcium stores, including inositol triphosphate-sensitive stores and caffeine/ryanodine-sensitive stores. In addition, calcium-calmodulin dependent protein kinase IV (CaMK IV), mitogen-activated protein kinase (MAPK), and cAMP response element-binding protein (CREB) were found to play important roles in the ES-induced BDNF release from SCs. In conclusion, ES is capable of activating SCs to secrete BDNF, which requires the involvement of calcium influx through T-type VGCC and calcium mobilization from internal calcium stores. In addition, activation of CaMK IV, MAPK, and CREB were also involved in the ES-induced BDNF release. The findings indicate that ES can improve the neurotrophic ability in SCs and raise the possibility of developing electrically stimulated SCs as a source of cell therapy for nerve injury in both peripheral and central nervous systems. PMID:24753179

  12. Schwann cell autophagy counteracts the onset and chronification of neuropathic pain.

    PubMed

    Marinelli, Sara; Nazio, Francesca; Tinari, Antonella; Ciarlo, Laura; D'Amelio, Marcello; Pieroni, Luisa; Vacca, Valentina; Urbani, Andrea; Cecconi, Francesco; Malorni, Walter; Pavone, Flaminia

    2014-01-01

    Axonal degeneration in peripheral nerves after injury is accompanied by myelin degradation initiated by Schwann cells (SCs). These cells activate autophagy, a ubiquitous cytoprotective process essential for degradation and recycling of cellular constituents. Concomitantly to nerve insult and axonal degeneration, neuropathic pain (NeP) arises. The role of SC autophagy in the mechanisms underlying NeP is still unknown. In this study, we examined the role of the autophagy during the early phase of Wallerian degeneration in NeP induction and chronification by using a murine model of peripheral nerve lesion (chronic constriction injury). We demonstrate that the autophagy inducer rapamycin, administered in the first week after nerve damage, induces long-lasting analgesic and antiinflammatory effects, facilitates nerve regeneration, and prevents pain chronification. Conversely, when autophagy is altered, by means of autophagic inhibitor 3-methyladenine administration or as occurs in activating molecule in Beclin-1-regulated autophagy transgenic mice (Ambra1(+/gt)), NeP is dramatically enhanced and prolonged. Immunohistochemical and ultrastructural evaluations show that rapamycin is able to increase autophagic flux in SCs, to accelerate myelin compaction, and to reduce inflammatory and immune reaction. Proteomic analysis combined with bioinformatic analysis suggests that a redox-sensitive mechanism could be responsible for SC autophagy activation. These data suggest that a deficiency of autophagic activity in SCs can be an early event in the origin of NeP chronification and that autophagy modulation may represent a powerful pharmacological approach to prevent the onset and chronification of NeP in the clinical setting.

  13. Varying the diameter of aligned electrospun fibers alters neurite outgrowth and Schwann cell migration.

    PubMed

    Wang, Han Bing; Mullins, Michael E; Cregg, Jared M; McCarthy, Connor W; Gilbert, Ryan J

    2010-08-01

    Aligned, electrospun fibers have shown great promise in facilitating directed neurite outgrowth within cell and animal models. While electrospun fiber diameter does influence cellular behavior, it is not known how aligned, electrospun fiber scaffolds of differing diameter influence neurite outgrowth and Schwann cell (SC) migration. Thus, the goal of this study was to first create highly aligned, electrospun fiber scaffolds of varying diameter and then assess neurite and SC behavior from dorsal root ganglia (DRG) explants. Three groups of highly aligned, electrospun poly-l-lactic acid (PLLA) fibers were created (1325+383 nm, large diameter fibers; 759+179 nm, intermediate diameter fibers; and 293+65 nm, small diameter fibers). Embryonic stage nine (E9) chick DRG were cultured on fiber substrates for 5 days and then the explants were stained against neurofilament and S100. DAPI stain was used to assess SC migration. Neurite length and SC migration distance were determined. In general, the direction of neurite extension and SC migration were guided along the aligned fibers. On the small diameter fiber substrate, the neurite length was 42% and 36% shorter than those on the intermediate and large fiber substrates, respectively. Interestingly, SC migration did not correlate with that of neurite extension in all situations. SCs migrated equivalently with extending neurites in both the small and large diameter scaffolds, but lagged behind neurites on the intermediate diameter scaffolds. Thus, in some situations, topography alone is sufficient to guide neurites without the leading support of SCs. Scanning electron microscopy images show that neurites cover the fibers and do not reside exclusively between fibers. Further, at the interface between fibers and neurites, filopodial extensions grab and attach to nearby fibers as they extend down the fiber substrate. Overall, the results and observations suggest that fiber diameter is an important parameter to consider when

  14. Evidence of involvement of the mannose receptor in the internalization of Streptococcus pneumoniae by Schwann cells

    PubMed Central

    2014-01-01

    Background The ability of S. pneumoniae to generate infections depends on the restrictions imposed by the host’s immunity, in order to prevent the bacterium from spreading from the nasopharynx to other tissues, such as the brain. Some authors claim that strains of S. pneumoniae, which fail to survive in the bloodstream, can enter the brain directly from the nasal cavity by axonal transport through the olfactory and/or trigeminal nerves. However, from the immunological point of view, glial cells are far more responsive to bacterial infections than are neurons. This hypothesis is consistent with several recent reports showing that bacteria can infect glial cells from the olfactory bulb and trigeminal ganglia. Since our group previously demonstrated that Schwann cells (SCs) express a functional and appropriately regulated mannose receptor (MR), we decided to test whether SCs are involved in the internalization of S. pneumoniae via MR. Results Immediately after the interaction step, as well as 3 h later, the percentage of association was approximately 56.5%, decreasing to 47.2% and 40.8% after 12 and 24 h, respectively. Competition assays by adding a 100-fold excess of mannan prior to the S. pneumoniae infection reduced the number of infected cells at 3 and 24 h. A cytochemistry assay with Man/BSA-FITC binding was performed in order to verify a possible overlap between mannosylated ligands and internalized bacteria. Incubation of the SCs with Man/BSA-FITC resulted in a large number of intracellular S. pneumoniae, with nearly complete loss of the capsule. Moreover, the anti-pneumococcal antiserum staining colocalized with the internalized man/BSA-FITC, suggesting that both markers are present within the same endocytic compartment of the SC. Conclusions Our data offer novel evidence that SCs could be essential for pneumococcal cells to escape phagocytosis and killing by innate immune cells. On the other hand, the results also support the idea that SCs are

  15. C3-induced release of neurotrophic factors from Schwann cells - potential mechanism behind its regeneration promoting activity.

    PubMed

    Rohrbeck, Astrid; Stahl, Frank; Höltje, Markus; Hettwer, Timo; Lindner, Patrick; Hagemann, Sandra; Pich, Andreas; Haastert-Talini, Kirsten

    2015-11-01

    Previous studies revealed a peripheral nerve regeneration (PNR)(1) promoting activity of Clostridium botulinum C3(2) exoenzyme or a 26(mer) C-terminal peptide fragment covering amino acids 156-181 (C3(156-181)),(3) when delivered as one-time injection at the lesion site. The current study was performed to 1) investigate if prolonged availability of C3 and C3(156-181) at the lesion site can further enhance PNR in vivo and to 2) elucidate effects of C3 and C3(156-181) on Schwann cells (SCs)(4)in vitro. For in vivo studies, 10 mm adult rat sciatic nerve gaps were reconstructed with the epineurial pouch technique or autologous nerve grafts. Epineurial pouches were filled with a hydrogel containing i) vehicle, ii) 40 μM C3 or iii) 40 μM C3(156-181). Sensory and motor functional recovery was monitored over 12 weeks and the outcome of PNR further analyzed by nerve morphometry. In vitro, we compared gene expression profiles (microarray analysis) and neurotrophic factor expression (western blot analysis) of untreated rat neonatal SCs with those treated with C3 or C3(156-181) for 72 h. Effects on neurotrophic factor expression levels were proven in adult human SCs. Unexpectedly, prolonged delivery of C3 and C3(156-181) at the lesion site did not increase the outcome of PNR. Regarding the potential mechanism underlying their previously detected PNR promoting action, however, 6 genes were found to be commonly altered in SCs upon treatment with C3 or C3(156-181). We demonstrate significant down-regulation of genes involved in glutamate uptake (Eaac1,(5)Grin2a(6)) and changes in neurotrophic factor expression (increase of FGF-2(7) and decrease of NGF(8)). Our microarray-based expression profiling revealed novel C3-regulated genes in SCs possibly involved in the axonotrophic (regeneration promoting) effects of C3 and C3(156-181). Detection of altered neurotrophic factor expression by C3 or C3(156-181) treated primary neonatal rat SCs and primary adult human SCs supports

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

    PubMed

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

    2014-03-15

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

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

    PubMed Central

    García-Mateo, Nadia; Ganfornina, Maria D.; Montero, Olimpio; Gijón, Miguel A.; Murphy, Robert C.; Sanchez, Diego

    2014-01-01

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

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

    PubMed

    García-Mateo, Nadia; Ganfornina, Maria D; Montero, Olimpio; Gijón, Miguel A; Murphy, Robert C; Sanchez, Diego

    2014-01-01

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

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

    PubMed

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

    2015-01-15

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

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

    PubMed

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

    2015-01-12

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

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

    PubMed Central

    Liu, Zhongyang; Huang, Liangliang; Liu, Liang; Luo, Beier; Liang, Miaomiao; Sun, Zhen; Zhu, Shu; Quan, Xin; Yang, Yafeng; Ma, Teng; Huang, Jinghui; Luo, Zhuojing

    2015-01-01

    Schwann cells (SCs) are attractive seed cells in neural tissue engineering, but their application is limited by attenuated biological activities and impaired functions with aging. Therefore, it is important to explore an approach to enhance the viability and biological properties of SCs. In the present study, a magnetic composite made of magnetically responsive magnetic nanoparticles (MNPs) and a biodegradable chitosan–glycerophosphate polymer were prepared and characterized. It was further explored whether such magnetic nanocomposites via applied magnetic fields would regulate SC biological activities. The magnetization of the magnetic nanocomposite was measured by a vibrating sample magnetometer. The compositional characterization of the magnetic nanocomposite was examined by Fourier-transform infrared and X-ray diffraction. The tolerance of SCs to the magnetic fields was tested by flow-cytometry assay. The proliferation of cells was examined by a 5-ethynyl-2-deoxyuridine-labeling assay, a PrestoBlue assay, and a Live/Dead assay. Messenger ribonucleic acid of BDNF, GDNF, NT-3, and VEGF in SCs was assayed by quantitative real-time polymerase chain reaction. The amount of BDNF, GDNF, NT-3, and VEGF secreted from SCs was determined by enzyme-linked immunosorbent assay. It was found that magnetic nanocomposites containing 10% MNPs showed a cross-section diameter of 32.33±1.81 µm, porosity of 80.41%±0.72%, and magnetization of 5.691 emu/g at 8 kOe. The 10% MNP magnetic nanocomposites were able to support cell adhesion and spreading and further promote proliferation of SCs under magnetic field exposure. Interestingly, a magnetic field applied through the 10% MNP magnetic scaffold significantly increased the gene expression and protein secretion of BDNF, GDNF, NT-3, and VEGF. This work is the first stage in our understanding of how to precisely regulate the viability and biological properties of SCs in tissue-engineering grafts, which combined with additional

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

    PubMed

    Liu, Zhongyang; Huang, Liangliang; Liu, Liang; Luo, Beier; Liang, Miaomiao; Sun, Zhen; Zhu, Shu; Quan, Xin; Yang, Yafeng; Ma, Teng; Huang, Jinghui; Luo, Zhuojing

    2015-01-01

    Schwann cells (SCs) are attractive seed cells in neural tissue engineering, but their application is limited by attenuated biological activities and impaired functions with aging. Therefore, it is important to explore an approach to enhance the viability and biological properties of SCs. In the present study, a magnetic composite made of magnetically responsive magnetic nanoparticles (MNPs) and a biodegradable chitosan-glycerophosphate polymer were prepared and characterized. It was further explored whether such magnetic nanocomposites via applied magnetic fields would regulate SC biological activities. The magnetization of the magnetic nanocomposite was measured by a vibrating sample magnetometer. The compositional characterization of the magnetic nanocomposite was examined by Fourier-transform infrared and X-ray diffraction. The tolerance of SCs to the magnetic fields was tested by flow-cytometry assay. The proliferation of cells was examined by a 5-ethynyl-2-deoxyuridine-labeling assay, a PrestoBlue assay, and a Live/Dead assay. Messenger ribonucleic acid of BDNF, GDNF, NT-3, and VEGF in SCs was assayed by quantitative real-time polymerase chain reaction. The amount of BDNF, GDNF, NT-3, and VEGF secreted from SCs was determined by enzyme-linked immunosorbent assay. It was found that magnetic nanocomposites containing 10% MNPs showed a cross-section diameter of 32.33±1.81 µm, porosity of 80.41%±0.72%, and magnetization of 5.691 emu/g at 8 kOe. The 10% MNP magnetic nanocomposites were able to support cell adhesion and spreading and further promote proliferation of SCs under magnetic field exposure. Interestingly, a magnetic field applied through the 10% MNP magnetic scaffold significantly increased the gene expression and protein secretion of BDNF, GDNF, NT-3, and VEGF. This work is the first stage in our understanding of how to precisely regulate the viability and biological properties of SCs in tissue-engineering grafts, which combined with additional

  3. Human umbilical cord Wharton's jelly-derived mesenchymal stem cells differentiate into a Schwann-cell phenotype and promote neurite outgrowth in vitro.

    PubMed

    Peng, Jiang; Wang, Yu; Zhang, Li; Zhao, Bin; Zhao, Zhe; Chen, JiFeng; Guo, QuanYi; Liu, ShuYun; Sui, Xiang; Xu, WenJing; Lu, ShiBi

    2011-02-28

    Cell-based therapy has achieved promising functional recovery for peripheral nerve repair. Although Schwann cells (SCs) and bone marrow derived mesenchymal stromal cells (BM-MSCs) are the main cell source for nerve tissue engineering, the clinical application is limited because of donor site morbidity, the invasive procedure, and the decreased number of SCs and BM-MSCs. Wharton's jelly-derived mesenchymal stem cells (WJMSCs) could be a promising cell source for nerve tissue engineering because they are easily accessible and their use has no ethical issues. We investigated the phenotypic, molecular and functional characteristics of WJMSCs differentiated along a Schwann-cell lineage. Cultured WJMSCs were isolated from human umbilical cord, and the undifferentiated WJMSCs were confirmed by the detection of MSC-specific cell-surface markers. WJMSCs treated with a mixture of glial growth factors (basic fibroblast growth factor, platelet-derived growth factor and forskolin) adopted a spindle-like morphology similar to SCs. Immunocytochemical staining, RT-PCR analysis, and Western blot analysis revealed that the treated cells expressed the glial markers glial fibrillary acidic protein, p75, S100 and P0 and indicative of differentiation. On co-culture with dorsal root ganglia neurons, the differentiated WJMSCs enhanced the number of sprouting neurites and neurite length in dorsal root ganglia neurons. Furthermore, using enzyme-linked immunosorbent assay and RT-PCR methodology, we found differentiated WJMSCs secrete and express neurotrophic factors, including brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophin-3 (NT-3). Quantification of neurite outgrowth from PC12 cells grown in differentiated WJMSCs-conditioned media demonstrates that the neurite length is significantly more than control medium and undifferentiated WJMSCs group. WJMSCs can be differentiated into cells that are Schwann-like in terms of morphologic features, phenotype, and

  4. Schwann cells but not olfactory ensheathing cells inhibit CNS myelination via the secretion of connective tissue growth factor.

    PubMed

    Lamond, Rebecca; Barnett, Susan C

    2013-11-20

    Cell transplantation is a promising strategy to promote CNS repair and has been studied for several decades with a focus on glial cells. Promising candidates include Schwann cells (SCs) and olfactory ensheathing cells (OECs). Both cell types are thought to be neural crest derived and share many properties in common, although OECs appear to be a better candidate for transplantation by evoking less astrogliosis. Using CNS mixed myelinating rat cultures plated on to a monolayer of astrocytes, we demonstrated that SCs, but not OECs, secrete a heat labile factor(s) that inhibits oligodendrocyte myelination. Comparative qRT-PCR and ELISA showed that SCs expressed higher levels of mRNA and protein for connective tissue growth factor (CTGF) than OECs. Anti-CTGF reversed the SCM-mediated effects on myelination. Both SCM and CTGF inhibited the differentiation of purified rat oligodendrocyte precursor cells (OPCs). Furthermore, pretreatment of astrocyte monolayers with SCM inhibited CNS myelination and led to transcriptional changes in the astrocyte, corresponding to upregulation of bone morphogenic protein 4 mRNA and CTGF mRNA (inhibitors of OPC differentiation) and the downregulation of insulin-like growth factor 2 mRNA (promoter of OPC differentiation). CTGF pretreatment of astrocytes increased their expression of CTGF, suggesting that this inhibitory factor can be positively regulated in astrocytes. These data provide evidence for the advantages of using OECs, and not mature SCs, for transplant-mediated repair and provide more evidence that they are a distinct and unique glial cell type.

  5. Requirement of cAMP Signaling for Schwann Cell Differentiation Restricts the Onset of Myelination

    PubMed Central

    Bacallao, Ketty; Monje, Paula V.

    2015-01-01

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

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

    PubMed

    Bacallao, Ketty; Monje, Paula V

    2015-01-01

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

  7. Downregulation of steroidogenic acute regulatory protein (StAR) gene expression by cyclic AMP in cultured Schwann cells.

    PubMed

    Benmessahel, Yasmina; Troadec, Jean-Denis; Cadepond, Françoise; Guennoun, Rachida; Hales, Dale Buchanan; Schumacher, Michael; Groyer, Ghislaine

    2004-02-01

    Steroidogenic acute regulatory protein (StAR) plays a key role in the availability of cholesterol to the inner mitochondrial membrane, where the first step of steroidogenesis, its conversion to pregnenolone, takes place. Here, we demonstrate for the first time that the StAR gene is also expressed in the rat sciatic nerve and in cultured Schwann cells. The addition to the culture medium of the cAMP-elevating agent forskolin or of the cAMP analogue 8Br-cAMP produced a time-course extinction of StAR gene expression. An inverse relationship was demonstrated between StAR gene expression and the intracellular cAMP content. Accordingly, pharmacological inhibition of the activities of Schwann cell adenylyl cyclase or of phosphodiesterase IV resulted in modifications of StAR gene expression. Since StAR gene expression is stimulated by cAMP in classical steroidogenic cells, our work is the first demonstration of a negative regulation of StAR gene by cAMP.

  8. Interplay between VEGF-A and cMET signaling in human vestibular schwannomas and schwann cells.

    PubMed

    Dilwali, Sonam; Roberts, Daniel; Stankovic, Konstantina M

    2015-01-01

    Vestibular schwannoma (VS), the fourth most common intracranial tumor, arises from the Schwann cells of the vestibular nerve. Although several pathways have been independently implicated in VS pathobiology, interactions among these pathways have not been explored in depth. We have investigated the potential cross-talk between hepatocyte growth factor (HGF) and vascular endothelial growth factor-A (VEGF-A) in human VS, an interaction that has been described in other physiological and pathological cell types. We affirmed previous findings that VEGF-A signaling is aberrantly upregulated in VS, and established that expression of HGF and its receptor cMET is also significantly higher in sporadic VS than in healthy nerves. In primary human VS and Schwann cell cultures, we found that VEGF-A and HGF signaling pathways modulate each other. siRNAs targeting cMET decreased both cMET and VEGF-A protein levels, and siRNAs targeting VEGF-A reduced cMET expression. Additionally, siRNA-mediated knockdown of VEGF-A or cMET and pharmacologic inhibition of cMET decreased cellular proliferation in primary human VS cultures. Our data suggest cross-talk between these 2 prominent pathways in VS and highlight the HGF/cMET pathway as an additional important therapeutic target in VS. PMID:25692621

  9. Nerve injury induces glial cell line-derived neurotrophic factor (GDNF) expression in Schwann cells through purinergic signaling and the PKC-PKD pathway.

    PubMed

    Xu, Pin; Rosen, Kenneth M; Hedstrom, Kristian; Rey, Osvaldo; Guha, Sushovan; Hart, Courtney; Corfas, Gabriel

    2013-07-01

    Upon peripheral nerve injury, specific molecular events, including increases in the expression of selected neurotrophic factors, are initiated to prepare the tissue for regeneration. However, the mechanisms underlying these events and the nature of the cells involved are poorly understood. We used the injury-induced upregulation of glial cell-derived neurotrophic factor (GDNF) expression as a tool to gain insights into these processes. We found that both myelinating and nonmyelinating Schwann cells are responsible for the dramatic increase in GDNF expression after injury. We also demonstrate that the GDNF upregulation is mediated by a signaling cascade involving activation of Schwann cell purinergic receptors, followed by protein kinase C signaling which activates protein kinase D (PKD), which leads to increased GDNF transcription. Given the potent effects of GDNF on survival and repair of injured peripheral neurons, we propose that targeting these pathways may yield therapeutic tools to treat peripheral nerve injury and neuropathies.

  10. Temporal Analysis of Gene Expression in the Murine Schwann Cell Lineage and the Acutely Injured Postnatal Nerve

    PubMed Central

    Touahri, Yacine; Stratton, Jo Anne; Biernaskie, Jeff; Schuurmans, Carol

    2016-01-01

    Schwann cells (SCs) arise from neural crest cells (NCCs) that first give rise to SC precursors (SCPs), followed by immature SCs, pro-myelinating SCs, and finally, non-myelinating or myelinating SCs. After nerve injury, mature SCs ‘de-differentiate’, downregulating their myelination program while transiently re-activating early glial lineage genes. To better understand molecular parallels between developing and de-differentiated SCs, we characterized the expression profiles of a panel of 12 transcription factors from the onset of NCC migration through postnatal stages, as well as after acute nerve injury. Using Sox10 as a pan-glial marker in co-expression studies, the earliest transcription factors expressed in E9.0 Sox10+ NCCs were Sox9, Pax3, AP2α and Nfatc4. E10.5 Sox10+ NCCs coalescing in the dorsal root ganglia differed slightly, expressing Sox9, Pax3, AP2α and Etv5. E12.5 SCPs continued to express Sox10, Sox9, AP2α and Pax3, as well as initiating Sox2 and Egr1 expression. E14.5 immature SCs were similar to SCPs, except that they lost Pax3 expression. By E18.5, AP2α, Sox2 and Egr1 expression was turned off in the nerve, while Jun, Oct6 and Yy1 expression was initiated in pro-myelinating Sox9+/Sox10+ SCs. Early postnatal and adult SCs continued to express Sox9, Jun, Oct6 and Yy1 and initiated Nfatc4 and Egr2 expression. Notably, at all stages, expression of each marker was observed only in a subset of Sox10+ SCs, highlighting the heterogeneity of the SC pool. Following acute nerve injury, Egr1, Jun, Oct6, and Sox2 expression was upregulated, Egr2 expression was downregulated, while Sox9, Yy1, and Nfatc4 expression was maintained at similar frequencies. Notably, de-differentiated SCs in the injured nerve did not display a transcription factor profile corresponding to a specific stage in the SC lineage. Taken together, we demonstrate that uninjured and injured SCs are heterogeneous and distinct from one another, and de-differentiation recapitulates

  11. Temporal Analysis of Gene Expression in the Murine Schwann Cell Lineage and the Acutely Injured Postnatal Nerve.

    PubMed

    Balakrishnan, Anjali; Stykel, Morgan G; Touahri, Yacine; Stratton, Jo Anne; Biernaskie, Jeff; Schuurmans, Carol

    2016-01-01

    Schwann cells (SCs) arise from neural crest cells (NCCs) that first give rise to SC precursors (SCPs), followed by immature SCs, pro-myelinating SCs, and finally, non-myelinating or myelinating SCs. After nerve injury, mature SCs 'de-differentiate', downregulating their myelination program while transiently re-activating early glial lineage genes. To better understand molecular parallels between developing and de-differentiated SCs, we characterized the expression profiles of a panel of 12 transcription factors from the onset of NCC migration through postnatal stages, as well as after acute nerve injury. Using Sox10 as a pan-glial marker in co-expression studies, the earliest transcription factors expressed in E9.0 Sox10+ NCCs were Sox9, Pax3, AP2α and Nfatc4. E10.5 Sox10+ NCCs coalescing in the dorsal root ganglia differed slightly, expressing Sox9, Pax3, AP2α and Etv5. E12.5 SCPs continued to express Sox10, Sox9, AP2α and Pax3, as well as initiating Sox2 and Egr1 expression. E14.5 immature SCs were similar to SCPs, except that they lost Pax3 expression. By E18.5, AP2α, Sox2 and Egr1 expression was turned off in the nerve, while Jun, Oct6 and Yy1 expression was initiated in pro-myelinating Sox9+/Sox10+ SCs. Early postnatal and adult SCs continued to express Sox9, Jun, Oct6 and Yy1 and initiated Nfatc4 and Egr2 expression. Notably, at all stages, expression of each marker was observed only in a subset of Sox10+ SCs, highlighting the heterogeneity of the SC pool. Following acute nerve injury, Egr1, Jun, Oct6, and Sox2 expression was upregulated, Egr2 expression was downregulated, while Sox9, Yy1, and Nfatc4 expression was maintained at similar frequencies. Notably, de-differentiated SCs in the injured nerve did not display a transcription factor profile corresponding to a specific stage in the SC lineage. Taken together, we demonstrate that uninjured and injured SCs are heterogeneous and distinct from one another, and de-differentiation recapitulates

  12. Zeb2 recruits HDAC-NuRD to inhibit Notch and controls Schwann cell differentiation and remyelination.

    PubMed

    Wu, Lai Man Natalie; Wang, Jincheng; Conidi, Andrea; Zhao, Chuntao; Wang, Haibo; Ford, Zachary; Zhang, Liguo; Zweier, Christiane; Ayee, Brian G; Maurel, Patrice; Zwijsen, An; Chan, Jonah R; Jankowski, Michael P; Huylebroeck, Danny; Lu, Q Richard

    2016-08-01

    The mechanisms that coordinate and balance a complex network of opposing regulators to control Schwann cell (SC) differentiation remain elusive. Here we demonstrate that zinc-finger E-box-binding homeobox 2 (Zeb2, also called Sip1) transcription factor is a critical intrinsic timer that controls the onset of SC differentiation by recruiting histone deacetylases HDAC 1 and 2 (HDAC1/2) and nucleosome remodeling and deacetylase complex (NuRD) co-repressor complexes in mice. Zeb2 deletion arrests SCs at an undifferentiated state during peripheral nerve development and inhibits remyelination after injury. Zeb2 antagonizes inhibitory effectors including Notch and Sox2. Importantly, genome-wide transcriptome analysis reveals a Zeb2 target gene encoding the Notch effector Hey2 as a potent inhibitor for Schwann cell differentiation. Strikingly, a genetic Zeb2 variant associated with Mowat-Wilson syndrome disrupts the interaction with HDAC1/2-NuRD and abolishes Zeb2 activity for SC differentiation. Therefore, Zeb2 controls SC maturation by recruiting HDAC1/2-NuRD complexes and inhibiting a Notch-Hey2 signaling axis, pointing to the critical role of HDAC1/2-NuRD activity in peripheral neuropathies caused by ZEB2 mutations. PMID:27294509

  13. Stem cells from human exfoliated deciduous teeth differentiate toward neural cells in a medium dynamically cultured with Schwann cells in a series of polydimethylsiloxanes scaffolds

    NASA Astrophysics Data System (ADS)

    Su, Wen-Ta; Pan, Yu-Jing

    2016-08-01

    Objective. Schwann cells (SCs) are primary structural and functional cells in the peripheral nervous system. These cells play a crucial role in peripheral nerve regeneration by releasing neurotrophic factors. This study evaluated the neural differentiation potential effects of stem cells from human exfoliated deciduous teeth (SHEDs) in a rat Schwann cell (RSC) culture medium. Approach. SHEDs and RSCs were individually cultured on a polydimethylsiloxane (PDMS) scaffold, and the effects of the RSC medium on the SHEDs differentiation between static and dynamic cultures were compared. Main results. Results demonstrated that the SHED cells differentiated by the RSC cultured medium in the static culture formed neurospheres after 7 days at the earliest, and SHED cells formed neurospheres within 3 days in the dynamic culture. These results confirm that the RSC culture medium can induce neurospheres formation, the speed of formation and the number of neurospheres (19.16 folds high) in a dynamic culture was superior to the static culture for 3 days culture. The SHED-derived spheres were further incubated in the RSCs culture medium, these neurospheres continuously differentiated into neurons and neuroglial cells. Immunofluorescent staining and RT-PCR revealed nestin, β-III tubulin, GFAP, and γ-enolase of neural markers on the differentiated cells. Significance. These results indicated that the RSC culture medium can induce the neural differentiation of SHED cells, and can be used as a new therapeutic tool to repair nerve damage.

  14. Combination of grafted Schwann cells and lentiviral-mediated prevention of glial scar formation improve recovery of spinal cord injured rats.

    PubMed

    Do-Thi, Anh; Perrin, Florence E; Desclaux, Mathieu; Saillour, Paulette; Amar, Lahouari; Privat, Alain; Mallet, Jacques

    2016-10-01

    The present study was intended to combine three therapeutic approaches in a well-defined rat model of spinal cord injury, a lateral hemisection at thoracic level. A guidance channel was implanted at the lesion site. This channel was seeded with native Schwann cells or Schwann cells that had been previously transduced with a lentiviral vector carrying the GDNF gene. Thereafter, these experiences were reproduced in animals injected with lentiviral vectors carrying a shRNA for GFAP (Lv-shGFAP), which has recently been shown to block glial scar formation. Functional evaluations showed that Lv-shGFAP induced a significant improvement in recovery in animals grafted with Schwann cells. Histological studies demonstrated the outgrowth of axons in the guidance channel containing Schwann cells transduced or not with GDNF. This axonal growth was enhanced in rats receiving Lv-shGFAP vector. Also, a significant increase of serotonergic innervation of the injured hemicord, distal to the lesion, was found only in animals treated with Lv-shGFAP vectors. Importantly, this study confirms that glial scar formation is a major impediment for axonal sprouting after spinal cord injury, and emphasizes the importance of serotonergic innervation for locomotor function. Moreover we show a significant additive effect of a combinatorial approach to axonal regeneration in the injured spinal cord.

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

    PubMed

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

    2012-12-01

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

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

    PubMed Central

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

    2006-01-01

    Terminal Schwann cells (TSCs) that cover motor neuron terminals, are known to play an important role in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, the molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. By using our previously reported method of selectively and efficiently collecting TSCs, we have analyzed the difference in expression patterns of lysophospholipid (LPL) receptor genes (LPA1, LPA2, LPA3, S1P1, S1P2, S1P3, S1P4, and S1P5) between TSCs and myelinating Schwann cells (MSCs). LPL, which includes lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), is the bioactive lipid that induces a myriad of cellular responses through specific members of G-protein coupled receptors for LPA. It turned out that LPA3 was expressed only in TSCs, whereas S1P1 was expressed in TSCs and skeletal muscle, but not in MSCs. Other types of LPL receptor genes, including LPA1, S1P2, S1P3, S1P4, were expressed in both types of Schwann cells. None of the LPL receptor gene family showed MSCs-specific expression. PMID:17375210

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

    PubMed

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

    2006-04-22

    Terminal Schwann cells (TSCs) that cover motor neuron terminals, are known to play an important role in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, the molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. By using our previously reported method of selectively and efficiently collecting TSCs, we have analyzed the difference in expression patterns of lysophospholipid (LPL) receptor genes (LPA1, LPA2, LPA3, S1P1, S1P2, S1P3, S1P4, and S1P5) between TSCs and myelinating Schwann cells (MSCs). LPL, which includes lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), is the bioactive lipid that induces a myriad of cellular responses through specific members of G-protein coupled receptors for LPA. It turned out that LPA3 was expressed only in TSCs, whereas S1P1 was expressed in TSCs and skeletal muscle, but not in MSCs. Other types of LPL receptor genes, including LPA1, S1P2, S1P3, S1P4, were expressed in both types of Schwann cells. None of the LPL receptor gene family showed MSCs-specific expression. PMID:17375210

  18. Tumor suppressor Nf2/merlin drives Schwann cell changes following electromagnetic field exposure through Hippo-dependent mechanisms

    PubMed Central

    Colciago, A; Melfi, S; Giannotti, G; Bonalume, V; Ballabio, M; Caffino, L; Fumagalli, F; Magnaghi, V

    2015-01-01

    Previous evidence showed mutations of the neurofibromin type 2 gene (Nf2), encoding the tumor suppressor protein merlin, in sporadic and vestibular schwannomas affecting Schwann cells (SCs). Accordingly, efforts have been addressed to identify possible factors, even environmental, that may regulate neurofibromas growth. In this context, we investigated the exposure of SC to an electromagnetic field (EMF), which is an environmental issue modulating biological processes. Here, we show that SC exposed to 50 Hz EMFs changes their morphology, proliferation, migration and myelinating capability. In these cells, merlin is downregulated, leading to activation of two intracellular signaling pathways, ERK/AKT and Hippo. Interestingly, SC changes their phenotype toward a proliferative/migrating state, which in principle may be pathologically relevant for schwannoma development. PMID:27551454

  19. Tumor suppressor Nf2/merlin drives Schwann cell changes following electromagnetic field exposure through Hippo-dependent mechanisms.

    PubMed

    Colciago, A; Melfi, S; Giannotti, G; Bonalume, V; Ballabio, M; Caffino, L; Fumagalli, F; Magnaghi, V

    2015-01-01

    Previous evidence showed mutations of the neurofibromin type 2 gene (Nf2), encoding the tumor suppressor protein merlin, in sporadic and vestibular schwannomas affecting Schwann cells (SCs). Accordingly, efforts have been addressed to identify possible factors, even environmental, that may regulate neurofibromas growth. In this context, we investigated the exposure of SC to an electromagnetic field (EMF), which is an environmental issue modulating biological processes. Here, we show that SC exposed to 50 Hz EMFs changes their morphology, proliferation, migration and myelinating capability. In these cells, merlin is downregulated, leading to activation of two intracellular signaling pathways, ERK/AKT and Hippo. Interestingly, SC changes their phenotype toward a proliferative/migrating state, which in principle may be pathologically relevant for schwannoma development. PMID:27551454

  20. Comparative proteomic analysis of primary schwann cells and a spontaneously immortalized schwann cell line RSC 96: a comprehensive overview with a focus on cell adhesion and migration related proteins.

    PubMed

    Ji, Yuhua; Shen, Mi; Wang, Xin; Zhang, Shuqiang; Yu, Shu; Chen, Gang; Gu, Xiaosong; Ding, Fei

    2012-06-01

    Schwann cells (SCs) are the principal glial cells of the peripheral nervous system (PNS). As a result of tissue heterogeneity and difficulties in the isolation and culture of primary SCs, a considerable understanding of SC biology is obtained from SC lines. However, the differences between the primary SCs and SC lines remain uncertain. In the present study, quantitative proteomic analysis based on isobaric tags for relative and absolute quantitation (iTRAQ) labeling was conducted to obtain an unbiased view of the proteomic profiles of primary rat SCs and RSC96, a spontaneously immortalized rat SC line. Out of 1757 identified proteins (FDR < 1%), 1702 were quantified, while 61 and 78 were found to be, respectively, up- or down-regulated (90% confidence interval) in RSC96. Bioinformatics analysis indicated the unique features of spontaneous immortalization, illustrated the dedifferentiated state of RSC96, and highlighted a panel of novel proteins associated with cell adhesion and migration including CADM4, FERMT2, and MCAM. Selected proteomic data and the requirement of these novel proteins in SC adhesion and migration were properly validated. Taken together, our data collectively revealed proteome differences between primary SCs and RSC96, validated several differentially expressed proteins with potential biological significance, and generated a database that may serve as a useful resource for studies of SC biology and pathology.

  1. Mild hypothermia combined with a scaffold of NgR-silenced neural stem cells/Schwann cells to treat spinal cord injury.

    PubMed

    Wang, Dong; Liang, Jinhua; Zhang, Jianjun; Liu, Shuhong; Sun, Wenwen

    2014-12-15

    Because the inhibition of Nogo proteins can promote neurite growth and nerve cell differentiation, a cell-scaffold complex seeded with Nogo receptor (NgR)-silenced neural stem cells and Schwann cells may be able to improve the microenvironment for spinal cord injury repair. Previous studies have found that mild hypothermia helps to attenuate secondary damage in the spinal cord and exerts a neuroprotective effect. Here, we constructed a cell-scaffold complex consisting of a poly(D,L-lactide-co-glycolic acid) (PLGA) scaffold seeded with NgR-silenced neural stem cells and Schwann cells, and determined the effects of mild hypothermia combined with the cell-scaffold complexes on the spinal cord hemi-transection injury in the T9 segment in rats. Compared with the PLGA group and the NgR-silencing cells + PLGA group, hindlimb motor function and nerve electrophysiological function were clearly improved, pathological changes in the injured spinal cord were attenuated, and the number of surviving cells and nerve fibers were increased in the group treated with the NgR-silenced cell scaffold + mild hypothermia at 34°C for 6 hours. Furthermore, fewer pathological changes to the injured spinal cord and more surviving cells and nerve fibers were found after mild hypothermia therapy than in injuries not treated with mild hypothermia. These experimental results indicate that mild hypothermia combined with NgR gene-silenced cells in a PLGA scaffold may be an effective therapy for treating spinal cord injury.

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

    PubMed Central

    Nishimoto, Shunsuke; Tanaka, Hiroyuki; Okamoto, Michio; Okada, Kiyoshi; Murase, Tsuyoshi; Yoshikawa, Hideki

    2015-01-01

    Schwann cells (SCs) are constituents of the peripheral nervous system. The differentiation of SCs in injured peripheral nerves is critical for regeneration after injury. Methylcobalamin (MeCbl) is a vitamin B12 analog that is necessary for the maintenance of the peripheral nervous system. In this study, we estimated the effect of MeCbl on SCs. We showed that MeCbl downregulated the activity of Erk1/2 and promoted the expression of the myelin basic protein in SCs. In a dorsal root ganglion neuron–SC coculture system, myelination was promoted by MeCbl. In a focal demyelination rat model, MeCbl promoted remyelination and motor and sensory functional regeneration. MeCbl promoted the in vitro differentiation of SCs and in vivo myelination in a rat demyelination model and may be a novel therapy for several types of nervous disorders. PMID:26300733

  3. Extensive cell migration, axon regeneration and improved function with polysialic acid-modified Schwann cells after spinal cord injury

    PubMed Central

    Ghosh, Mousumi; Tuesta, Luis M.; Puentes, Rocio; Patel, Samik; Melendez, Kiara; Maarouf, Abderrahman El; Rutishauser, Urs; Pearse, Damien Daniel

    2015-01-01

    Schwann cells (SC) implantation after spinal cord injury (SCI) promotes axonal regeneration, remyelination repair and functional recovery. Reparative efficacy, however, may be limited due to the inability of SCs to migrate outward from the lesion-implant site. Altering SC cell surface properties by over-expressing polysialic acid (PSA) has been shown to promote SC migration. In the current study, a SCI contusion was used to evaluate the migration, supraspinal axon growth support and functional recovery associated with polysialyltransferase (PST)-over-expressing SCs (PST-GFP SCs) or controls (GFP SCs). Compared to GFP SCs, which remained confined to the injection site at the injury center, PST-GFP SCs migrated across the lesion:host cord interface for distances of up to 4.4 mm within adjacent host tissue. In addition, with PST-GFP SCs, there was extensive serotonergic and corticospinal axon in-growth within the implants that was limited in the GFP SC controls. The enhanced migration of PST-GFP SCs was accompanied by significant growth of these axons caudal to lesion. Animals receiving PST-GFP SCs exhibited improved functional outcome, both in the open-field and on the gridwalk test, over modest improvements provided by GFP SC controls. The current study for the first time demonstrates that a lack of migration by SC may hinder their reparative benefits and that cell surface overexpression of PSA enhances the ability of implanted SCs to associate with and support the growth of corticospinal axons. These results provide further promise that PSA modified SCs will be a potent reparative approach for SCI. PMID:22460918

  4. Extensive cell migration, axon regeneration, and improved function with polysialic acid-modified Schwann cells after spinal cord injury.

    PubMed

    Ghosh, Mousumi; Tuesta, Luis M; Puentes, Rocio; Patel, Samik; Melendez, Kiara; El Maarouf, Abderrahman; Rutishauser, Urs; Pearse, Damien Daniel

    2012-05-01

    Schwann cell (SC) implantation after spinal cord injury (SCI) promotes axonal regeneration, remyelination repair, and functional recovery. Reparative efficacy, however, may be limited because of the inability of SCs to migrate outward from the lesion-implant site. Altering SC cell surface properties by overexpressing polysialic acid (PSA) has been shown to promote SC migration. In this study, a SCI contusion model was used to evaluate the migration, supraspinal axon growth support, and functional recovery associated with polysialyltransferase (PST)-overexpressing SCs [PST-green fluorescent protein (GFP) SCs] or controls (GFP SCs). Compared with GFP SCs, which remained confined to the injection site at the injury center, PST-GFP SCs migrated across the lesion:host cord interface for distances of up to 4.4 mm within adjacent host tissue. In addition, with PST-GFP SCs, there was extensive serotonergic and corticospinal axon in-growth within the implants that was limited in the GFP SC controls. The enhanced migration of PST-GFP SCs was accompanied by significant growth of these axons caudal to lesion. Animals receiving PST-GFP SCs exhibited improved functional outcome, both in the open-field and on the gridwalk test, beyond the modest improvements provided by GFP SC controls. This study for the first time demonstrates that a lack of migration by SCs may hinder their reparative benefits and that cell surface overexpression of PSA enhances the ability of implanted SCs to associate with and support the growth of corticospinal axons. These results provide further promise that PSA-modified SCs will be a potent reparative approach for SCI. © 2012 Wiley Periodicals, Inc.

  5. Extensive cell migration, axon regeneration, and improved function with polysialic acid-modified Schwann cells after spinal cord injury.

    PubMed

    Ghosh, Mousumi; Tuesta, Luis M; Puentes, Rocio; Patel, Samik; Melendez, Kiara; El Maarouf, Abderrahman; Rutishauser, Urs; Pearse, Damien Daniel

    2012-05-01

    Schwann cell (SC) implantation after spinal cord injury (SCI) promotes axonal regeneration, remyelination repair, and functional recovery. Reparative efficacy, however, may be limited because of the inability of SCs to migrate outward from the lesion-implant site. Altering SC cell surface properties by overexpressing polysialic acid (PSA) has been shown to promote SC migration. In this study, a SCI contusion model was used to evaluate the migration, supraspinal axon growth support, and functional recovery associated with polysialyltransferase (PST)-overexpressing SCs [PST-green fluorescent protein (GFP) SCs] or controls (GFP SCs). Compared with GFP SCs, which remained confined to the injection site at the injury center, PST-GFP SCs migrated across the lesion:host cord interface for distances of up to 4.4 mm within adjacent host tissue. In addition, with PST-GFP SCs, there was extensive serotonergic and corticospinal axon in-growth within the implants that was limited in the GFP SC controls. The enhanced migration of PST-GFP SCs was accompanied by significant growth of these axons caudal to lesion. Animals receiving PST-GFP SCs exhibited improved functional outcome, both in the open-field and on the gridwalk test, beyond the modest improvements provided by GFP SC controls. This study for the first time demonstrates that a lack of migration by SCs may hinder their reparative benefits and that cell surface overexpression of PSA enhances the ability of implanted SCs to associate with and support the growth of corticospinal axons. These results provide further promise that PSA-modified SCs will be a potent reparative approach for SCI. © 2012 Wiley Periodicals, Inc. PMID:22460918

  6. Rac1 is required for Prkar1a-mediated Nf2 suppression in Schwann cell tumors.

    PubMed

    Manchanda, P K; Jones, G N; Lee, A A; Pringle, D R; Zhang, M; Yu, L; La Perle, K M D; Kirschner, L S

    2013-07-25

    Schwannomas are peripheral nerve sheath tumors that often occur in the setting of an inherited tumor predisposition syndrome, including neurofibromatosis types 1 (NF1) and 2 (NF2), familial schwannomatosis and Carney complex. Loss of the NF2 tumor suppressor (encoding NF2, or Merlin) is associated with upregulation of the Rac1 small GTPase, which is thought to have a key role in mediating tumor formation. In prior studies, we generated a mouse model of schwannomas by performing tissue-specific knockout (KO) of the Carney complex gene Prkar1a, which encodes the type 1A regulatory subunit of protein kinase A. These tumors exhibited down-regulation of Nf2 protein and an increase in activated Rac1. To assess the requirement for Rac1 in schwannoma formation, we generated a double KO (DKO) of Prkar1a and Rac1 in Schwann cells and monitored tumor formation. Loss of Rac1 reduced tumor formation by reducing proliferation and enhancing apoptosis. Surprisingly, the reduction of tumor formation was accompanied by re-expression of the Nf2 protein. Furthermore, activated Rac1 was able to downregulate Nf2 in vitro in a Pak-dependent manner. These in vivo data indicate that activation of Rac1 is responsible for suppression of Nf2 protein production; deficiency of Nf2 in Schwann cells leads to loss of cellular growth control and tumor formation. Further, PKA activation through mutation in Prkar1a is sufficient to initiate Rac1 signaling, with subsequent reduction of Nf2 and schwannomagenesis. Although in vitro evidence has shown that loss of Nf2 activates Rac1, our data indicate that signaling between Nf2 and Rac1 occurs in a bidirectional fashion, and these interactions are modulated by PKA. PMID:23045281

  7. Rac1 is required for Prkar1a-mediated Nf2 suppression in Schwann cell tumors

    PubMed Central

    Manchanda, Parmeet K.; Jones, Georgette N.; Lee, Audrey A.; Pringle, Daphne R.; Zhang, Mei; Yu, Lianbo; La Perle, Krista M. D.; Kirschner, Lawrence S.

    2012-01-01

    Schwannomas are peripheral nerve sheath tumors that often occur in the setting of an inherited tumor predisposition syndrome, including Neurofibromatosis Types 1 (NF1) and 2 (NF2), Familial Schwannomatosis (FS) and Carney Complex (CNC). Loss of the NF2 tumor suppressor (encoding NF2, or Merlin) is associated with upregulation of the Rac1 small GTPase, which is thought to play a key role in mediating tumor formation. In prior studies, we generated a mouse model of schwannomas by performing tissue-specific knockout of the CNC gene Prkar1a, which encodes the type 1A regulatory subunit of Protein Kinase A. These tumors exhibited down-regulation of Nf2 protein and an increase in activated Rac1. To assess the requirement for Rac1 in schwannoma formation, we generated a double knockout of Prkar1a and Rac1 in Schwann cells and monitored tumor formation. Loss of Rac1 reduced tumor formation by reducing proliferation and enhancing apoptosis. Surprisingly, the reduction of tumor formation was accompanied by re-expression of the Nf2 protein. Furthermore, activated Rac1 was able to downregulate Nf2 in vitro in a Pak-dependent manner. These in vivo data indicate that activation of Rac1 is responsible for suppression of Nf2 protein production; deficiency of Nf2 in Schwann cells leads to loss of cellular growth control and tumor formation.. Further, PKA activation through mutation in Prkar1a is sufficient to initiate Rac1 signaling, with subsequent reduction of Nf2 and schwannomagenesis. Although in vitro evidence has shown that loss of Nf2 activates Rac1, our data indicates that signaling between Nf2 and Rac1 occurs in a bidirectional fashion, and these interactions are modulated by PKA. PMID:23045281

  8. Myelin basic protein and P2 protein are not immunohistochemical markers for Schwann cell neoplasms. A comparative study using antisera to S-100, P2, and myelin basic proteins.

    PubMed Central

    Clark, H. B.; Minesky, J. J.; Agrawal, D.; Agrawal, H. C.

    1985-01-01

    Immunohistochemical localization of tissue specific or cell-specific antigenic markers in neoplastic cells has become an increasingly important tool in the pathologic diagnosis of tumors. The myelin-specific proteins of peripheral nervous system myelin, because they are normally synthesized in Schwann cells, are potentially useful markers for neoplasms arising from peripheral nerves. The authors carried out immunohistochemical studies on 18 cases of Schwann cell neoplasms, including schwannomas, neurofibromas, and granular cell tumors, to determine whether two myelin-specific proteins, myelin basic protein and P2 protein, were present in neoplastic Schwann cells. None of these tumors showed immunostaining for either myelin basic protein or P2 protein in neoplastic cells. In contrast, S-100 protein, which is a well established marker for normal and neoplastic Schwann cells, was localized by immunohistochemistry to neoplastic cells in all 18 neoplasms. Therefore, although myelin basic protein and P2 protein are known to be Schwann-cell-specific proteins, they do not appear to be expressed commonly in neoplastic Schwann cells. Images Figure 2 Figure 1 Figure 3 PMID:2413766

  9. Nanobiocomposite of poly(lactide-co-glycolide)/chitosan electrospun scaffold can promote proliferation and transdifferentiation of Schwann-like cells from human adipose-derived stem cells.

    PubMed

    Razavi, Shahnaz; Zarkesh-Esfahani, Hamid; Morshed, Mohammad; Vaezifar, Sedigheh; Karbasi, Saeed; Golozar, Mohammad Ali

    2015-08-01

    The transdifferentiation of human adipose-derived stem cells (ADSCs) into Schwann-like cells on biocomposite scaffolds may be a critical issue in nerve regeneration medicine. In this study, tissue-engineered scaffold with chitosan (CS) nanopowders and poly(lactide-co-glycolide) (PLGA) was investigated for its potential Schwann cells (SCs) transdifferentiation. The differentiation of human ADSCs into S-like cells was induced with different CS content and direction of nanofibers on PLGA/CS scaffolds. Cell morphology and proliferation of differentiated cells were investigated by scanning electron microscopy and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay respectively. For assessment efficiency of transdifferentiation, the expression of SC markers (glial fibrillary acidic protein and S100), and myelinogenic marker (myelin basic protein) was investigated in different nanochitosan content and direction of nanofibers scaffolds, using immunocytochemistry technique. The nanochitosan can significantly promote cell proliferation of differentiated cells (p < 0.05). The mean percentage of S-like cells on greater CS content nanofibers scaffold was significantly higher than others (p < 0.05). In addition, the align orientation of nanofibers in scaffolds guided the differentiation of ADSCs toward myelinating S-like cells on the constructs. Overall, we found that high CS content and aligned-orientation of nanofibers in biocomposite scaffold (70/30A) can promote differentiation and myelinogenic capacity of S-like cells induced from human ADSCs. PMID:25614290

  10. Neurotrophin 3 activation of TrkC induces Schwann cell migration through the c-Jun N-terminal kinase pathway

    PubMed Central

    Yamauchi, Junji; Chan, Jonah R.; Shooter, Eric M.

    2003-01-01

    During development and nerve injury, complex interactions between glial cells and neurons are essential for establishing proper nerve function. Neurotrophins play multiple roles in the developing nervous system, including cell survival, growth, and differentiation. Here we show that migration of Schwann cells, isolated from sciatic nerves, is significantly enhanced by neurotrophin 3, but not by nerve growth factor or brain-derived neurotrophic factor. The neurotrophin-3-induced cell migration was also observed in Schwann cells isolated from sciatic nerves of p75NTR-/- mice, indicating that neurotrophin 3 enhances cell migration through TrkC. This effect was blocked by K252a, an inhibitor of the Trk receptor family. Additionally, the neurotrophin-3-induced cell migration depended on Rho GTPases (Rac1 and Cdc42) and c-Jun N-terminal kinase. We obtained the same results with Cos-7 cells expressing TrkC. Taken together, these results suggest that neurotrophin 3 activation of TrkC induces Schwann cell migration through the c-Jun N-terminal kinase signaling pathway. PMID:14614136

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

    PubMed

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

    2015-06-08

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

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

    PubMed Central

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

    2015-01-01

    Electrospun fibrous substrates mimicking extracellular matrices can be prepared by electrospinning, yielding aligned fibrous matrices as internal fillers to manufacture artificial nerves. Gelatin aligned nano-fibers were prepared by electrospinning after tuning the collector rotation speed. The effect of alignment on cell adhesion and proliferation was tested in vitro using primary cultures, the Schwann cell line, RT4-D6P2T, and the sensory neuron-like cell line, 50B11. Cell adhesion and proliferation were assessed by quantifying at several time-points. Aligned nano-fibers reduced adhesion and proliferation rate compared with random fibers. Schwann cell morphology and organization were investigated by immunostaining of the cytoskeleton. Cells were elongated with their longitudinal body parallel to the aligned fibers. B5011 neuron-like cells were aligned and had parallel axon growth when cultured on the aligned gelatin fibers. The data show that the alignment of electrospun gelatin fibers can modulate Schwann cells and axon organization in vitro, suggesting that this substrate shows promise as an internal filler for the design of artificial nerves for peripheral nerve reconstruction. PMID:26062130

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

    PubMed Central

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

    2012-01-01

    Objective: Several studies have shown that, although transplantation of neural stem cells into the contusion model of spinal cord injury (SCI) promotes locomotor function and improves functional recovery, it induces a painful response, Allodynia. Different studies indicate that bone marrow stromal cells (BMSCs) and Schwann cells (SCs) can improve locomotor recovery when transplanted into the injured rat spinal cord. Since these cells are commonly used in cell therapy, we investigated whether co-transplantation of these cells leads to the development of Allodynia. Materials and Methods: In this experimental research, the contusion model of SCI was induced by laminectomy at the T8-T9 level of the spinal cord in adult female wistar rats (n=40) weighting (250-300g) using the New York University Device. BMSCs and SCs were cultured and prelabeled with 5-bromo-2-deoxyuridine (BrdU) and 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) respectively. The rats were divided into five groups of 8 including: a control group (laminectomy only), three experimental groups (BMSC, SC and Co-transplant) and a sham group. The experimental groups received BMSCs, SCs, and BMSCs and SCs respectively by intraspinal injection 7 days after injury and the sham group received serum only. Locomotion was assessed using Basso, Beattie and Bresnahan (BBB) test and Allodynia by the withdrawal threshold test using Von Frey Filaments at 1, 7, 14, 21, 28, 35, 42, 49 and 56 days after SCI. The statistical comparisons between groups were carried out by using repeated measures analysis of variances (ANOVA). Results: Significant differences were observed in BBB scores in the Co- transplant group compared to the BMSC and SC groups (p< 0.05). There were also significant differences in the withdrawal threshold means between animals in the sham group and the BMSC, SC and the Co-transplant groups (p<0.05).BBB scores and withdrawal threshold means showed that co-transplation improved

  14. Improvements in neuroelectrophysiological and rear limb functions in rats with spinal cord injury after Schwann cell transplantation in combination with a C5a receptor antagonist.

    PubMed

    Zhang, S-Q; Wu, M-F; Peng, C-G; Lv, Y; Wu, D-K; Liu, J; Yang, Q

    2015-01-01

    We measured the effect of Schwann cell transplantation and complement factor 5a (C5a) receptor antagonist on nerve function recovery in rats with spinal cord injury. Experimental spinal cord injury was induced in eighty Wistar rats and these were randomly divided into four treatment groups: culture medium and saline injection (control group), Schwann cell injection (cell transplantation group), C5a receptor antagonist injection (C5a receptor antagonist group), and both Schwann cell and C5a receptor antagonist injections (combination group). Rear limb functional recovery was assessed 1, 2, 4, 6, and 8 weeks after the spinal cord injury with the tilt table test and the Basso, Beattie, Bresnahan scale. Sex-determining region Y (SRY) gene expression was measured at week 4 and horseradish peroxidase (HRP) labeling was used at week 8 to further assess the recovery of neuroelectrophysiological functions. The rear limb functional assessment showed that the combination group had better outcomes than the cell transplantation and C5a receptor antagonist groups. All treatment groups had better outcomes than control. Only the cell transplantation and combination groups showed SRY expression. The number of HRP-positive nerve fibers in the different groups ranked as follows: combination group > cell transplantation and C5a receptor antagonist > control. The refractory period and amplitude of the induced potential in the combination group were significantly greater than in the other three groups. These results suggest that the combination of Schwann cell transplantation and the C5a receptor antagonist enhances the regeneration of injured synapses and improves limb function and electrophysiology. PMID:26634479

  15. Nerves Control Redox Levels in Mature Tissues Through Schwann Cells and Hedgehog Signaling

    PubMed Central

    Meda, Francesca; Gauron, Carole; Rampon, Christine; Teillon, Jérémie; Volovitch, Michel

    2016-01-01

    Abstract Aims: Recent advances in redox biology have emphasized the role of hydrogen peroxide (H2O2) in the modulation of signaling pathways and revealed that H2O2 plays a role in cellular remodeling in adults. Thus, an understanding of the mechanisms that control H2O2 levels in mature tissue would be of great interest. Results: We used a denervation strategy to demonstrate that sensory neurons are responsible for controlling H2O2 levels under normal conditions and after being lesioned. Moreover, we demonstrate that severed nerves respond to appendage amputation via the induction of Hedgehog signaling and that this signaling is responsible for H2O2 production in the wounded epidermis. Finally, we show that H2O2 and nerve growth are regulated via reciprocal action in adults. Innovation and Conclusion: These data support a new paradigm for the regulation of tissue homeostasis: H2O2 attracts nerves and nerves control H2O2 levels in a positive feedback loop. This finding suggests that the peripheral nerve redox environment could be a target for manipulating cell plasticity in adults. Antioxid. Redox Signal. 24, 299–311. PMID:26442784

  16. A microscale neuron and Schwann cell coculture model for increasing detection sensitivity of botulinum neurotoxin type A.

    PubMed

    Hong, Won S; Young, Edmond W K; Tepp, William H; Johnson, Eric A; Beebe, David J

    2013-07-01

    Botulinum neurotoxin (BoNT) is a potent and specific biomolecule that is both implicated as a potential threat in bioterrorism and used in therapeutics. Highly sensitive and robust assays that measure BoNT activity are needed to manage outbreak or controlled distribution of BoNT. Current in vivo and in vitro assays have limitations, including high costs and variability for mouse bioassays, extensive preparations for primary and stem cell-derived neurons, and inherent low sensitivity for cell lines. Sensitivity of cell lines can be increased by direct differentiation and with their physiological relevance (compared with cell-free strategies) and robustness (compared with primary cell strategies); adopting cell lines is an attractive alternative to in vivo assays. Here, we present two distinct strategies that improved sensitivity of a cell line to BoNT serotype A (BoNT/A) without direct differentiation. We developed a cell-based BoNT assay using microscale culture and coculture of neuronal and Schwann cell lines, NG108-15 and S16, respectively, to improve both sensitivity and physiological relevance. Results showed that NG108-15 and S16 coculture decreased EC50 from 12.5 to 0.8ng/µl (p < 0.001) in macroscale and from 2.6 to 1.1ng/µl (p = 0.006) in microscale. In addition, NG108-15 monoculture at microscale decreased EC50 from 12.5 to 2.6ng/µl (p < 0.001) compared with macroscale. Finally, controlling the spatial arrangement of microscale coculture revealed that S16-derived soluble factors can increase sensitivity. Thus, our study demonstrates two distinct strategies for increasing the sensitivity of a cell line to BoNT using coculture and microscale culture, thereby advancing assay technology for BoNT detection. PMID:23564642

  17. Extracellular Signal-regulated Kinase Activation Is Required for Serine 727 Phosphorylation of STAT3 in Schwann Cells in vitro and in vivo

    PubMed Central

    Lee, Hyun Kyoung; Jung, Junyang; Lee, Sang Hwa; Seo, Su-Yeong; Suh, Duk Joon

    2009-01-01

    In the peripheral nerves, injury-induced cytokines and growth factors perform critical functions in the activation of both the MEK/ERK and JAK/STAT3 pathways. In this study, we determined that nerve injury-induced ERK activation was temporally correlated with STAT3 phosphorylation at the serine 727 residue. In cultured Schwann cells, we noted that ERK activation is required for the serine phosphorylation of STAT3 by neuropoietic cytokine interleukin-6 (IL-6). Serine phosphorylated STAT3 by IL-6 was transported into Schwann cell nuclei, thereby indicating that ERK may regulate the transcriptional activity of STAT3 via the induction of serine phosphorylation of STAT3. Neuregulin-1 (NRG) also induced the serine phosphorylation of STAT3 in an ERK-dependent fashion. In contrast with the IL-6 response, serine phosphorylated STAT3 induced by NRG was not detected in the nucleus, thus indicating the non-nuclear function of serine phosphorylated STAT3 in response to NRG. Finally, we determined that the inhibition of ERK prevented injury-induced serine phosphorylation of STAT3 in an ex-vivo explants culture of the sciatic nerves. Collectively, the results of this study show that ERK may be an upstream kinase for the serine phosphorylation of STAT3 induced by multiple stimuli in Schwann cells after peripheral nerve injury. PMID:19885032

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

    SciTech Connect

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

    2014-10-17

    Highlights: • PolySia expressed on neurons primarily during early stages of neuronal development. • PolySia–NCAM is expressed on neural stem cells from adult guinea pig spiral ganglion. • PolySia is a biomarker that modulates neuronal differentiation in inner ear stem cells. - Abstract: During brain development, polysialylated (polySia) neural cell adhesion molecules (polySia–NCAMs) modulate cell–cell adhesive interactions involved in synaptogenesis, neural plasticity, myelination, and neural stem cell (NSC) proliferation and differentiation. Our findings show that polySia–NCAM is expressed on NSC isolated from adult guinea pig spiral ganglion (GPSG), and in neurons and Schwann cells after differentiation of the NSC with epidermal, glia, fibroblast growth factors (GFs) and neurotrophins. These differentiated cells were immunoreactive with mAb’s to polySia, NCAM, β-III tubulin, nestin, S-100 and stained with BrdU. NSC could regenerate and be differentiated into neurons and Schwann cells. We conclude: (1) polySia is expressed on NSC isolated from adult GPSG and on neurons and Schwann cells differentiated from these NSC; (2) polySia is expressed on neurons primarily during the early stage of neuronal development and is expressed on Schwann cells at points of cell–cell contact; (3) polySia is a functional biomarker that modulates neuronal differentiation in inner ear stem cells. These new findings suggest that replacement of defective cells in the inner ear of hearing impaired patients using adult spiral ganglion neurons may offer potential hope to improve the quality of life for patients with auditory dysfunction and impaired hearing disorders.

  19. The effect of synthetic oxygen carrier-enriched fibrin hydrogel on Schwann cells under hypoxia condition in vitro.

    PubMed

    Ma, Teng; Wang, Yuqing; Qi, Fengyu; Zhu, Shu; Huang, Liangliang; Liu, Zhongyang; Huang, Jinghui; Luo, Zhuojing

    2013-12-01

    Schwann cell (SC), which plays a key role in peripheral nerve regeneration, is one of the most classic supportive cells in neural tissue engineering. However, the biological activity of SCs seeded in nerve scaffolds decays subsequently due to local hypoxia induced by ischemia. Thus, we aimed to investigate whether a synthetic oxygen carrier-enriched fibrin gel would provide a sustained oxygen release to cultured SCs in vitro for overcoming a temporary (48 h) oxygen deprivation. In this study, perfluorotributylamine (PFTBA)-based oxygen carrying fibrin gel was prepared to provide oxygen for SCs under normoxic or hypoxic conditions. The dissolved oxygen within the culture media was measured by a blood-gas analyzer to quantify the time course of oxygen release from the PFTBA-enriched fibrin gel. SCs were cultured in the presence or absence of PFTBA-enriched fibrin gel under normoxic or hypoxic conditions. The tolerance of SCs to hypoxia was examined by a cell apoptosis assay. The growth of cells was characterized using S-100 staining and a CCK-8 assay. The migration of cells was examined using a Transwell chamber. The mRNA of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), glial cell derived neurotrophic factor (GDNF), neural cell adhesion molecule (N-CAM) and vascular endothelial growth factor (VEGF) in SCs were assayed by RT-PCR. In addition, SCs cultured in 3D PFTBA-enriched hydrogel were characterized by Live/Dead staining and the mRNA levels of BDNF, NGF, GDNF, N-CAM and VEGF were assayed by RT-PCR. The results showed that the PFTBA-enriched fibrin hydrogel was able to promote cell adhesion, migration, and proliferation under hypoxic conditions. Interestingly, PFTBA applied through the fibrin hydrogel dramatically enhanced the mRNA of BDNF, NGF, GDNF, N-CAM and VEGF under hypoxic condition. These findings highlight the possibility of enhancing nerve regeneration in cellular nerve grafts through PFTBA increased neurotropic secretion in SCs.

  20. Fibroblast-derived tenascin-C promotes Schwann cell migration through β1-integrin dependent pathway during peripheral nerve regeneration.

    PubMed

    Zhang, Zhanhu; Yu, Bin; Gu, Yun; Zhou, Songlin; Qian, Tianmei; Wang, Yongjun; Ding, Guohui; Ding, Fei; Gu, Xiaosong

    2016-03-01

    Peripheral nerve regeneration requires precise coordination and dynamic interaction among various types of cells in the tissue. It remains unclear, however, whether the cellular crosstalk between fibroblasts and Schwann cells (SCs) is related to phenotype modulation of SCs, a critical cellular process after peripheral nerve injury. In this study, microarray analysis revealed that a total of 6,046 genes were differentially expressed in the proximal nerve segment after sciatic nerve transection in rats, and bioinformatics analysis further identified tenascin-C (TNC), an extracellular matrix (ECM) protein, as a key gene regulator. TNC was abundantly produced by nerve fibroblasts accumulating at the lesion site, rather than by SCs as usually expected. TNC significantly promoted SC migration without effects on SC proliferation in primary culture. In co-culture of fibroblasts and SCs, inhibition of TNC expression either by siRNA transfection or antibody blockade could suppress SC migration, while TNC-stimulated SC migration was mediated by TNC binding to β1-integrin receptor in SCs through activation of Rac1 effectors. The in vivo evidence showed that exogenous TNC protein enhanced SC migration and axonal regrowth. Our results highlight that TNC-mediated cellular interaction between fibroblasts and SCs may regulate SC migration through β1-integrin-dependent pathway during peripheral nerve regeneration.

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

    PubMed Central

    Gao, Hongyang; You, Yang; Zhang, Guoping; Zhao, Feng; Sha, Ziyi; Shen, Yong

    2013-01-01

    To explore the feasibility of biodegradable fiber-reinforced 3D scaffolds with satisfactory mechanical properties for the repair of long-distance sciatic nerve defect in rabbits and effects of vascularized graft in early stage on the recovery of neurological function, Schwann cells and vascular endothelial cells were cocultured in the fiber-reinforced 3D scaffolds. Experiment group which used prevascularized nerve complex for the repair of sciatic nerve defect and control group which only cultured with Schwann cells were set. The animals in both groups underwent electromyography to show the status of the neurological function recovery at 4, 8, and 16 weeks after the surgery. Sciatic nerve regeneration and myelination were observed under the light microscope and electron microscope. Myelin sheath thickness, axonal diameter, and number of myelinated nerve fiber were quantitatively analyzed using image analysis system. The recovery of foot ulcer, the velocity of nerve conduction, the number of regenerating nerve fiber, and the recovery of ultrastructure were increased in the experimental group than those in the control group. Prevascularized tissue engineered fiber-reinforced 3D scaffolds for the repair of sciatic nerve defects in rabbits can effectively promote the recovery of neurological function. PMID:24490158

  2. Muscarinic Ca2+ responses resistant to muscarinic antagonists at perisynaptic Schwann cells of the frog neuromuscular junction.

    PubMed Central

    Robitaille, R; Jahromi, B S; Charlton, M P

    1997-01-01

    1. Acetylcholine causes a rise of intracellular Ca2+ in perisynaptic Schwann cells (PSCs) of the frog neuromuscular junction. The signalling pathway was characterized using the fluorescent Ca2+ indicator fluo-3 and fluorescence microscopy. 2. Nicotinic antagonists had no effect on Ca2+ responses evoked by ACh and no Ca2+ responses were evoked with the nicotinic agonist nicotine. The muscarinic agonists muscarine and oxotremorine-M induced Ca2+ signals in PSCs. 3. Ca2+ responses remained unchanged when extracellular Ca2+ was removed, indicating that they are due to the release of Ca2+ from internal stores. Incubation with pertussis toxin did not alter the Ca2+ signals induced by muscarine, but did block depression of transmitter release induced by adenosine and prevented Ca2+ responses in PSCs induced by adenosine. 4. The general muscarinic antagonists atropine, quinuclidinyl benzilate and N-methyl-scopolamine failed to block Ca2+ responses to muscarinic agonists. Atropine (at 20,000-fold excess concentration) also failed to reduce the proportion of cells responding to a threshold muscarine concentration sufficient to cause responses in less than 50% of cells. Only the allosteric, non-specific blocker, gallamine (1-10 microM) was effective in blocking muscarine-induced Ca2+ responses. 5. In preparations denervated 7 days prior to experiments, low concentrations of atropine reversibly and completely blocked Ca2+ responses to muscarine. 6. The lack of blockade by general muscarinic antagonists in innervated, in situ preparations suggests that muscarinic Ca2+ responses at PSCs are not mediated by any of the five known muscarinic receptors or that post-translational modification prevented antagonist binding. Images Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 PMID:9365908

  3. Microprocessor complex subunit DiGeorge syndrome critical region gene 8 (Dgcr8) is required for schwann cell myelination and myelin maintenance.

    PubMed

    Lin, Hsin-Pin; Oksuz, Idil; Hurley, Edward; Wrabetz, Lawrence; Awatramani, Rajeshwar

    2015-10-01

    We investigated the role of a key component of the Microprocessor complex, DGCR8, in the regulation of myelin formation and maintenance. We found that conditionally ablating Dgcr8 in Schwann cells (SCs) during development results in an arrest of SC differentiation. Dgcr8 conditional knock-out (cKO) SCs fail to form 1:1 relationships with axons or, having achieved this, fail to form myelin sheaths. The expression of genes normally found in immature SCs, such as sex-determining region Y-box 2 (Sox2), is increased in Dgcr8 cKO SCs, whereas the expression of myelin-related genes, including the master regulatory transcription factor early growth response 2 (Egr2), is decreased. Additionally, expression of a novel gene expression program involving sonic hedgehog (Shh), activated de novo in injured nerves, is elevated in Dgcr8 cKOs but not in Egr2 null mice, a model of SC differentiation arrest, suggesting that the injury-related gene expression program in Dgcr8 cKOs cannot be attributed to differentiation arrest. Inducible ablation of Dgcr8 in adult SCs results in gene expression changes similar to those found in cKOs, including an increase in the expression of Sox2 and Shh. Analyses of these nerves mainly reveal normal myelin thickness and axon size distribution but some dedifferentiated SCs and increased macrophage infiltration. Together our data suggest that Dgcr8 is responsible for modulation of gene expression programs underlying myelin formation and maintenance as well as suppression of an injury-related gene expression program. PMID:26272614

  4. Microprocessor complex subunit DiGeorge syndrome critical region gene 8 (Dgcr8) is required for schwann cell myelination and myelin maintenance.

    PubMed

    Lin, Hsin-Pin; Oksuz, Idil; Hurley, Edward; Wrabetz, Lawrence; Awatramani, Rajeshwar

    2015-10-01

    We investigated the role of a key component of the Microprocessor complex, DGCR8, in the regulation of myelin formation and maintenance. We found that conditionally ablating Dgcr8 in Schwann cells (SCs) during development results in an arrest of SC differentiation. Dgcr8 conditional knock-out (cKO) SCs fail to form 1:1 relationships with axons or, having achieved this, fail to form myelin sheaths. The expression of genes normally found in immature SCs, such as sex-determining region Y-box 2 (Sox2), is increased in Dgcr8 cKO SCs, whereas the expression of myelin-related genes, including the master regulatory transcription factor early growth response 2 (Egr2), is decreased. Additionally, expression of a novel gene expression program involving sonic hedgehog (Shh), activated de novo in injured nerves, is elevated in Dgcr8 cKOs but not in Egr2 null mice, a model of SC differentiation arrest, suggesting that the injury-related gene expression program in Dgcr8 cKOs cannot be attributed to differentiation arrest. Inducible ablation of Dgcr8 in adult SCs results in gene expression changes similar to those found in cKOs, including an increase in the expression of Sox2 and Shh. Analyses of these nerves mainly reveal normal myelin thickness and axon size distribution but some dedifferentiated SCs and increased macrophage infiltration. Together our data suggest that Dgcr8 is responsible for modulation of gene expression programs underlying myelin formation and maintenance as well as suppression of an injury-related gene expression program.

  5. Activated Schwann Cell-Like Cells on Aligned Fibrin-Poly(Lactic-Co-Glycolic Acid) Structures: A Novel Construct for Application in Peripheral Nerve Regeneration.

    PubMed

    Schuh, Christina M A P; Morton, Tatjana J; Banerjee, Asmita; Grasl, Christian; Schima, Heinrich; Schmidhammer, Robert; Redl, Heinz; Ruenzler, Dominik

    2015-01-01

    Tissue engineering approaches in nerve regeneration search for ways to support gold standard therapy (autologous nerve grafts) and to improve results by bridging nerve defects with different kinds of conduits. In this study, we describe electrospinning of aligned fibrin-poly(lactic-co-glycolic acid) (PLGA) fibers in an attempt to create a biomimicking tissue-like material seeded with Schwann cell-like cells (SCLs) in vitro for potential use as an in vivo scaffold. Rat adipose-derived stem cells (rASCs) were differentiated into SCLs and evaluated with flow cytometry concerning their differentiation and activation status [S100b, P75, myelin-associated glycoprotein (MAG), and protein 0 (P0)]. After receiving the proliferation stimulus forskolin, SCLs expressed S100b and P75; comparable to native, activated Schwann cells, while cultured without forskolin, cells switched to a promyelinating phenotype and expressed S100b, MAG, and P0. Human fibrinogen and thrombin, blended with PLGA, were electrospun and the alignment and homogeneity of the fibers were proven by scanning electron microscopy. Electrospun scaffolds were seeded with SCLs and the formation of Büngner-like structures in SCLs was evaluated with phalloidin/propidium iodide staining. Carrier fibrin gels containing rASCs acted as a self-shaping matrix to form a tubular structure. In this study, we could show that rASCs can be differentiated into activated, proliferating SCLs and that these cells react to minimal changes in stimulus, switching to a promyelinating phenotype. Aligned electrospun fibrin-PLGA fibers promoted the formation of Büngner-like structures in SCLs, which also rolled the fibrin-PLGA matrix into a tubular scaffold. These in vitro findings favor further in vivo testing. PMID:26372904

  6. Selective knockdown of mutant SOD1 in Schwann cells ameliorates disease in G85R mutant SOD1 transgenic mice.

    PubMed

    Wang, Lijun; Pytel, Peter; Feltri, M Laura; Wrabetz, Lawrence; Roos, Raymond P

    2012-10-01

    Mutants of superoxide dismutase type 1 (mtSOD1) that have full dismutase activity (e.g., G37R) as well as none (e.g., G85R) cause familial amyotrophic lateral sclerosis (FALS), indicating that mtSOD1-induced FALS results from a toxicity rather than loss in SOD1 enzymatic activity. Still, it has remained unclear whether mtSOD1 dismutase activity can influence disease. A previous study demonstrated that Cre-mediated knockdown of G37R expression in Schwann cells (SCs) of G37R transgenic mice shortened the late phase of disease and survival. These results suggested that the neuroprotective effect of G37R expressed in SCs was greater than its toxicity, presumably because its dismutase activity counteracted reactive oxygen species (ROS). In order to further investigate this, we knocked down G85R in SCs by crossing G85R(flox) mice with myelin-protein-zero (P(0)):Cre mice, which express Cre recombinase in SCs. Knockdown of G85R in SCs of G85R mice delayed disease onset and extended survival indicating that G85R expression in SCs is neurotoxic. These results demonstrate differences in the effect on disease of dismutase active vs. inactive mtSOD1 suggesting that both a loss as well as gain in function of mtSOD1 influence FALS pathogenesis. The results suggest that mtSOD1-induced FALS treatment may have to be adjusted depending on the cell type targeted and particular mtSOD1 involved.

  7. Late Onset Neuropathy with Spontaneous Clinical Remission in Mice Lacking the POZ Domain of the Transcription Factor Myc-interacting Zinc Finger Protein 1 (Miz1) in Schwann Cells*

    PubMed Central

    Sanz-Moreno, Adrián; Fuhrmann, David; Zankel, Armin; Reingruber, Herbert; Kern, Lara; Meijer, Dies; Niemann, Axel; Elsässer, Hans-Peter

    2015-01-01

    The transcription factor Miz1 (Myc-interacting zinc finger 1) is a known regulator of the cell cycle but also has cell cycle-independent functions. Here we analyzed the role of Miz1 in the peripheral nervous system, using an early embryonic conditional knock-out model in which the Miz1 POZ domain is ablated in Schwann cells. Although the development of myelinated nerve fibers was not impaired, Miz1ΔPOZ mice acquired behavioral signs of a peripheral neuropathy at the age of 3 months. At this time, ultrastructural analysis of the sciatic nerve showed de- and dysmyelination of fibers, with massive outfoldings and a focal infiltration of macrophages. Although the expression of genes encoding structural myelin proteins, such as periaxin, myelin basic protein, and myelin protein zero, was decreased, genes associated with a negative regulation of myelination, including c-Jun, Sox2, and Id2, were up-regulated in Miz1ΔPOZ mice compared with controls. In animals older than 4 months, the motor disabilities vanished, and the ultrastructure of the sciatic nerve exhibited numerous tomacula and remyelinated fibers, as indicated by thinner myelin. No second acute attack was observed up to the age of 1 year. Thus, the deletion of the Miz1 POZ domain in Schwann cells induces an acute neuropathy with a subsequent regeneration in which there is ongoing balancing between de- and remyelination. Miz1ΔPOZ mice are impaired in the maintenance of myelinated fibers and are a promising model for studying remyelination in adult peripheral nerves. PMID:25416780

  8. Dixdc1 targets CyclinD1 and p21 via PI3K pathway activation to promote Schwann cell proliferation after sciatic nerve crush.

    PubMed

    Wu, Weijie; Liu, Qingqing; Liu, Yuxi; Yu, Zhaohui; Wang, Youhua

    2016-09-16

    Dixdc1 (DIX domain containing-1), the mammalian homolog of Ccd1 (Coiled-coil-Dishevelled-Axin1), is a protein containing a coiled-coil domain and a Dishevelled-Axin (DIX) domain. As a novel component of the Wnt pathway, Dixdc1 has been reported to be able to promote neural progenitor proliferation and neuronal differentiation via Wnt/β-catenin signaling. But there still remains something unknown about Dixdc1 distribution and functions in the lesion and regeneration of the peripheral nervous system (PNS), so we tried to investigate dynamic changes of Dixdc1 expression in a rat sciatic nerve crush (SNC) model in this study. First of all, we detected SNC-induced increased levels of Dixdc1 in Schwann cells and interestingly identified parallel expression of PCNA (proliferation cell nuclear antigen) with Dixdc1. Besides, we observed up-regulated Dixdc1 during the process of TNF-α-induced Schwann cell proliferation. Also, we discovered that Dixdc1 could promote G1-S phase transition accompanied with the up-regulation of CyclinD1 and down-regulation of p21. More importantly, enhanced effects of Dixdc1 on cell proliferation were confirmed to be associated with PI3K activation. Not only blocking of the PI3K but Dixdc1 knockdown led to significantly decreased ability for proliferation, as well as down-regulation of CyclinD1 and up-regulation of p21. In summary, these data demonstrated that Dixdc1 might participate in Schwann cell proliferation by targeting CyclinD1 and p21 at least partially through the PI3K/AKT activation. PMID:27521891

  9. Combination of engineered Schwann cell grafts to secrete neurotrophin and chondroitinase promotes axonal regeneration and locomotion after spinal cord injury.

    PubMed

    Kanno, Haruo; Pressman, Yelena; Moody, Alison; Berg, Randall; Muir, Elizabeth M; Rogers, John H; Ozawa, Hiroshi; Itoi, Eiji; Pearse, Damien D; Bunge, Mary Bartlett

    2014-01-29

    Transplantation of Schwann cells (SCs) is a promising therapeutic strategy for spinal cord repair. SCs introduced into lesions support axon regeneration, but because these axons do not exit the transplant, additional approaches with SCs are needed. Here, we transplanted SCs genetically modified to secrete a bifunctional neurotrophin (D15A) and chondroitinase ABC (ChABC) into a subacute contusion injury in rats. We examined the effects of these modifications on graft volume, SC number, degradation of chondroitin sulfate proteoglycans (CSPGs), astrogliosis, SC myelination of axons, propriospinal and supraspinal axon numbers, locomotor outcome (BBB scoring, CatWalk gait analysis), and mechanical and thermal sensitivity on the hind paws. D15A secreted from transplanted SCs increased graft volume and SC number and myelinated axon number. SCs secreting ChABC significantly decreased CSPGs, led to some egress of SCs from the graft, and increased propriospinal and 5-HT-positive axons in the graft. SCs secreting both D15A and ChABC yielded the best responses: (1) the largest number of SC myelinated axons, (2) more propriospinal axons in the graft and host tissue around and caudal to it, (3) more corticospinal axons closer to the graft and around and caudal to it, (4) more brainstem neurons projecting caudal to the transplant, (5) increased 5-HT-positive axons in the graft and caudal to it, (6) significant improvement in aspects of locomotion, and (7) improvement in mechanical and thermal allodynia. This is the first evidence that the combination of SC transplants engineered to secrete neurotrophin and chondroitinase further improves axonal regeneration and locomotor and sensory function.

  10. Curcumin derivatives promote Schwann cell differentiation and improve neuropathy in R98C CMT1B mice

    PubMed Central

    Patzkó, Ágnes; Bai, Yunhong; Saporta, Mario A.; Katona, István; Wu, XingYao; Vizzuso, Domenica; Feltri, M. Laura; Wang, Suola; Dillon, Lisa M.; Kamholz, John; Kirschner, Daniel; Sarkar, Fazlul H.; Wrabetz, Lawrence

    2012-01-01

    Charcot–Marie–Tooth disease type 1B is caused by mutations in myelin protein zero. R98C mice, an authentic model of early onset Charcot–Marie–Tooth disease type 1B, develop neuropathy in part because the misfolded mutant myelin protein zero is retained in the endoplasmic reticulum where it activates the unfolded protein response. Because oral curcumin, a component of the spice turmeric, has been shown to relieve endoplasmic reticulum stress and decrease the activation of the unfolded protein response, we treated R98C mutant mice with daily gastric lavage of curcumin or curcumin derivatives starting at 4 days of age and analysed them for clinical disability, electrophysiological parameters and peripheral nerve morphology. Heterozygous R98C mice treated with curcumin dissolved in sesame oil or phosphatidylcholine curcumin performed as well as wild-type littermates on a rotarod test and had increased numbers of large-diameter axons in their sciatic nerves. Treatment with the latter two compounds also increased compound muscle action potential amplitudes and the innervation of neuromuscular junctions in both heterozygous and homozygous R98C animals, but it did not improve nerve conduction velocity, myelin thickness, G-ratios or myelin period. The expression of c-Jun and suppressed cAMP-inducible POU (SCIP)—transcription factors that inhibit myelination when overexpressed—was also decreased by treatment. Consistent with its role in reducing endoplasmic reticulum stress, treatment with curcumin dissolved in sesame oil or phosphatidylcholine curcumin was associated with decreased X-box binding protein (XBP1) splicing. Taken together, these data demonstrate that treatment with curcumin dissolved in sesame oil or phosphatidylcholine curcumin improves the peripheral neuropathy of R98C mice by alleviating endoplasmic reticulum stress, by reducing the activation of unfolded protein response and by promoting Schwann cell differentiation. PMID:23250879

  11. Curcumin derivatives promote Schwann cell differentiation and improve neuropathy in R98C CMT1B mice.

    PubMed

    Patzkó, Agnes; Bai, Yunhong; Saporta, Mario A; Katona, István; Wu, Xingyao; Vizzuso, Domenica; Feltri, M Laura; Wang, Suola; Dillon, Lisa M; Kamholz, John; Kirschner, Daniel; Sarkar, Fazlul H; Wrabetz, Lawrence; Shy, Michael E

    2012-12-01

    Charcot-Marie-Tooth disease type 1B is caused by mutations in myelin protein zero. R98C mice, an authentic model of early onset Charcot-Marie-Tooth disease type 1B, develop neuropathy in part because the misfolded mutant myelin protein zero is retained in the endoplasmic reticulum where it activates the unfolded protein response. Because oral curcumin, a component of the spice turmeric, has been shown to relieve endoplasmic reticulum stress and decrease the activation of the unfolded protein response, we treated R98C mutant mice with daily gastric lavage of curcumin or curcumin derivatives starting at 4 days of age and analysed them for clinical disability, electrophysiological parameters and peripheral nerve morphology. Heterozygous R98C mice treated with curcumin dissolved in sesame oil or phosphatidylcholine curcumin performed as well as wild-type littermates on a rotarod test and had increased numbers of large-diameter axons in their sciatic nerves. Treatment with the latter two compounds also increased compound muscle action potential amplitudes and the innervation of neuromuscular junctions in both heterozygous and homozygous R98C animals, but it did not improve nerve conduction velocity, myelin thickness, G-ratios or myelin period. The expression of c-Jun and suppressed cAMP-inducible POU (SCIP)-transcription factors that inhibit myelination when overexpressed-was also decreased by treatment. Consistent with its role in reducing endoplasmic reticulum stress, treatment with curcumin dissolved in sesame oil or phosphatidylcholine curcumin was associated with decreased X-box binding protein (XBP1) splicing. Taken together, these data demonstrate that treatment with curcumin dissolved in sesame oil or phosphatidylcholine curcumin improves the peripheral neuropathy of R98C mice by alleviating endoplasmic reticulum stress, by reducing the activation of unfolded protein response and by promoting Schwann cell differentiation. PMID:23250879

  12. Neutralization of Schwann Cell-Secreted VEGF Is Protective to In Vitro and In Vivo Experimental Diabetic Neuropathy

    PubMed Central

    Taiana, Michela M.; Lombardi, Raffaella; Porretta-Serapiglia, Carla; Ciusani, Emilio; Oggioni, Norberto; Sassone, Jenny; Bianchi, Roberto; Lauria, Giuseppe

    2014-01-01

    The pathogenetic role of vascular endothelial growth factor (VEGF) in long-term retinal and kidney complications of diabetes has been demonstrated. Conversely, little is known in diabetic neuropathy. We examined the modulation of VEGF pathway at mRNA and protein level on dorsal root ganglion (DRG) neurons and Schwann cells (SC) induced by hyperglycaemia. Moreover, we studied the effects of VEGF neutralization on hyperglycemic DRG neurons and streptozotocin-induced diabetic neuropathy. Our findings demonstrated that DRG neurons were not affected by the direct exposition to hyperglycaemia, whereas showed an impairment of neurite outgrowth ability when exposed to the medium of SC cultured in hyperglycaemia. This was mediated by an altered regulation of VEGF and FLT-1 receptors. Hyperglycaemia increased VEGF and FLT-1 mRNA without changing their intracellular protein levels in DRG neurons, decreased intracellular and secreted protein levels without changing mRNA level in SC, while reduced the expression of the soluble receptor sFLT-1 both in DRG neurons and SC. Bevacizumab, a molecule that inhibits VEGF activity preventing the interaction with its receptors, restored neurite outgrowth and normalized FLT-1 mRNA and protein levels in co-cultures. In diabetic rats, it both prevented and restored nerve conduction velocity and nociceptive thresholds. We demonstrated that hyperglycaemia early affected neurite outgrowth through the impairment of SC-derived VEGF/FLT-1 signaling and that the neutralization of SC-secreted VEGF was protective both in vitro and in vivo models of diabetic neuropathy. PMID:25268360

  13. Opposing roles of PKA and EPAC in the cAMP-dependent regulation of schwann cell proliferation and differentiation [corrected].

    PubMed

    Bacallao, Ketty; Monje, Paula V

    2013-01-01

    In Schwann cells (SCs), cyclic adenosine monophosphate (cAMP) not only induces differentiation into a myelinating SC-related phenotype, but also synergistically enhances the mitogenic action of growth factors such as neuregulin. To better understand the molecular mechanism by which cAMP exerts these apparently contradictory functions, we investigated the role of the two main effectors of cAMP, protein kinase A (PKA) and the exchange protein activated by cAMP (EPAC), on the proliferation and differentiation of both isolated and axon-related SCs. For these studies, a variety of PKA and EPAC agonists and antagonists were used, including pathway-selective analogs of cAMP and pharmacological inhibitors. Our studies indicated that the activity of PKA rather than EPAC was required for the adjuvant effect of cAMP on S-phase entry, whereas the activity of EPAC rather than PKA was required for SC differentiation and myelin formation. Even though selective EPAC activation had an overall anti-proliferative effect in SCs, it failed to drive the expression of Krox-20, a master regulator of myelination, and that of myelin-specific proteins and lipids, suggesting that EPAC activation was insufficient to drive a full differentiating response. Interestingly, inhibition of EPAC activity resulted in a drastic impairment of SC differentiation and myelin formation but not Krox-20 expression, which indicates an independent mechanism of Krox-20 regulation in response to cAMP. In conclusion, our data supports the idea that the outcome of cAMP signaling in SCs depends on the particular set of effectors activated. Whereas the mitogenic action of cAMP relies exclusively on PKA activity, the differentiating action of cAMP requires a PKA-independent (non-canonical) cAMP-specific pathway that is partially transduced by EPAC.

  14. Combination of Engineered Schwann Cell Grafts to Secrete Neurotrophin and Chondroitinase Promotes Axonal Regeneration and Locomotion after Spinal Cord Injury

    PubMed Central

    Pressman, Yelena; Moody, Alison; Berg, Randall; Muir, Elizabeth M.; Rogers, John H.; Ozawa, Hiroshi; Itoi, Eiji; Pearse, Damien D.; Bunge, Mary Bartlett

    2014-01-01

    Transplantation of Schwann cells (SCs) is a promising therapeutic strategy for spinal cord repair. SCs introduced into lesions support axon regeneration, but because these axons do not exit the transplant, additional approaches with SCs are needed. Here, we transplanted SCs genetically modified to secrete a bifunctional neurotrophin (D15A) and chondroitinase ABC (ChABC) into a subacute contusion injury in rats. We examined the effects of these modifications on graft volume, SC number, degradation of chondroitin sulfate proteoglycans (CSPGs), astrogliosis, SC myelination of axons, propriospinal and supraspinal axon numbers, locomotor outcome (BBB scoring, CatWalk gait analysis), and mechanical and thermal sensitivity on the hind paws. D15A secreted from transplanted SCs increased graft volume and SC number and myelinated axon number. SCs secreting ChABC significantly decreased CSPGs, led to some egress of SCs from the graft, and increased propriospinal and 5-HT-positive axons in the graft. SCs secreting both D15A and ChABC yielded the best responses: (1) the largest number of SC myelinated axons, (2) more propriospinal axons in the graft and host tissue around and caudal to it, (3) more corticospinal axons closer to the graft and around and caudal to it, (4) more brainstem neurons projecting caudal to the transplant, (5) increased 5-HT-positive axons in the graft and caudal to it, (6) significant improvement in aspects of locomotion, and (7) improvement in mechanical and thermal allodynia. This is the first evidence that the combination of SC transplants engineered to secrete neurotrophin and chondroitinase further improves axonal regeneration and locomotor and sensory function. PMID:24478364

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

    PubMed

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

    2013-01-01

    Following spinal cord injury (SCI), both an inhibitory environment and lack of intrinsic growth capacity impede axonal regeneration. In a previous study, prevention of cyclic adenosine monophosphate (AMP) hydrolysis by the phosphodiesterase-4 inhibitor rolipram, in combination with Schwann cell (SC) grafts, promoted significant supraspinal and proprioceptive fiber growth and/or sparing and improved locomotion. In another study, transplanted SCs transduced to generate a bifunctional neurotrophin (D15A) led to significant increases in graft SCs and axons, including supraspinal and myelinated axons. Here we studied the growth and myelination of local and supraspinal axons and functional outcome following the combination of rolipram administration and neurotrophin-transduced SC implantation after SCI. Rolipram was administered subcutaneously for 4 weeks immediately after contusion at vertebral T8 (25.0-mm weight drop, MASCIS impactor). GFP or GFP-D15A-transduced SCs were injected into the injury epicenter 1 week after SCI. GFP-D15A SC grafts and GFP SC grafts with rolipram contained significantly more serotonergic fibers compared to GFP SCs. SC myelinated axons were increased significantly in GFP SC with rolipram-treated animals compared to animals receiving SCI alone. Rolipram administered with either GFP or GFP-D15A SCs significantly increased numbers of brain stem-derived axons below the lesion/implant area and improved hindlimb function. Compared to the single treatments, the combination led to the largest SC grafts, the highest numbers of serotonergic fibers in the grafts, and increased numbers of axons from the reticular formation below the lesion/implant area and provided the greatest improvement in hindlimb function. These findings demonstrate the therapeutic potential for a combination therapy involving the maintenance of cyclic AMP levels and neurotrophin-transduced SCs to repair the subacutely injured spinal cord. PMID:23146351

  16. Rat sciatic nerve reconstruction across a 30 mm defect bridged by an oriented porous PHBV tube with Schwann cell as artificial nerve graft.

    PubMed

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

    2014-01-01

    An oriented poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit has been used to evaluate its efficiency based on the promotion of peripheral nerve regeneration in rats. The oriented porous micropatterned artificial nerve conduit was designed onto the micropatterned silicon wafers, and then their surfaces were modified with oxygen plasma to increase cell adhesion. The designed conduits were investigated by cell culture analyses with Schwann cells (SCs). The conduits were implanted into a 30 mm gap in sciatic nerves of rats. Four months after surgery, the regenerated nerves were monitored and evaluated by macroscopic assessments and histology and behavioral analyses. Results of cellular analyses showed suitable properties of designed conduit for nerve regeneration. The results demonstrated that in the polymeric graft with SCs, the rat sciatic nerve trunk had been reconstructed with restoration of nerve continuity and formatted nerve fibers with myelination. Histological results demonstrated the presence of Schwann and glial cells in regenerated nerves. Functional recovery such as walking, swimming, and recovery of nociceptive function was illustrated for all the grafts especially conduits with SCs. This study proves the feasibility of the artificial nerve graft filled with SCs for peripheral nerve regeneration by bridging a longer defect in an animal model. PMID:24399063

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

    PubMed Central

    2014-01-01

    An oriented poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nerve conduit has been used to evaluate its efficiency based on the promotion of peripheral nerve regeneration in rats. The oriented porous micropatterned artificial nerve conduit was designed onto the micropatterned silicon wafers, and then their surfaces were modified with oxygen plasma to increase cell adhesion. The designed conduits were investigated by cell culture analyses with Schwann cells (SCs). The conduits were implanted into a 30 mm gap in sciatic nerves of rats. Four months after surgery, the regenerated nerves were monitored and evaluated by macroscopic assessments and histology and behavioral analyses. Results of cellular analyses showed suitable properties of designed conduit for nerve regeneration. The results demonstrated that in the polymeric graft with SCs, the rat sciatic nerve trunk had been reconstructed with restoration of nerve continuity and formatted nerve fibers with myelination. Histological results demonstrated the presence of Schwann and glial cells in regenerated nerves. Functional recovery such as walking, swimming, and recovery of nociceptive function was illustrated for all the grafts especially conduits with SCs. This study proves the feasibility of the artificial nerve graft filled with SCs for peripheral nerve regeneration by bridging a longer defect in an animal model. PMID:24399063

  18. Enhancement of Schwann cell myelin formation by K252a in the Trembler-J mouse dorsal root ganglion explant culture.

    PubMed

    Liu, Ning; Varma, Sushama; Shooter, Eric M; Tolwani, Ravi J

    2005-02-01

    The Trembler-J (TrJ) mouse, containing a point mutation in the peripheral myelin protein 22 gene, is characterized by severe hypomyelination and is a representative model of Charcot-Marie-Tooth 1A disease/Dejerine-Sottas Syndrome. Previous studies have shown that protein kinase inhibitor K252a enhances wild-type Schwann cell myelination in culture. We used a dorsal root ganglion (DRG) explant culture system from the heterozygous TrJ/+ mouse to investigate if myelination could be enhanced by K252a. The TrJ/+ DRG explant cultures replicated some important features of the TrJ/+ mouse, showing reduced myelin protein accumulation, thinner myelin sheaths, and shortened myelin internodes. K252a increased myelin protein accumulation and myelin sheath thickness but did not substantially increase myelin internode length. Furthermore, the TrJ/+ DRG explant culture and sciatic nerves continued to respond to K252a during the stage when myelination is complete in the wild type. A general tyrosine kinase inhibitor, genistein, but not inhibitors of serine/threonine protein kinase inhibitors, had a similar effect to K252a. K252a is therefore able to partially overcome hypomyelination by enhancing mutant Schwann cell myelin formation in the TrJ/+ mouse. PMID:15605381

  19. The Analgesic Effect on Neuropathic Pain of Retrogradely Transported botulinum Neurotoxin A Involves Schwann Cells and Astrocytes

    PubMed Central

    Ricordy, Ruggero; Uggenti, Carolina; Tata, Ada Maria; Luvisetto, Siro; Pavone, Flaminia

    2012-01-01

    In recent years a growing debate is about whether botulinum neurotoxins are retrogradely transported from the site of injection. Immunodetection of cleaved SNAP-25 (cl-SNAP-25), the protein of the SNARE complex targeted by botulinum neurotoxin serotype A (BoNT/A), could represent an excellent approach to investigate the mechanism of action on the nociceptive pathways at peripheral and/or central level. After peripheral administration of BoNT/A, we analyzed the expression of cl-SNAP-25, from the hindpaw’s nerve endings to the spinal cord, together with the behavioral effects on neuropathic pain. We used the chronic constriction injury of the sciatic nerve in CD1 mice as animal model of neuropathic pain. We evaluated immunostaining of cl-SNAP-25 in the peripheral nerve endings, along the sciatic nerve, in dorsal root ganglia and in spinal dorsal horns after intraplantar injection of saline or BoNT/A, alone or colocalized with either glial fibrillar acidic protein, GFAP, or complement receptor 3/cluster of differentiation 11b, CD11b, or neuronal nuclei, NeuN, depending on the area investigated. Immunofluorescence analysis shows the presence of the cl-SNAP-25 in all tissues examined, from the peripheral endings to the spinal cord, suggesting a retrograde transport of BoNT/A. Moreover, we performed in vitro experiments to ascertain if BoNT/A was able to interact with the proliferative state of Schwann cells (SC). We found that BoNT/A modulates the proliferation of SC and inhibits the acetylcholine release from SC, evidencing a new biological effect of the toxin and further supporting the retrograde transport of the toxin along the nerve and its ability to influence regenerative processes. The present results strongly sustain a combinatorial action at peripheral and central neural levels and encourage the use of BoNT/A for the pathological pain conditions difficult to treat in clinical practice and dramatically impairing patients’ quality of life. PMID:23110146

  20. A comparison of the release of a vasoactive-intestinal-peptide-like peptide and acetylcholine in the giant axon-Schwann cell preparation of the tropical squid Sepioteuthis sepioidea.

    PubMed

    Evans; Reale; Merzon; Villegas

    1999-01-21

    A vasoactive intestinal peptide (VIP)-like peptide is released by axonal stimulation in the giant axon-Schwann cell preparation from the tropical squid Sepioteuthis sepioidea. It is also released by direct application of l-glutamate, the giant axon-Schwann cell signalling molecule in this preparation. The release of the peptide parallels the release of acetylcholine from the Schwann cells themselves in this preparation in a number of different ways. The release of both acetylcholine and the VIP-like peptide have the same threshold (between 2x10(-10) and 5x10(-10 )mol l-1) for l-glutamate application and the same recovery time after inhibition of release by exposure of the preparation to a prolonged pulse of l-glutamate. A prolonged l-glutamate pulse of 10(-8 )mol l-1 releases both substances for as long as the pulse is applied to the preparation, whereas a prolonged pulse of 10(-9 )mol l-1 l-glutamate releases acetylcholine in the same way but releases the VIP-like peptide only transiently. The VIP-like peptide is likely to be co-released with acetylcholine from the Schwann cells.

  1. A Silk Fibroin/Collagen Nerve Scaffold Seeded with a Co-Culture of Schwann Cells and Adipose-Derived Stem Cells for Sciatic Nerve Regeneration.

    PubMed

    Xu, Yunqiang; Zhang, Zhenhui; Chen, Xuyi; Li, Ruixin; Li, Dong; Feng, Shiqing

    2016-01-01

    As a promising alternative to autologous nerve grafts, tissue-engineered nerve grafts have been extensively studied as a way to bridge peripheral nerve defects and guide nerve regeneration. The main difference between autogenous nerve grafts and tissue-engineered nerve grafts is the regenerative microenvironment formed by the grafts. If an appropriate regenerative microenvironment is provided, the repair of a peripheral nerve is feasible. In this study, to mimic the body's natural regenerative microenvironment closely, we co-cultured Schwann cells (SCs) and adipose-derived stem cells (ADSCs) as seed cells and introduced them into a silk fibroin (SF)/collagen scaffold to construct a tissue-engineered nerve conduit (TENC). Twelve weeks after the three different grafts (plain SF/collagen scaffold, TENC, and autograft) were transplanted to bridge 1-cm long sciatic nerve defects in rats, a series of electrophysiological examinations and morphological analyses were performed to evaluate the effect of the tissue-engineered nerve grafts on peripheral nerve regeneration. The regenerative outcomes showed that the effect of treatment with TENCs was similar to that with autologous nerve grafts but superior to that with plain SF/collagen scaffolds. Meanwhile, no experimental animals had inflammation around the grafts. Based on this evidence, our findings suggest that the TENC we developed could improve the regenerative microenvironment and accelerate nerve regeneration compared to plain SF/collagen and may serve as a promising strategy for peripheral nerve repair. PMID:26799619

  2. MpzR98C arrests Schwann cell development in a mouse model of early-onset Charcot–Marie–Tooth disease type 1B

    PubMed Central

    Saporta, Mario A. C.; Shy, Brian R.; Patzko, Agnes; Bai, Yunhong; Pennuto, Maria; Ferri, Cinzia; Tinelli, Elisa; Saveri, Paola; Kirschner, Dan; Crowther, Michelle; Southwood, Cherie; Wu, Xingyao; Gow, Alexander; Feltri, M. Laura; Wrabetz, Lawrence

    2012-01-01

    Mutations in myelin protein zero (MPZ) cause Charcot–Marie–Tooth disease type 1B. Many dominant MPZ mutations, including R98C, present as infantile onset dysmyelinating neuropathies. We have generated an R98C ‘knock-in’ mouse model of Charcot–Marie–Tooth type 1B, where a mutation encoding R98C was targeted to the mouse Mpz gene. Both heterozygous (R98C/+) and homozygous (R98C/R98C) mice develop weakness, abnormal nerve conduction velocities and morphologically abnormal myelin; R98C/R98C mice are more severely affected. MpzR98C is retained in the endoplasmic reticulum of Schwann cells and provokes a transitory, canonical unfolded protein response. Ablation of Chop, a mediator of the protein kinase RNA-like endoplasmic reticulum kinase unfolded protein response pathway restores compound muscle action potential amplitudes of R98C/+ mice but does not alter the reduced conduction velocities, reduced axonal diameters or clinical behaviour of these animals. R98C/R98C Schwann cells are developmentally arrested in the promyelinating stage, whereas development is delayed in R98C/+ mice. The proportion of cells expressing c-Jun, an inhibitor of myelination, is elevated in mutant nerves, whereas the proportion of cells expressing the promyelinating transcription factor Krox-20 is decreased, particularly in R98C/R98C mice. Our results provide a potential link between the accumulation of MpzR98C in the endoplasmic reticulum and a developmental delay in myelination. These mice provide a model by which we can begin to understand the early onset dysmyelination seen in patients with R98C and similar mutations. PMID:22689911

  3. AQP1 expression alterations affect morphology and water transport in Schwann cells and hypoxia-induced up-regulation of AQP1 occurs in a HIF-1α-dependent manner.

    PubMed

    Zhang, J; Xiong, Y; Lu, L X; Wang, H; Zhang, Y F; Fang, F; Song, Y L; Jiang, H

    2013-11-12

    Aquaporin-1 (AQP1) is the principle water channel in the peripheral nervous system (PNS) and is specifically localized to Schwann cells in the PNS. However, the pathophysiological role of AQP1 in peripheral nerves is poorly understood. Here, we utilized RNA interference by lentiviral transduction to specifically down-regulate AQP1 expression and a lentiviral overexpression protocol to up-regulate AQP1 expression, in primary Schwann cell cultures. AQP1 gene silencing resulted in a cell shrinkage phenotype, while AQP1 gene overexpression caused a cell swelling phenotype, as validated by cell volume determinations. Secondly, we utilized an in vitro hypoxia model in Schwann cells to mimic in vivo facial nerve injury. We demonstrated that AQP1 expression was induced within 8h following hypoxia injury in vitro, and that AQP1 knockdown (KD) caused the cells to resist edema following hypoxia. Finally, we investigated the hypoxic regulation of the AQP1 gene, as well as the involvement of Hypoxia-inducible factor-1α (HIF-1α) in AQP1 modulation and we found that KD of HIF-1α decreased hypoxia-dependent induction of endogenous AQP1 expression at both the mRNA and protein levels. Taken together, these results indicate that (1) AQP1 is an important factor responsible for the fast water transport of cultured Schwann cells and is involved in cell plasticity; (2) AQP1 alterations may be a primary factor in hypoxia-induced peripheral nerve edema; (3) HIF-1α participates in the hypoxic induction of the AQP1 gene; (4) AQP1 inhibition might provide a new therapeutic alternative for the treatment of some forms of peripheral nerve edema.

  4. PTEN and NF1 inactivation in Schwann cells produces a severe phenotype in the peripheral nervous system that promotes the development and malignant progression of peripheral nerve sheath tumors

    PubMed Central

    Keng, Vincent W.; Rahrmann, Eric P.; Watson, Adrienne L.; Tschida, Barbara R.; Moertel, Christopher L.; Jessen, Walter J.; Rizvi, Tilat A.; Collins, Margaret H.; Ratner, Nancy; Largaespada, David A.

    2012-01-01

    The genetic evolution from a benign neurofibroma to a malignant sarcoma in patients with neurofibromatosis type 1 (NF1) syndrome remains unclear. Schwann cells and/or their precursor cells are believed to be the primary pathogenic cell in neurofibromas because they harbor biallelic neurofibromin 1 (NF1) gene mutations. However, the phosphatase and tensin homolog (Pten) and neurofibromatosis 1 (Nf1) genes recently were found to be co-mutated in high-grade peripheral nerve sheath tumors (PNSTs) in mice. In this study, we created transgenic mice that lack both Pten and Nf1 in Schwann cells and Schwann cell precursor cells in order to validate the role of these two genes in PNST formation in vivo. Haploinsufficiency or complete loss of Pten dramatically accelerated neurofibroma development and led to the development of higher-grade PNSTs in the context of Nf1 loss. Pten dosage, together with Nf1 loss, was sufficient for the progression from low-grade to high-grade PNSTs. Genetic analysis of human sporadic malignant pheripheral nerve sheath tumors (MPNSTs) also revealed down-regulation of PTEN expression, suggesting that Pten-regulated pathways are major tumor suppressive barriers to neurofibroma progression. Together, our findings establish a novel mouse model that can rapidly recapitulate the onset of human neurofibroma tumorigenesis and the progression to MPNSTs. PMID:22700876

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

    PubMed

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

    2015-01-01

    Schwann cell (SC) transplantation exhibits significant potential for spinal cord injury (SCI) repair and its use as a therapeutic modality has now progressed to clinical trials for subacute and chronic human SCI. Although SC implants provide a receptive environment for axonal regrowth and support functional recovery in a number of experimental SCI models, axonal regeneration is largely limited to local systems and the behavioral improvements are modest without additional combinatory approaches. In the current study we investigated whether the concurrent delivery of the polyamine putrescine, started either 30 min or 1 week after SCI, could enhance the efficacy of SCs when implanted subacutely (1 week after injury) into the contused rat spinal cord. Polyamines are ubiquitous organic cations that play an important role in the regulation of the cell cycle, cell division, cytoskeletal organization, and cell differentiation. We show that the combination of putrescine with SCs provides a significant increase in implant size, an enhancement in axonal (sensory and serotonergic) sparing and/or growth, and improved open field locomotion after SCI, as compared to SC implantation alone. These findings demonstrate that polyamine supplementation can augment the effectiveness of SCs when used as a therapeutic approach for subacute SCI repair. PMID:26550496

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

    PubMed Central

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

    2015-01-01

    Schwann cell (SC) transplantation exhibits significant potential for spinal cord injury (SCI) repair and its use as a therapeutic modality has now progressed to clinical trials for subacute and chronic human SCI. Although SC implants provide a receptive environment for axonal regrowth and support functional recovery in a number of experimental SCI models, axonal regeneration is largely limited to local systems and the behavioral improvements are modest without additional combinatory approaches. In the current study we investigated whether the concurrent delivery of the polyamine putrescine, started either 30 min or 1 week after SCI, could enhance the efficacy of SCs when implanted subacutely (1 week after injury) into the contused rat spinal cord. Polyamines are ubiquitous organic cations that play an important role in the regulation of the cell cycle, cell division, cytoskeletal organization, and cell differentiation. We show that the combination of putrescine with SCs provides a significant increase in implant size, an enhancement in axonal (sensory and serotonergic) sparing and/or growth, and improved open field locomotion after SCI, as compared to SC implantation alone. These findings demonstrate that polyamine supplementation can augment the effectiveness of SCs when used as a therapeutic approach for subacute SCI repair. PMID:26550496

  7. Fabrication of growth factor- and extracellular matrix-loaded, gelatin-based scaffolds and their biocompatibility with Schwann cells and dorsal root ganglia

    PubMed Central

    Gámez Sazo, Rodolfo E.; Maenaka, Katsumi; Gu, Weiyong; Wood, Patrick M.; Bunge, Mary Bartlett

    2012-01-01

    One of the most exciting new avenues of research to repair the injured spinal cord is to combine cells for implantation with scaffolds that protect the cells and release growth factors to improve their survival and promote host axonal regeneration. To realize this goal, we fabricated biodegradable, photocurable gelatin tubes and membranes for exploratory in vitro studies. Detailed methods are described for their fabrication with a high gelatin concentration. Gelatin membranes fabricated in the same way as tubes and photo-co-immobilized with rhBDNF or rhNT-3, with or without Schwann cells (SCs), showed an initial burst of neurotrophin release within 24h, with release diminishing progressively for 21 days thereafter. SCs attained their typical bipolar conformation on membranes without neurotrophins but adhesion, alignment and proliferation were improved with neurotrophins, particularly rhBDNF. When dorsal root ganglion explants were cultured on membranes containing laminin and fibronectin plus both neurotrophins, neurite outgrowth was lengthier compared to combining one neurotrophin with laminin and fibronectin. Thus, these gelatin membranes allow SC survival and effectively release growth factors and harbor extracellular matrix components to improve cell survival and neurite growth. These scaffolds, based on the combination of cross-linked gelatin technology and incorporation of neurotrophins and extracellular matrix components, are promising candidates for spinal cord repair. PMID:22906605

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

    SciTech Connect

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

    2015-02-20

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

  9. Exclusive expression of the Rab11 effector SH3TC2 in Schwann cells links integrin-α6 and myelin maintenance to Charcot-Marie-Tooth disease type 4C.

    PubMed

    Vijay, Sauparnika; Chiu, Meagan; Dacks, Joel B; Roberts, Rhys C

    2016-07-01

    Charcot-Marie-Tooth disease type 4C (CMT4C) is one of the commonest autosomal recessive inherited peripheral neuropathies and is associated with mutations in the Rab11 effector, SH3TC2. Disruption of the SH3TC2-Rab11 interaction is the molecular abnormality underlying this disease. However, why SH3TC2 mutations cause an isolated demyelinating neuropathy remains unanswered. Here we show that SH3TC2 is an exclusive Schwann cell protein expressed late in myelination and is downregulated following denervation suggesting a functional role in myelin sheath maintenance. We support our data with an evolutionary cell biological analysis showing that the SH3TC2 gene, and its paralogue SH3TC1, are derived from an ancestral homologue, the duplication of which occurred in the common ancestor of jawed vertebrates, coincident with the appearance of Schwann cells and peripheral axon myelination. Furthermore, we report that SH3TC2 associates with integrin-α6, suggesting that aberrant Rab11-dependent endocytic trafficking of this critical laminin receptor in myelinated Schwann cells is connected to the demyelination seen in affected nerves. Our study therefore highlights the inherent evolutionary link between SH3TC2 and peripheral nerve myelination, pointing also towards a molecular mechanism underlying the specific demyelinating neuropathy that characterizes CMT4C.

  10. Chitosan/silk fibroin-based, Schwann cell-derived extracellular matrix-modified scaffolds for bridging rat sciatic nerve gaps.

    PubMed

    Gu, Yun; Zhu, Jianbin; Xue, Chengbin; Li, Zhenmeiyu; Ding, Fei; Yang, Yumin; Gu, Xiaosong

    2014-02-01

    Extracellular matrix (ECM) plays a prominent role in establishing and maintaining an ideal microenvironment for tissue regeneration, and ECM scaffolds are used as a feasible alternative to cellular and molecular therapy in the fields of tissue engineering. Because of their advantages over tissue-derived ECM scaffolds, cultured cell-derived ECM scaffolds are beginning to attract attention, but they have been scarcely studied for peripheral nerve repair. Here we aimed to develop a tissue engineered nerve scaffold by reconstituting nerve cell-derived ECM with natural biomaterials. A protocol was adopted to prepare and characterize the cultured Schwann cell (SC)-derived ECM. A chitosan conduit and silk fibroin (SF) fibers were prepared, cultured with SCs for ECM deposition, and subjected to decellularization, followed by assembly into a chitosan/SF-based, SC-derived ECM-modified scaffold, which was used to bridge a 10 mm rat sciatic nerve gap. The results from morphological analysis as well as electrophysiological examination indicated that regenerative outcomes achieved by our developed scaffold were similar to those by an acellular nerve graft (namely a nerve tissue-derived ECM scaffold), but superior to those by a plain chitosan/SF scaffold. Moreover, blood and histopathological parameters confirmed the safety of scaffold modification by SC-derived ECM. Therefore, a hybrid scaffold based on joint use of acellular and classical biomaterials represents a promising approach to nerve tissue engineering.

  11. Hypoxia-Induced Upregulation of miR-132 Promotes Schwann Cell Migration After Sciatic Nerve Injury by Targeting PRKAG3.

    PubMed

    Yao, Chun; Shi, Xiangxiang; Zhang, Zhanhu; Zhou, Songlin; Qian, Tianmei; Wang, Yaxian; Ding, Fei; Gu, Xiaosong; Yu, Bin

    2016-10-01

    Following peripheral nerve injury, hypoxia is formed as a result of defects in blood supply at the injury site. Despite accumulating evidence on the effects of microRNAs (miRNAs) on phenotype modulation of Schwann cells (SCs) after peripheral nerve injury, the impact of hypoxia on SC behaviors through miRNAs during peripheral nerve regeneration has not been estimated. In this study, we confirmed our previous microarray data on the upregulation of miR-132 after sciatic nerve injury in rats and observed that overexpression of miR-132 significantly promoted cell migration of primary cultured SCs. Interestingly, hypoxia-increased expression of miR-132 also enhanced SC migration while inhibition of miR-132 suppressed hypoxia-induced increase in SC migration. miR-132 downregulated PRKAG3 through binding to its 3'-UTR, and PRKAG3 knockdown compromised the reducing effect of miR-132 inhibition on SC migration under normal or hypoxia condition. Moreover, in vivo injection of miR-132 agomir into rats with sciatic nerve transection accelerated SC migration from the proximal to distal stump. Overall, our results suggest that the hypoxia-induced upregulation of miR-132 could promote SC migration and facilitate peripheral nerve regeneration.

  12. Regulation of Schwann cell proliferation and migration by miR-1 targeting brain-derived neurotrophic factor after peripheral nerve injury

    PubMed Central

    Yi, Sheng; Yuan, Ying; Chen, Qianqian; Wang, Xinghui; Gong, Leilei; Liu, Jie; Gu, Xiaosong; Li, Shiying

    2016-01-01

    Peripheral nerve injury is a global problem that causes disability and severe socioeconomic burden. Brain-derived neurotrophic factor (BDNF) benefits peripheral nerve regeneration and becomes a promising therapeutic molecule. In the current study, we found that microRNA-1 (miR-1) directly targeted BDNF by binding to its 3′-UTR and caused both mRNA degradation and translation suppression of BDNF. Moreover, miR-1 induced BDNF mRNA degradation primarily through binding to target site 3 rather than target site 1 or 2 of BDNF 3′-UTR. Following rat sciatic nerve injury, a rough inverse correlation was observed between temporal expression profiles of miR-1 and BDNF in the injured nerve. The overexpression or silencing of miR-1 in cultured Schwann cells (SCs) inhibited or enhanced BDNF secretion from the cells, respectively, and also suppressed or promoted SC proliferation and migration, respectively. Interestingly, BDNF knockdown could attenuate the enhancing effect of miR-1 inhibitor on SC proliferation and migration. These findings will contribute to the development of a novel therapeutic strategy for peripheral nerve injury, which overcomes the limitations of direct administration of exogenous BDNF by using miR-1 to regulate endogenous BDNF expression. PMID:27381812

  13. Merosin, a protein specific for basement membranes of Schwann cells, striated muscle, and trophoblast, is expressed late in nerve and muscle development.

    PubMed Central

    Leivo, I; Engvall, E

    1988-01-01

    We have identified a tissue-specific basement membrane-associated protein by using monoclonal antibodies prepared against a protein fraction of human placenta. In immunofluorescence, the monoclonal antibodies stained basement membranes of Schwann cells, striated muscle, and trophoblast, whereas no reaction was seen with any other basement membrane or tissue structure. In antibody-affinity chromatography of proteolytic digests of human placenta, a 65-kDa polypeptide was bound by these monoclonal antibodies. Rabbit antisera and monoclonal antibodies raised against the isolated 65-kDa polypeptide stained human and monkey tissues identically to the original monoclonal antibodies and reacted with an 80-kDa polypeptide in tissue extracts prepared without proteolysis. The 65-kDa and 80-kDa polypeptides were shown to be immunologically distinct from laminin, type IV collagen, fibronectin, and major serum proteins. They presumably represent a novel basement membrane-associated protein, which we have named merosin. No merosin immunoreactivity could be detected in cultures of any of 28 established cell lines. In developing mouse tissues, merosin staining first appeared at the newborn stage. The restricted tissue distribution and late developmental appearance of merosin suggest that the protein has a tissue-specific function associated with a high level of differentiation. Images PMID:3278318

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

    PubMed

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

    2015-10-01

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

  15. Fabrication and characterization of vitamin B5 loaded poly (l-lactide-co-caprolactone)/silk fiber aligned electrospun nanofibers for schwann cell proliferation.

    PubMed

    Bhutto, M Aqeel; Wu, Tong; Sun, Binbin; Ei-Hamshary, Hany; Al-Deyab, Salem S; Mo, Xiumei

    2016-08-01

    Bioengineering strategies for peripheral nerve regeneration have been focusing on the development of alternative treatments for nerve repair. In present study we have blended the Vitamin B5 (50mg) with 8% P(LLA-CL) and P(LLA-CL)/SF solutions and produced aligned electrospun nanofiber mashes and characterized the material for its physiochemical and mechanical characteristics. The vitamin loaded composites nanofibers showed tensile strength of 8.73±1.38 and 8.4±1.37 in P(LLA-CL)/Vt and P(LLA-CL)/SF/Vt nanofibers mashes, respectively. By the addition of vitamin B5 the P(LLA-CL) nanofibers become hydrophilic and the contact angle decreased from 96° to 0° in 6min of duration. The effect of vitamin B5 on Schwann cells proliferation and viability were analyzed by using MTT assay and the number of cells cultured on vitamin loaded nanofiber mashes was significantly higher than the without vitamin loaded nanofiber samples after 5th day (p<0.05) whereas, P (LLA-CL)/SF/Vt exhibit the consistently highest cell numbers after 7th days culture as compare to P (LLA-CL)/Vt. The in vitro vitamin release behavior was observed in PBS solution and released vitamin was calculated by revers phase HPLC method. The sustain release behavior of vitamin B5 were noted higher in P(LLA-CL)/Vt (80%) nanofibers as compared to P (LLA-CL)/SF/Vt (62%) nanofibers after 24h. The present work provided a basis for further studies of this novel aligned nanofibrous material in nerve tissue repair or regeneration.

  16. Fabrication and characterization of vitamin B5 loaded poly (l-lactide-co-caprolactone)/silk fiber aligned electrospun nanofibers for schwann cell proliferation.

    PubMed

    Bhutto, M Aqeel; Wu, Tong; Sun, Binbin; Ei-Hamshary, Hany; Al-Deyab, Salem S; Mo, Xiumei

    2016-08-01

    Bioengineering strategies for peripheral nerve regeneration have been focusing on the development of alternative treatments for nerve repair. In present study we have blended the Vitamin B5 (50mg) with 8% P(LLA-CL) and P(LLA-CL)/SF solutions and produced aligned electrospun nanofiber mashes and characterized the material for its physiochemical and mechanical characteristics. The vitamin loaded composites nanofibers showed tensile strength of 8.73±1.38 and 8.4±1.37 in P(LLA-CL)/Vt and P(LLA-CL)/SF/Vt nanofibers mashes, respectively. By the addition of vitamin B5 the P(LLA-CL) nanofibers become hydrophilic and the contact angle decreased from 96° to 0° in 6min of duration. The effect of vitamin B5 on Schwann cells proliferation and viability were analyzed by using MTT assay and the number of cells cultured on vitamin loaded nanofiber mashes was significantly higher than the without vitamin loaded nanofiber samples after 5th day (p<0.05) whereas, P (LLA-CL)/SF/Vt exhibit the consistently highest cell numbers after 7th days culture as compare to P (LLA-CL)/Vt. The in vitro vitamin release behavior was observed in PBS solution and released vitamin was calculated by revers phase HPLC method. The sustain release behavior of vitamin B5 were noted higher in P(LLA-CL)/Vt (80%) nanofibers as compared to P (LLA-CL)/SF/Vt (62%) nanofibers after 24h. The present work provided a basis for further studies of this novel aligned nanofibrous material in nerve tissue repair or regeneration. PMID:27085042

  17. Dissociated Predegenerated Peripheral Nerve Transplants for Spinal Cord Injury Repair: A Comprehensive Assessment of Their Effects on Regeneration and Functional Recovery Compared to Schwann Cell Transplants

    PubMed Central

    Brodak, Danika M.; Bartlett Bunge, Mary

    2012-01-01

    Abstract Several recent studies suggest that predegenerated nerves (PDNs) or dissociated PDNs (dPDNs) can improve behavioral and histological outcomes following transplantation into the injured rat spinal cord. In the current study we tested the efficacy of dPDN transplantation by grafting cells isolated from the sciatic nerve 7 days after crush. We did not replicate one study, but rather assessed what appeared, based on five published reports, to be a reported robust effect of dPDN grafts on corticospinal tract (CST) regeneration and locomotor recovery. Using a standardized rodent spinal cord injury model (200 kD IH contusion) and transplantation procedure (injection of GFP+ cells 7 days post-SCI), we demonstrate that dPDN grafts survive within the injured spinal cord and promote the ingrowth of axons to a similar extent as purified Schwann cell (SC) grafts. We also demonstrate for the first time that while both dPDN and SC grafts promote the ingrowth of CGRP axons, neither graft results in mechanical or thermal hyperalgesia. Unlike previous studies, dPDN grafts did not promote long-distance axonal growth of CST axons, brainstem spinal axons, or ascending dorsal column sensory axons. Moreover, using a battery of locomotor tests (Basso Beattie Bresnahan [BBB] score, BBB subscore, inked footprint, Catwalk, and ladderwalk), we failed to detect any beneficial effects of dPDN transplantation on the recovery of locomotor function after SCI. We conclude that dPDN transplants are not sufficient to promote CST regeneration or locomotor recovery after SCI. PMID:22655857

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

    PubMed

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

    2015-02-20

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

  19. Calcitriol prevents peripheral RSC96 Schwann neural cells from high glucose & methylglyoxal-induced injury through restoration of CBS/H2S expression.

    PubMed

    Zhang, Hui; Zhuang, Xiao-dong; Meng, Fu-hui; Chen, Li; Dong, Xiao-bian; Liu, Guo-Hui; Li, Jian-hua; Dong, Qi; Xu, Ji-de; Yang, Chun-tao

    2016-01-01

    A meta-analysis has suggested that vitamin D deficiency is involved in diabetic peripheral neuropathy (DPN) and the levels of hydrogen sulfide (H2S) are also decreased in type 2 diabetes. The injection of vitamin D induces cystathionine-β-synthase (CBS) expression and H2S generation. However, it remains unclear whether the supplementation of vitamin D prevents DPN through improvement of CBS/H2S expression. In the present study, RSC96 cells, a rat Schwann cell line, were exposed to high glucose and methylglyoxal (HG&MG) to simulate diabetic peripheral nerve injury in vivo. Before the exposure to HG&MG, the cells were preconditioned with calcitriol (CCT), an active form of vitamin D, and then CCT-mediated neuroprotection was investigated in respect of cellular viability, superoxide anion (O2(-)) generation, inducible nitric oxide (NO) synthase (iNOS)/NO expression, mitochondrial membrane potential (MMP), as well as CBS expression and activity. It was found that both high glucose and MGO decreased cell viability and co-treatment with the two induced a more serious injury in RSC96 cells. Therefore, the exposure to HG&MG was used in the present study. The exposure to HG&MG markedly induced iNOS expression, NO and O2(-) generation, as well as MMP loss. In addition, the exposure to HG&MG depressed CBS expression and activity in RSC96 cells. However, the preconditioning with CCT significantly antagonized HG&MG-induced cell injury including the decreased viability, iNOS overexpression, NO and O2(-) accumulation, as well as MMP loss. CCT also partially restored the decreased CBS expression and activity triggered by HG&MG, while the inhibition of CBS with hydroxylamine attenuated CCT-mediated neuroprotection. Moreover, the exogenous donation of H2S produced similar cellular protective effects to CCT. The data indicate that the supplementation of vitamin D prevents HG&MG-induced peripheral nerve injury involving the restoration of endogenous H2S system, which may provide a

  20. Adult Stem and Progenitor Cells

    NASA Astrophysics Data System (ADS)

    Geraerts, Martine; Verfaillie, Catherine M.

    The discovery of adult stem cells in most adult tissues is the basis of a number of clinical studies that are carried out, with therapeutic use of hematopoietic stem cells as a prime example. Intense scientific debate is still ongoing as to whether adult stem cells may have a greater plasticity than previously thought. Although cells with some features of embryonic stem cells that, among others, express Oct4, Nanog and SSEA1 are isolated from fresh tissue, it is not clear if the greater differentiation potential is acquired during cell culture. Moreover, adult more pluripotent cells do not have all pluripotent characteristics typical for embryonic stem cells. Recently, some elegant studies were published in which adult cells could be completely reprogrammed to embryonic stem cell-like cells by overexpression of some key transcription factors for pluripotency (Oct4, Sox2, Klf4 and c-Myc). It will be interesting for the future to investigate the exact mechanisms underlying this reprogramming and whether similar transcription factor pathways are present and/or can be activated in adult more pluripotent stem cells.

  1. ApoER2 and Reelin are expressed in regenerating peripheral nerve and regulate Schwann cell migration by activating the Rac1 GEF protein, Tiam1.

    PubMed

    Pasten, Consuelo; Cerda, Joaquín; Jausoro, Ignacio; Court, Felipe A; Cáceres, Alfredo; Marzolo, Maria-Paz

    2015-11-01

    ApoER2 and its ligand Reelin participate in neuronal migration during development. Upon receptor binding, Reelin induces the proteolytic processing of ApoER2 as well as the activation of signaling pathway, including small Rho GTPases. Besides its presence in the central nervous system (CNS), Reelin is also secreted by Schwann cells (SCs), the glial cells of the peripheral nervous system (PNS). Reelin deficient mice (reeler) show decreased axonal regeneration in the PNS; however neither the presence of ApoER2 nor the role of the Reelin signaling pathway in the PNS have been evaluated. Interestingly SC migration occurs during PNS development and during injury-induced regeneration and involves activation of small Rho GTPases. Thus, Reelin-ApoER2 might regulate SC migration during axon regeneration in the PNS. Here we demonstrate the presence of ApoER2 in PNS. After sciatic nerve injury Reelin was induced and its receptor ApoER2 was proteolytically processed. In vitro, SCs express both Reelin and ApoER2 and Reelin induces SC migration. To elucidate the molecular mechanism underlying Reelin-dependent SC migration, we examined the involvement of Rac1, a conspicuous small GTPase family member. FRET experiments revealed that Reelin activates Rac1 at the leading edge of SCs. In addition, Tiam1, a major Rac1-specific GEF was required for Reelin-induced SC migration. Moreover, Reelin-induced SC migration was decreased after suppression of the polarity protein PAR3, consistent with its association to Tiam1. Even more interesting, we demonstrated that PAR3 binds preferentially to the full-length cytoplasmic tail of ApoER2 corresponding to the splice-variant containing the exon 19 that encodes a proline-rich insert and that ApoER2 was required for SC migration. Our study reveals a novel function for Reelin/ApoER2 in PNS, inducing cell migration of SCs, a process relevant for PNS development and regeneration.

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

    SciTech Connect

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

    2012-10-01

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

  3. Characterization of a Unique Cell Population Marked by Transgene Expression in the Adult Cochlea of Nestin-CreERT2/tdTomato-Reporter Mice

    PubMed Central

    Chow, Cynthia L.; Guo, Weixiang; Trivedi, Parul; Zhao, Xinyu; Gubbels, Samuel P.

    2015-01-01

    Hair cells in the adult mammalian cochlea cannot spontaneously regenerate after damage resulting in the permanency of hearing loss. Stem cells have been found to be present in the cochlea of young rodents; however, there has been little evidence for their existence into adulthood. We used nestin-CreERT2/tdTomato-reporter mice to trace the lineage of putative nestin-expressing cells and their progeny in the cochleae of adult mice. Nestin, an intermediate filament found in neural progenitor cells during early development and adulthood, is regarded as a multi-potent and neural stem cell marker. Other investigators have reported its presence in postnatal and young adult rodents; however, there are discrepancies amongst these reports. Using lineage tracing, we documented a robust population of tdTomato-expressing cells and evaluated these cells at a series of adult time points. Upon activation of the nestin promoter, tdTomato was observed just below and medial to the inner hair cell layer. All cells co-localized with the stem cell and cochlear-supporting-cell marker Sox2 as well as the supporting cell and Schwann cell marker Sox10; however, they did not co-localize with the Schwann cell marker Krox20, spiral ganglion marker NF200, or GFAP-expressing supporting cell marker. The cellular identity of this unique population of tdTomato-expressing cells in the adult cochlea of nestin-CreERT2/tdTomato mice remains unclear however these cells may represent a type of supporting cell on the neural aspect of the inner hair cell layer. PMID:25611038

  4. Characterization of a unique cell population marked by transgene expression in the adult cochlea of nestin-CreER(T2)/tdTomato-reporter mice.

    PubMed

    Chow, Cynthia L; Guo, Weixiang; Trivedi, Parul; Zhao, Xinyu; Gubbels, Samuel P

    2015-07-01

    Hair cells in the adult mammalian cochlea cannot spontaneously regenerate after damage, resulting in the permanency of hearing loss. Stem cells have been found to be present in the cochlea of young rodents; however, there has been little evidence for their existence into adulthood. We used nestin-CreER(T2)/tdTomato-reporter mice to trace the lineage of putative nestin-expressing cells and their progeny in the cochleae of adult mice. Nestin, an intermediate filament found in neural progenitor cells during early development and adulthood, is regarded as a multipotent and neural stem cell marker. Other investigators have reported its presence in postnatal and young adult rodents; however, there are discrepancies among these reports. Using lineage tracing, we documented a robust population of tdTomato-expressing cells and evaluated these cells at a series of adult time points. Upon activation of the nestin promoter, tdTomato was observed just below and medial to the inner hair cell layer. All cells colocalized with the stem cell and cochlear-supporting-cell marker Sox2 as well as the supporting cell and Schwann cell marker Sox10; however, they did not colocalize with the Schwann cell marker Krox20, spiral ganglion marker NF200, nor glial fibrillary acidic acid (GFAP)-expressing supporting cell marker. The cellular identity of this unique population of tdTomato-expressing cells in the adult cochlea of nestin-CreER(T2)/tdTomato mice remains unclear; however, these cells may represent a type of supporting cell on the neural aspect of the inner hair cell layer. PMID:25611038

  5. [Langerhans cell histiocytosis in adults].

    PubMed

    Néel, A; Artifoni, M; Donadieu, J; Lorillon, G; Hamidou, M; Tazi, A

    2015-10-01

    Langerhans cell histiocytosis (LCH) is a rare disease characterized by the infiltration of one or more organs by Langerhans cell-like dendritic cells, most often organized in granulomas. The disease has been initially described in children. The clinical picture of LCH is highly variable. Bone, skin, pituitary gland, lung, central nervous system, lymphoid organs are the main organs involved whereas liver and intestinal tract localizations are less frequently encountered. LCH course ranges from a fulminant multisystem disease to spontaneous resolution. Several randomized controlled trials have enable pediatricians to refine the management of children with LCH. Adult LCH has some specific features and poses distinct therapeutic challenges, knowing that data on these patients are limited. Herein, we will provide an overview of current knowledge regarding adult LCH and its management. We will also discuss recent advances in the understanding of the disease, (i.e. the role of BRAF oncogene) that opens the way toward targeted therapies.

  6. [Langerhans cell histiocytosis in adults].

    PubMed

    Néel, A; Artifoni, M; Donadieu, J; Lorillon, G; Hamidou, M; Tazi, A

    2015-10-01

    Langerhans cell histiocytosis (LCH) is a rare disease characterized by the infiltration of one or more organs by Langerhans cell-like dendritic cells, most often organized in granulomas. The disease has been initially described in children. The clinical picture of LCH is highly variable. Bone, skin, pituitary gland, lung, central nervous system, lymphoid organs are the main organs involved whereas liver and intestinal tract localizations are less frequently encountered. LCH course ranges from a fulminant multisystem disease to spontaneous resolution. Several randomized controlled trials have enable pediatricians to refine the management of children with LCH. Adult LCH has some specific features and poses distinct therapeutic challenges, knowing that data on these patients are limited. Herein, we will provide an overview of current knowledge regarding adult LCH and its management. We will also discuss recent advances in the understanding of the disease, (i.e. the role of BRAF oncogene) that opens the way toward targeted therapies. PMID:26150351

  7. Conjunctival biopsy in adult form galactosialidosis.

    PubMed Central

    Usui, T; Sawaguchi, S; Abe, H; Iwata, K; Oyanagi, K

    1993-01-01

    Conjunctival biopsy was performed in two siblings with adult-form galactosialidosis. Electron microscopically, several types of intracytoplasmic inclusion were observed in the fibroblasts in conjunctival stroma, lymphatic capillary endothelial cells, Schwann cells, and epithelial cells. Membrane-bound vesicles with fibrillogranular content were frequently observed, and occasional lamellar structures were noted in these inclusions. Dense granular inclusions and oil droplets were also seen. Dense granular inclusions have not been reported in this disease previously. Images PMID:8384473

  8. Generalized Potential of Adult Neural Stem Cells

    NASA Astrophysics Data System (ADS)

    Clarke, Diana L.; Johansson, Clas B.; Wilbertz, Johannes; Veress, Biborka; Nilsson, Erik; Karlström, Helena; Lendahl, Urban; Frisén, Jonas

    2000-06-01

    The differentiation potential of stem cells in tissues of the adult has been thought to be limited to cell lineages present in the organ from which they were derived, but there is evidence that some stem cells may have a broader differentiation repertoire. We show here that neural stem cells from the adult mouse brain can contribute to the formation of chimeric chick and mouse embryos and give rise to cells of all germ layers. This demonstrates that an adult neural stem cell has a very broad developmental capacity and may potentially be used to generate a variety of cell types for transplantation in different diseases.

  9. Adult-brain-derived neural stem cells grafting into a vein bridge increases postlesional recovery and regeneration in a peripheral nerve of adult pig.

    PubMed

    Liard, Olivier; Segura, Stéphanie; Sagui, Emmanuel; Nau, André; Pascual, Aurélie; Cambon, Melissa; Darlix, Jean-Luc; Fusai, Thierry; Moyse, Emmanuel

    2012-01-01

    We attempted transplantation of adult neural stem cells (ANSCs) inside an autologous venous graft following surgical transsection of nervis cruralis with 30 mm long gap in adult pig. The transplanted cell suspension was a primary culture of neurospheres from adult pig subventricular zone (SVZ) which had been labeled in vitro with BrdU or lentivirally transferred fluorescent protein. Lesion-induced loss of leg extension on the thigh became definitive in controls but was reversed by 45-90 days after neurosphere-filled vein grafting. Electromyography showed stimulodetection recovery in neurosphere-transplanted pigs but not in controls. Postmortem immunohistochemistry revealed neurosphere-derived cells that survived inside the venous graft from 10 to 240 post-lesion days and all displayed a neuronal phenotype. Newly formed neurons were distributed inside the venous graft along the severed nerve longitudinal axis. Moreover, ANSC transplantation increased CNPase expression, indicating activation of intrinsic Schwann cells. Thus ANSC transplantation inside an autologous venous graft provides an efficient repair strategy. PMID:22448170

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

    PubMed Central

    Liard, Olivier; Segura, Stéphanie; Sagui, Emmanuel; Nau, André; Pascual, Aurélie; Cambon, Melissa; Darlix, Jean-Luc; Fusai, Thierry; Moyse, Emmanuel

    2012-01-01

    We attempted transplantation of adult neural stem cells (ANSCs) inside an autologous venous graft following surgical transsection of nervis cruralis with 30 mm long gap in adult pig. The transplanted cell suspension was a primary culture of neurospheres from adult pig subventricular zone (SVZ) which had been labeled in vitro with BrdU or lentivirally transferred fluorescent protein. Lesion-induced loss of leg extension on the thigh became definitive in controls but was reversed by 45–90 days after neurosphere-filled vein grafting. Electromyography showed stimulodetection recovery in neurosphere-transplanted pigs but not in controls. Postmortem immunohistochemistry revealed neurosphere-derived cells that survived inside the venous graft from 10 to 240 post-lesion days and all displayed a neuronal phenotype. Newly formed neurons were distributed inside the venous graft along the severed nerve longitudinal axis. Moreover, ANSC transplantation increased CNPase expression, indicating activation of intrinsic Schwann cells. Thus ANSC transplantation inside an autologous venous graft provides an efficient repair strategy. PMID:22448170

  11. Adult stem cells and tissue repair.

    PubMed

    Körbling, M; Estrov, Z; Champlin, R

    2003-08-01

    Recently, adult stem cells originating from bone marrow or peripheral blood have been suggested to contribute to repair and genesis of cells specific for liver, cardiac and skeletal muscle, gut, and brain tissue. The mechanism involved has been termed transdifferentiation, although other explanations including cell fusion have been postulated. Using adult stem cells to generate or repair solid organ tissue obviates the immunologic, ethical, and teratogenic issues that accompany embryonic stem cells.

  12. Progenitor cells in the adult pancreas.

    PubMed

    Holland, Andrew M; Góñez, L Jorge; Harrison, Leonard C

    2004-01-01

    The beta-cell mass in the adult pancreas possesses the ability to undergo limited regeneration following injury. Identifying the progenitor cells involved in this process and understanding the mechanisms leading to their maturation will open new avenues for the treatment of type 1 diabetes. However, despite steady advances in determining the molecular basis of early pancreatic development, the identification of pancreatic stem cells or beta-cell progenitors and the molecular mechanisms underlying beta-cell regeneration remain unclear. Recent advances in the directed differentiation of embryonic and adult stem cells has heightened interest in the possible application of stem cell therapy in the treatment of type 1 diabetes. Drawing on the expanding knowledge of pancreas development, beta-cell regeneration and stem cell research, this review focuses on progenitor cells in the adult pancreas as a potential source of beta-cells. PMID:14737742

  13. Immunological control of adult neural stem cells

    PubMed Central

    Gonzalez-Perez, Oscar; Quiñones-Hinojosa, Alfredo; Garcia-Verdugo, Jose Manuel

    2010-01-01

    Adult neurogenesis occurs only in discrete regions of adult central nervous system: the subventricular zone and the subgranular zone. These areas are populated by adult neural stem cells (aNSC) that are regulated by a number of molecules and signaling pathways, which control their cell fate choices, survival and proliferation rates. For a long time, it was believed that the immune system did not exert any control on neural proliferative niches. However, it has been observed that many pathological and inflammatory conditions significantly affect NSC niches. Even more, increasing evidence indicates that chemokines and cytokines play an important role in regulating proliferation, cell fate choices, migration and survival of NSCs under physiological conditions. Hence, the immune system is emerging is an important regulator of neurogenic niches in the adult brain, which may have clinical relevance in several brain diseases. PMID:20861925

  14. Adult Stem Cells and Diabetes Therapy

    PubMed Central

    Ilgun, Handenur; Kim, Joseph William; Luo, LuGuang

    2016-01-01

    The World Health Organization estimates that diabetes will be the fourth most prevalent disease by 2050. Developing a new therapy for diabetes is a challenge for researchers and clinicians in field. Many medications are being used for treatment of diabetes however with no conclusive and effective results therefore alternative therapies are required. Stem cell therapy is a promising tool for diabetes therapy, and it has involved embryonic stem cells, adult stem cells, and pluripotent stem cells. In this review, we focus on adult stem cells, especial human bone marrow stem cells (BM) for diabetes therapy, its history, and current development. We discuss prospects for future diabetes therapy such as induced pluripotent stem cells which have popularity in stem cell research area. PMID:27123495

  15. Adult stem-like cells in kidney

    PubMed Central

    Hishikawa, Keiichi; Takase, Osamu; Yoshikawa, Masahiro; Tsujimura, Taro; Nangaku, Masaomi; Takato, Tsuyoshi

    2015-01-01

    Human pluripotent cells are promising for treatment for kidney diseases, but the protocols for derivation of kidney cell types are still controversial. Kidney tissue regeneration is well confirmed in several lower vertebrates such as fish, and the repair of nephrons after tubular damages is commonly observed after renal injury. Even in adult mammal kidney, renal progenitor cell or system is reportedly presents suggesting that adult stem-like cells in kidney can be practical clinical targets for kidney diseases. However, it is still unclear if kidney stem cells or stem-like cells exist or not. In general, stemness is defined by several factors such as self-renewal capacity, multi-lineage potency and characteristic gene expression profiles. The definite use of stemness may be obstacle to understand kidney regeneration, and here we describe the recent broad findings of kidney regeneration and the cells that contribute regeneration. PMID:25815133

  16. Adult stem-like cells in kidney.

    PubMed

    Hishikawa, Keiichi; Takase, Osamu; Yoshikawa, Masahiro; Tsujimura, Taro; Nangaku, Masaomi; Takato, Tsuyoshi

    2015-03-26

    Human pluripotent cells are promising for treatment for kidney diseases, but the protocols for derivation of kidney cell types are still controversial. Kidney tissue regeneration is well confirmed in several lower vertebrates such as fish, and the repair of nephrons after tubular damages is commonly observed after renal injury. Even in adult mammal kidney, renal progenitor cell or system is reportedly presents suggesting that adult stem-like cells in kidney can be practical clinical targets for kidney diseases. However, it is still unclear if kidney stem cells or stem-like cells exist or not. In general, stemness is defined by several factors such as self-renewal capacity, multi-lineage potency and characteristic gene expression profiles. The definite use of stemness may be obstacle to understand kidney regeneration, and here we describe the recent broad findings of kidney regeneration and the cells that contribute regeneration. PMID:25815133

  17. Adult Stem Cell Responses to Nanostimuli

    PubMed Central

    Tsimbouri, Penelope M.

    2015-01-01

    Adult or mesenchymal stem cells (MSCs) have been found in different tissues in the body, residing in stem cell microenvironments called “stem cell niches”. They play different roles but their main activity is to maintain tissue homeostasis and repair throughout the lifetime of an organism. Their ability to differentiate into different cell types makes them an ideal tool to study tissue development and to use them in cell-based therapies. This differentiation process is subject to both internal and external forces at the nanoscale level and this response of stem cells to nanostimuli is the focus of this review. PMID:26193326

  18. Adult Stem Cells and Diseases of Aging

    PubMed Central

    Boyette, Lisa B.; Tuan, Rocky S.

    2014-01-01

    Preservation of adult stem cells pools is critical for maintaining tissue homeostasis into old age. Exhaustion of adult stem cell pools as a result of deranged metabolic signaling, premature senescence as a response to oncogenic insults to the somatic genome, and other causes contribute to tissue degeneration with age. Both progeria, an extreme example of early-onset aging, and heritable longevity have provided avenues to study regulation of the aging program and its impact on adult stem cell compartments. In this review, we discuss recent findings concerning the effects of aging on stem cells, contributions of stem cells to age-related pathologies, examples of signaling pathways at work in these processes, and lessons about cellular aging gleaned from the development and refinement of cellular reprogramming technologies. We highlight emerging therapeutic approaches to manipulation of key signaling pathways corrupting or exhausting adult stem cells, as well as other approaches targeted at maintaining robust stem cell pools to extend not only lifespan but healthspan. PMID:24757526

  19. The Use of Cell Transplantation in Spinal Cord Injuries.

    PubMed

    Schroeder, Gregory D; Kepler, Christopher K; Vaccaro, Alexander R

    2016-04-01

    Acute spinal cord injuries are life-changing events that lead to substantial morbidity and mortality, but the role of cell-based treatment for these injuries is unclear. Cell therapy is a rapidly evolving treatment methodology, with basic science and early phase I/II human trials showing promise. Multiple cell lines can be used in cell therapy, including adult or embryonic stem cells, Schwann cells, olfactory ensheathing cells, and induced pluripotent stem cells. Adult stem cells, Schwann cells, and olfactory ensheathing cells are readily available but lack the ability to differentiate into cells of the central nervous system. Mesenchymal stem cells can decrease cell death by modifying the local environment into which they are introduced. Peripheral nerve cells, such as Schwann cells and olfactory ensheathing cells, can myelinate existing axons and foster axonal growth in the central nervous system, and embryonic stem cells can differentiate into neural progenitor stem cells of the central nervous system. Induced pluripotent stem cells are the basis of an emerging technology that has yet to be implemented in human trials but may offer a means of cell therapy without the ethical dilemmas associated with embryonic cells. PMID:26945167

  20. Convergent genesis of an adult neural crest-like dermal stem cell from distinct developmental origins.

    PubMed

    Jinno, Hiroyuki; Morozova, Olena; Jones, Karen L; Biernaskie, Jeffrey A; Paris, Maryline; Hosokawa, Ryoichi; Rudnicki, Michael A; Chai, Yang; Rossi, Fabio; Marra, Marco A; Miller, Freda D

    2010-11-01

    Skin-derived precursors (SKPs) are multipotent dermal stem cells that reside within a hair follicle niche and that share properties with embryonic neural crest precursors. Here, we have asked whether SKPs and their endogenous dermal precursors originate from the neural crest or whether, like the dermis itself, they originate from multiple developmental origins. To do this, we used two different mouse Cre lines that allow us to perform lineage tracing: Wnt1-cre, which targets cells deriving from the neural crest, and Myf5-cre, which targets cells of a somite origin. By crossing these Cre lines to reporter mice, we show that the endogenous follicle-associated dermal precursors in the face derive from the neural crest, and those in the dorsal trunk derive from the somites, as do the SKPs they generate. Despite these different developmental origins, SKPs from these two locations are functionally similar, even with regard to their ability to differentiate into Schwann cells, a cell type only thought to be generated from the neural crest. Analysis of global gene expression using microarrays confirmed that facial and dorsal SKPs exhibit a very high degree of similarity, and that they are also very similar to SKPs derived from ventral dermis, which has a lateral plate origin. However, these developmentally distinct SKPs also retain differential expression of a small number of genes that reflect their developmental origins. Thus, an adult neural crest-like dermal precursor can be generated from a non-neural crest origin, a finding with broad implications for the many neuroendocrine cells in the body.

  1. Adult neural stem cells stake their ground

    PubMed Central

    Lim, Daniel A.; Alvarez-Buylla, Arturo

    2014-01-01

    The birth of new neurons in the walls of the adult brain lateral ventricles has captured the attention of many neuroscientists for over two decades, yielding key insights into the identity and regulation of neural stem cells (NSCs). In the adult ventricular-subventricular zone (V-SVZ), NSCs are a specialized form of astrocyte that generates several types of neurons for the olfactory bulb. Here we discuss recent findings regarding the unique organization of the V-SVZ NSCs niche, the multiple regulatory controls of neuronal production, the distinct regional identities of adult NSCs, and the epigenetic mechanisms that maintain adult neurogenesis. Understanding how V-SVZ NSCs establish and maintain lifelong neurogenesis continues to provide surprising insights into the cellular and molecular regulation of neural development. PMID:25223700

  2. Translational research of adult stem cell therapy.

    PubMed

    Suzuki, Gen

    2015-11-26

    Congestive heart failure (CHF) secondary to chronic coronary artery disease is a major cause of morbidity and mortality world-wide. Its prevalence is increasing despite advances in medical and device therapies. Cell based therapies generating new cardiomyocytes and vessels have emerged as a promising treatment to reverse functional deterioration and prevent the progression to CHF. Functional efficacy of progenitor cells isolated from the bone marrow and the heart have been evaluated in preclinical large animal models. Furthermore, several clinical trials using autologous and allogeneic stem cells and progenitor cells have demonstrated their safety in humans yet their clinical relevance is inconclusive. This review will discuss the clinical therapeutic applications of three specific adult stem cells that have shown particularly promising regenerative effects in preclinical studies, bone marrow derived mesenchymal stem cell, heart derived cardiosphere-derived cell and cardiac stem cell. We will also discuss future therapeutic approaches.

  3. Transglial pathway of diffusion in the Schwann sheath of the squid giant axon.

    PubMed

    Zwahlen, M J; Sandri, C; Greeff, N G

    1988-04-01

    In order to investigate the transglial pathways in the Schwann sheath of squid giant axons, an electron microscopic study of thin sections and freeze-fracture replicas was carried out. Hitherto the mesaxonal clefts between Schwann cells were regarded as the only pathway between the extracellular space and the periaxonal space which, like the clefts, is about 10 nm in width. The clefts were now found to be obstructed by a putative single-stranded tight junction between neighbouring Schwann cells along the entire border near the axon. The Schwann cells were found to be penetrated like a sponge by a three-dimensional tubular transglial lattice that is confluent with the periaxonal space, the mesaxonal clefts and the extracellular space. The transglial channel system (TGCS) would, therefore, serve as an alternative diffusional pathway, provided that the tubular lumen was permeable. The diameter of the tubules is about 40 nm. In freeze-fracture replicas the density of tubular openings towards the axon was estimated to be 3.3 +/- 0.72 per micron 2. In relation to the periaxonal cell surface, this constitutes a relative opening area of 0.42% as compared to the 0.15% of the mesaxonal clefts (neglecting their tight junctions). Therefore, the TGCS would provide a ubiquitous access for ionic flow between axolemma and extracellular space. The fact that the TGCS has only recently been observed in squid, but has been described for some time in the giant nerve fibres of crayfish and lobster, can be explained by the use of different fixation methods. The TGCS system is preserved in aldehyde fixation as used in the present study, whereas osmium tetroxide was applied in earlier work on squid. The comparison with the results obtained in other species suggests strongly that the TGCS is permeable and constitutes a transglial pathway for rapid ionic flow.

  4. Neural Crest As the Source of Adult Stem Cells

    PubMed Central

    Pierret, Chris; Spears, Kathleen; Maruniak, Joel A.; Kirk, Mark D.

    2012-01-01

    Recent studies suggest that adult stem cells can cross germ layer boundaries. For example, bone marrow-derived stem cells appear to differentiate into neurons and glial cells, as well as other types of cells. How can stem cells from bone marrow, pancreas, skin, or fat become neurons and glia; in other words, what molecular and cellular events direct mesodermal cells to a neural fate? Transdifferentiation, dediffereniation, and fusion of donor adult stem cells with fully differentiated host cells have been proposed to explain the plasticity of adult stem cells. Here we review the origin of select adult stem cell populations and propose a unifying hypothesis to explain adult stem cell plasticity. In addition, we outline specific experiments to test our hypothesis. We propose that peripheral, tissue-derived, or adult stem cells are all progeny of the neural crest. PMID:16646675

  5. Adult Mouse Cortical Cell Taxonomy by Single Cell Transcriptomics

    PubMed Central

    Tasic, Bosiljka; Menon, Vilas; Nguyen, Thuc Nghi; Kim, Tae Kyung; Jarsky, Tim; Yao, Zizhen; Levi, Boaz; Gray, Lucas T.; Sorensen, Staci A.; Dolbeare, Tim; Bertagnolli, Darren; Goldy, Jeff; Shapovalova, Nadiya; Parry, Sheana; Lee, Changkyu; Smith, Kimberly; Bernard, Amy; Madisen, Linda; Sunkin, Susan M.; Hawrylycz, Michael; Koch, Christof; Zeng, Hongkui

    2016-01-01

    Nervous systems are composed of various cell types, but the extent of cell type diversity is poorly understood. Here, we construct a cellular taxonomy of one cortical region, primary visual cortex, in adult mice based on single cell RNA-sequencing. We identify 49 transcriptomic cell types including 23 GABAergic, 19 glutamatergic and seven non-neuronal types. We also analyze cell-type specific mRNA processing and characterize genetic access to these transcriptomic types by many transgenic Cre lines. Finally, we show that some of our transcriptomic cell types display specific and differential electrophysiological and axon projection properties, thereby confirming that the single cell transcriptomic signatures can be associated with specific cellular properties. PMID:26727548

  6. Adult mouse cortical cell taxonomy revealed by single cell transcriptomics.

    PubMed

    Tasic, Bosiljka; Menon, Vilas; Nguyen, Thuc Nghi; Kim, Tae Kyung; Jarsky, Tim; Yao, Zizhen; Levi, Boaz; Gray, Lucas T; Sorensen, Staci A; Dolbeare, Tim; Bertagnolli, Darren; Goldy, Jeff; Shapovalova, Nadiya; Parry, Sheana; Lee, Changkyu; Smith, Kimberly; Bernard, Amy; Madisen, Linda; Sunkin, Susan M; Hawrylycz, Michael; Koch, Christof; Zeng, Hongkui

    2016-02-01

    Nervous systems are composed of various cell types, but the extent of cell type diversity is poorly understood. We constructed a cellular taxonomy of one cortical region, primary visual cortex, in adult mice on the basis of single-cell RNA sequencing. We identified 49 transcriptomic cell types, including 23 GABAergic, 19 glutamatergic and 7 non-neuronal types. We also analyzed cell type-specific mRNA processing and characterized genetic access to these transcriptomic types by many transgenic Cre lines. Finally, we found that some of our transcriptomic cell types displayed specific and differential electrophysiological and axon projection properties, thereby confirming that the single-cell transcriptomic signatures can be associated with specific cellular properties.

  7. Ovarian adult stem cells: hope or pitfall?

    PubMed Central

    2014-01-01

    For many years, ovarian biology has been based on the dogma that oocytes reserve in female mammals included a finite number, established before or at birth and it is determined by the number and quality of primordial follicles developed during the neonatal period. The restricted supply of oocytes in adult female mammals has been disputed in recent years by supporters of postnatal neo-oogenesis. Recent experimental data showed that ovarian surface epithelium and cortical tissue from both mouse and human were proved to contain very low proportion of cells able to propagate themselves, but also to generate immature oocytes in vitro or in vivo, when transplanted into immunodeficient mice ovaries. By mentioning several landmarks of ovarian stem cell reserve and addressing the exciting perspective of translation into clinical practice as treatment for infertility pathologies, the purpose of this article is to review the knowledge about adult mammalian ovarian stem cells, a topic that, since the first approach quickly attracted the attention of both the scientific media and patients. PMID:25018783

  8. Adult Stem Cell Therapy for Stroke: Challenges and Progress

    PubMed Central

    Bang, Oh Young; Kim, Eun Hee; Cha, Jae Min; Moon, Gyeong Joon

    2016-01-01

    Stroke is one of the leading causes of death and physical disability among adults. It has been 15 years since clinical trials of stem cell therapy in patients with stroke have been conducted using adult stem cells like mesenchymal stem cells and bone marrow mononuclear cells. Results of randomized controlled trials showed that adult stem cell therapy was safe but its efficacy was modest, underscoring the need for new stem cell therapy strategies. The primary limitations of current stem cell therapies include (a) the limited source of engraftable stem cells, (b) the presence of optimal time window for stem cell therapies, (c) inherited limitation of stem cells in terms of growth, trophic support, and differentiation potential, and (d) possible transplanted cell-mediated adverse effects, such as tumor formation. Here, we discuss recent advances that overcome these hurdles in adult stem cell therapy for stroke. PMID:27733032

  9. Evidence of nestin-positive cells in the human cutaneus Meissner and Pacinian corpuscles.

    PubMed

    Calavia, Marta; Viña, Eliso; Menéndez-González, Manuel; López-Muñiz, Alfonso; Alonso-Guervós, Marta; Cobo, Juan; Otero, Jesús; Arias-Carrión, Oscar; Vega, José Antonio; García-Suárez, Olivia

    2012-11-01

    Nestin is an intermediate filament protein expressed in neuroepithelial stem cells during development and it is later replaced by cell specific neuronal or glial filaments. Nevertheless, nestin⁺ cells remain within adult tissues and they can be regarded as potential neural stem cell (NSC). Nestin⁺ cells have been detected in Schwann cells related with sensory corpuscles of rodent and they have been demonstrated to be NSC. We have investigated the existence of nestin⁺ in human cutaneous cells Meissner and Pacinian corpuscles through the use of immunohistochemistry techniques and in situ hybridization. S100 protein (also regarded as a marker for NSC) and vimentin (the intermediate filament of mature Schwann cells in sensory corpuscles) were also investigated. The results show that the adult human cutaneous sensory Meissner and Pacinian corpuscles contains a small population of Schwann-related cells (vimentin⁺) which on the basis of their basic immunohistochemical characteristics (S100 protein⁺, nestin⁺) can be potential NSCs. Cells sharing identical immunohistochemical profile were also found in the close vicinity of Meissner corpuscles. Because their localization they are easily accessible and may represent a peripheral niche of NSC to be used for therapeutic goals.

  10. [Progress in treating diabetes mellitus with adult stem cells].

    PubMed

    Zhang, Lixin; Teng, Chunbo; An, Tiezhu

    2008-02-01

    Diabetes mellitus is a metabolic diseases, mainly including type 1 and type 2 diabetes. Treatment for type 1 and part of type 2 often involves regular insulin injection. However, this treatment neither precisely controls the blood sugar levels, nor prevents the diabetes complications. Transplantation of islets of Langerhans offers an attractive strategy for diabetes therapies, but its wide application has been limited by donor shortage and immunological rejection after transplantation. Stem cells with strong proliferation capacity and multipotential may be potential cell sources in diabetes therapies. For this, adult stem cells are interesting because of absence of teratoma formation and ethnical problems. Adult pancreatic stem cells (PSCs) really exist and could produce insulin-secreting cells both under the condition of pancreatic injury and in vitro culture, but lack of effective markers to enrich PSCs hampers the studies of exploring the expanding and differentiating conditions in vitro. Some other adult stem cells, such as hepatic stem cells, marrow stem cells or intestine stem cells, were also suggested to transdifferentiate into insulin-producing cells under special culture conditions in vitro or by genetic modifications. Moreover, transplanting these adult stem cells-derived insulin-secreting cells into the diabetic mouse could cure diabetes. Thus, adult stem cells would supply the abundant beta-cell sources for cell replacement therapy of diabetes. PMID:18464596

  11. [Progress in treating diabetes mellitus with adult stem cells].

    PubMed

    Zhang, Lixin; Teng, Chunbo; An, Tiezhu

    2008-02-01

    Diabetes mellitus is a metabolic diseases, mainly including type 1 and type 2 diabetes. Treatment for type 1 and part of type 2 often involves regular insulin injection. However, this treatment neither precisely controls the blood sugar levels, nor prevents the diabetes complications. Transplantation of islets of Langerhans offers an attractive strategy for diabetes therapies, but its wide application has been limited by donor shortage and immunological rejection after transplantation. Stem cells with strong proliferation capacity and multipotential may be potential cell sources in diabetes therapies. For this, adult stem cells are interesting because of absence of teratoma formation and ethnical problems. Adult pancreatic stem cells (PSCs) really exist and could produce insulin-secreting cells both under the condition of pancreatic injury and in vitro culture, but lack of effective markers to enrich PSCs hampers the studies of exploring the expanding and differentiating conditions in vitro. Some other adult stem cells, such as hepatic stem cells, marrow stem cells or intestine stem cells, were also suggested to transdifferentiate into insulin-producing cells under special culture conditions in vitro or by genetic modifications. Moreover, transplanting these adult stem cells-derived insulin-secreting cells into the diabetic mouse could cure diabetes. Thus, adult stem cells would supply the abundant beta-cell sources for cell replacement therapy of diabetes.

  12. Adult T-cell leukemia-lymphoma.

    PubMed

    Tsukasaki, Kunihiro

    2012-04-01

    Adult T-cell leukemia-lymphoma (ATL) was first described in 1977 as a distinct clinico-pathological entity with a suspected viral etiology. Subsequently, a novel RNA retrovirus, human T-cell leukemia/lymphotropic virus type 1 (HTLV-1) was isolated from a cell line established from the leukemic cells of an ATL patient, and the finding of a clear association with ATL led to its inclusion among human carcinogenic pathogens. The three major routes of HTLV-1 transmission are mother-to-child infections via breast milk, sexual intercourse, and blood transfusions. HTLV-1 infection early in life, presumably from breast feeding, is crucial in the development of ATL. The diversity in clinical features and prognosis of patients with this disease has led to its subtype-classification into four categories, acute, lymphoma, chronic, and smoldering types defined by organ involvement, and LDH and calcium values. In cases of acute, lymphoma, or unfavorable chronic subtypes (aggressive ATL), intensive chemotherapy such as VCAP-AMP-VECP is usually recommended. In cases of favorable chronic or smoldering ATL (indolent ATL), watchful waiting until disease progression has been recommended although the long term prognosis was inferior to those of, for instance, chronic lymphoid leukemia. Retrospective analysis suggested that the combination of interferon alpha and zidovudine was apparently promising for the treatment of ATL, especially for types with leukemic manifestation. Allogeneic hematopoietic stem cell transplantation is also promising for the treatment of aggressive ATL possibly reflecting graft vs. ATL effect. Several new agent-trials for ATL are ongoing and in preparation, including a defucosylated humanized anti-CC chemokine receptor 4 monoclonal antibody. Two steps should be considered for the prevention of HTLV-1-associated ATL. The first is the prevention of HTLV-1 infections and the second is the prevention of ATL among HTLV-1 carriers. So far, no agent has been found to be

  13. The effect of modified polysialic acid based hydrogels on the adhesion and viability of primary neurons and glial cells.

    PubMed

    Haile, Yohannes; Berski, Silke; Dräger, Gerald; Nobre, Andrè; Stummeyer, Katharina; Gerardy-Schahn, Rita; Grothe, Claudia

    2008-04-01

    In this study we present the enzymatic and biological analysis of polysialic acid (polySia) based hydrogel in terms of its degradation and cytocompatibility. PolySia based hydrogel is completely degradable by endosialidase enzyme which may avoid second surgery after tissue recovery. Viability assay showed that soluble components of polySia hydrogel did not cause any toxic effect on cultured Schwann cells. Moreover, green fluorescence protein transfected neonatal and adult Schwann cells, neural stem cells and dorsal root ganglionic cells (unlabelled) were seeded on polySia hydrogel modified with poly-L-lysine (Pll), poly-L-ornithine-laminin (porn-laminin) or collagen. Water soluble tetrazolium salt assay revealed that modification of the hydrogel significantly improved cell adhesion and viability. These results infer that polySia based scaffolds in combination with cell adhesion molecules and cells genetically modified to express growth factors would potentially be promising alternative in reconstructive therapeutic strategies. PMID:18255143

  14. The effect of modified polysialic acid based hydrogels on the adhesion and viability of primary neurons and glial cells.

    PubMed

    Haile, Yohannes; Berski, Silke; Dräger, Gerald; Nobre, Andrè; Stummeyer, Katharina; Gerardy-Schahn, Rita; Grothe, Claudia

    2008-04-01

    In this study we present the enzymatic and biological analysis of polysialic acid (polySia) based hydrogel in terms of its degradation and cytocompatibility. PolySia based hydrogel is completely degradable by endosialidase enzyme which may avoid second surgery after tissue recovery. Viability assay showed that soluble components of polySia hydrogel did not cause any toxic effect on cultured Schwann cells. Moreover, green fluorescence protein transfected neonatal and adult Schwann cells, neural stem cells and dorsal root ganglionic cells (unlabelled) were seeded on polySia hydrogel modified with poly-L-lysine (Pll), poly-L-ornithine-laminin (porn-laminin) or collagen. Water soluble tetrazolium salt assay revealed that modification of the hydrogel significantly improved cell adhesion and viability. These results infer that polySia based scaffolds in combination with cell adhesion molecules and cells genetically modified to express growth factors would potentially be promising alternative in reconstructive therapeutic strategies.

  15. Cell Phone Use by Adults with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Bryen, Diane Nelson; Carey, Allison; Friedman, Mark

    2007-01-01

    Although cell phone use has grown dramatically, there is a gap in cell phone access between people with disabilities and the general public. The importance of cell phone use among people with intellectual disabilities and studies about use of cell phones by adults with intellectual disabilities was described. Our goal was to determine the extent…

  16. Markers of epidermal stem cell subpopulations in adult mammalian skin.

    PubMed

    Kretzschmar, Kai; Watt, Fiona M

    2014-10-01

    The epidermis is the outermost layer of mammalian skin and comprises a multilayered epithelium, the interfollicular epidermis, with associated hair follicles, sebaceous glands, and eccrine sweat glands. As in other epithelia, adult stem cells within the epidermis maintain tissue homeostasis and contribute to repair of tissue damage. The bulge of hair follicles, where DNA-label-retaining cells reside, was traditionally regarded as the sole epidermal stem cell compartment. However, in recent years multiple stem cell populations have been identified. In this review, we discuss the different stem cell compartments of adult murine and human epidermis, the markers that they express, and the assays that are used to characterize epidermal stem cell properties.

  17. Potential of embryonic and adult stem cells in vitro.

    PubMed

    Czyz, Jaroslaw; Wiese, Cornelia; Rolletschek, Alexandra; Blyszczuk, Przemyslaw; Cross, Michael; Wobus, Anna M

    2003-01-01

    Recent developments in the field of stem cell research indicate their enormous potential as a source of tissue for regenerative therapies. The success of such applications will depend on the precise properties and potentials of stem cells isolated either from embryonic, fetal or adult tissues. Embryonic stem cells established from the inner cell mass of early mouse embryos are characterized by nearly unlimited proliferation, and the capacity to differentiate into derivatives of essentially all lineages. The recent isolation and culture of human embryonic stem cell lines presents new opportunities for reconstructive medicine. However, important problems remain; first, the derivation of human embryonic stem cells from in vitro fertilized blastocysts creates ethical problems, and second, the current techniques for the directed differentiation into somatic cell populations yield impure products with tumorigenic potential. Recent studies have also suggested an unexpectedly wide developmental potential of adult tissue-specific stem cells. Here too, many questions remain concerning the nature and status of adult stem cells both in vivo and in vitro and their proliferation and differentiation/transdifferentiation capacity. This review focuses on those issues of embryonic and adult stem cell biology most relevant to their in vitro propagation and differentiation. Questions and problems related to the use of human embryonic and adult stem cells in tissue regeneration and transplantation are discussed.

  18. Reprogramming adult cells during organ regeneration in forest species

    PubMed Central

    Abarca, Dolores

    2009-01-01

    The possibility of regenerating whole plants from somatic differentiated cells emphasizes the plasticity of plant development. Cell-type respecification during regeneration can be induced in adult tissues as a consequence of injuries, changes in external or internal stimuli or changes in positional information. However, in many plant species, switching the developmental program of adult cells prior to organ regeneration is difficult, especially in forest species. Besides its impact on forest productivity, basic information on the flexibility of cell differentiation is necessary for a comprehensive understanding of the epigenetic control of cell differentiation and plant development. Studies of reprogramming adult cells in terms of regulative expression changes of selected genes will be of great interest to unveil basic mechanisms regulating cellular plasticity. PMID:19820297

  19. Histomorphometric study on blood cells in male adult ostrich

    PubMed Central

    Tadjalli, Mina; Nazifi, Saeed; Marzban Abbasabadi, Behrokh; Majidi, Banafsheh

    2013-01-01

    In order to perform a histomorphometric study of blood cells in male adult ostrich, blood samples were obtained from jugular vein of 10 clinically healthy male adult ostriches (2 - 3 years old). The slides were stained with the Giemsa methods and the smears were evaluated for cellular morphology, with cellular size being determined by micrometry. The findings of this study revealed that the shape of the cell, cytoplasm and nucleus of erythrocytes in male adult ostriches were similar to those in other birds such as quails, chickens, Iranian green-head ducks. PMID:25653798

  20. ENHANCING ADULT NERVE REGENERATION THROUGH THE KNOCKDOWN OF RETINOBLASTOMA PROTEIN

    PubMed Central

    Christie, Kimberly J.; Krishnan, Anand; Martinez, Jose A.; Purdy, Kaylynn; Singh, Bhagat; Eaton, Shane; Zochodne, Douglas

    2016-01-01

    Tumour suppressor pathways may offer novel targets capable of altering the plasticity of post-mitotic adult neurons. Here we describe a role for retinoblastoma (Rb) protein, widely expressed in adult sensory neurons and their axons, during regeneration. In adult sensory neurons, Rb siRNA knockdown or Rb1 deletion in vitro enhances neurite outgrowth and branching. Plasticity is achieved in part through upregulation of neuronal PPARγ; its antagonism inhibits Rb siRNA plasticity whereas a PPARγ agonist increases growth. In an in vivo regenerative paradigm following complete peripheral nerve trunk transection, direct delivery of Rb siRNA prompts increased outgrowth of axons from proximal stumps and entrains Schwann cells to accompany them for greater distances. Similarly Rb siRNA delivery following a nerve crush improves behavioural indices of motor and sensory recovery in mice. The overall findings indicate that inhibition of tumour suppressor molecules has a role to play in promoting adult neuron regeneration. PMID:24752312

  1. Strategies to Optimize Adult Stem Cell Therapy for Tissue Regeneration

    PubMed Central

    Liu, Shan; Zhou, Jingli; Zhang, Xuan; Liu, Yang; Chen, Jin; Hu, Bo; Song, Jinlin; Zhang, Yuanyuan

    2016-01-01

    Stem cell therapy aims to replace damaged or aged cells with healthy functioning cells in congenital defects, tissue injuries, autoimmune disorders, and neurogenic degenerative diseases. Among various types of stem cells, adult stem cells (i.e., tissue-specific stem cells) commit to becoming the functional cells from their tissue of origin. These cells are the most commonly used in cell-based therapy since they do not confer risk of teratomas, do not require fetal stem cell maneuvers and thus are free of ethical concerns, and they confer low immunogenicity (even if allogenous). The goal of this review is to summarize the current state of the art and advances in using stem cell therapy for tissue repair in solid organs. Here we address key factors in cell preparation, such as the source of adult stem cells, optimal cell types for implantation (universal mesenchymal stem cells vs. tissue-specific stem cells, or induced vs. non-induced stem cells), early or late passages of stem cells, stem cells with endogenous or exogenous growth factors, preconditioning of stem cells (hypoxia, growth factors, or conditioned medium), using various controlled release systems to deliver growth factors with hydrogels or microspheres to provide apposite interactions of stem cells and their niche. We also review several approaches of cell delivery that affect the outcomes of cell therapy, including the appropriate routes of cell administration (systemic, intravenous, or intraperitoneal vs. local administration), timing for cell therapy (immediate vs. a few days after injury), single injection of a large number of cells vs. multiple smaller injections, a single site for injection vs. multiple sites and use of rodents vs. larger animal models. Future directions of stem cell-based therapies are also discussed to guide potential clinical applications. PMID:27338364

  2. Strategies to Optimize Adult Stem Cell Therapy for Tissue Regeneration.

    PubMed

    Liu, Shan; Zhou, Jingli; Zhang, Xuan; Liu, Yang; Chen, Jin; Hu, Bo; Song, Jinlin; Zhang, Yuanyuan

    2016-06-21

    Stem cell therapy aims to replace damaged or aged cells with healthy functioning cells in congenital defects, tissue injuries, autoimmune disorders, and neurogenic degenerative diseases. Among various types of stem cells, adult stem cells (i.e., tissue-specific stem cells) commit to becoming the functional cells from their tissue of origin. These cells are the most commonly used in cell-based therapy since they do not confer risk of teratomas, do not require fetal stem cell maneuvers and thus are free of ethical concerns, and they confer low immunogenicity (even if allogenous). The goal of this review is to summarize the current state of the art and advances in using stem cell therapy for tissue repair in solid organs. Here we address key factors in cell preparation, such as the source of adult stem cells, optimal cell types for implantation (universal mesenchymal stem cells vs. tissue-specific stem cells, or induced vs. non-induced stem cells), early or late passages of stem cells, stem cells with endogenous or exogenous growth factors, preconditioning of stem cells (hypoxia, growth factors, or conditioned medium), using various controlled release systems to deliver growth factors with hydrogels or microspheres to provide apposite interactions of stem cells and their niche. We also review several approaches of cell delivery that affect the outcomes of cell therapy, including the appropriate routes of cell administration (systemic, intravenous, or intraperitoneal vs. local administration), timing for cell therapy (immediate vs. a few days after injury), single injection of a large number of cells vs. multiple smaller injections, a single site for injection vs. multiple sites and use of rodents vs. larger animal models. Future directions of stem cell-based therapies are also discussed to guide potential clinical applications.

  3. [Multipotency of adult stem cells derived from human amnion].

    PubMed

    Shi, Mingxia; Li, Weijia; Li, Bingzong; Li, Jing; Zhao, Chunhua

    2009-05-01

    Adult stem cells are drawing more and more attention due to the potential application in degenerative medicine without posing any moral problem. There is growing evidence showing that the human amnion contains various types of adult stem cell. Since amniotic tissue is readily available, it has the potential to be an important source of regenerative medicine material. In this study we tried to find multipotent adult stem cells in human amnion. We isolated stem cells from amniotic mesenchymal cells by limiting dilution assay. Similar to bone marrow derived mesenchymal stem cells, these cells displayed a fibroblast like appearance. They were positive for CD105, CD29, CD44, negative for haematopoietic (GlyA, CD31, CD34, CD45) and epithelial cell (pan-CK) markers. These stem cells had the potential to differentiate not only into osteogenic, adipogenic and endothelial lineages, but also hepatocyte-like cells and neural cells at the single-cell level depending on the culture conditions. They had the capacity for self-renewal and multilineage differentiation even after being expanded for more than 30 population doublings in vitro. So they may be an ideal stem cell source for inherited or degenerative diseases treatment.

  4. Expansion of Multipotent Stem Cells from the Adult Human Brain

    PubMed Central

    Murrell, Wayne; Palmero, Emily; Bianco, John; Stangeland, Biljana; Joel, Mrinal; Paulson, Linda; Thiede, Bernd; Grieg, Zanina; Ramsnes, Ingunn; Skjellegrind, Håvard K.; Nygård, Ståle; Brandal, Petter; Sandberg, Cecilie; Vik-Mo, Einar; Palmero, Sheryl; Langmoen, Iver A.

    2013-01-01

    The discovery of stem cells in the adult human brain has revealed new possible scenarios for treatment of the sick or injured brain. Both clinical use of and preclinical research on human adult neural stem cells have, however, been seriously hampered by the fact that it has been impossible to passage these cells more than a very few times and with little expansion of cell numbers. Having explored a number of alternative culturing conditions we here present an efficient method for the establishment and propagation of human brain stem cells from whatever brain tissue samples we have tried. We describe virtually unlimited expansion of an authentic stem cell phenotype. Pluripotency proteins Sox2 and Oct4 are expressed without artificial induction. For the first time multipotency of adult human brain-derived stem cells is demonstrated beyond tissue boundaries. We characterize these cells in detail in vitro including microarray and proteomic approaches. Whilst clarification of these cells’ behavior is ongoing, results so far portend well for the future repair of tissues by transplantation of an adult patient’s own-derived stem cells. PMID:23967194

  5. Multipotent progenitor cells isolated from adult human pancreatic tissue.

    PubMed

    Todorov, I; Nair, I; Ferreri, K; Rawson, J; Kuroda, A; Pascual, M; Omori, K; Valiente, L; Orr, C; Al-Abdullah, I; Riggs, A; Kandeel, F; Mullen, Y

    2005-10-01

    The supply of islet cells is a limiting factor for the widespread application of islet transplantation of type-1 diabetes. Islets constitute 1% to 2% of pancreatic tissue, leaving approximately 98% as discard after islet isolation and purification. In this report we present our data on the isolation of multipotent progenitor cells from discarded adult human pancreatic tissue. The collected cells from discarded nonislet fractions, after enzymatic digestion and gradient purification of islets, were dissociated for suspension culture in a serum-free medium. The cell clusters grown to a size of 100 to 150 mum contained cells staining for stage-specific embryonic antigens, but not insulin or C-peptide. To direct cell differentiation toward islets, clusters were recultured in a pancreatic differentiation medium. Insulin and C-peptide-positive cells by immunocytochemistry appeared within a week, reaching over 10% of the cell population. Glucagon and somatostatin-positive cells were also detected. The cell clusters were found to secrete insulin in response to glucose stimulation. Cells from the same clusters also had the capacity for differentiation into neural cells, as documented by staining for neural and glial cell markers when cultured as monolayers in media containing neurotrophic factors. These data suggest that multipotent pancreatic progenitor cells exist within the human pancreatic tissue that is typically discarded during islet isolation procedures. These adult progenitor cells can be successfully differentiated into insulin-producing cells, and thus they have the potential for treatment of type-1 diabetes mellitus. PMID:16298614

  6. Therapeutics from Adult Stem Cells and the Hype Curve.

    PubMed

    Maguire, Greg

    2016-05-12

    The Gartner curve for regenerative and stem cell therapeutics is currently climbing out of the "trough of disillusionment" and into the "slope of enlightenment". Understanding that the early years of stem cell therapy relied on the model of embryonic stem cells (ESCs), and then moved into a period of the overhype of induced pluripotent stem cells (iPSCs), instead of using the model of 40 years of success, i.e. adult stem cells used in bone marrow transplants, the field of stem cell therapy has languished for years, trying to move beyond the early and poorly understood success of bone marrow transplants. Recent studies in the lab and clinic show that adult stem cells of various types, and the molecules that they release, avoid the issues associated with ESCs and iPSCs and lead to better therapeutic outcomes and into the slope of enlightenment. PMID:27190588

  7. [Generation of new nerve cells in the adult human brain].

    PubMed

    Poulsen, Frantz Rom; Meyer, Morten; Rasmussen, Jens Zimmer

    2003-03-31

    Generation of new nerve cells (neurogenesis) is normally considered to be limited to the fetal and early postnatal period. Thus, damaged nerve cells are not expected to be replaced by generation of new cells. The brain is, however, more plastic than previously assumed. This also includes neurogenesis in the adult human brain. In particular two brain regions show continuous division of neural stem and progenitor cells generating neurons and glial cells, namely the subgranular zone of the dentate gyrus and the subventricular zones of the lateral ventricles. From the latter region newly generated neuroblasts (immature nerve cells) migrate toward the olfactory bulb where they differentiate into neurons. In the dentate gyrus the newly generated neurons become functionally integrated in the granule cell layer, where they are believed to be of importance to learning and memory. It is at present not known whether neurogenesis in the adult human brain can be manipulated for specific repair after brain damage.

  8. Therapeutics from Adult Stem Cells and the Hype Curve.

    PubMed

    Maguire, Greg

    2016-05-12

    The Gartner curve for regenerative and stem cell therapeutics is currently climbing out of the "trough of disillusionment" and into the "slope of enlightenment". Understanding that the early years of stem cell therapy relied on the model of embryonic stem cells (ESCs), and then moved into a period of the overhype of induced pluripotent stem cells (iPSCs), instead of using the model of 40 years of success, i.e. adult stem cells used in bone marrow transplants, the field of stem cell therapy has languished for years, trying to move beyond the early and poorly understood success of bone marrow transplants. Recent studies in the lab and clinic show that adult stem cells of various types, and the molecules that they release, avoid the issues associated with ESCs and iPSCs and lead to better therapeutic outcomes and into the slope of enlightenment.

  9. Cell proliferation and neurogenesis in adult mouse brain.

    PubMed

    Bordiuk, Olivia L; Smith, Karen; Morin, Peter J; Semënov, Mikhail V

    2014-01-01

    Neurogenesis, the formation of new neurons, can be observed in the adult brain of many mammalian species, including humans. Despite significant progress in our understanding of adult neurogenesis, we are still missing data about the extent and location of production of neural precursors in the adult mammalian brain. We used 5-ethynyl-2'-deoxyuridine (EdU) to map the location of proliferating cells throughout the entire adult mouse brain and found that neurogenesis occurs at two locations in the mouse brain. The larger one we define as the main proliferative zone (MPZ), and the smaller one corresponds to the subgranular zone of the hippocampus. The MPZ can be divided into three parts. The caudate migratory stream (CMS) occupies the middle part of the MPZ. The cable of proliferating cells emanating from the most anterior part of the CMS toward the olfactory bulbs forms the rostral migratory stream. The thin layer of proliferating cells extending posteriorly from the CMS forms the midlayer. We have not found any additional aggregations of proliferating cells in the adult mouse brain that could suggest the existence of other major neurogenic zones in the adult mouse brain.

  10. Cell proliferation and neurogenesis in adult mouse brain.

    PubMed

    Bordiuk, Olivia L; Smith, Karen; Morin, Peter J; Semënov, Mikhail V

    2014-01-01

    Neurogenesis, the formation of new neurons, can be observed in the adult brain of many mammalian species, including humans. Despite significant progress in our understanding of adult neurogenesis, we are still missing data about the extent and location of production of neural precursors in the adult mammalian brain. We used 5-ethynyl-2'-deoxyuridine (EdU) to map the location of proliferating cells throughout the entire adult mouse brain and found that neurogenesis occurs at two locations in the mouse brain. The larger one we define as the main proliferative zone (MPZ), and the smaller one corresponds to the subgranular zone of the hippocampus. The MPZ can be divided into three parts. The caudate migratory stream (CMS) occupies the middle part of the MPZ. The cable of proliferating cells emanating from the most anterior part of the CMS toward the olfactory bulbs forms the rostral migratory stream. The thin layer of proliferating cells extending posteriorly from the CMS forms the midlayer. We have not found any additional aggregations of proliferating cells in the adult mouse brain that could suggest the existence of other major neurogenic zones in the adult mouse brain. PMID:25375658

  11. Stem Cell-Mediated Regeneration of the Adult Brain

    PubMed Central

    Jessberger, Sebastian

    2016-01-01

    Acute or chronic injury of the adult mammalian brain is often associated with persistent functional deficits as its potential for regeneration and capacity to rebuild lost neural structures is limited. However, the discovery that neural stem cells (NSCs) persist throughout life in discrete regions of the brain, novel approaches to induce the formation of neuronal and glial cells, and recently developed strategies to generate tissue for exogenous cell replacement strategies opened novel perspectives how to regenerate the adult brain. Here, we will review recently developed approaches for brain repair and discuss future perspectives that may eventually allow for developing novel treatment strategies in acute and chronic brain injury. PMID:27781019

  12. Tax fingerprint in adult T-cell leukemia.

    PubMed

    Bazarbachi, Ali

    2016-04-01

    In this issue of Blood, Fujikawa et al demonstrate that the human T-cell leukemia virus type 1 (HTLV-1) oncoprotein Tax induces an epigenetic-dependent global modification of host gene expression in adult T-cell leukemia-lymphoma (ATL). Hence, the fingerprint of Tax is all over ATL and this may be used for finally capturing ATL. PMID:27056993

  13. Multiple skin tumors of indeterminate cells in an adult.

    PubMed

    Kolde, G; Bröcker, E B

    1986-10-01

    An adult patient with multiple unusual histiocytic tumors of the skin is described. As shown by immunohistologic study, electron microscopy, and immunoelectron microscopy, the tumors represent circumscribed proliferations of the Langerhans cell-related indeterminate dendritic cells of the skin. This distinct cutaneous histiocytosis may represent a paraneoplastic syndrome.

  14. Differentiated cells are more efficient than adult stem cells for cloning by somatic cell nuclear transfer.

    PubMed

    Sung, Li-Ying; Gao, Shaorong; Shen, Hongmei; Yu, Hui; Song, Yifang; Smith, Sadie L; Chang, Ching-Chien; Inoue, Kimiko; Kuo, Lynn; Lian, Jin; Li, Ao; Tian, X Cindy; Tuck, David P; Weissman, Sherman M; Yang, Xiangzhong; Cheng, Tao

    2006-11-01

    Since the creation of Dolly via somatic cell nuclear transfer (SCNT), more than a dozen species of mammals have been cloned using this technology. One hypothesis for the limited success of cloning via SCNT (1%-5%) is that the clones are likely to be derived from adult stem cells. Support for this hypothesis comes from the findings that the reproductive cloning efficiency for embryonic stem cells is five to ten times higher than that for somatic cells as donors and that cloned pups cannot be produced directly from cloned embryos derived from differentiated B and T cells or neuronal cells. The question remains as to whether SCNT-derived animal clones can be derived from truly differentiated somatic cells. We tested this hypothesis with mouse hematopoietic cells at different differentiation stages: hematopoietic stem cells, progenitor cells and granulocytes. We found that cloning efficiency increases over the differentiation hierarchy, and terminally differentiated postmitotic granulocytes yield cloned pups with the greatest cloning efficiency.

  15. Neural stem cells in the adult human brain

    PubMed Central

    Gonzalez-Perez, Oscar

    2012-01-01

    For decades, it was believed that the adult brain was a quiescent organ unable to produce new neurons. At the beginning of the1960's, this dogma was challenged by a small group of neuroscientists. To date, it is well-known that new neurons are generated in the adult brain throughout life. Adult neurogenesis is primary confined to the subventricular zone (SVZ) of the forebrain and the subgranular zone of the dentate gyrus within the hippocampus. In both the human and the rodent brain, the primary progenitor of adult SVZ is a subpopulation of astrocytes that have stem-cell-like features. The human SVZ possesses a peculiar cell composition and displays important organizational differences when compared to the SVZ of other mammals. Some evidence suggests that the human SVZ may be not only an endogenous source of neural precursor cells for brain repair, but also a source of brain tumors. In this review, we described the cytoarchitecture and cellular composition of the SVZ in the adult human brain. We also discussed some clinical implications of SVZ, such as: stem-cell-based therapies against neurodegenerative diseases and its potential as a source of malignant cells. Understanding the biology of human SVZ and its neural progenitors is one of the crucial steps to develop novel therapies against neurological diseases in humans. PMID:23181200

  16. Primary Afferent Synapses on Developing and Adult Renshaw Cells

    PubMed Central

    Mentis, George Z.; Siembab, Valerie C.; Zerda, Ricardo; O’Donovan, Michael J.; Alvarez, Francisco J.

    2010-01-01

    The mechanisms that diversify adult interneurons from a few pools of embryonic neurons are unknown. Renshaw cells, Ia inhibitory interneurons (IaINs), and possibly other types of mammalian spinal interneurons have common embryonic origins within the V1 group. However, in contrast to IaINs and other V1-derived interneurons, adult Renshaw cells receive motor axon synapses and lack proprioceptive inputs. Here, we investigated how this specific pattern of connectivity emerges during the development of Renshaw cells. Tract tracing and immunocytochemical markers [parvalbumin and vesicular glutamate transporter 1 (VGLUT1)] showed that most embryonic (embryonic day 18) Renshaw cells lack dorsal root inputs, but more than half received dorsal root synapses by postnatal day 0 (P0) and this input spread to all Renshaw cells by P10–P15. Electrophysiological recordings in neonates indicated that this input is functional and evokes Renshaw cell firing. VGLUT1-IR bouton density on Renshaw cells increased until P15 but thereafter decreased because of limited synapse proliferation coupled with the enlargement of Renshaw cell dendrites. In parallel, Renshaw cell postsynaptic densities apposed to VGLUT1-IR synapses became smaller in adult compared with P15. In contrast, vesicular acetylcholine transporter-IR motor axon synapses contact embryonic Renshaw cells and proliferate postnatally matching Renshaw cell growth. Like other V1 neurons, Renshaw cells are thus competent to receive sensory synapses. However, after P15, these sensory inputs appear deselected through arrested proliferation and synapse weakening. Thus, Renshaw cells shift from integrating sensory and motor inputs in neonates to predominantly motor inputs in adult. Similar synaptic weight shifts on interneurons may be involved in the maturation of motor reflexes and locomotor circuitry. PMID:17182780

  17. DNA damage response in adult stem cells.

    PubMed

    Insinga, Alessandra; Cicalese, Angelo; Pelicci, Pier Giuseppe

    2014-04-01

    This review discusses the processes of DNA-damage-response and DNA-damage repair in stem and progenitor cells of several tissues. The long life-span of stem cells suggests that they may respond differently to DNA damage than their downstream progeny and, indeed, studies have begun to elucidate the unique stem cell response mechanisms to DNA damage. Because the DNA damage responses in stem cells and progenitor cells are distinctly different, stem and progenitor cells should be considered as two different entities from this point of view. Hematopoietic and mammary stem cells display a unique DNA-damage response, which involves active inhibition of apoptosis, entry into the cell-cycle, symmetric division, partial DNA repair and maintenance of self-renewal. Each of these biological events depends on the up-regulation of the cell-cycle inhibitor p21. Moreover, inhibition of apoptosis and symmetric stem cell division are the consequence of the down-regulation of the tumor suppressor p53, as a direct result of p21 up-regulation. A deeper understanding of these processes is required before these findings can be translated into human anti-aging and anti-cancer therapies. One needs to clarify and dissect the pathways that control p21 regulation in normal and cancer stem cells and define (a) how p21 blocks p53 functions in stem cells and (b) how p21 promotes DNA repair in stem cells. Is this effect dependent on p21s ability to inhibit p53? Such molecular knowledge may pave the way to methods for maintaining short-term tissue reconstitution while retaining long-term cellular and genomic integrity.

  18. Markers of Epidermal Stem Cell Subpopulations in Adult Mammalian Skin

    PubMed Central

    Kretzschmar, Kai; Watt, Fiona M.

    2014-01-01

    The epidermis is the outermost layer of mammalian skin and comprises a multilayered epithelium, the interfollicular epidermis, with associated hair follicles, sebaceous glands, and eccrine sweat glands. As in other epithelia, adult stem cells within the epidermis maintain tissue homeostasis and contribute to repair of tissue damage. The bulge of hair follicles, where DNA-label-retaining cells reside, was traditionally regarded as the sole epidermal stem cell compartment. However, in recent years multiple stem cell populations have been identified. In this review, we discuss the different stem cell compartments of adult murine and human epidermis, the markers that they express, and the assays that are used to characterize epidermal stem cell properties. PMID:24993676

  19. Effects of Neuroendocrine CB1 Activity on Adult Leydig Cells

    PubMed Central

    Cobellis, Gilda; Meccariello, Rosaria; Chianese, Rosanna; Chioccarelli, Teresa; Fasano, Silvia; Pierantoni, Riccardo

    2016-01-01

    Endocannabinoids control male reproduction acting at central and local level via cannabinoid receptors. The cannabinoid receptor CB1 has been characterized in the testis, in somatic and germ cells of mammalian and non-mammalian animal models, and its activity related to Leydig cell differentiation, steroidogenesis, spermiogenesis, sperm quality, and maturation. In this short review, we provide a summary of the insights concerning neuroendocrine CB1 activity in male reproduction focusing on adult Leydig cell ontogenesis and steroid biosynthesis. PMID:27375550

  20. Langerhans cells increase in the dermal lesions of adult T cell leukaemia in Japan

    PubMed Central

    Shamoto, M

    1983-01-01

    In cases of adult T cell leukaemia neoplastic T cell infiltration in the skin was accompanied by an increase in Langerhans cells. This is in keeping with the view that Langerhans cells may induce antigen-specific and allogenic T cell activation. Images PMID:6600750

  1. Immature rat Leydig cells are intrinsically less sensitive than adult Leydig cells to ethane dimethanesulfonate.

    PubMed

    Kelce, W R; Zirkin, B R; Ewing, L L

    1991-11-01

    Leydig cells from immature rat testes appear to be insensitive to doses of ethane-1,2-dimethanesulfonate (EDS) which eliminate Leydig cells from adult rat testes. We sought to determine whether this differential response to EDS is intrinsic to the Leydig cell or mediated by other intra- or extratesticular differences between adult and immature rats. To differentiate among these possibilities, Leydig cells were exposed to EDS (1) in vivo, (2) through in vitro testicular perfusion, or (3) in highly purified Leydig cell primary cultures. Four days after ip injections of 85 mg EDS/kg body wt Leydig cells were eliminated from testes of adult, but not immature rats. Total androgen production by testes perfused in vitro with 94 micrograms EDS/ml was dramatically reduced in adult, but not immature rats. Highly purified adult, but not immature, rat Leydig cells were far more sensitive to the effects of EDS on luteinizing hormone-stimulated androgen production (functional effects; apparent EC50 = 94 for adult and 407 micrograms/ml for immature rat Leydig cells) and on [35S]methionine incorporation (cytotoxic effects; apparent EC50 = 140 for adult and 1000 micrograms/ml for immature rat Leydig cells). Finally, the in vitro effects of EDS were both cell type and chemical specific. Since the differential response of adult and immature rat Leydig cells to EDS was manifest in vivo, during in vitro testicular perfusion, and in highly purified Leydig cell primary cultures, we conclude that immature rat Leydig cells are intrinsically less sensitive to the specific cytotoxic effects of EDS than adult rat Leydig cells.

  2. Adult granulosa cell tumor of the testis masquerading as hydrocele

    PubMed Central

    Vallonthaiel, Archana George; Kakkar, Aanchal; Singh, Animesh; Dogra, Prem N; Ray, Ruma

    2015-01-01

    ABSTRACT Adult testicular granulosa cell tumor is a rare, potentially malignant sex cord-stromal tumor, of which 30 cases have been described to date. We report the case of a 43-year-old male who complained of a left testicular swelling. Scrotal ultrasound showed a cystic lesion, suggestive of hydrocele. However, due to a clinical suspicion of a solid-cystic neoplasm, a high inguinal orchidectomy was performed, which, on pathological examination, was diagnosed as adult granulosa cell tumor. Adult testicular granulosa cell tumors have aggressive behaviour as compared to their ovarian counterparts. They may rarely be predominantly cystic and present as hydrocele. Lymph node and distant metastases have been reported in few cases. Role of MIB-1 labelling index in prognostication is not well defined. Therefore, their recognition and documentation of their behaviour is important from a diagnostic, prognostic and therapeutic point of view. PMID:26742984

  3. Purinergic signaling promotes proliferation of adult mouse subventricular zone cells.

    PubMed

    Suyama, Satoshi; Sunabori, Takehiko; Kanki, Hiroaki; Sawamoto, Kazunobu; Gachet, Christian; Koizumi, Schuichi; Okano, Hideyuki

    2012-07-01

    In adult mammalian brains, neural stem cells (NSCs) exist in the subventricular zone (SVZ), where persistent neurogenesis continues throughout life. Those NSCs produce neuroblasts that migrate into the olfactory bulb via formation of transit-amplifying cells, which are committed precursor cells of the neuronal lineage. In this SVZ niche, cell-cell communications conducted by diffusible factors as well as physical cell-cell contacts are important for the regulation of the proliferation and fate determination of NSCs. Previous studies have suggested that extracellular purinergic signaling, which is mediated by purine compounds such as ATP, plays important roles in cell-cell communication in the CNS. Purinergic signaling also promotes the proliferation of adult NSCs in vitro. However, the in vivo roles of purinergic signaling in the neurogenic niche still remain unknown. In this study, ATP infusion into the lateral ventricle of the mouse brain resulted in an increase in the numbers of rapidly dividing cells and Mash1-positive transit-amplifying cells (Type C cells) in the SVZ. Mash1-positive cells express the P2Y1 purinergic signaling receptor and infusion of the P2Y1 receptor-specific antagonist MRS2179 decreased the number of rapidly dividing bromodeoxyuridine (BrdU)-positive cells and Type C cells. Moreover, a 17% reduction of rapidly dividing BrdU-positive cells and a 19% reduction of Mash1-positive cells were observed in P2Y1 knock-out mice. Together, these results suggest that purinergic signaling promotes the proliferation of rapidly dividing cells and transit-amplifying cells, in the SVZ niche through the P2Y1 receptor. PMID:22764232

  4. Spatial control of adult stem cell fate using nanotopographic cues

    PubMed Central

    An, Steven S.; Afzal, Junaid; Lee, Suengwon; Kwak, Moonkyu; Suh, Kahp-Yang; Levchenko, Andre

    2015-01-01

    Adult stem cells hold great promise as a source of diverse terminally differentiated cell types for tissue engineering applications. However, due to the complexity of chemical and mechanical cues specifying differentiation outcomes, development of arbitrarily complex geometric and structural arrangements of cells, adopting multiple fates from the same initial stem cell population, has been difficult. Here, we show that the topography of the cell adhesion substratum can be an instructive cue to adult stem cells and topographical variations can strongly bias the differentiation outcome of the cells towards adipocyte or osteocyte fates. Switches in cell fate decision from adipogenic to osteogenic lineages were accompanied by changes in cytoskeletal stiffness, spanning a considerable range in the cell softness/rigidity spectrum. Our findings suggest that human mesenchymal stem cells (hMSC) can respond to the varying density of nanotopographical cues by regulating their internal cytoskeletal network and use these mechanical changes to guide them toward making cell fate decisions. We used this finding to design a complex two-dimensional pattern of co-localized cells preferentially adopting two alternative fates, thus paving the road for designing and building more complex tissue constructs with diverse biomedical applications. PMID:24388388

  5. Adult stem cells and their ability to differentiate.

    PubMed

    Tarnowski, Maciej; Sieron, Aleksander L

    2006-08-01

    This is a review of the current status of knowledge on adult stem cells as well as the criteria and evidence for their potential to transform into different cell types and cell lineages. Reports on stem cell sources, focusing on tissues from adult subjects, were also investigated. Numerous reports have been published on the search for early markers of both stem cells and the precursors of various cell lineages. The question is still open about the characteristics of the primary stem cell. The existing proofs and hypotheses have not yielded final solutions to this problem. From a practical point of view it is also crucial to find a minimal set of markers determining the phenotypes of the precursor cells of a particular cell lineage. Several lines of evidence seem to bring closer the day when we will be able to detect the right stem cell niche and successfully isolate precursor cells that are needed for the treatment of a particular disorder. Recent reports on cases of cancer in patients subjected to stem cell therapy are yet another controversial issue looked into in this review, although the pros and cons emerging from the results of published studies still do not provide satisfying evidence to fully understand this issue.

  6. Walking stability during cell phone use in healthy adults.

    PubMed

    Kao, Pei-Chun; Higginson, Christopher I; Seymour, Kelly; Kamerdze, Morgan; Higginson, Jill S

    2015-05-01

    The number of falls and/or accidental injuries associated with cellular phone use during walking is growing rapidly. Understanding the effects of concurrent cell phone use on human gait may help develop safety guidelines for pedestrians. It was shown previously that older adults had more pronounced dual-task interferences than younger adults when concurrent cognitive task required visual information processing. Thus, cell phone use might have greater impact on walking stability in older than in younger adults. This study examined gait stability and variability during a cell phone dialing task (phone) and two classic cognitive tasks, the Paced Auditory Serial Addition Test (PASAT) and Symbol Digit Modalities Test (SDMT). Nine older and seven younger healthy adults walked on a treadmill at four different conditions: walking only, PASAT, phone, and SDMT. We computed short-term local divergence exponent (LDE) of the trunk motion (local stability), dynamic margins of stability (MOS), step spatiotemporal measures, and kinematic variability. Older and younger adults had similar values of short-term LDE during all conditions, indicating that local stability was not affected by the dual-task. Compared to walking only, older and younger adults walked with significantly greater average mediolateral MOS during phone and SDMT conditions but significantly less ankle angle variability during all dual-tasks and less knee angle variability during PASAT. The current findings demonstrate that healthy adults may try to control foot placement and joint kinematics during cell phone use or another cognitive task with a visual component to ensure sufficient dynamic margins of stability and maintain local stability.

  7. Walking Stability during Cell Phone Use in Healthy Adults

    PubMed Central

    Kao, Pei-Chun; Higginson, Christopher I.; Seymour, Kelly; Kamerdze, Morgan; Higginson, Jill S.

    2015-01-01

    The number of falls and/or accidental injuries associated with cellular phone use during walking is growing rapidly. Understanding the effects of concurrent cell phone use on human gait may help develop safety guidelines for pedestrians. It was shown previously that older adults had more pronounced dual-task interferences than younger adults when concurrent cognitive task required visual information processing. Thus, cell phone use might have greater impact on walking stability in older than in younger adults. This study examined gait stability and variability during a cell phone dialing task (phone) and two classic cognitive tasks, the Paced Auditory Serial Addition Test (PASAT) and Symbol Digit Modalities Test (SDMT). Nine older and seven younger healthy adults walked on a treadmill at four different conditions: walking only, PASAT, phone, and SDMT. We computed short-term local divergence exponent (LDE) of the trunk motion (local stability), dynamic margins of stability (MOS), step spatiotemporal measures, and kinematic variability. Older and younger adults had similar values of short-term LDE during all conditions, indicating that local stability was not affected by the dual-task. Compared to walking only, older and younger adults walked with significantly greater average mediolateral MOS during phone and SDMT conditions but significantly less ankle angle variability during all dual-tasks and less knee angle variability during PASAT. The current findings demonstrate that healthy adults may try to control foot placement and joint kinematics during cell phone use or another cognitive task with a visual component to ensure sufficient dynamic margins of stability and maintain local stability. PMID:25890490

  8. Embryonic and adult stem cell therapy.

    PubMed

    Brignier, Anne C; Gewirtz, Alan M

    2010-02-01

    There are many types of stem cells. All share the characteristics of being able to self-renew and to give rise to differentiated progeny. Over the last decades, great excitement has been generated by the prospect of being able to exploit these properties for the repair, improvement, and/or replacement of damaged organs. However, many hurdles, both scientific and ethical, remain in the path of using human embryonic stem cells for tissue-engineering purposes. In this report we review current strategies for isolating, enriching, and, most recently, inducing the development of human pluripotent stem cells. In so doing, we discuss the scientific and ethical issues associated with this endeavor. Finally, progress in the use of stem cells as therapies for type 1 diabetes mellitus, congestive heart failure, and various neurologic and immunohematologic disorders, and as vehicles for the delivery of gene therapy, is briefly discussed. PMID:20061008

  9. In Vivo Dedifferentiation of Adult Adipose Cells

    PubMed Central

    Lu, Feng; Dong, Ziqing; Chang, Qiang; Gao, Jianhua

    2015-01-01

    Introduction Adipocytes can dedifferentiate into fibroblast-like cells in vitro and thereby acquire proliferation and multipotent capacities to participate in the repair of various organs and tissues. Whether dedifferentiation occurs under physiological or pathological conditions in vivo is unknown. Methods A tissue expander was placed under the inguinal fat pads of rats and gradually expanded by injection of water. Samples were collected at various time points, and morphological, histological, cytological, ultrastructural, and gene expression analyses were conducted. In a separate experiment, purified green fluorescent protein+ adipocytes were transplanted into C57 mice and collected at various time points. The transplanted adipocytes were assessed by bioluminescence imaging and whole-mount staining. Results The expanded fat pad was obviously thinner than the untreated fat pad on the opposite side. It was also tougher in texture and with more blood vessels attached. Hematoxylin and eosin staining and transmission electron microscopy indicated there were fewer monolocular adipocytes in the expanded fat pad and the morphology of these cells was altered, most notably their lipid content was discarded. Immunohistochemistry showed that the expanded fat pad contained an increased number of proliferative cells, which may have been derived from adipocytes. Following removal of the tissue expander, many small adipocytes were observed. Bioluminescence imaging suggested that some adipocytes survived when transplanted into an ischemic-hypoxic environment. Whole-mount staining revealed that surviving adipocytes underwent a process similar to adipocyte dedifferentiation in vitro. Monolocular adipocytes became multilocular adipocytes and then fibroblast-like cells. Conclusions Mature adipocytes may be able to dedifferentiate in vivo, and this may be an adipose tissue self-repair mechanism. The capacity of adipocytes to dedifferentiate into stem cell-like cells may also have a

  10. EMPOWERING ADULT STEM CELLS FOR MYOCARDIAL REGENERATION

    PubMed Central

    Mohsin, Sadia; Siddiqi, Sailay; Collins, Brett; Sussman, Mark A.

    2012-01-01

    Treatment strategies for heart failure remain a high priority for ongoing research due to the profound unmet need in clinical disease coupled with lack of significant translational progress. The underlying issue is the same whether the cause is acute damage, chronic stress from disease, or aging: progressive loss of functional cardiomyocytes and diminished hemodynamic output. To stave off cardiomyocyte losses, a number of strategic approaches have been embraced in recent years involving both molecular and cellular approaches to augment myocardial structure and performance. Resultant excitement surrounding regenerative medicine in the heart has been tempered by realizations that reparative processes in the heart are insufficient to restore damaged myocardium to normal functional capacity and that cellular cardiomyoplasty is hampered by poor survival, proliferation, engraftment and differentiation of the donated population. To overcome these limitations, a combination of molecular and cellular approaches needs to be adopted involving use of genetic engineering to enhance resistance to cell death and increase regenerative capacity. This review will highlight biological properties of approached to potentiate stem cell-mediated regeneration to promote enhanced myocardial regeneration, persistence of donated cells, and long lasting tissue repair. Optimizing cell delivery and harnessing the power of survival signaling cascades for ex vivo genetic modification of stem cells prior to reintroduction into the patient will be critical to enhance the efficacy of cellular cardiomyoplasty. Once this goal is achieved, then cell-based therapy has great promise for treatment of heart failure to combat the loss of cardiac structure and function associated with acute damage, chronic disease or aging. PMID:22158649

  11. Enhanced expression of the peripheral benzodiazepine receptor (PBR) and its endogenous ligand octadecaneuropeptide (ODN) in the regenerating adult rat sciatic nerve.

    PubMed

    Lacor, P; Benavides, J; Ferzaz, B

    1996-12-01

    In this study we have investigated the expression of the peripheral benzodiazepine receptor (PBR) and its endogenous ligand octadecaneuropeptide (ODN) in the sciatic nerve of the adult rat by immunohistochemistry. We have also determined the effect of nerve freezing lesion or chronic denervation on PBR and ODN expression. In the sciatic nerve of control rats PBR- and ODN-immunoreactivities (IR) were associated to Schwann cells. Ten days after nerve injury, PBR- and ODN-IR increased significantly in the distal stump. PBR-IR was associated to Schwann cells and macrophages, whereas ODN-IR was only detected in Schwann cells. Immunoreactivities returned to normal levels when axons were allowed to regenerate for 2 months after nerve freezing-injury. Under chronic denervation conditions, PBR- and ODN-IR remained elevated in the distal stump, at least for this period of time. These results suggest that PBR and ODN are regulated by signals from regenerating axons and that PBR and its endogenous ligand may play a role in peripheral nerve regeneration.

  12. Intestinal stem cells in the adult Drosophila midgut

    SciTech Connect

    Jiang, Huaqi; Edgar, Bruce A.

    2011-11-15

    Drosophila has long been an excellent model organism for studying stem cell biology. Notably, studies of Drosophila's germline stem cells have been instrumental in developing the stem cell niche concept. The recent discovery of somatic stem cells in adult Drosophila, particularly the intestinal stem cells (ISCs) of the midgut, has established Drosophila as an exciting model to study stem cell-mediated adult tissue homeostasis and regeneration. Here, we review the major signaling pathways that regulate the self-renewal, proliferation and differentiation of Drosophila ISCs, discussing how this regulation maintains midgut homeostasis and mediates regeneration of the intestinal epithelium after injury. -- Highlights: Black-Right-Pointing-Pointer The homeostasis and regeneration of adult fly midguts are mediated by ISCs. Black-Right-Pointing-Pointer Damaged enterocytes induce the proliferation of intestinal stem cells (ISC). Black-Right-Pointing-Pointer EGFR and Jak/Stat signalings mediate compensatory ISC proliferation. Black-Right-Pointing-Pointer Notch signaling regulates ISC self-renewal and differentiation.

  13. Stirred bioreactors for the expansion of adult pancreatic stem cells.

    PubMed

    Serra, Margarida; Brito, Catarina; Leite, Sofia B; Gorjup, Erwin; von Briesen, Hagen; Carrondo, Manuel J T; Alves, Paula M

    2009-01-01

    Adult pluripotent stem cells are a cellular resource representing unprecedented potential for cell therapy and tissue engineering. Complementary to this promise, there is a need for efficient bioprocesses for their large scale expansion and/or differentiation. With this goal in mind, our work focused on the development of three-dimensional (3-D) culture systems for controlled expansion of adult pancreatic stem cells (PSCs). For this purpose, two different culturing strategies were evaluated, using spinner vessels: cell aggregated cultures versus microcarrier technology. The use of microcarrier supports (Cytodex 1 and Cytodex 3) rendered expanded cell populations which retained their self-renewal ability, cell marker, and the potential to differentiate into adipocytes. This strategy surmounted the drawbacks of aggregates in culture which were demonstrably unfeasible as cells clumped together did not proliferate and lost PSC marker expression. Furthermore, the results obtained showed that although both microcarriers tested here were suitable for sustaining cell expansion, Cytodex 3 provided a better substrate for the promotion of cell adherence and growth. For the latter approach, the potential of bioreactor technology was combined with the efficient Cytodex 3 strategy under controlled environmental conditions (pH-7.2, pO2-30% and temperature-37 degrees C); cell growth was more efficient, as shown by faster doubling time, higher growth rate and higher fold increase in cell concentration, when compared to spinner cultures. This study describes a robust bioprocess for the controlled expansion of adult PSC, representing an efficient starting point for the development of novel technologies for cell therapy.

  14. New Nerve Cells for the Adult Brain.

    ERIC Educational Resources Information Center

    Kempermann, Gerd; Gage, Fred H.

    1999-01-01

    Contrary to dogma, the human brain does produce new nerve cells in adulthood. The mature human brain spawns neurons routinely in the hippocampus, an area important to memory and learning. This research can make it possible to ease any number of disorders involving neurological damage and death. (CCM)

  15. Isolation, culture and analysis of adult subependymal neural stem cells.

    PubMed

    Belenguer, Germán; Domingo-Muelas, Ana; Ferrón, Sacri R; Morante-Redolat, José Manuel; Fariñas, Isabel

    2016-01-01

    Individual cells dissected from the subependymal neurogenic niche of the adult mouse brain proliferate in medium containing basic fibroblast growth factor (bFGF) and/or epidermal growth factor (EGF) as mitogens, to produce multipotent clonal aggregates called neurospheres. These cultures constitute a powerful tool for the study of neural stem cells (NSCs) provided that they allow the analysis of their features and potential capacity in a controlled environment that can be modulated and monitored more accurately than in vivo. Clonogenic and population analyses under mitogen addition or withdrawal allow the quantification of the self-renewing and multilineage potency of these cells and the identification of the mechanisms involved in these properties. Here, we describe a set of procedures developed and/or modified by our group including several experimental options that can be used either independently or in combination for the ex vivo assessment of cell properties of NSCs obtained from the adult subependymal niche. PMID:27016251

  16. Live Imaging of Adult Neural Stem Cells in Rodents

    PubMed Central

    Ortega, Felipe; Costa, Marcos R.

    2016-01-01

    The generation of cells of the neural lineage within the brain is not restricted to early development. New neurons, oligodendrocytes, and astrocytes are produced in the adult brain throughout the entire murine life. However, despite the extensive research performed in the field of adult neurogenesis during the past years, fundamental questions regarding the cell biology of adult neural stem cells (aNSCs) remain to be uncovered. For instance, it is crucial to elucidate whether a single aNSC is capable of differentiating into all three different macroglial cell types in vivo or these distinct progenies constitute entirely separate lineages. Similarly, the cell cycle length, the time and mode of division (symmetric vs. asymmetric) that these cells undergo within their lineage progression are interesting questions under current investigation. In this sense, live imaging constitutes a valuable ally in the search of reliable answers to the previous questions. In spite of the current limitations of technology new approaches are being developed and outstanding amount of knowledge is being piled up providing interesting insights in the behavior of aNSCs. Here, we will review the state of the art of live imaging as well as the alternative models that currently offer new answers to critical questions. PMID:27013941

  17. Hematopoietic stem cells, progenitor cells and leukemic stem cells in adult myeloproliferative neoplasms.

    PubMed

    Ng, Ashley P

    2013-05-01

    The understanding of myeloproliferative neoplasms has changed dramatically since Dameshek proposed his classification over 50 years ago. Our knowledge of the types of cells which constitute the hematopoietic system and of how they are regulated has also appreciated significantly over this time. This review relates what is currently known about the acquired genetic mutations associated with adult myeloproliferative neoplasms to how they lead to the hematopoietic perturbations of myeloproliferative disease. There is a particular focus on how stem and progenitor cell compartments are affected by BCR-ABL1 and JAK2V617F mutations, and the particular issue of resistance of leukemic stem cells to conventional and targeted therapies. PMID:23013358

  18. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    PubMed Central

    Webb, Carol F.; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

    2015-01-01

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. PMID:26111446

  19. Intraganglionic interactions between satellite cells and adult sensory neurons.

    PubMed

    Christie, Kimberly; Koshy, Dilip; Cheng, Chu; Guo, GuiFang; Martinez, Jose A; Duraikannu, Arul; Zochodne, Douglas W

    2015-07-01

    Perineuronal satellite cells have an intimate anatomical relationship with sensory neurons that suggests close functional collaboration and mutual support. We examined several facets of this relationship in adult sensory dorsal root ganglia (DRG). Collaboration included the support of process outgrowth by clustering of satellite cells, induction of distal branching behavior by soma signaling, the capacity of satellite cells to respond to distal axon injury of its neighboring neurons, and evidence of direct neuron-satellite cell exchange. In vitro, closely adherent coharvested satellite cells routinely clustered around new outgrowing processes and groups of satellite cells attracted neurite processes. Similar clustering was encountered in the pseudounipolar processes of intact sensory neurons within intact DRG in vivo. While short term exposure of distal growth cones of unselected adult sensory neurons to transient gradients of a PTEN inhibitor had negligible impacts on their behavior, exposure of the soma induced early and substantial growth of their distant neurites and branches, an example of local soma signaling. In turn, satellite cells sensed when distal neuronal axons were injured by enlarging and proliferating. We also observed that satellite cells were capable of internalizing and expressing a neuron fluorochrome label, diamidino yellow, applied remotely to distal injured axons of the neuron and retrogradely transported to dorsal root ganglia sensory neurons. The findings illustrate a robust interaction between intranganglionic neurons and glial cells that involve two way signals, features that may be critical for both regenerative responses and ongoing maintenance. PMID:25979201

  20. Intraganglionic interactions between satellite cells and adult sensory neurons.

    PubMed

    Christie, Kimberly; Koshy, Dilip; Cheng, Chu; Guo, GuiFang; Martinez, Jose A; Duraikannu, Arul; Zochodne, Douglas W

    2015-07-01

    Perineuronal satellite cells have an intimate anatomical relationship with sensory neurons that suggests close functional collaboration and mutual support. We examined several facets of this relationship in adult sensory dorsal root ganglia (DRG). Collaboration included the support of process outgrowth by clustering of satellite cells, induction of distal branching behavior by soma signaling, the capacity of satellite cells to respond to distal axon injury of its neighboring neurons, and evidence of direct neuron-satellite cell exchange. In vitro, closely adherent coharvested satellite cells routinely clustered around new outgrowing processes and groups of satellite cells attracted neurite processes. Similar clustering was encountered in the pseudounipolar processes of intact sensory neurons within intact DRG in vivo. While short term exposure of distal growth cones of unselected adult sensory neurons to transient gradients of a PTEN inhibitor had negligible impacts on their behavior, exposure of the soma induced early and substantial growth of their distant neurites and branches, an example of local soma signaling. In turn, satellite cells sensed when distal neuronal axons were injured by enlarging and proliferating. We also observed that satellite cells were capable of internalizing and expressing a neuron fluorochrome label, diamidino yellow, applied remotely to distal injured axons of the neuron and retrogradely transported to dorsal root ganglia sensory neurons. The findings illustrate a robust interaction between intranganglionic neurons and glial cells that involve two way signals, features that may be critical for both regenerative responses and ongoing maintenance.

  1. Wnt signaling in adult intestinal stem cells and cancer.

    PubMed

    Krausova, Michaela; Korinek, Vladimir

    2014-03-01

    Signaling initiated by secreted glycoproteins of the Wnt family regulates many aspects of embryonic development and it is involved in homeostasis of adult tissues. In the gastrointestinal (GI) tract the Wnt pathway maintains the self-renewal capacity of epithelial stem cells. The stem cell attributes are conferred by mutual interactions of the stem cell with its local microenvironment, the stem cell niche. The niche ensures that the threshold of Wnt signaling in the stem cell is kept in physiological range. In addition, the Wnt pathway involves various feedback loops that balance the opposing processes of cell proliferation and differentiation. Today, we have compelling evidence that mutations causing aberrant activation of the Wnt pathway promote expansion of undifferentiated progenitors and lead to cancer. The review summarizes recent advances in characterization of adult epithelial stem cells in the gut. We mainly focus on discoveries related to molecular mechanisms regulating the output of the Wnt pathway. Moreover, we present novel experimental approaches utilized to investigate the epithelial cell signaling circuitry in vivo and in vitro. Pivotal aspects of tissue homeostasis are often deduced from studies of tumor cells; therefore, we also discuss some latest results gleaned from the deep genome sequencing studies of human carcinomas of the colon and rectum. PMID:24308963

  2. Satellite cell proliferation in adult skeletal muscle

    NASA Technical Reports Server (NTRS)

    Booth, Frank W. (Inventor); Thomason, Donald B. (Inventor); Morrison, Paul R. (Inventor); Stancel, George M. (Inventor)

    1995-01-01

    Novel methods of retroviral-mediated gene transfer for the in vivo corporation and stable expression of eukaryotic or prokaryotic foreign genes in tissues of living animals is described. More specifically, methods of incorporating foreign genes into mitotically active cells are disclosed. The constitutive and stable expression of E. coli .beta.-galactosidase gene under the promoter control of the Moloney murine leukemia virus long terminal repeat is employed as a particularly preferred embodiment, by way of example, establishes the model upon which the incorporation of a foreign gene into a mitotically-active living eukaryotic tissue is based. Use of the described methods in therapeutic treatments for genetic diseases, such as those muscular degenerative diseases, is also presented. In muscle tissue, the described processes result in genetically-altered satellite cells which proliferate daughter myoblasts which preferentially fuse to form a single undamaged muscle fiber replacing damaged muscle tissue in a treated animal. The retroviral vector, by way of example, includes a dystrophin gene construct for use in treating muscular dystrophy. The present invention also comprises an experimental model utilizable in the study of the physiological regulation of skeletal muscle gene expression in intact animals.

  3. GFRalpha-3, a protein related to GFRalpha-1, is expressed in developing peripheral neurons and ensheathing cells.

    PubMed

    Widenfalk, J; Tomac, A; Lindqvist, E; Hoffer, B; Olson, L

    1998-04-01

    We report here the identification of a gene, termed GFRalpha-3 (glial cell line-derived neurotrophic factor family receptor alpha-3), related to GFRalpha-1 and GFRalpha-2 (also known as GDNFR-alpha and GDNFR-beta), and describe distribution of GDNFalpha-3 in the nervous system and other parts of the mouse body during development and in the adult. GFRalpha-3 in situ hybridization signals were found mainly in the peripheral nervous system, with prominent signals in developing dorsal root and trigeminal ganglia. Sympathetic ganglia were also positive. Developing nerves manifested strong GFRalpha-3 mRNA signals, presumably generated by the Schwann cells. Olfactory ensheathing cells were also positive. Other non-neuronal cells appearing positive during development included chromaffin cells in the adrenal gland and small clusters of cells in the intestinal epithelium. In the central nervous system no robust signals could be detected at any stage investigated with the present probes. Compared with the previously described GFRalpha-1 and GFRalpha-2 mRNAs, which are widely distributed in the central nervous system and peripheral organs, the expression of GFRalpha-3 mRNA is much more restricted. The prominent expression in Schwann cells during development suggests a key role for GFRalpha-3 in the development of the peripheral nervous system. As Schwann cells are known to lack expression of the transducing RET receptor, we propose that a possible function of GFRalpha-3 during development could be to bind Schwann cell-derived GDNF-like ligands, thus presenting such molecules to growing axons. PMID:9749804

  4. Axonal control of the adult neural stem cell niche.

    PubMed

    Tong, Cheuk Ka; Chen, Jiadong; Cebrián-Silla, Arantxa; Mirzadeh, Zaman; Obernier, Kirsten; Guinto, Cristina D; Tecott, Laurence H; García-Verdugo, Jose Manuel; Kriegstein, Arnold; Alvarez-Buylla, Arturo

    2014-04-01

    The ventricular-subventricular zone (V-SVZ) is an extensive germinal niche containing neural stem cells (NSCs) in the walls of the lateral ventricles of the adult brain. How the adult brain's neural activity influences the behavior of adult NSCs remains largely unknown. We show that serotonergic (5HT) axons originating from a small group of neurons in the raphe form an extensive plexus on most of the ventricular walls. Electron microscopy revealed intimate contacts between 5HT axons and NSCs (B1) or ependymal cells (E1) and these cells were labeled by a transsynaptic viral tracer injected into the raphe. B1 cells express the 5HT receptors 2C and 5A. Electrophysiology showed that activation of these receptors in B1 cells induced small inward currents. Intraventricular infusion of 5HT2C agonist or antagonist increased or decreased V-SVZ proliferation, respectively. These results indicate that supraependymal 5HT axons directly interact with NSCs to regulate neurogenesis via 5HT2C. PMID:24561083

  5. Axonal Control of the Adult Neural Stem Cell Niche

    PubMed Central

    Tong, Cheuk Ka; Chen, Jiadong; Cebrián-Silla, Arantxa; Mirzadeh, Zaman; Obernier, Kirsten; Guinto, Cristina D.; Tecott, Laurence H.; García-Verdugo, Jose Manuel; Kriegstein, Arnold; Alvarez-Buylla, Arturo

    2014-01-01

    SUMMARY The ventricular-subventricular zone (V-SVZ) is an extensive germinal niche containing neural stem cells (NSC) in the walls of the lateral ventricles of the adult brain. How the adult brain’s neural activity influences the behavior of adult NSCs remains largely unknown. We show that serotonergic (5HT) axons originating from a small group of neurons in the raphe form an extensive plexus on most of the ventricular walls. Electron microscopy revealed intimate contacts between 5HT axons and NSCs (B1) or ependymal cells (E1) and these cells were labeled by a transsynaptic viral tracer injected into the raphe. B1 cells express the 5HT receptors 2C and 5A. Electrophysiology showed that activation of these receptors in B1 cells induced small inward currents. Intraventricular infusion of 5HT2C agonist or antagonist increased or decreased V-SVZ proliferation, respectively. These results indicate that supraependymal 5HT axons directly interact with NSCs to regulate neurogenesis via 5HT2C. PMID:24561083

  6. Direct transcriptional reprogramming of adult cells to embryonic nephron progenitors.

    PubMed

    Hendry, Caroline E; Vanslambrouck, Jessica M; Ineson, Jessica; Suhaimi, Norseha; Takasato, Minoru; Rae, Fiona; Little, Melissa H

    2013-09-01

    Direct reprogramming involves the enforced re-expression of key transcription factors to redefine a cellular state. The nephron progenitor population of the embryonic kidney gives rise to all cells within the nephron other than the collecting duct through a mesenchyme-to-epithelial transition, but this population is exhausted around the time of birth. Here, we sought to identify the conditions under which adult proximal tubule cells could be directly transcriptionally reprogrammed to nephron progenitors. Using a combinatorial screen for lineage-instructive transcription factors, we identified a pool of six genes (SIX1, SIX2, OSR1, EYA1, HOXA11, and SNAI2) that activated a network of genes consistent with a cap mesenchyme/nephron progenitor phenotype in the adult proximal tubule (HK2) cell line. Consistent with these reprogrammed cells being nephron progenitors, we observed differential contribution of the reprogrammed population into the Six2(+) nephron progenitor fields of an embryonic kidney explant. Dereplication of the pool suggested that SNAI2 can suppress E-CADHERIN, presumably assisting in the epithelial-to-mesenchymal transition (EMT) required to form nephron progenitors. However, neither TGFβ-induced EMT nor SNAI2 overexpression alone was sufficient to create this phenotype, suggesting that additional factors are required. In conclusion, these results suggest that reinitiation of kidney development from a population of adult cells by generating embryonic progenitors may be feasible, opening the way for additional cellular and bioengineering approaches to renal repair and regeneration.

  7. Adult stem cells applied to tissue engineering and regenerative medicine.

    PubMed

    Cuenca-López, M D; Zamora-Navas, P; García-Herrera, J M; Godino, M; López-Puertas, J M; Guerado, E; Becerra, J; Andrades, J A

    2008-01-01

    Regeneration takes place in the body at a moment or another throughout life. Bone, cartilage, and tendons (the key components of the structure and articulation in the body) have a limited capacity for self-repair and, after traumatic injury or disease, the regenerative power of adult tissue is often insufficient. When organs or tissues are irreparably damaged, they may be replaced by an artificial device or by a donor organ. However, the number of available donor organs is considerably limited. Generation of tissue-engineered replacement organs by extracting stem cells from the patient, growing them and modifying them in clinical conditions after re-introduction in the body represents an ideal source for corrective treatment. Mesenchymal stem cells (MSCs) are the multipotential progenitors that give rise to skeletal cells, vascular smooth muscle cells, muscle (skeletal and cardiac muscle), adipocytes (fat tissue) and hematopoietic (blood)-supportive stromal cells. MSCs are found in multiple connective tissues, in adult bone marrow, skeletal muscles and fat pads. The wide representation in adult tissues may be related to the existence of a circulating blood pool or that MSCs are associated to the vascular system.

  8. Germ Cell Tumors in Adolescents and Young Adults.

    PubMed

    Calaminus, Gabriele; Joffe, Jonathan

    2016-01-01

    Germ cell tumors (GCTs) represent a group of biologically complex malignancies that affect patients at different sites within the body and at different ages. The varying nature of these tumors reflects their cell of origin which is the primordial germ cell, which normally gives rise to ovarian and testicular egg and sperm producing cells. These cells retain an ability to give rise to all types of human tissues, and this is illustrated by the different kinds of GCTs that occur. In adolescent and young adult (AYA) patients, GCTs predominantly present as testicular, ovarian or mediastinal primary GCTs, and represent some of the most complex therapeutic challenges within any AYA practice. The varying types of GCTs, defined by primary site and/or age at presentation, can look very similar microscopically. However, there is growing evidence that they may have different molecular characteristics, different biology and different requirements for curative treatments. Whilst in adult testicular GCTs there is evidence for an environmental cause during fetal development and a genetic component, these causative factors are much less well understood in other GCTs. GCTs are some of the most curable cancers in adults, but some patients exhibit resistance to standard treatments. Because of this, today's clinical research is directed at understanding how to best utilize toxic therapies and promote healthy survivorship. This chapter explores the biology, behavior and treatment of GCTs and discusses how the AYA group of GCTs may hold some of the keys to understanding fundamental unanswered questions of biological variance and curability in GCTs. PMID:27595361

  9. Biology of the adult enteric neural stem cell.

    PubMed

    Estrada-Mondaca, Sandino; Carreón-Rodríguez, Alfonso; Belkind-Gerson, Jaime

    2007-01-01

    An increasing body of evidence has accumulated in recent years supporting the existence of neural stem cells in the adult gut. There are at least three groups that have obtained them using different methodologies and have described them in vitro. There is a growing amount of knowledge on their biology, but many questions are yet unanswered. Among these questions is whether these cells are part of a permanent undifferentiated pool or are recruited in a regular basis; in addition, the factors and genes involved in their survival, proliferation, migration, and differentiation are largely unknown. Finally, with between 10 and 20% of adults suffering from diseases involving the enteric nervous system, most notably irritable bowel syndrome and gastroesophageal reflux, what is the possible role of enteric nervous stem cells in health and disease?

  10. In vivo cell tracking and quantification method in adult zebrafish

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Alt, Clemens; Li, Pulin; White, Richard M.; Zon, Leonard I.; Wei, Xunbin; Lin, Charles P.

    2012-03-01

    Zebrafish have become a powerful vertebrate model organism for drug discovery, cancer and stem cell research. A recently developed transparent adult zebrafish using double pigmentation mutant, called casper, provide unparalleled imaging power in in vivo longitudinal analysis of biological processes at an anatomic resolution not readily achievable in murine or other systems. In this paper we introduce an optical method for simultaneous visualization and cell quantification, which combines the laser scanning confocal microscopy (LSCM) and the in vivo flow cytometry (IVFC). The system is designed specifically for non-invasive tracking of both stationary and circulating cells in adult zebrafish casper, under physiological conditions in the same fish over time. The confocal imaging part in this system serves the dual purposes of imaging fish tissue microstructure and a 3D navigation tool to locate a suitable vessel for circulating cell counting. The multi-color, multi-channel instrument allows the detection of multiple cell populations or different tissues or organs simultaneously. We demonstrate initial testing of this novel instrument by imaging vasculature and tracking circulating cells in CD41: GFP/Gata1: DsRed transgenic casper fish whose thrombocytes/erythrocytes express the green and red fluorescent proteins. Circulating fluorescent cell incidents were recorded and counted repeatedly over time and in different types of vessels. Great application opportunities in cancer and stem cell researches are discussed.

  11. Recent advances in bone regeneration using adult stem cells.

    PubMed

    Zigdon-Giladi, Hadar; Rudich, Utai; Michaeli Geller, Gal; Evron, Ayelet

    2015-04-26

    Bone is a highly vascularized tissue reliant on the close spatial and temporal association between blood vessels and bone cells. Therefore, cells that participate in vasculogenesis and osteogenesis play a pivotal role in bone formation during prenatal and postnatal periods. Nevertheless, spontaneous healing of bone fracture is occasionally impaired due to insufficient blood and cellular supply to the site of injury. In these cases, bone regeneration process is interrupted, which might result in delayed union or even nonunion of the fracture. Nonunion fracture is difficult to treat and have a high financial impact. In the last decade, numerous technological advancements in bone tissue engineering and cell-therapy opened new horizon in the field of bone regeneration. This review starts with presentation of the biological processes involved in bone development, bone remodeling, fracture healing process and the microenvironment at bone healing sites. Then, we discuss the rationale for using adult stem cells and listed the characteristics of the available cells for bone regeneration. The mechanism of action and epigenetic regulations for osteogenic differentiation are also described. Finally, we review the literature for translational and clinical trials that investigated the use of adult stem cells (mesenchymal stem cells, endothelial progenitor cells and CD34(+) blood progenitors) for bone regeneration.

  12. Wildtype adult stem cells, unlike tumor cells, are resistant to cellular damages in Drosophila.

    PubMed

    Ma, Meifang; Zhao, Hang; Zhao, Hanfei; Binari, Richard; Perrimon, Norbert; Li, Zhouhua

    2016-03-15

    Adult stem cells or residential progenitor cells are critical to maintain the structure and function of adult tissues (homeostasis) throughout the lifetime of an individual. Mis-regulation of stem cell proliferation and differentiation often leads to diseases including cancer, however, how wildtype adult stem cells and cancer cells respond to cellular damages remains unclear. We find that in the adult Drosophila midgut, intestinal stem cells (ISCs), unlike tumor intestinal cells, are resistant to various cellular damages. Tumor intestinal cells, unlike wildtype ISCs, are easily eliminated by apoptosis. Further, their proliferation is inhibited upon autophagy induction, and autophagy-mediated tumor inhibition is independent of caspase-dependent apoptosis. Interestingly, inhibition of tumorigenesis by autophagy is likely through the sequestration and degradation of mitochondria, as compromising mitochondria activity in these tumor models mimics the induction of autophagy and increasing the production of mitochondria alleviates the tumor-suppression capacity of autophagy. Together, these data demonstrate that wildtype adult stem cells and tumor cells show dramatic differences in sensitivity to cellular damages, thus providing potential therapeutic implications targeting tumorigenesis. PMID:26845534

  13. Haploidentical Stem Cell Transplantation in Adult Haematological Malignancies

    PubMed Central

    Parmesar, Kevon; Raj, Kavita

    2016-01-01

    Haematopoietic stem cell transplantation is a well-established treatment option for both hematological malignancies and nonmalignant conditions such as aplastic anemia and haemoglobinopathies. For those patients lacking a suitable matched sibling or matched unrelated donor, haploidentical donors are an alternative expedient donor pool. Historically, haploidentical transplantation led to high rates of graft rejection and GVHD. Strategies to circumvent these issues include T cell depletion and management of complications thereof or T replete transplants with GVHD prophylaxis. This review is an overview of these strategies and contemporaneous outcomes for hematological malignancies in adult haploidentical stem cell transplant recipients. PMID:27313619

  14. Adult stem cell plasticity: will engineered tissues be rejected?

    PubMed Central

    Fang, Te-Chao; Alison, Malcolm R; Wright, Nicholas A; Poulsom, Richard

    2004-01-01

    The dogma that adult tissue-specific stem cells remain committed to supporting only their own tissue has been challenged; a new hypothesis, that adult stem cells demonstrate plasticity in their repertoires, is being tested. This is important because it seems possible that haematopoietic stem cells, for example, could be exploited to generate and perhaps deliver cell-based therapies deep within existing nonhaematopoietic organs. Much of the evidence for plasticity derives from histological studies of tissues from patients or animals that have received grafts of cells or whole organs, from a donor bearing (or lacking) a definitive marker. Detection in the recipient of appropriately differentiated cells bearing the donor marker is indicative of a switch in phenotype of a stem cell or a member of a transit amplifying population or of a differentiated cell. In this review, we discuss evidence for these changes occurring but do not consider the molecular basis of cell commitment. In general, the extent of engraftment is low but may be increased if tissues are damaged. In model systems of liver regeneration, the repeated application of a selection pressure increases levels of engraftment considerably; how this occurs is unclear. Cell fusion plays a part in regeneration and remodelling of the liver, skeletal muscle and even regions of the brain. Genetic disease may be amenable to some forms of cell therapy, yet immune rejection will present challenges. Graft-vs.-host disease will continue to present problems, although this may be avoided if the cells were derived from the recipient or they were tolerized. Despite great expectations for cellular therapies, there are indications that attempts to replace missing proteins could be confounded simply by the development of specific immunity that rejects the new phenotype. PMID:15255965

  15. Differentiation of embryonic and adult stem cells into insulin producing cells.

    PubMed

    Zulewski, H

    2008-03-01

    Replacement of insulin producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans is successful in experienced centers. The wider application of this therapy, however, is limited by the lack of donor organs. Insulin producing cells generated from stem cells represent an attractive alternative. Stem cells with the potential to differentiate into insulin producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns but research with human ESC may help us to decipher important steps in the differentiation process in vitro since almost all information available on pancreas development are based on animal studies. The present review summarizes the current knowledge on the development of insulin producing cells from embryonic and adult stem cells with special emphasis on pancreatic, hepatic and human mesenchymal stem cells. PMID:18427390

  16. First cloned swamp buffalo produced from adult ear fibroblast cell.

    PubMed

    Tasripoo, K; Suthikrai, W; Sophon, S; Jintana, R; Nualchuen, W; Usawang, S; Bintvihok, A; Techakumphu, M; Srisakwattana, K

    2014-07-01

    The world's first cloned swamp buffalo (Bubalus bubalis) derived from adult ear skin fibroblast has been reported. Donor fibroblast cells were produced from biopsies taken from adult male ear skin and in vitro matured oocytes obtained from a slaughterhouse were used as cytoplasts. A total of 39 blastocysts and 19 morulae fresh embryos were transferred into 12 recipient buffaloes. Progesterone assays indicated establishment of pregnancy in 10 of the 12 buffaloes (83.3%) after 45 days, with six animals still pregnant at 3 months. One recipient maintained pregnancy to term and naturally delivered a 40 kg male calf after 326 days of gestation. DNA analysis showed that the cloned calf was genetically identical to the donor cells. Genotype analyses, using 12 buffalo microsatellite markers, confirmed that the cloned calf was derived from the donor cell lines. In conclusion, the present study reports, for the first time, the establishment of pregnancy and birth of the first cloned Thai swamp buffalo derived from adult ear skin fibroblast cells.

  17. [Therapeutic use of stem cells. II. Adult stem cells].

    PubMed

    Uzan, Georges

    2004-09-30

    Many degenerative diseases are not curable by means of classical medicine. The long term objective of cell therapy is to treat the patients with their own stem cells that could be either purified from the diseased organ or from "reservoirs" of stem cells such as that constituted by the bone marrow. The existence of stem cells in the organs or reservoirs is now established in vitro and in some cases, in animal models. Numbers of technical problems linked to the scarcity of these cells still delay the clinical use of purified stem cells. However, clinical protocols using heterogeneous cell populations have already started to treat a growing number of diseases. In some case, autologous cells can be used, as it is the case for bone marrow transplantation in blood diseases. Mesenchymal cells, also purified from the bone marrow are currently used in orthopaedic diseases. Because these cells reveal a broad differentiation potential, active research programs explore their possible use for treatment of other diseases. Bone marrow also contains vascular stem cells that could be active in reappearing defective vessels responsible for ischaemic diseases. Indeed, clinical trials in which bone marrow cells are injected in the cardiac muscle of patients with myocardial infarction or in the leg muscle (gastrocnemius) of patients with hind limb ischaemia have already started. Artificial skin prepared from skin biopsies is used for the reconstitution of the derma of severely burned patients. Clinical trials have also started, using allogenic cells. The patients must be treated by immunosuppressive drugs. Neurodegenerative diseases such as Parkinson have been successfully treated by intra-cerebral injection of foetal neurones. Pancreatic islets implanted in the liver have shown to re-establish a normal glycaemia in diabetic patients. However, all these clinical trials use differentiated cells or at least progenitors which display differentiation potential and lifetime much more

  18. A developmentally plastic adult mouse kidney cell line spontaneously generates multiple adult kidney structures

    SciTech Connect

    Webb, Carol F.; Ratliff, Michelle L.; Powell, Rebecca; Wirsig-Wiechmann, Celeste R.; Lakiza, Olga; Obara, Tomoko

    2015-08-07

    Despite exciting new possibilities for regenerative therapy posed by the ability to induce pluripotent stem cells, recapitulation of three-dimensional kidneys for repair or replacement has not been possible. ARID3a-deficient mouse tissues generated multipotent, developmentally plastic cells. Therefore, we assessed the adult mouse ARID3a−/− kidney cell line, KKPS5, which expresses renal progenitor surface markers as an alternative cell source for modeling kidney development. Remarkably, these cells spontaneously developed into multicellular nephron-like structures in vitro, and engrafted into immunocompromised medaka mesonephros, where they formed mouse nephron structures. These data implicate KKPS5 cells as a new model system for studying kidney development. - Highlights: • An ARID3a-deficient mouse kidney cell line expresses multiple progenitor markers. • This cell line spontaneously forms multiple nephron-like structures in vitro. • This cell line formed mouse kidney structures in immunocompromised medaka fish kidneys. • Our data identify a novel model system for studying kidney development.

  19. Cell secretion from the adult lamprey supraneural body tissues possesses cytocidal activity against tumor cells.

    PubMed

    Pang, Yue; Wang, Shiyue; Ba, Wei; Li, Qingwei

    2015-01-01

    The supraneural body was identified in the adult lamprey, and its secretions induced the death of a variety of tumor cells but had no effect on normal cells. The cell secretions from different lamprey tissues were separated, and these secretions killed human tumor cells to varying degrees. The cell secretions induced remarkable cell morphological alterations such as cell blebbing, and the plasma membrane was destroyed by the secretions. In addition, the secretions induced morphological alterations of the mitochondria, cytoskeletal structure, and endoplasmic reticulum, eventually leading to cell death. These observations suggest the presence of a novel protein in the lamprey and the possibility of new applications for the protein in the medical field.

  20. Adult Langerhans Cell Histiocytosis with Hepatic and Pulmonary Involvement

    PubMed Central

    Araujo, Bruno; Costa, Francisco; Lopes, Joanne; Castro, Ricardo

    2015-01-01

    Langerhans cell histiocytosis (LCH) is a rare proliferative disorder of Langerhans cells of unknown etiology. It can involve multiple organ systems with different clinical presentation, which complicates the diagnosis. It can range from isolated to multisystem disease with different prognosis. Although common among children, liver involvement is relatively rare in adults and frequently overlooked. Natural history of liver LCH fits into two stages: an early stage with infiltration by histiocytes and a late stage with sclerosis of the biliary tree. Pulmonary findings are more common and include multiple nodules in different stages of cavitation, predominantly in the upper lobes. We present a case of adult LCH with pulmonary and biopsy proven liver involvement with resolution of the hepatic findings after treatment. PMID:25977828

  1. Mesenchymal stem cells instruct oligodendrogenic fate decision on adult neural stem cells.

    PubMed

    Rivera, Francisco J; Couillard-Despres, Sebastien; Pedre, Xiomara; Ploetz, Sonja; Caioni, Massimiliano; Lois, Carlos; Bogdahn, Ulrich; Aigner, Ludwig

    2006-10-01

    Adult stem cells reside in different tissues and organs of the adult organism. Among these cells are MSCs that are located in the adult bone marrow and NSCs that exist in the adult central nervous system (CNS). In transplantation experiments, MSCs demonstrated neuroprotective and neuroregenerative effects that were associated with functional improvements. The underlying mechanisms are largely unidentified. Here, we reveal that the interactions between adult MSCs and NSCs, mediated by soluble factors, induce oligodendrogenic fate decision in NSCs at the expense of astrogenesis. This was demonstrated (a) by an increase in the percentage of cells expressing the oligodendrocyte markers GalC and myelin basic protein, (b) by a reduction in the percentage of glial fibrillary acidic protein (GFAP)-expressing cells, and (c) by the expression pattern of cell fate determinants specific for oligodendrogenic differentiation. Thus, it involved enhanced expression of the oligodendrogenic transcription factors Olig1, Olig2, and Nkx2.2 and diminished expression of Id2, an inhibitor of oligodendrogenic differentiation. Results of (a) 5-bromo-2'-deoxyuridine pulse-labeling of cells, (b) cell fate analysis, and (c) cell death/survival analysis suggested an inductive mechanism and excluded a selection process. A candidate factor screen excluded a number of growth factors, cytokines, and neurotrophins that have previously been shown to influence neurogenesis and neural differentiation from the oligodendrogenic activity derived from the MSCs. This work might have major implications for the development of future transplantation strategies for the treatment of degenerative diseases in the CNS. PMID:16763198

  2. Emerging restorative treatments for Parkinson's disease: manipulation and inducement of dopaminergic neurons from adult stem cells.

    PubMed

    Zhao, Junpeng; Xu, Qunyuan

    2011-06-01

    Parkinson's disease (PD) is a common neurodegenerative disease, characterized by a selective loss of midbrain Dopaminergic (DA) neurons. To address this problem, various types of stem cells that have potential to differentiate into DA neurons are being investigated as cellular therapies for PD, including cells derived from embryonic or adult donor tissue, and embryonic stem cells. These cell sources, however, have raised certain questions with regard to ethical and rejection issues. Recent progress in adult stems has further proved that the cells derived from adult tissue could be expanded and differentiated into DA precursor cells in vitro, and cell therapy with adult stem cells could produce a clear improvement for PD models. Using adult stem cells for clinic application may not only overcome the ethical problem inherent in using human fetal tissue or embryonic stem cells, but also open the possibility for autologous transplantation. The patient-specific adult stem cell is therefore a potential and prospective candidate for PD treatment.

  3. Neural stem/progenitor cell properties of glial cells in the adult mouse auditory nerve

    PubMed Central

    Lang, Hainan; Xing, Yazhi; Brown, LaShardai N.; Samuvel, Devadoss J.; Panganiban, Clarisse H.; Havens, Luke T.; Balasubramanian, Sundaravadivel; Wegner, Michael; Krug, Edward L.; Barth, Jeremy L.

    2015-01-01

    The auditory nerve is the primary conveyor of hearing information from sensory hair cells to the brain. It has been believed that loss of the auditory nerve is irreversible in the adult mammalian ear, resulting in sensorineural hearing loss. We examined the regenerative potential of the auditory nerve in a mouse model of auditory neuropathy. Following neuronal degeneration, quiescent glial cells converted to an activated state showing a decrease in nuclear chromatin condensation, altered histone deacetylase expression and up-regulation of numerous genes associated with neurogenesis or development. Neurosphere formation assays showed that adult auditory nerves contain neural stem/progenitor cells (NSPs) that were within a Sox2-positive glial population. Production of neurospheres from auditory nerve cells was stimulated by acute neuronal injury and hypoxic conditioning. These results demonstrate that a subset of glial cells in the adult auditory nerve exhibit several characteristics of NSPs and are therefore potential targets for promoting auditory nerve regeneration. PMID:26307538

  4. Adult stem cells therapy for urine incontinence in women.

    PubMed

    Stangel-Wójcikiewicz, Klaudia; Majka, Marcin; Basta, Antoni; Stec, Małgorzata; Pabian, Wojciech; Piwowar, Monika; Chancellor, Michael B

    2010-05-01

    The past few years brought high development in obtaining and culturing autologous adult stem cells. In this paper we review publications of experimental investigations and clinical trials of the muscle-derived cells and the application in the treatment of stress urinary incontinence among women. Mesenchymal stem cells (MSCs) can be obtained from bone marrow but it is associated with a painful biopsy procedure. Collection of muscle-derived stem cells (MDSCs) is less harmful because the skeletal muscle biopsy is performed with a small caliber needle in local anesthesia. The stem-based therapy could be the next step in the treatment of urinary incontinence. There are still many elements of therapy such as effectiveness or long-term side effects which need to be researched.

  5. Switching roles: the functional plasticity of adult tissue stem cells

    PubMed Central

    Wabik, Agnieszka; Jones, Philip H

    2015-01-01

    Adult organisms have to adapt to survive, and the same is true for their tissues. Rates and types of cell production must be rapidly and reversibly adjusted to meet tissue demands in response to both local and systemic challenges. Recent work reveals how stem cell (SC) populations meet these requirements by switching between functional states tuned to homoeostasis or regeneration. This plasticity extends to differentiating cells, which are capable of reverting to SCs after injury. The concept of the niche, the micro-environment that sustains and regulates stem cells, is broadening, with a new appreciation of the role of physical factors and hormonal signals. Here, we review different functions of SCs, the cellular mechanisms that underlie them and the signals that bias the fate of SCs as they switch between roles. PMID:25812989

  6. Dental Stem Cell in Tooth Development and Advances of Adult Dental Stem Cell in Regenerative Therapies.

    PubMed

    Tan, Jiali; Xu, Xin; Lin, Jiong; Fan, Li; Zheng, Yuting; Kuang, Wei

    2015-01-01

    Stem cell-based therapies are considered as a promising treatment for many clinical usage such as tooth regeneration, bone repairation, spinal cord injury, and so on. However, the ideal stem cell for stem cell-based therapy still remains to be elucidated. In the past decades, several types of stem cells have been isolated from teeth, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSCs), dental follicle progenitor stem cells (DFPCs) and stem cells from apical papilla (SCAP), which may be a good source for stem cell-based therapy in certain disease, especially when they origin from neural crest is considered. In this review, the specific characteristics and advantages of the adult dental stem cell population will be summarized and the molecular mechanisms of the differentiation of dental stem cell during tooth development will be also discussed.

  7. A novel view of the adult bone marrow stem cell hierarchy and stem cell trafficking.

    PubMed

    Ratajczak, M Z

    2015-04-01

    This review presents a novel view and working hypothesis about the hierarchy within the adult bone marrow stem cell compartment and the still-intriguing question of whether adult bone marrow contains primitive stem cells from early embryonic development, such as cells derived from the epiblast, migrating primordial germ cells or yolk sac-derived hemangioblasts. It also presents a novel view of the mechanisms that govern stem cell mobilization and homing, with special emphasis on the role of the complement cascade as a trigger for egress of hematopoietic stem cells from bone marrow into blood as well as the emerging role of novel homing factors and priming mechanisms that support stromal-derived factor 1-mediated homing of hematopoietic stem/progenitor cells after transplantation.

  8. A novel view of the adult bone marrow stem cell hierarchy and stem cell trafficking

    PubMed Central

    Ratajczak, M Z

    2015-01-01

    This review presents a novel view and working hypothesis about the hierarchy within the adult bone marrow stem cell compartment and the still-intriguing question of whether adult bone marrow contains primitive stem cells from early embryonic development, such as cells derived from the epiblast, migrating primordial germ cells or yolk sac-derived hemangioblasts. It also presents a novel view of the mechanisms that govern stem cell mobilization and homing, with special emphasis on the role of the complement cascade as a trigger for egress of hematopoietic stem cells from bone marrow into blood as well as the emerging role of novel homing factors and priming mechanisms that support stromal-derived factor 1-mediated homing of hematopoietic stem/progenitor cells after transplantation. PMID:25486871

  9. Robust G2 pausing of adult stem cells in Hydra.

    PubMed

    Buzgariu, Wanda; Crescenzi, Marco; Galliot, Brigitte

    2014-01-01

    Hydra is a freshwater hydrozoan polyp that constantly renews its two tissue layers thanks to three distinct stem cell populations that cannot replace each other, epithelial ectodermal, epithelial endodermal, and multipotent interstitial. These adult stem cells, located in the central body column, exhibit different cycling paces, slow for the epithelial, fast for the interstitial. To monitor the changes in cell cycling in Hydra, we established a fast and efficient flow cytometry procedure, which we validated by confirming previous findings, as the Nocodazole-induced reversible arrest of cell cycling in G2/M, and the mitogenic signal provided by feeding. Then to dissect the cycling and differentiation behaviors of the interstitial stem cells, we used the AEP_cnnos1 and AEP_Icy1 transgenic lines that constitutively express GFP in this lineage. For the epithelial lineages we used the sf-1 strain that rapidly eliminates the fast cycling cells upon heat-shock and progressively becomes epithelial. This study evidences similar cycling patterns for the interstitial and epithelial stem cells, which all alternate between the G2 and S-phases traversing a minimal G1-phase. We also found interstitial progenitors with a shorter G2 that pause in G1/G0. At the animal extremities, most cells no longer cycle, the epithelial cells terminally differentiate in G2 and the interstitial progenitors in G1/G0. At the apical pole ~80% cells are post-mitotic differentiated cells, reflecting the higher density of neurons and nematocytes in this region. We discuss how the robust G2 pausing of stem cells, maintained over weeks of starvation, may contribute to regeneration.

  10. Epigenomic Reprogramming of Adult Cardiomyocyte-Derived Cardiac Progenitor Cells

    PubMed Central

    Zhang, Yiqiang; Zhong, Jiang F; Qiu, Hongyu; Robb MacLellan, W.; Marbán, Eduardo; Wang, Charles

    2015-01-01

    It has been believed that mammalian adult cardiomyocytes (ACMs) are terminally-differentiated and are unable to proliferate. Recently, using a bi-transgenic ACM fate mapping mouse model and an in vitro culture system, we demonstrated that adult mouse cardiomyocytes were able to dedifferentiate into cardiac progenitor-like cells (CPCs). However, little is known about the molecular basis of their intrinsic cellular plasticity. Here we integrate single-cell transcriptome and whole-genome DNA methylation analyses to unravel the molecular mechanisms underlying the dedifferentiation and cell cycle reentry of mouse ACMs. Compared to parental cardiomyocytes, dedifferentiated mouse cardiomyocyte-derived CPCs (mCPCs) display epigenomic reprogramming with many differentially-methylated regions, both hypermethylated and hypomethylated, across the entire genome. Correlated well with the methylome, our transcriptomic data showed that the genes encoding cardiac structure and function proteins are remarkably down-regulated in mCPCs, while those for cell cycle, proliferation, and stemness are significantly up-regulated. In addition, implantation of mCPCs into infarcted mouse myocardium improves cardiac function with augmented left ventricular ejection fraction. Our study demonstrates that the cellular plasticity of mammalian cardiomyocytes is the result of a well-orchestrated epigenomic reprogramming and a subsequent global transcriptomic alteration. PMID:26657817

  11. Isolation, characterization, and differentiation of human multipotent dermal stem cells.

    PubMed

    Li, Ling; Fukunaga-Kalabis, Mizuho; Herlyn, Meenhard

    2013-01-01

    Skin, as the body's largest organ, has been extensively used to study adult stem cells. Most previous skin-related studies have focused on stem cells isolated from hair follicles and from keratinocytes. Here we present a protocol to isolate multipotent neural crest stem-like dermis-derived stem cells (termed dermal stem cells or DSCs) from human neonatal foreskins. DSCs grow like neural spheres in human embryonic stem cell medium and gain the ability to self-renew and differentiate into several cell lineages including melanocytes, neuronal cells, Schwann cells, smooth muscle cells, adipocytes, and chondrocytes. These cells express neural crest stem cell markers (NGFRp75 and nestin) as well as an embryonic stem cell marker (OCT4).

  12. Integrated molecular analysis of adult T cell leukemia/lymphoma.

    PubMed

    Kataoka, Keisuke; Nagata, Yasunobu; Kitanaka, Akira; Shiraishi, Yuichi; Shimamura, Teppei; Yasunaga, Jun-Ichirou; Totoki, Yasushi; Chiba, Kenichi; Sato-Otsubo, Aiko; Nagae, Genta; Ishii, Ryohei; Muto, Satsuki; Kotani, Shinichi; Watatani, Yosaku; Takeda, June; Sanada, Masashi; Tanaka, Hiroko; Suzuki, Hiromichi; Sato, Yusuke; Shiozawa, Yusuke; Yoshizato, Tetsuichi; Yoshida, Kenichi; Makishima, Hideki; Iwanaga, Masako; Ma, Guangyong; Nosaka, Kisato; Hishizawa, Masakatsu; Itonaga, Hidehiro; Imaizumi, Yoshitaka; Munakata, Wataru; Ogasawara, Hideaki; Sato, Toshitaka; Sasai, Ken; Muramoto, Kenzo; Penova, Marina; Kawaguchi, Takahisa; Nakamura, Hiromi; Hama, Natsuko; Shide, Kotaro; Kubuki, Yoko; Hidaka, Tomonori; Kameda, Takuro; Nakamaki, Tsuyoshi; Ishiyama, Ken; Miyawaki, Shuichi; Yoon, Sung-Soo; Tobinai, Kensei; Miyazaki, Yasushi; Takaori-Kondo, Akifumi; Matsuda, Fumihiko; Takeuchi, Kengo; Nureki, Osamu; Aburatani, Hiroyuki; Watanabe, Toshiki; Shibata, Tatsuhiro; Matsuoka, Masao; Miyano, Satoru; Shimoda, Kazuya; Ogawa, Seishi

    2015-11-01

    Adult T cell leukemia/lymphoma (ATL) is a peripheral T cell neoplasm of largely unknown genetic basis, associated with human T cell leukemia virus type-1 (HTLV-1) infection. Here we describe an integrated molecular study in which we performed whole-genome, exome, transcriptome and targeted resequencing, as well as array-based copy number and methylation analyses, in a total of 426 ATL cases. The identified alterations overlap significantly with the HTLV-1 Tax interactome and are highly enriched for T cell receptor-NF-κB signaling, T cell trafficking and other T cell-related pathways as well as immunosurveillance. Other notable features include a predominance of activating mutations (in PLCG1, PRKCB, CARD11, VAV1, IRF4, FYN, CCR4 and CCR7) and gene fusions (CTLA4-CD28 and ICOS-CD28). We also discovered frequent intragenic deletions involving IKZF2, CARD11 and TP73 and mutations in GATA3, HNRNPA2B1, GPR183, CSNK2A1, CSNK2B and CSNK1A1. Our findings not only provide unique insights into key molecules in T cell signaling but will also guide the development of new diagnostics and therapeutics in this intractable tumor. PMID:26437031

  13. Survival of glucose phosphate isomerase null somatic cells and germ cells in adult mouse chimaeras.

    PubMed

    Keighren, Margaret A; Flockhart, Jean H; West, John D

    2016-05-15

    The mouse Gpi1 gene encodes the glycolytic enzyme glucose phosphate isomerase. Homozygous Gpi1(-/-) null mouse embryos die but a previous study showed that some homozygous Gpi1(-/-) null cells survived when combined with wild-type cells in fetal chimaeras. One adult female Gpi1(-/-)↔Gpi1(c/c) chimaera with functional Gpi1(-/-) null oocytes was also identified in a preliminary study. The aims were to characterise the survival of Gpi1(-/-) null cells in adult Gpi1(-/-)↔Gpi1(c/c) chimaeras and determine if Gpi1(-/-) null germ cells are functional. Analysis of adult Gpi1(-/-)↔Gpi1(c/c) chimaeras with pigment and a reiterated transgenic lineage marker showed that low numbers of homozygous Gpi1(-/-) null cells could survive in many tissues of adult chimaeras, including oocytes. Breeding experiments confirmed that Gpi1(-/-) null oocytes in one female Gpi1(-/-)↔Gpi1(c/c) chimaera were functional and provided preliminary evidence that one male putative Gpi1(-/-)↔Gpi1(c/c) chimaera produced functional spermatozoa from homozygous Gpi1(-/-) null germ cells. Although the male chimaera was almost certainly Gpi1(-/-)↔Gpi1(c/c), this part of the study is considered preliminary because only blood was typed for GPI. Gpi1(-/-) null germ cells should survive in a chimaeric testis if they are supported by wild-type Sertoli cells. It is also feasible that spermatozoa could bypass a block at GPI, but not blocks at some later steps in glycolysis, by using fructose, rather than glucose, as the substrate for glycolysis. Although chimaera analysis proved inefficient for studying the fate of Gpi1(-/-) null germ cells, it successfully identified functional Gpi1(-/-) null oocytes and revealed that some Gpi1(-/-) null cells could survive in many adult tissues.

  14. Mitochondrial DNA heteroplasmy in cloned cattle produced by fetal and adult cell cloning.

    PubMed

    Steinborn, R; Schinogl, P; Zakhartchenko, V; Achmann, R; Schernthaner, W; Stojkovic, M; Wolf, E; Müller, M; Brem, G

    2000-07-01

    Mammals have been cloned from adult donor cells. Here we report the first cases of mitochondrial DNA (mtDNA) heteroplasmy in adult mammalian clones generated from fetal and adult donor cells. The heteroplasmic clones included a healthy cattle equivalent of the sheep Dolly, for which a lack of heteroplasmy was reported.

  15. Mitochondrial DNA heteroplasmy in cloned cattle produced by fetal and adult cell cloning.

    PubMed

    Steinborn, R; Schinogl, P; Zakhartchenko, V; Achmann, R; Schernthaner, W; Stojkovic, M; Wolf, E; Müller, M; Brem, G

    2000-07-01

    Mammals have been cloned from adult donor cells. Here we report the first cases of mitochondrial DNA (mtDNA) heteroplasmy in adult mammalian clones generated from fetal and adult donor cells. The heteroplasmic clones included a healthy cattle equivalent of the sheep Dolly, for which a lack of heteroplasmy was reported. PMID:10888867

  16. Optimizing Management of Patients with Adult T Cell Leukemia-Lymphoma

    PubMed Central

    Yared, Jean A.; Kimball, Amy S.

    2015-01-01

    Adult T cell leukemia-lymphoma is a rare disease with a high mortality rate, and is challenging for the clinician. Early allogeneic stem cell transplant can confer durable remission. As novel therapeutic agents become available to treat T cell malignancies, it is increasingly important that medical oncologists, hematologists, and hematopathologists recognize and accurately diagnose adult T cell leukemia-lymphoma. There is no uniform standard of treatment of adult T cell leukemia-lymphoma, and clinical trials remain critical to improving outcomes. Here we present one management approach based on the recent advances in treatment for adult T cell leukemia-lymphoma patients. PMID:26610571

  17. Human germ cell differentiation from fetal- and adult-derived induced pluripotent stem cells

    PubMed Central

    Panula, Sarita; Medrano, Jose V.; Kee, Kehkooi; Bergström, Rosita; Nguyen, Ha Nam; Byers, Blake; Wilson, Kitchener D.; Wu, Joseph C.; Simon, Carlos; Hovatta, Outi; Reijo Pera, Renee A.

    2011-01-01

    Historically, our understanding of molecular genetic aspects of human germ cell development has been limited, at least in part due to inaccessibility of early stages of human development to experimentation. However, the derivation of pluripotent stem cells may provide the necessary human genetic system to study germ cell development. In this study, we compared the potential of human induced pluripotent stem cells (iPSCs), derived from adult and fetal somatic cells to form primordial and meiotic germ cells, relative to human embryonic stem cells. We found that ∼5% of human iPSCs differentiated to primordial germ cells (PGCs) following induction with bone morphogenetic proteins. Furthermore, we observed that PGCs expressed green fluorescent protein from a germ cell-specific reporter and were enriched for the expression of endogenous germ cell-specific proteins and mRNAs. In response to the overexpression of intrinsic regulators, we also observed that iPSCs formed meiotic cells with extensive synaptonemal complexes and post-meiotic haploid cells with a similar pattern of ACROSIN staining as observed in human spermatids. These results indicate that human iPSCs derived from reprogramming of adult somatic cells can form germline cells. This system may provide a useful model for molecular genetic studies of human germline formation and pathology and a novel platform for clinical studies and potential therapeutical applications. PMID:21131292

  18. Adult human adipose tissue contains several types of multipotent cells.

    PubMed

    Tallone, Tiziano; Realini, Claudio; Böhmler, Andreas; Kornfeld, Christopher; Vassalli, Giuseppe; Moccetti, Tiziano; Bardelli, Silvana; Soldati, Gianni

    2011-04-01

    Multipotent mesenchymal stromal cells (MSCs) are a type of adult stem cells that can be easily isolated from various tissues and expanded in vitro. Many reports on their pluripotency and possible clinical applications have raised hopes and interest in MSCs. In an attempt to unify the terminology and the criteria to label a cell as MSC, in 2006 the International Society for Cellular Therapy (ISCT) proposed a standard set of rules to define the identity of these cells. However, MSCs are still extracted from different tissues, by diverse isolation protocols, are cultured and expanded in different media and conditions. All these variables may have profound effects on the selection of cell types and the composition of heterogeneous subpopulations, on the selective expansion of specific cell populations with totally different potentials and ergo, on the long-term fate of the cells upon in vitro culture. Therefore, specific molecular and cellular markers that identify MSCs subsets as well as standardization of expansion protocols for these cells are urgently needed. Here, we briefly discuss new useful markers and recent data supporting the rapidly emerging concept that many different types of progenitor cells are found in close association with blood vessels. This knowledge may promote the necessary technical improvements required to reduce variability and promote higher efficacy and safety when isolating and expanding these cells for therapeutic use. In the light of the discussed data, particularly the identification of new markers, and advances in the understanding of fundamental MSC biology, we also suggest a revision of the 2006 ISCT criteria.

  19. S-adenosylmethionine levels regulate the schwann cell DNA methylome.

    PubMed

    Varela-Rey, Marta; Iruarrizaga-Lejarreta, Marta; Lozano, Juan José; Aransay, Ana María; Fernandez, Agustín F; Lavin, José Luis; Mósen-Ansorena, David; Berdasco, María; Turmaine, Marc; Luka, Zigmund; Wagner, Conrad; Lu, Shelly C; Esteller, Manel; Mirsky, Rhona; Jessen, Kristján R; Fraga, Mario F; Martínez-Chantar, María L; Mato, José M; Woodhoo, Ashwin

    2014-03-01

    Axonal myelination is essential for rapid saltatory impulse conduction in the nervous system, and malformation or destruction of myelin sheaths leads to motor and sensory disabilities. DNA methylation is an essential epigenetic modification during mammalian development, yet its role in myelination remains obscure. Here, using high-resolution methylome maps, we show that DNA methylation could play a key gene regulatory role in peripheral nerve myelination and that S-adenosylmethionine (SAMe), the principal methyl donor in cytosine methylation, regulates the methylome dynamics during this process. Our studies also point to a possible role of SAMe in establishing the aberrant DNA methylation patterns in a mouse model of diabetic neuropathy, implicating SAMe in the pathogenesis of this disease. These critical observations establish a link between SAMe and DNA methylation status in a defined biological system, providing a mechanism that could direct methylation changes during cellular differentiation and in diverse pathological situations. PMID:24607226

  20. S-adenosylmethionine levels regulate the Schwann cell DNA methylome

    PubMed Central

    Varela-Rey, Marta; Iruarrizaga-Lejarreta, Marta; Lozano, Juan José; Aransay, Ana María; Fernandez, Agustín F.; Lavin, José Luis; Mósen-Ansorena, David; Berdasco, María; Turmaine, Marc; Luka, Zigmund; Wagner, Conrad; Lu, Shelly C.; Esteller, Manel; Mirsky, Rhona; Jessen, Kristján R.; Fraga, Mario F.; Martínez-Chantar, María L.; Mato, José M.; Woodhoo, Ashwin

    2014-01-01

    SUMMARY Axonal myelination is essential for rapid saltatory impulse conduction in the nervous system, and malformation or destruction of myelin sheaths leads to motor and sensory disabilities. DNA methylation is an essential epigenetic modification during mammalian development, yet its role in myelination remains obscure. Here, using high-resolution methylome maps, we show that DNA methylation could play a key gene regulatory role in peripheral nerve myelination and that S-adenosylmethionine (SAMe), the principal methyl donor in cytosine methylation, regulates the methylome dynamics during this process. Our studies also point to a possible role of SAMe in establishing the aberrant DNA methylation patterns in a mouse model of diabetic neuropathy, implicating SAMe in the pathogenesis of this disease. These critical observations establish a link between SAMe and DNA methylation status in a defined biological system, and provides a novel mechanism that could direct methylation changes during cellular differentiation and in diverse pathological situations. PMID:24607226

  1. Microarray analysis of gene expression in adult retinal ganglion cells.

    PubMed

    Ivanov, Dmitry; Dvoriantchikova, Galina; Nathanson, Lubov; McKinnon, Stuart J; Shestopalov, Valery I

    2006-01-01

    Retinal ganglion cells (RGCs) transfer visual information to the brain and are known to be susceptible to selective degeneration in various neuropathies such as glaucoma. This selective vulnerability suggests that these highly specialized neurons possess a distinct gene expression profile that becomes altered by neuropathy-associated stresses, which lead to the RGC death. In this study, to identify genes expressed predominantly in adult RGCs, a global transcriptional profile of purified primary RGCs has been compared to that of the whole retina. To avoid alterations of the original gene expression profile by cell culture conditions, we isolated RNA directly from adult RGCs purified by immunopanning without prior sub-cultivation. Genes expressed predominantly in RGCs included: Nrg1, Rgn, 14-3-3 family (Ywhah, Ywhaz, Ywhab), Nrn1, Gap43, Vsnl1, Rgs4. Some of these genes may serve as novel markers for these neurons. Our analysis revealed enrichment in genes controlling the pro-survival pathways in RGCs as compared to other retinal cells. PMID:16376886

  2. Chronic ethanol consumption transiently reduces adult neural progenitor cell proliferation.

    PubMed

    Rice, Ann C; Bullock, M Ross; Shelton, Keith L

    2004-06-11

    Adult neural stem/progenitor cells proliferate throughout the life of the animal in the subependymal zone and the subgranular zone of the dentate gyrus (DG). Treatments such as enriched environment, dietary restriction, running and anti-depressants increase proliferation, however, stress and opiates have been shown to decrease proliferation. While models of binge ethanol drinking decreases proliferation, few studies have characterized the effect chronic ethanol usage has on progenitor cell proliferation. In this study, we have examined changes in the progenitor cell proliferation rate following chronic ethanol consumption. Animals were given a nutritionally balanced liquid diet containing 6.5% v/v ethanol or an isocalorically balanced liquid diet. Bromodeoxyuridine (BrdU) was administered (150 mg/kg x 3) and the animals sacrificed 2 h after the last injection on days 3, 10 or 30 of the ethanol diet. Coronal brain blocks were paraffin embedded and 6 microm sections sliced and immunohistochemically stained for BrdU. Quantitation of the number of BrdU-labeled cells in the subgranular zone of the DG revealed a significant decrease only at the 3-day time-point, with recovery by the 10- and 30-day time-points. Thus, the progenitor cell proliferation rate is transiently decreased by chronic ethanol usage. This data suggests that chronic alcohol use results in a compensatory response that restores the progenitor cell proliferation rate.

  3. The simplest method for in vitro β-cell production from human adult stem cells.

    PubMed

    Bhandari, Dilli Ram; Seo, Kwang-Won; Sun, Bo; Seo, Min-Soo; Kim, Hyung-Sik; Seo, Yoo-Jin; Marcin, Jurga; Forraz, Nicolas; Roy, Helene Le; Larry, Denner; Colin, McGuckin; Kang, Kyung-Sun

    2011-10-01

    Diabetes mellitus is a challenging autoimmune disease. Biomedical researchers are currently exploring efficient and effective ways to solve this challenge. The potential of stem cell therapies for treating diabetes represents one of the major focuses of current research on diabetes treatment. Here, we have attempted to differentiate adult stem cells from umbilical cord blood-derived mesenchymal cells (UCB-MSC), Wharton's jelly-derived mesenchymal stem cells (WJ-MSC) and amniotic epithelial stem cells (AE-SC) into insulin-producing cells. The serum-free protocol developed in this study resulted in the differentiation of cells into definitive endoderm, pancreatic foregut, pancreatic endoderm and, finally, pancreatic endocrine cells, which expressed the marker genes SOX17, PDX1, NGN3, NKX6.1, INS, GCG, and PPY, respectively. Detection of the expression of the gap junction-related gene connexin-36 (CX36) using RT-PCR provided conclusive evidence for insulin-producing cell differentiation. In addition to this RT-PCR result, insulin and C-peptide protein were detected by immunohistochemistry and ELISA. Glucose stimulation test results showed that significantly greater amounts of C-peptide and insulin were released from differentiated cells than from undifferentiated cells. In conclusion, the methods investigated in this study can be considered an effective and efficient means of obtaining insulin-producing cells from adult stem cells within a week.

  4. Telomere-to-centromere ratio of bovine clones, embryos, gametes, fetal cells, and adult cells.

    PubMed

    Meerdo, Lora N; Reed, William A; White, Kenneth L

    2005-01-01

    In 1997, Dolly, the first animal cloned from an adult cell, was born. It was announced in 1999 that Dolly might be aging faster than normal because her telomeres were shorter than age-matched control sheep. Telomeres, a repeated DNA sequence located at the ends of linear chromosomes, allow for base pair loss during DNA replication. Telomere shortening acts as a "mitotic clock," leading to replicative senescence. By using whole cell lysate and slot-blot analysis, we determined the telomere-to-centromere ratio (T/C) for bovine gametes, embryos, fetal tissues (brain, heart, lung, kidney, uterus, ovary, and skin), adult donor cells, and cloned embryos. Our data indicates a consistency in T/C among the various fetal tissues. The T/C of sperm is significantly lower than in oocytes. The T/C decreases from the oocyte to the 2-8-cell stage embryo, increases dramatically at the morula stage, and decreases at the blastocyst stage. Our data shows no significant difference in T/C between cloned embryos and in vitro fertilized (IVF) embryos, but there is a significant difference between cloned embryos and adult donor cells. In conclusion, the enucleated bovine oocyte has the ability to reestablish the telomere length of adult somatic cell donor nuclei. PMID:15996118

  5. Development of Adult-Generated Cell Connectivity with Excitatory and Inhibitory Cell Populations in the Hippocampus.

    PubMed

    Restivo, Leonardo; Niibori, Yosuke; Mercaldo, Valentina; Josselyn, Sheena A; Frankland, Paul W

    2015-07-22

    New neurons are generated continuously in the subgranular zone of the hippocampus and integrate into existing hippocampal circuits throughout adulthood. Although the addition of these new neurons may facilitate the formation of new memories, as they integrate, they provide additional excitatory drive to CA3 pyramidal neurons. During development, to maintain homeostasis, new neurons form preferential contacts with local inhibitory circuits. Using retroviral and transgenic approaches to label adult-generated granule cells, we first asked whether a comparable process occurs in the adult hippocampus in mice. Similar to development, we found that, during adulthood, new neurons form connections with inhibitory cells in the dentate gyrus, hilus, and CA3 regions as they integrate into hippocampal circuits. In particular, en passant bouton and filopodia connections with CA3 interneurons peak when adult-generated dentate granule cells (DGCs) are ∼4 weeks of age, a time point when these cells are most excitable. Consistent with this, optical stimulation of 4-week-old (but not 6- or 8-week-old) adult-generated DGCs strongly activated CA3 interneurons. Finally, we found that CA3 interneurons were activated robustly during learning and that their activity was strongly coupled with activity of 4-week-old (but not older) adult-generated DGCs. These data indicate that, as adult-generated neurons integrate into hippocampal circuits, they transiently form strong anatomical, effective, and functional connections with local inhibitory circuits in CA3. Significance statement: New neurons are generated continuously in the subgranular zone of the hippocampus and integrate into existing hippocampal circuits throughout adulthood. Understanding how these cells integrate within well formed circuits will increase our knowledge about the basic principles governing circuit assembly in the adult hippocampus. This study uses a combined connectivity analysis (anatomical, functional, and effective

  6. Conditionally reprogrammed cells represent a stem-like state of adult epithelial cells

    PubMed Central

    Suprynowicz, Frank A.; Upadhyay, Geeta; Krawczyk, Ewa; Kramer, Sarah C.; Hebert, Jess D.; Liu, Xuefeng; Yuan, Hang; Cheluvaraju, Chaitra; Clapp, Phillip W.; Boucher, Richard C.; Kamonjoh, Christopher M.; Randell, Scott H.; Schlegel, Richard

    2012-01-01

    The combination of irradiated fibroblast feeder cells and Rho kinase inhibitor, Y-27632, conditionally induces an indefinite proliferative state in primary mammalian epithelial cells. These conditionally reprogrammed cells (CRCs) are karyotype-stable and nontumorigenic. Because self-renewal is a recognized property of stem cells, we investigated whether Y-27632 and feeder cells induced a stem-like phenotype. We found that CRCs share characteristics of adult stem cells and exhibit up-regulated expression of α6 and β1 integrins, ΔNp63α, CD44, and telomerase reverse transcriptase, as well as decreased Notch signaling and an increased level of nuclear β-catenin. The induction of CRCs is rapid (occurs within 2 d) and results from reprogramming of the entire cell population rather than the selection of a minor subpopulation. CRCs do not overexpress the transcription factor sets characteristic of embryonic or induced pluripotent stem cells (e.g., Sox2, Oct4, Nanog, or Klf4). The induction of CRCs is also reversible, and removal of Y-27632 and feeders allows the cells to differentiate normally. Thus, when CRCs from ectocervical epithelium or tracheal epithelium are placed in an air–liquid interface culture system, the cervical cells form a well differentiated stratified squamous epithelium, whereas the tracheal cells form a ciliated airway epithelium. We discuss the diagnostic and therapeutic opportunities afforded by a method that can generate adult stem-like cells in vitro without genetic manipulation. PMID:23169653

  7. Sox2-mediated regulation of adult neural crest precursors and skin repair.

    PubMed

    Johnston, Adam P W; Naska, Sibel; Jones, Karen; Jinno, Hiroyuki; Kaplan, David R; Miller, Freda D

    2013-01-01

    Nerve-derived neural crest cells are essential for regeneration in certain animals, such as newts. Here, we asked whether they play a similar role during mammalian tissue repair, focusing on Sox2-positive neural crest precursors in skin. In adult skin, Sox2 was expressed in nerve-terminal-associated neural crest precursor cells (NCPCs) around the hair follicle bulge, and following injury was induced in nerve-derived cells, likely dedifferentiated Schwann cell precursors. At later times postinjury, Sox2-positive cells were scattered throughout the regenerating dermis, and lineage tracing showed that these were all neural-crest-derived NCPCs. These Sox2-positive NCPCs were functionally important, since acute deletion of Sox2 prior to injury caused a decrease of NCPCs in the wound and aberrant skin repair. These data demonstrate that Sox2 regulates skin repair, likely by controlling NCPCs, and raise the possibility that nerve-derived NCPCs may play a general role in mammalian tissue repair.

  8. Comparison of immune response to nerve allograft segments in fetal and adult rabbits: a histological study.

    PubMed

    Ağaoğlu, G; Kayikçioğlu, A; Sargon, M; Erk, Y; Mavili, E

    2000-04-01

    Fetuses, as opposed to adults, are immature immunologically and it has been proved that they can tolerate allograft materials much better than adults. In this study the rejection phenomenon of nerve allografts was compared histologically in fetuses and adults. The study was performed in 60 New Zealand rabbits (30 pregnant and 30 nonpregnant), and allograft nerve segments were obtained from Chinchilla rabbits. The animals were divided into fetal and adult groups. Each group was studied at various time periods. Nerve allografts were placed under the panniculus carnosus in the interscapular region of the fetuses and adults. In both fetal and adult groups, the nerve allograft segments were assessed histologically after 1, 7, and 30 days. The criteria used during the evaluation were the degenerative findings in the myelinated axons (large, medium, and small axons), changes in Schwann's cells, and the quantity of infiltrating cells. The changes were graded microscopically from 0 (no change) to 3 (severe destruction and cellular infiltration). Cellular infiltration was more extensive in the adult groups than in the fetal groups. Earlier fetal groups showed minimal infiltration, but the response became more extensive in the later fetal groups. This is probably related to the removal of the fetuses from their intrauterine environment. When comparing fetal and adult groups, the results were significant (p < 0.05). The fetuses tolerated the nerve allograft segments better than the adults. This may be related to the immature immune system of the fetuses.

  9. Adult somatic stem cells in the human parasite, Schistosoma mansoni

    PubMed Central

    Collins, James J.; Wang, Bo; Lambrus, Bramwell G.; Tharp, Marla; Iyer, Harini; Newmark, Phillip A.

    2013-01-01

    Summary Schistosomiasis is among the most prevalent human parasitic diseases, affecting more than 200 million people worldwide1. The etiological agents of this disease are trematode flatworms (Schistosoma) that live and lay eggs within the vasculature of the host. These eggs lodge in host tissues, causing inflammatory responses that are the primary cause of morbidity. Because these parasites can live and reproduce within human hosts for decades2, elucidating the mechanisms that promote their longevity is of fundamental importance. Although adult pluripotent stem cells, called neoblasts, drive long-term homeostatic tissue maintenance in long-lived free-living flatworms3,4 (e.g., planarians), and neoblast-like cells have been described in some parasitic tapeworms5, little is known about whether similar cell types exist in any trematode species. Here, we describe a population of neoblast-like cells in the trematode Schistosoma mansoni. These cells resemble planarian neoblasts morphologically and share their ability to proliferate and differentiate into derivatives of multiple germ layers. Capitalizing on available genomic resources6,7 and RNAseq-based gene expression profiling, we find that these schistosome neoblast-like cells express a fibroblast growth factor receptor ortholog. Using RNA interference we demonstrate that this gene is required for the maintenance of these neoblast-like cells. Our observations suggest that adaptation of developmental strategies shared by free-living ancestors to modern-day schistosomes likely contributed to the success of these animals as long-lived obligate parasites. We expect that future studies deciphering the function of these neoblast-like cells will have important implications for understanding the biology of these devastating parasites. PMID:23426263

  10. Regenerative capacity of adult cortical thymic epithelial cells.

    PubMed

    Rode, Immanuel; Boehm, Thomas

    2012-02-28

    Involution of the thymus is accompanied by a decline in the number of thymic epithelial cells (TECs) and a severely restricted peripheral repertoire of T-cell specificities. TECs are essential for T-cell differentiation; they originate from a bipotent progenitor that gives rise to cells of cortical (cTEC) and medullary (mTEC) phenotypes, via compartment-specific progenitors. Upon acute selective near-total ablation during embryogenesis, regeneration of TECs fails, suggesting that losses from the pool of TEC progenitors are not compensated. However, it is unclear whether this is also true for the compartment-specific progenitors. The decline of cTECs is a prominent feature of thymic involution. Because cTECs support early stages of T-cell development and hence determine the overall lymphopoietic capacity of the thymus, it is possible that the lack of sustained regenerative capacity of cTEC progenitor cells underlies the process of thymic involution. Here, we examine this hypothesis by cell-type-specific conditional ablation of cTECs. Expression of the human diphtheria toxin receptor (hDTR) gene under the regulatory influence of the chemokine receptor Ccx-ckr1 gene renders cTECs sensitive to the cytotoxic effects of diphtheria toxin (DT). As expected, DT treatment of preadolescent and adult mice led to a dramatic loss of cTECs, accompanied by a rapid demise of immature thymocytes. Unexpectedly, however, the cTEC compartment regenerated after cessation of treatment, accompanied by the restoration of T-cell development. These findings provide the basis for the development of targeted interventions unlocking the latent regenerative potential of cTECs to counter thymic involution.

  11. Abnormal Pulmonary Function in Adults with Sickle Cell Anemia

    PubMed Central

    Klings, Elizabeth S.; Wyszynski, Diego F.; Nolan, Vikki G.; Steinberg, Martin H.

    2006-01-01

    Rationale: Pulmonary complications of sickle cell anemia (Hb-SS) commonly cause morbidity, yet few large studies of pulmonary function tests (PFTs) in this population have been reported. Objectives: PFTs (spirometry, lung volumes, and diffusion capacity for carbon monoxide [DLCO]) from 310 adults with Hb-SS were analyzed to determine the pattern of pulmonary dysfunction and their association with other systemic complications of sickle cell disease. Methods: Raw PFT data were compared with predicted values. Each subject was subclassified into one of five groups: obstructive physiology, restrictive physiology, mixed obstructive/restrictive physiology, isolated low DLCO, or normal. The association between laboratory data of patients with decreased DLCO or restrictive physiology and those of normal subjects was assessed by multivariate linear regression. Measurements and Main Results: Normal PFTs were present in only 31 of 310 (10%) patients. Overall, adults with Hb-SS were characterized by decreased total lung capacities (70.2 ± 14.7% predicted) and DlCO (64.5 ± 19.9%). The most common PFT patterns were restrictive physiology (74%) and isolated low DlCO (13%). Decreased DLCO was associated with thrombocytosis (p = 0.05), with hepatic dysfunction (elevated alanine aminotransferase; p = 0.07), and a trend toward renal dysfunction (elevated blood urea nitrogen and creatinine; p = 0.05 and 0.07, respectively). Conclusions: Pulmonary function is abnormal in 90% of adult patients with Hb-SS. Common abnormalities include restrictive physiology and decreased DLCO. Decreased DLCO may indicate more severe sickle vasculopathy characterized by impaired hepatic and renal function. PMID:16556694

  12. Contribution of Bone Marrow Hematopoietic Stem Cells to Adult Mouse Inner Ear: Mesenchymal Cells and Fibrocytes

    PubMed Central

    Lang, Hainan; Ebihara, Yasuhiro; Schmiedt, Richard A.; Minamiguchi, Hitoshi; Zhou, Daohong; Smythe, Nancy; Liu, Liya; Ogawa, Makio; Schulte, Bradley A.

    2008-01-01

    Bone marrow (BM)-derived stem cells have shown plasticity with a capacity to differentiate into a variety of specialized cells. To test the hypothesis that some cells in the inner ear are derived from BM, we transplanted either isolated whole BM cells or clonally expanded hematopoietic stem cells (HSCs) prepared from transgenic mice expressing enhanced green fluorescent protein (EGFP) into irradiated adult mice. Isolated GFP+ BM cells also were transplanted into conditioned newborn mice derived from pregnant mice injected with busulfan (which ablates HSCs in the newborns). Quantification of GFP+ cells was performed 3-20 months after transplant. GFP+ cells were found in the inner ear with all transplant conditions. They were most abundant within the spiral ligament but were also found in other locations normally occupied by fibrocytes and mesenchymal cells. No GFP+ neurons or hair cells were observed in inner ears of transplanted mice. Dual immunofluorescence assays demonstrated that most of the GFP+ cells were negative for CD45, a macrophage and hematopoietic cell marker. A portion of the GFP+ cells in the spiral ligament expressed immunoreactive Na, K-ATPase or the Na-K-Cl transporter (NKCC), proteins used as markers for specialized ion transport fibrocytes. Phenotypic studies indicated that the GFP+ cells did not arise from fusion of donor cells with endogenous cells. This study provides the first evidence for the origin of inner ear cells from BM and more specifically from HSCs. The results suggest that mesenchymal cells, including fibrocytes in the adult inner ear, may be derived continuously from HSCs. PMID:16538683

  13. Adult mesenchymal stem cells for tissue engineering versus regenerative medicine.

    PubMed

    Caplan, Arnold I

    2007-11-01

    Adult mesenchymal stem cells (MSCs) can be isolated from bone marrow or marrow aspirates and because they are culture-dish adherent, they can be expanded in culture while maintaining their multipotency. The MSCs have been used in preclinical models for tissue engineering of bone, cartilage, muscle, marrow stroma, tendon, fat, and other connective tissues. These tissue-engineered materials show considerable promise for use in rebuilding damaged or diseased mesenchymal tissues. Unanticipated is the realization that the MSCs secrete a large spectrum of bioactive molecules. These molecules are immunosuppressive, especially for T-cells and, thus, allogeneic MSCs can be considered for therapeutic use. In this context, the secreted bioactive molecules provide a regenerative microenvironment for a variety of injured adult tissues to limit the area of damage and to mount a self-regulated regenerative response. This regenerative microenvironment is referred to as trophic activity and, therefore, MSCs appear to be valuable mediators for tissue repair and regeneration. The natural titers of MSCs that are drawn to sites of tissue injury can be augmented by allogeneic MSCs delivered via the bloodstream. Indeed, human clinical trials are now under way to use allogeneic MSCs for treatment of myocardial infarcts, graft-versus-host disease, Crohn's Disease, cartilage and meniscus repair, stroke, and spinal cord injury. This review summarizes the biological basis for the in vivo functioning of MSCs through development and aging. PMID:17620285

  14. Evidence for a Notch1-mediated transition during olfactory ensheathing cell development.

    PubMed

    Miller, Sophie R; Perera, Surangi N; Benito, Cristina; Stott, Simon R W; Baker, Clare V H

    2016-09-01

    Olfactory ensheathing cells (OECs) are a unique glial population found in both the peripheral and central nervous system: they ensheath bundles of unmyelinated olfactory axons from their peripheral origin in the olfactory epithelium to their central synaptic targets in the glomerular layer of the olfactory bulb. Like all other peripheral glia (Schwann cells, satellite glia, enteric glia), OECs are derived from the embryonic neural crest. However, in contrast to Schwann cells, whose development has been extensively characterised, relatively little is known about their normal development in vivo. In the Schwann cell lineage, the transition from multipotent Schwann cell precursor to immature Schwann cell is promoted by canonical Notch signalling. Here, in situ hybridisation and immunohistochemistry data from chicken, mouse and human embryos are presented that suggest a canonical Notch-mediated transition also occurs during OEC development. PMID:27271278

  15. Multipotent adult progenitor cells on an allograft scaffold facilitate the bone repair process

    PubMed Central

    LoGuidice, Amanda; Houlihan, Alison; Deans, Robert

    2016-01-01

    Multipotent adult progenitor cells are a recently described population of stem cells derived from the bone marrow stroma. Research has demonstrated the potential of multipotent adult progenitor cells for treating ischemic injury and cardiovascular repair; however, understanding of multipotent adult progenitor cells in orthopedic applications remains limited. In this study, we evaluate the osteogenic and angiogenic capacity of multipotent adult progenitor cells, both in vitro and loaded onto demineralized bone matrix in vivo, with comparison to mesenchymal stem cells, as the current standard. When compared to mesenchymal stem cells, multipotent adult progenitor cells exhibited a more robust angiogenic protein release profile in vitro and developed more extensive vasculature within 2 weeks in vivo. The establishment of this vascular network is critical to the ossification process, as it allows nutrient exchange and provides an influx of osteoprogenitor cells to the wound site. In vitro assays confirmed the multipotency of multipotent adult progenitor cells along mesodermal lineages and demonstrated the enhanced expression of alkaline phosphatase and production of calcium-containing mineral deposits by multipotent adult progenitor cells, necessary precursors for osteogenesis. In combination with a demineralized bone matrix scaffold, multipotent adult progenitor cells demonstrated enhanced revascularization and new bone formation in vivo in an orthotopic defect model when compared to mesenchymal stem cells on demineralized bone matrix or demineralized bone matrix–only control groups. The potent combination of angiogenic and osteogenic properties provided by multipotent adult progenitor cells appears to create a synergistic amplification of the bone healing process. Our results indicate that multipotent adult progenitor cells have the potential to better promote tissue regeneration and healing and to be a functional cell source for use in orthopedic applications

  16. Multipotent adult progenitor cells on an allograft scaffold facilitate the bone repair process.

    PubMed

    LoGuidice, Amanda; Houlihan, Alison; Deans, Robert

    2016-01-01

    Multipotent adult progenitor cells are a recently described population of stem cells derived from the bone marrow stroma. Research has demonstrated the potential of multipotent adult progenitor cells for treating ischemic injury and cardiovascular repair; however, understanding of multipotent adult progenitor cells in orthopedic applications remains limited. In this study, we evaluate the osteogenic and angiogenic capacity of multipotent adult progenitor cells, both in vitro and loaded onto demineralized bone matrix in vivo, with comparison to mesenchymal stem cells, as the current standard. When compared to mesenchymal stem cells, multipotent adult progenitor cells exhibited a more robust angiogenic protein release profile in vitro and developed more extensive vasculature within 2 weeks in vivo. The establishment of this vascular network is critical to the ossification process, as it allows nutrient exchange and provides an influx of osteoprogenitor cells to the wound site. In vitro assays confirmed the multipotency of multipotent adult progenitor cells along mesodermal lineages and demonstrated the enhanced expression of alkaline phosphatase and production of calcium-containing mineral deposits by multipotent adult progenitor cells, necessary precursors for osteogenesis. In combination with a demineralized bone matrix scaffold, multipotent adult progenitor cells demonstrated enhanced revascularization and new bone formation in vivo in an orthotopic defect model when compared to mesenchymal stem cells on demineralized bone matrix or demineralized bone matrix-only control groups. The potent combination of angiogenic and osteogenic properties provided by multipotent adult progenitor cells appears to create a synergistic amplification of the bone healing process. Our results indicate that multipotent adult progenitor cells have the potential to better promote tissue regeneration and healing and to be a functional cell source for use in orthopedic applications. PMID

  17. Pluripotency of adult stem cells derived from human and rat pancreas

    NASA Astrophysics Data System (ADS)

    Kruse, C.; Birth, M.; Rohwedel, J.; Assmuth, K.; Goepel, A.; Wedel, T.

    Adult stem cells are undifferentiated cells found within fully developed tissues or organs of an adult individuum. Until recently, these cells have been considered to bear less self-renewal ability and differentiation potency compared to embryonic stem cells. In recent studies an undifferentiated cell type was found in primary cultures of isolated acini from exocrine pancreas termed pancreatic stellate cells. Here we show that pancreatic stellate-like cells have the capacity of extended self-renewal and are able to differentiate spontaneously into cell types of all three germ layers expressing markers for smooth muscle cells, neurons, glial cells, epithelial cells, chondrocytes and secretory cells (insulin, amylase). Differentiation and subsequent formation of three-dimensional cellular aggregates (organoid bodies) were induced by merely culturing pancreatic stellate-like cells in hanging drops. These cells were developed into stable, long-term, in vitro cultures of both primary undifferentiated cell lines as well as organoid cultures. Thus, evidence is given that cell lineages of endodermal, mesodermal, and ectodermal origin arise spontaneously from a single adult undifferentiated cell type. Based on the present findings it is assumed that pancreatic stellate-like cells are a new class of lineage uncommitted pluripotent adult stem cells with a remarkable self-renewal ability and differentiation potency. The data emphasize the versatility of adult stem cells and may lead to a reappraisal of their use for the treatment of inherited disorders or acquired degenerative diseases.

  18. Adult bone marrow: which stem cells for cellular therapy protocols in neurodegenerative disorders?

    PubMed

    Wislet-Gendebien, Sabine; Laudet, Emerence; Neirinckx, Virginie; Rogister, Bernard

    2012-01-01

    The generation of neuronal cells from stem cells obtained from adult bone marrow is of significant clinical interest in order to design new cell therapy protocols for several neurological disorders. The recent identification in adult bone marrow of stem cells derived from the neural crests (NCSCs) might explain the neuronal phenotypic plasticity shown by bone marrow cells. However, little information is available about the nature of these cells compared to mesenchymal stem cells (MSCs). In this paper, we will review all information available concerning NCSC from adult tissues and their possible use in regenerative medicine. Moreover, as multiple recent studies showed the beneficial effect of bone marrow stromal cells in neurodegenerative diseases, we will discuss which stem cells isolated from adult bone marrow should be more suitable for cell replacement therapy.

  19. Cells from the adult corneal stroma can be reprogrammed to a neuron-like cell using exogenous growth factors

    SciTech Connect

    Greene, Carol Ann Chang, Chuan-Yuan; Fraser, Cameron J.; Nelidova, Dasha E.; Chen, Jing A.; Lim, Angela; Brebner, Alex; McGhee, Jennifer; Sherwin, Trevor; Green, Colin R.

    2014-03-10

    Cells thought to be stem cells isolated from the cornea of the eye have been shown to exhibit neurogenic potential. We set out to uncover the identity and location of these cells within the cornea and to elucidate their neuronal protein and gene expression profile during the process of switching to a neuron-like cell. Here we report that every cell of the adult human and rat corneal stroma is capable of differentiating into a neuron-like cell when treated with neurogenic differentiation specifying growth factors. Furthermore, the expression of genes regulating neurogenesis and mature neuronal structure and function was increased. The switch from a corneal stromal cell to a neuron-like cell was also shown to occur in vivo in intact corneas of living rats. Our results clearly indicate that lineage specifying growth factors can affect changes in the protein and gene expression profiles of adult cells, suggesting that possibly many adult cell populations can be made to switch into another type of mature cell by simply modifying the growth factor environment. - Highlights: • Adult corneal stromal cells can differentiated into neuron-like cells. • Neuronal specification of the adult stromal cell population is stochastic. • Neuronal specification in an adult cell population can be brought about by growth factors.

  20. Label-Retaining Cells in the Adult Murine Salivary Glands Possess Characteristics of Adult Progenitor Cells

    PubMed Central

    Chibly, Alejandro M.; Querin, Lauren; Harris, Zoey; Limesand, Kirsten H.

    2014-01-01

    Radiotherapy is the primary treatment for patients with head and neck cancer, which account for roughly 500,000 annual cases worldwide. Dysfunction of the salivary glands and associated conditions like xerostomia and dysphagia are often developed by these patients, greatly diminishing their life quality. Current preventative and palliative care fail to deliver an improvement in the quality of life, thus accentuating the need for regenerative therapies. In this study, a model of label retaining cells (LRCs) in murine salivary glands was developed, in which LRCs demonstrated proliferative potential and possessed markers of putative salivary progenitors. Mice were labeled with 5-Ethynyl-2′-deoxyuridine (EdU) at postnatal day 10 and chased for 8 weeks. Tissue sections from salivary glands obtained at the end of chase demonstrated co-localization between LRCs and the salivary progenitor markers keratin 5 and keratin 14, as well as kit mRNA, indicating that LRCs encompass a heterogeneous population of salivary progenitors. Proliferative potential of LRCs was demonstrated by a sphere assay, in which LRCs were found in primary and secondary spheres and they co-localized with the proliferation marker Ki67 throughout sphere formation. Surprisingly, LRCs were shown to be radio-resistant and evade apoptosis following radiation treatment. The clinical significance of these findings lie in the potential of this model to study the mechanisms that prevent salivary progenitors from maintaining homeostasis upon exposure to radiation, which will in turn facilitate the development of regenerative therapies for salivary gland dysfunction. PMID:25238060

  1. Label-retaining cells in the adult murine salivary glands possess characteristics of adult progenitor cells.

    PubMed

    Chibly, Alejandro M; Querin, Lauren; Harris, Zoey; Limesand, Kirsten H

    2014-01-01

    Radiotherapy is the primary treatment for patients with head and neck cancer, which account for roughly 500,000 annual cases worldwide. Dysfunction of the salivary glands and associated conditions like xerostomia and dysphagia are often developed by these patients, greatly diminishing their life quality. Current preventative and palliative care fail to deliver an improvement in the quality of life, thus accentuating the need for regenerative therapies. In this study, a model of label retaining cells (LRCs) in murine salivary glands was developed, in which LRCs demonstrated proliferative potential and possessed markers of putative salivary progenitors. Mice were labeled with 5-Ethynyl-2'-deoxyuridine (EdU) at postnatal day 10 and chased for 8 weeks. Tissue sections from salivary glands obtained at the end of chase demonstrated co-localization between LRCs and the salivary progenitor markers keratin 5 and keratin 14, as well as kit mRNA, indicating that LRCs encompass a heterogeneous population of salivary progenitors. Proliferative potential of LRCs was demonstrated by a sphere assay, in which LRCs were found in primary and secondary spheres and they co-localized with the proliferation marker Ki67 throughout sphere formation. Surprisingly, LRCs were shown to be radio-resistant and evade apoptosis following radiation treatment. The clinical significance of these findings lie in the potential of this model to study the mechanisms that prevent salivary progenitors from maintaining homeostasis upon exposure to radiation, which will in turn facilitate the development of regenerative therapies for salivary gland dysfunction.

  2. Adult T-Cell Leukemia: A Review of Epidemiological Evidence

    PubMed Central

    Iwanaga, Masako; Watanabe, Toshiki; Yamaguchi, Kazunari

    2012-01-01

    Adult T-cell leukemia (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type I (HTLV-1) infection and often occurs in HTLV-1-endemic areas, such as southwestern Japan, the Caribbean islands, Central and South America, Intertropical Africa, and Middle East. To date, many epidemiological studies have been conducted to investigate the incidence of ATL among general population or HTLV-1 carriers and to identify a variety of laboratory, molecular, and host-specific markers to be possible predictive factors for developing ATL because HTLV-1 infection alone is not sufficient to develop ATL. This literature review focuses on the epidemiology of ATL and the risk factors for the development of ATL from HTLV-1 carriers, while keeping information on the epidemiology of HTLV-1 to a minimum. The main lines of epidemiological evidence are: (1) ATL occurs mostly in adults, at least 20–30 years after the HTLV-1 infection, (2) age at onset differs across geographic areas: the average age in the Central and South America (around 40 years old) is younger than that in Japan (around 60 years old), (3) ATL occurs in those infected in childhood, but seldom occurs in those infected in adulthood, (4) male carriers have about a three- to fivefold higher risk of developing ATL than female, (5) the estimated lifetime risk of developing ATL in HTLV-1 carriers is 6–7% for men and 2–3% for women in Japan, (6) a low anti-Tax reactivity, a high soluble interleukin-2 receptor level, a high anti-HTLV-1 titer, and high levels of circulating abnormal lymphocytes and white blood cell count are accepted risk factors for the development of ATL, and (7) a higher proviral load (more than 4 copies/100 peripheral blood mononuclear cells) is an independent risk factor for progression of ATL. Nevertheless, the current epidemiological evidence is insufficient to fully understand the oncogenesis of ATL. Further well-designed epidemiological studies are needed. PMID

  3. Topography of Purkinje cells and other calbindin-immunoreactive cells within adult and hatchling turtle cerebellum.

    PubMed

    Ariel, Michael; Ward, Kyle C; Tolbert, Daniel L

    2009-12-01

    The turtle's cerebellum (Cb) is an unfoliated sheet, so the topography of its entire cortex can be easily studied physiologically by optical recordings. However, unlike the mammalian Cb, little is known about the topography of turtle Purkinje cells (PCs). Here, topography was examined using calbindin-D(28K) immunohistochemistry of adult and hatchling turtles (Trachemys scripta elegans, 2.5-15 cm carapace length). Each Cb was flattened between two Sylgard sheets and fixed in paraformaldehyde. Sections (52 microm thick) were cut parallel to the flattened cortex (tangential), resulting in calbindin-immunolabeled PCs being localized to three to six sections for each turtle. PC position and size were quantified using Neurolucida Image Analysis system. Although hatchling Cb were medial-laterally narrower (3.0 vs. 6.5 mm) and rostral-caudally shorter (2.5 vs. 5.5 mm) than adult Cb, both averaged near 15,000 PCs distributed uniformly. Hatchling PCs were smaller than adult PCs (178 vs. 551 microm(2)) and more densely packed (2,180 vs. 625 cells/mm(2)). Calbindin immunoreactivity also labeled non-PCs along the Cb's marginal rim and its caudal pole. Many of these were very small (22.9 microm(2)) ovoid-shaped cells clustered together, possibly proliferating external granule layer cells. Other labeled cells were larger and fusiform-shaped (12.6 x 33.4 microm) adjacent to inner granule cells along the marginal rim, suggestive of migrating cells. It is not known whether these are new neurons being generated within the adult and hatchling Cb and if they connect to efferent and afferent paths. Based on these anatomical findings, we suggest that unique physiological features may exist along the rim of the turtle Cb.

  4. Molecular Pathology of Adult T-Cell Leukemia/Lymphoma.

    PubMed

    Ohshima, Koichi

    2015-01-01

    Adult T-cell leukemia/lymphoma (ATLL) is a peripheral T-cell neoplasm of highly pleomorphic lymphoid cells. ATLL is usually widely disseminated, and it is caused by human T-cell leukemia virus type 1 (HTLV-1). It is a disease with a long latency, and affected individuals are usually exposed to the virus very early in life. The cumulative incidence of ATLL is estimated to be 2.5% among HTLV-1 carriers. ATLL cells express CD2, CD3, CD5, CD4, and CD25, as well as CCR4 and FoxP3 of the regulatory T-cell marker. HTLV-1 is causally linked to ATLL, but infection alone is not sufficient to result in neoplastic transformation. A significant finding in this connection is that the Tax viral protein leads to transcriptional activation of many genes, while the HTLV-1 basic leucine zipper factor is thought to be important for T-cell proliferation and oncogenesis. Half of ATLL cases retain the ability to express HTLV-1 Tax, which is a target of HTLV-1-specific cytotoxic T lymphocytes (CTL). An increase in HTLV-1-specific CTL responses is observed in some asymptomatic HTLV-1 carriers. Although HTLV-1-specific CTL are also present in the peripheral blood of ATLL patients, they do not expand sufficiently. We investigated the clinicopathological features and analyzed the staining of Tax-specific CTL and FoxP3. Tax-specific CTL correlated inversely with FoxP3, an increase in the ratio of CD163+ tumor-associated macrophages was associated with worse clinical prognosis, and ATLL cell lines proliferated significantly following direct co-culture with M2 macrophages. Several clinical variants of ATLL have been identified: acute, lymphomatous, chronic, and smoldering. Oligo-array comparative genomic hybridization revealed that genomic loss of 9p21.3 was a significant characteristic of acute-type, but not of chronic-type ATLL. Furthermore, we found that genomic alteration of CD58, which is implicated in immune escape, is more frequently observed in acute than in chronic ATLL. Interestingly

  5. Embryonic and adult stem cells as a source for cell therapy in Parkinson's disease.

    PubMed

    Levy, Yossef S; Stroomza, Merav; Melamed, Eldad; Offen, Daniel

    2004-01-01

    The rationale behind the use of cells as therapeutic modalities for neurodegenerative diseases in general, and in Parkinson's disease (PD) in particular, is that they will improve patient's functioning by replacing the damaged cell population. It is reasoned that these cells will survive, grow neurites, establish functional synapses, integrate best and durably with the host tissue mainly in the striatum, renew the impaired wiring, and lead to meaningful clinical improvement. To increase the generation of dopamine, researchers have already transplanted non-neuronal cells, without any genetic manipulation or after introduction of genes such as tyrosine hydroxylase, in animal models of PD. Because these cells were not of neuronal origin, they developed without control, did not integrate well into the brain parenchyma, and their survival rates were low. Clinical experiments using cell transplantation as a therapy for PD have been conducted since the 1980s. Most of these experiments used fetal dopaminergic cells originating in the ventral mesencephalic tissue obtained from fetuses. Although it was shown that the transplanted cells survived and some patients benefited from this treatment, others suffered from severe dyskinesia, probably caused by the graft's excessive and uncontrolled production and release of dopamine. It is now recognized that cell-replacement strategy will be effective in PD only if the transplanted cells have the same abilities, such as dopamine synthesis and control release, reuptake, and metabolizing dopamine, as the original dopaminergic neurons. Recent studies on embryonic and adult stem cells have demonstrated that cells are able to both self-renew and produce differentiated tissues, including dopaminergic neurons. These new methods offer real hope for tissue replacement in a wide range of diseases, especially PD. In this review we summarize the evidence of dopaminergic neuron generation from embryonic and adult stem cells, and discuss their

  6. Survival of glucose phosphate isomerase null somatic cells and germ cells in adult mouse chimaeras

    PubMed Central

    Keighren, Margaret A.; Flockhart, Jean H.

    2016-01-01

    ABSTRACT The mouse Gpi1 gene encodes the glycolytic enzyme glucose phosphate isomerase. Homozygous Gpi1−/− null mouse embryos die but a previous study showed that some homozygous Gpi1−/− null cells survived when combined with wild-type cells in fetal chimaeras. One adult female Gpi1−/−↔Gpi1c/c chimaera with functional Gpi1−/− null oocytes was also identified in a preliminary study. The aims were to characterise the survival of Gpi1−/− null cells in adult Gpi1−/−↔Gpi1c/c chimaeras and determine if Gpi1−/− null germ cells are functional. Analysis of adult Gpi1−/−↔Gpi1c/c chimaeras with pigment and a reiterated transgenic lineage marker showed that low numbers of homozygous Gpi1−/− null cells could survive in many tissues of adult chimaeras, including oocytes. Breeding experiments confirmed that Gpi1−/− null oocytes in one female Gpi1−/−↔Gpi1c/c chimaera were functional and provided preliminary evidence that one male putative Gpi1−/−↔Gpi1c/c chimaera produced functional spermatozoa from homozygous Gpi1−/− null germ cells. Although the male chimaera was almost certainly Gpi1−/−↔Gpi1c/c, this part of the study is considered preliminary because only blood was typed for GPI. Gpi1−/− null germ cells should survive in a chimaeric testis if they are supported by wild-type Sertoli cells. It is also feasible that spermatozoa could bypass a block at GPI, but not blocks at some later steps in glycolysis, by using fructose, rather than glucose, as the substrate for glycolysis. Although chimaera analysis proved inefficient for studying the fate of Gpi1−/− null germ cells, it successfully identified functional Gpi1−/− null oocytes and revealed that some Gpi1−/− null cells could survive in many adult tissues. PMID:27103217

  7. Robust regeneration of adult zebrafish lateral line hair cells reflects continued precursor pool maintenance.

    PubMed

    Cruz, Ivan A; Kappedal, Ryan; Mackenzie, Scott M; Hailey, Dale W; Hoffman, Trevor L; Schilling, Thomas F; Raible, David W

    2015-06-15

    We have examined lateral line hair cell and support cell maintenance in adult zebrafish when growth is largely complete. We demonstrate that adult zebrafish not only replenish hair cells after a single instance of hair cell damage, but also maintain hair cells and support cells after multiple rounds of damage and regeneration. We find that hair cells undergo continuous turnover in adult zebrafish in the absence of damage. We identify mitotically-distinct support cell populations and show that hair cells regenerate from underlying support cells in a region-specific manner. Our results demonstrate that there are two distinct support cell populations in the lateral line, which may help explain why zebrafish hair cell regeneration is extremely robust, retained throughout life, and potentially unlimited in regenerative capacity.

  8. Ascl3 marks adult progenitor cells of the mouse salivary gland.

    PubMed

    Rugel-Stahl, Anastasia; Elliott, Marilyn E; Ovitt, Catherine E

    2012-05-01

    The Ascl3 transcription factor marks a subset of salivary gland duct cells present in the three major salivary glands of the mouse. In vivo, these cells generate both duct and secretory acinar cell descendants. Here, we have analyzed whether Ascl3-expressing cells retain this multipotent lineage potential in adult glands. Cells isolated from mouse salivary glands were cultured in vitro as non-adherent spheres. Lineage tracing of the Ascl3-expressing cells within the spheres demonstrates that Ascl3+ cells isolated from adult glands remain multipotent, generating both duct and acinar cell types in vitro. Furthermore, we demonstrate that the progenitor cells characterized by Keratin 5 expression are an independent population from Ascl3+ progenitor cells. We conclude that the Ascl3+ cells are intermediate lineage-restricted progenitor cells of the adult salivary glands.

  9. Robust regeneration of adult zebrafish lateral line hair cells reflects continued precursor pool maintenance

    PubMed Central

    Cruz, Ivan A.; Kappedal, Ryan; Mackenzie, Scott M.; Hailey, Dale W.; Hoffman, Trevor L.; Schilling, Thomas F.; Raible, David W.

    2015-01-01

    We have examined lateral line hair cell and support cell maintenance in adult zebrafish when growth is largely complete. We demonstrate that adult zebrafish not only replenish hair cells after a single instance of hair cell damage, but also maintain hair cells and support cells after multiple rounds of damage and regeneration. We find that hair cells undergo continuous turnover in adult zebrafish in the absence of damage. We identify mitotically-distinct support cell populations and show that hair cells regenerate from underlying support cells in a region-specific manner. Our results demonstrate that there are two distinct support cell populations in the lateral line, which may help explain why zebrafish hair cell regeneration is extremely robust, retained throughout life, and potentially unlimited in regenerative capacity. PMID:25869855

  10. A single cell bioengineering approach to elucidate mechanisms of adult stem cell self-renewal.

    PubMed

    Gilbert, Penney M; Corbel, Stephane; Doyonnas, Regis; Havenstrite, Karen; Magnusson, Klas E G; Blau, Helen M

    2012-04-01

    The goal of regenerative medicine is to restore form and function to damaged and aging tissues. Adult stem cells, present in tissues such as skeletal muscle, comprise a reservoir of cells with a remarkable capacity to proliferate and repair tissue damage. Muscle stem cells, known as satellite cells, reside in a quiescent state in an anatomically distinct compartment, or niche, ensheathed between the membrane of the myofiber and the basal lamina. Recently, procedures for isolating satellite cells were developed and experiments testing their function upon transplantation into muscles revealed an extraordinary potential to contribute to muscle fibers and access and replenish the satellite cell compartment. However, these properties are rapidly lost once satellite cells are plated in culture. Accordingly, elucidating the role of extrinsic factors in controlling muscle stem cell fate, in particular self-renewal, is critical. Through careful design of bioengineered culture platforms, analysis of specific proteins presented to stem cells is possible. Critical to the success of the approach is single cell analysis, as more rapidly proliferating progenitors may mask the behavior of stem cells that proliferate slowly. Bioengineering approaches provide a potent means of gaining insight into the role of extrinsic factors in the stem cell microenvironment on stem cell function and the mechanisms that control their diverse fates. Ultimately, the multidisciplinary approach presented here will lead to novel therapeutic strategies for degenerative diseases. PMID:22327505

  11. Endothelial juxtaposition of distinct adult stem cells activates angiogenesis signaling molecules in endothelial cells.

    PubMed

    Mohammadi, Elham; Nassiri, Seyed Mahdi; Rahbarghazi, Reza; Siavashi, Vahid; Araghi, Atefeh

    2015-12-01

    Efficacy of therapeutic angiogenesis needs a comprehensive understanding of endothelial cell (EC) function and biological factors and cells that interplay with ECs. Stem cells are considered the key components of pro- and anti-angiogenic milieu in a wide variety of physiopathological states, and interactions of EC-stem cells have been the subject of controversy in recent years. In this study, the potential effects of three tissue-specific adult stem cells, namely rat marrow-derived mesenchymal stem cells (rBMSCs), rat adipose-derived stem cells (rADSCs) and rat muscle-derived satellite cells (rSCs), on the endothelial activation of key angiogenic signaling molecules, including VEGF, Ang-2, VEGFR-2, Tie-2, and Tie2-pho, were investigated. Human umbilical vein endothelial cells (HUVECs) and rat lung microvascular endothelial cells (RLMECs) were cocultured with the stem cells or incubated with the stem cell-derived conditioned media on Matrigel. Following HUVEC-stem cell coculture, CD31-positive ECs were flow sorted and subjected to western blotting to analyze potential changes in the expression of the pro-angiogenic signaling molecules. Elongation and co-alignment of the stem cells were seen along the EC tubes in the EC-stem cell cocultures on Matrigel, with cell-to-cell dye communication in the EC-rBMSC cocultures. Moreover, rBMSCs and rADSCs significantly improved endothelial tubulogenesis in both juxtacrine and paracrine manners. These two latter stem cells dynamically up-regulated VEGF, Ang-2, VREGR-2, and Tie-2 but down-regulated Tie2-pho and the Tie2-pho/Tie-2 ratio in HUVECs. Induction of pro-angiogenic signaling in ECs by marrow- and adipose-derived MSCs further indicates the significance of stem cell milieu in angiogenesis dynamics. PMID:26068799

  12. Regulation of seminiferous tubule-associated stem Leydig cells in adult rat testes.

    PubMed

    Li, Xiaoheng; Wang, Zhao; Jiang, Zhenming; Guo, Jingjing; Zhang, Yuxi; Li, Chenhao; Chung, Jinyong; Folmer, Janet; Liu, June; Lian, Qingquan; Ge, Renshan; Zirkin, Barry R; Chen, Haolin

    2016-03-01

    Testicular Leydig cells are the primary source of testosterone in males. Adult Leydig cells have been shown to arise from stem cells present in the neonatal testis. Once established, adult Leydig cells turn over only slowly during adult life, but when these cells are eliminated experimentally from the adult testis, new Leydig cells rapidly reappear. As in the neonatal testis, stem cells in the adult testis are presumed to be the source of the new Leydig cells. As yet, the mechanisms involved in regulating the proliferation and differentiation of these stem cells remain unknown. We developed a unique in vitro system of cultured seminiferous tubules to assess the ability of factors from the seminiferous tubules to regulate the proliferation of the tubule-associated stem cells, and their subsequent entry into the Leydig cell lineage. The proliferation of the stem Leydig cells was stimulated by paracrine factors including Desert hedgehog (DHH), basic fibroblast growth factor (FGF2), platelet-derived growth factor (PDGF), and activin. Suppression of proliferation occurred with transforming growth factor β (TGF-β). The differentiation of the stem cells was regulated positively by DHH, lithium- induced signaling, and activin, and negatively by TGF-β, PDGFBB, and FGF2. DHH functioned as a commitment factor, inducing the transition of stem cells to the progenitor stage and thus into the Leydig cell lineage. Additionally, CD90 (Thy1) was found to be a unique stem cell surface marker that was used to obtain purified stem cells by flow cytometry.

  13. Regulation of seminiferous tubule-associated stem Leydig cells in adult rat testes

    PubMed Central

    Li, Xiaoheng; Wang, Zhao; Jiang, Zhenming; Guo, Jingjing; Zhang, Yuxi; Li, Chenhao; Chung, Jinyong; Folmer, Janet; Liu, June; Lian, Qingquan; Ge, Renshan; Zirkin, Barry R.; Chen, Haolin

    2016-01-01

    Testicular Leydig cells are the primary source of testosterone in males. Adult Leydig cells have been shown to arise from stem cells present in the neonatal testis. Once established, adult Leydig cells turn over only slowly during adult life, but when these cells are eliminated experimentally from the adult testis, new Leydig cells rapidly reappear. As in the neonatal testis, stem cells in the adult testis are presumed to be the source of the new Leydig cells. As yet, the mechanisms involved in regulating the proliferation and differentiation of these stem cells remain unknown. We developed a unique in vitro system of cultured seminiferous tubules to assess the ability of factors from the seminiferous tubules to regulate the proliferation of the tubule-associated stem cells, and their subsequent entry into the Leydig cell lineage. The proliferation of the stem Leydig cells was stimulated by paracrine factors including Desert hedgehog (DHH), basic fibroblast growth factor (FGF2), platelet-derived growth factor (PDGF), and activin. Suppression of proliferation occurred with transforming growth factor β (TGF-β). The differentiation of the stem cells was regulated positively by DHH, lithium- induced signaling, and activin, and negatively by TGF-β, PDGFBB, and FGF2. DHH functioned as a commitment factor, inducing the transition of stem cells to the progenitor stage and thus into the Leydig cell lineage. Additionally, CD90 (Thy1) was found to be a unique stem cell surface marker that was used to obtain purified stem cells by flow cytometry. PMID:26929346

  14. Fetal programming of adult Leydig cell function by androgenic effects on stem/progenitor cells

    PubMed Central

    Kilcoyne, Karen R.; Smith, Lee B.; Atanassova, Nina; Macpherson, Sheila; McKinnell, Chris; van den Driesche, Sander; Jobling, Matthew S.; Chambers, Thomas J. G.; De Gendt, Karel; Verhoeven, Guido; O’Hara, Laura; Platts, Sophie; Renato de Franca, Luiz; Lara, Nathália L. M.; Anderson, Richard A.; Sharpe, Richard M.

    2014-01-01

    Fetal growth plays a role in programming of adult cardiometabolic disorders, which in men, are associated with lowered testosterone levels. Fetal growth and fetal androgen exposure can also predetermine testosterone levels in men, although how is unknown, because the adult Leydig cells (ALCs) that produce testosterone do not differentiate until puberty. To explain this conundrum, we hypothesized that stem cells for ALCs must be present in the fetal testis and might be susceptible to programming by fetal androgen exposure during masculinization. To address this hypothesis, we used ALC ablation/regeneration to identify that, in rats, ALCs derive from stem/progenitor cells that express chicken ovalbumin upstream promoter transcription factor II. These stem cells are abundant in the fetal testis of humans and rodents, and lineage tracing in mice shows that they develop into ALCs. The stem cells also express androgen receptors (ARs). Reduction in fetal androgen action through AR KO in mice or dibutyl phthalate (DBP) -induced reduction in intratesticular testosterone in rats reduced ALC stem cell number by ∼40% at birth to adulthood and induced compensated ALC failure (low/normal testosterone and elevated luteinizing hormone). In DBP-exposed males, this failure was probably explained by reduced testicular steroidogenic acute regulatory protein expression, which is associated with increased histone methylation (H3K27me3) in the proximal promoter. Accordingly, ALCs and ALC stem cells immunoexpressed increased H3K27me3, a change that was also evident in ALC stem cells in fetal testes. These studies highlight how a key component of male reproductive development can fundamentally reprogram adult hormone production (through an epigenetic change), which might affect lifetime disease risk. PMID:24753613

  15. Adult stem cells for cardiac repair: a choice between skeletal myoblasts and bone marrow stem cells.

    PubMed

    Ye, Lei; Haider, Husnain Kh; Sim, Eugene K W

    2006-01-01

    The real promise of a stem cell-based approach for cardiac regeneration and repair lies in the promotion of myogenesis and angiogenesis at the site of the cell graft to achieve both structural and functional benefits. Despite all of the progress and promise in this field, many unanswered questions remain; the answers to these questions will provide the much-needed breakthrough to harness the real benefits of cell therapy for the heart in the clinical perspective. One of the major issues is the choice of donor cell type for transplantation. Multiple cell types with varying potentials have been assessed for their ability to repopulate the infarcted myocardium; however, only the adult stem cells, that is, skeletal myoblasts (SkM) and bone marrow-derived stem cells (BMC), have been translated from the laboratory bench to clinical use. Which of these two cell types will provide the best option for clinical application in heart cell therapy remains arguable. With results pouring in from the long-term follow-ups of previously conducted phase I clinical studies, and with the onset of phase II clinical trials involving larger population of patients, transplantation of stem cells as a sole therapy without an adjunct conventional revascularization procedure will provide a deeper insight into the effectiveness of this approach. The present article discusses the pros and cons of using SkM and BMC individually or in combination for cardiac repair, and critically analyzes the progress made with each cell type.

  16. Insulin withdrawal-induced cell death in adult hippocampal neural stem cells as a model of autophagic cell death.

    PubMed

    Baek, Seung-Hoon; Kim, Eun-Kyoung; Goudreau, John L; Lookingland, Keith J; Kim, Seong Who; Yu, Seong-Woon

    2009-02-01

    The term "autophagic cell death" was coined to describe a form of cell death associated with the massive formation of autophagic vacuoles without signs of apoptosis. However, questions about the actual role of autophagy and its molecular basis in cell death remain to be elucidated. We recently reported that adult hippocampal neural stem (HCN) cells undergo autophagic cell death following insulin withdrawal. Insulin-deprived HCN cells exhibit morphological and biochemical markers of autophagy, including accumulation of Beclin 1 and the type II form of microtubule-associated protein 1 light chain 3 (LC3) without evidence of apoptosis. Suppression of autophagy by knockdown of Atg7 reduces cell death, whereas promotion of autophagy with rapamycin augments cell death in insulin-deficient HCN cells. These data reveal a causative role of autophagy in insulin withdrawal-induced HCN cell death. HCN cells have intact apoptotic capability despite the lack of apoptosis following insulin withdrawal. Our study demonstrates that autophagy is the default cell death mechanism in insulin-deficient HCN cells, and provides a genuine model of autophagic cell death in apoptosis-intact cells. Novel insight into molecular mechanisms of this underappreciated form of programmed cell death should facilitate the development of therapeutic methods to cope with human diseases caused by dysregulated cell death.

  17. Biology of the Sertoli Cell in the Fetal, Pubertal, and Adult Mammalian Testis.

    PubMed

    Chojnacka, Katarzyna; Zarzycka, Marta; Mruk, Dolores D

    2016-01-01

    A healthy man typically produces between 50 × 10(6) and 200 × 10(6) spermatozoa per day by spermatogenesis; in the absence of Sertoli cells in the male gonad, this individual would be infertile. In the adult testis, Sertoli cells are sustentacular cells that support germ cell development by secreting proteins and other important biomolecules that are essential for germ cell survival and maturation, establishing the blood-testis barrier, and facilitating spermatozoa detachment at spermiation. In the fetal testis, on the other hand, pre-Sertoli cells form the testis cords, the future seminiferous tubules. However, the role of pre-Sertoli cells in this process is much less clear than the function of Sertoli cells in the adult testis. Within this framework, we provide an overview of the biology of the fetal, pubertal, and adult Sertoli cell, highlighting relevant cell biology studies that have expanded our understanding of mammalian spermatogenesis.