scholarly journals Studies on cultured Schwann cells: the induction of myelin synthesis, and the control of their proliferation by a new growth factor

1981 ◽  
Vol 95 (1) ◽  
pp. 215-230
Author(s):  
J. P. Brockes ◽  
K. J. Fryxell ◽  
G. E. Lemke
Keyword(s):  
Molecular Weight ◽  
Growth Factor ◽  
Schwann Cell ◽  
Schwann Cells ◽  
Solid Phase ◽  
Immunological Methods ◽  
Subunit Molecular Weight ◽  
Cultured Schwann Cells

We have recently described the use of immunological methods to identify and purify rat Schwann cells. In dissociated cultures of neonatal sciatic nerve, all of the cells can be identified by antigenic criteria as either Schwann cells or fibroblasts. The fibroblasts may be removed by treatment with antiserum to the Thy-1 antigen and complement. The purified Schwann cells have been used to study the regulation of the expression of myelin components, and the stimulation of Schwann cell division by a soluble growth factor. Among the components of myelin, we have concentrated on the peripheral myelin glycoprotein P0, which constitutes 50–60% of the protein in peripheral myelin. We have studied the distribution of P0 in vitro and in vivo by immunofluorescence, immuno-autoradiography on SDS gels, and solid-phase radioimmunoassay. Our results support the hypothesis that P0 is induced specifically as a consequence of the interaction between the Schwann cell and the myelinated type of axon. The level of P0 in the myelin membrane is at least 1000-fold higher than in the Schwann cell membrane. Purified Schwann cells divide very slowly in a conventional tissue culture medium. This has allowed us to purify a new growth factor from extracts of brain and pituitary, tentatively named Glial Growth Factor (GGF). The activity resides in a basic protein with a native molecular weight of 6 × 10(4) daltons and a subunit molecular weight of 3 × 10(4) daltons, which is active at levels comparable to those of epidermal growth factor. GGF is mitogenic for Schwann cells, astrocytes and muscle fibroblasts.

Spontaneous immortalisation of Schwann cells in culture: short-term cultured Schwann cells secrete growth inhibitory activity

Development ◽  
1991 ◽  
Vol 112 (1) ◽  
pp. 33-42
Author(s):  
P.A. Eccleston ◽  
R. Mirsky ◽  
K.R. Jessen
Keyword(s):  
Growth Factor ◽  
Schwann Cell ◽  
Dna Synthesis ◽  
Schwann Cells ◽  
Inhibitory Activity ◽  
Short Term ◽  
Growth Inhibitory ◽  
Growth Inhibitory Activity ◽  
Cultured Schwann Cells

In the developing peripheral nerve, Schwann cells proliferate rapidly and then become quiescent, an essential step in control of Schwann cell differentiation. Cell proliferation is controlled by growth factors that can exert positive or inhibitory influences on DNA synthesis. It has been well established that neonatal Schwann cells divide very slowly in culture when separated from neurons but here we show that when culture was continued for several months some cells began to proliferate rapidly and non-clonal lines of immortalised Schwann cells were established which could be passaged for over two years. These cells had a similar molecular phenotype to short-term cultured Schwann cells, except that they expressed intracellular and cell surface fibronectin. The difference in proliferation rates between short- and long-term cultured Schwann cells appeared to be due in part to the secretion by short-term cultured Schwann cells of growth inhibitory activity since DNA synthesis of long-term, immortalised Schwann cells was inhibited by conditioned medium from short-term cultures. This conditioned medium also inhibited DNA synthesis in short-term Schwann cells stimulated to divide by glial growth factor or elevation of intracellular cAMP. The growth inhibitory activity was not detected in the medium of long-term immortalised Schwann cells, epineurial fibroblasts, a Schwannoma (33B), astrocytes or a fibroblast-like cell-line (3T3) and it did not inhibit serum-induced DNA synthesis in epineurial fibroblasts, 33B cells or 3T3 cells. The activity was apparently distinct from transforming growth factor-beta, activin, IL6, epidermal growth factor, atrial natriuretic peptide and gamma-interferon and was heat and acid stable, resistant to collagenase and destroyed by trypsin treatment. We raise the possibility that loss of an inhibitory autocrine loop may contribute to the rapid proliferation of long-term cultured Schwann cells and that an autocrine growth inhibitor may have a role in the cessation of Schwann cell division that precedes differentiation in peripheral nerve development.

scholarly journals A Novel Solid-Phase Site-Specific PEGylation Enhances the In Vitro and In Vivo Biostabilty of Recombinant Human Keratinocyte Growth Factor 1

PLoS ONE ◽  
2012 ◽  
Vol 7 (5) ◽  
pp. e36423 ◽  
Author(s):  
Zhifeng Huang ◽  
Guanghui Zhu ◽  
Chuanchuan Sun ◽  
Jingui Zhang ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Solid Phase ◽  
Keratinocyte Growth Factor ◽  
Site Specific ◽  
Human Keratinocyte

Axonal signalling and the making of olfactory ensheathing cells: a hypothesis

2006 ◽  
Vol 2 (3) ◽  
pp. 217-224 ◽  
Author(s):  
KONSTANTIN WEWETZER ◽  
GUDRUN BRANDES
Keyword(s):  
Schwann Cell ◽  
Schwann Cells ◽  
Specific Interaction ◽  
Neurotrophin Receptor ◽  
Olfactory Ensheathing Cells ◽  
Experimental Conditions ◽  
Neural Repair ◽  
Ensheathing Cells

Olfactory ensheathing cells (OECs) are Schwann cell-like glial cells of the olfactory system that promote neural repair under experimental conditions. It is a matter of debate in how far OECs resemble Schwann cells and whether they possess specific properties. Although OECs have been characterized mainly with respect to their regenerative effects after transplantation, both their cellular identity and the regulating factors involved have remained vague. The aim of this article is to define OEC and Schwann-cell identity in molecular terms, and to discuss crucial factors that are involved in determination in vitro and in vivo. Distinct OEC features such as the down-regulation of the low affinity neurotrophin receptor p75NTR by neuronal contact are apparent in vivo under physiological conditions, whereas OECs acquire a Schwann cell-like phenotype and up-regulate p75NTR expression in vitro and following transplantation into the lesioned spinal cord. This might indicate that establishment of the OEC phenotype depends on specific axonal stimuli. In this review we hypothesize that OECs and Schwann cells possess malleable cellular phenotypes that acquire distinct features only upon specific interaction with their natural neuronal partner. This concept is consistent with previous findings in vitro and in vivo, and might be relevant for studies that use OECs and Schwann cells for nervous system repair.

Immunology of nerve growth factor (NGF). The effect of NGF-antiserum on sensory ganglia in vitro

Development ◽  
1970 ◽  
Vol 23 (2) ◽  
pp. 273-287
Author(s):  
H. Hoffman
Keyword(s):  
Molecular Weight ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Sympathetic Ganglion ◽  
Sympathetic Ganglia ◽  
Sensory Ganglia ◽  
Nerve Growth ◽  
Adult Organism

The properties of the ‘Nerve Growth Factor’ (NGF) have been described extensively (Levi-Montalcini & Booker, 1960; Levi-Montalcini, 1965) and reviewed recently (Levi-Montalcini, 1966). This factor is a protein of molecular weight about 130000 in its aggregated form (Varon, Nomura & Shooter, 1967, 1968) but may be active in lower molecular weight forms (Cohen, 1959, 1960; Banks et al. 1968). It is widely distributed in the adult organism (Bueker, Schenkein & Bane, 1960) and exerts a controlling influence on the differentiation of sensory and sympathetic ganglia in developing chick embryos. In newborn mammals its administration influences sympathetic ganglion growth only. A possible role in the adult nervous system is suggested by Scott, Gutmann & Horsky (1966), who showed that injected NGF will increase protein synthesis in regenerating sensory neurons in vivo. Active proteins in complex biological systems may be removed in a highly selective fashion by specific antibodies which thus provide a valuable means of studying their action.

scholarly journals Neuron Regeneration and Proliferation Effects of Danshen and Tanshinone IIA

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jui-Lung Shen ◽  
Yueh-Sheng Chen ◽  
Jing-Ying Lin ◽  
Yun-Chen Tien ◽  
Wen-Huang Peng ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Schwann Cell ◽  
Schwann Cells ◽  
Map Kinases ◽  
Mapk Signaling ◽  
Tanshinone Iia ◽  
Dependent Manner ◽  
Neuron Regeneration

This study evaluates the proliferative effects of danshen and its monomer extract, tanshinone IIA, on Schwann cell proliferation. A piece of silicone rubber was guided across a 15-mm gap in the sciatic nerve of a rat. This nerve gap was then filled with different concentrations of danshen (0–100 mg/mL). The results showed that danshen increased the expressions of uPA, cyclin D1, E and ERK, JNK, and P38 MAP kinases via the FGF-2 signaling pathway in a dose-dependent manner. RSC96, Schwann cells were also administered with danshen (0, 20, 40, 60, 80, and 100 μg/mL) and tanshinone IIA (0, 2, 4, 6, 8, and 10 μg/mL). In lower concentrations, danshen and tanshinone IIA exhibited an apparent effect on Schwann cells. Similar effects were also demonstrated in the FGF-2-uPA regulating cascade and cell cycle proliferative protein results. Schwann cell migration was elevated as well. We used MAPK-signaling chemical inhibitors and identified the proliferative effects of danshen and tanshinone IIA as MAPK-signaling dependent. The results from thein vitrosystems indicate that danshen and tanshinone IIA can be used to induce Schwann cell proliferation, andin vivoresults potentially suggest that danshen and tanshinone IIA might enhance neuron regeneration.

scholarly journals Immunoreactive myelin basic proteins are not detected when shiverer mutant Schwann cells and fibroblasts are co-cultured with normal neurons.

1984 ◽  
Vol 98 (4) ◽  
pp. 1291-1295 ◽  
Author(s):  
H D Shine ◽  
R L Sidman
Keyword(s):  
Nervous System ◽  
Schwann Cell ◽  
Schwann Cells ◽  
Genetic Locus ◽  
Neuronal Cells ◽  
Recessive Mutation ◽  
Basic Proteins ◽  
Cellular Target

Shiverer (shi) is an autosomal recessive mutation in mice that results in hypomyelination in the central nervous system (CNS) but normal myelination in the peripheral nervous system (PNS). Myelin basic proteins (MBPs) are virtually absent in both PNS and CNS. It is not known whether the cellular target in the PNS is the myelin-forming Schwann cell or another cell type which secondarily affects the Schwann cell. To determine the cellular target of the shi gene, we have adapted tissue culture techniques that allow co-culture of pure populations of mouse sensory neurons of one genotype with Schwann cells and fibroblasts of another genotype under conditions that permit myelin formation. These cultures were stained immunocytochemically as whole mounts to determine whether MBPs were expressed under various in vitro conditions. In single-genotype cultures, presence or absence of MBPs was consistent with earlier in vivo results: +/+ cultures were MBP-positive and shi/shi cultures were MBP-negative. In mixed-genotype cultures, visualization of MBPs in myelin accorded with the genotype of the non-neuronal Schwann cells and fibroblasts and not with the neurons--those cultures that contained +/+ non-neuronal cells were MBP-positive and those with shi/shi non-neuronal cells were MBP-negative, independent of the neuronal genotype. These results rule out neurons or circulating substances as mediators of the influence of the shi genetic locus on MBP synthesis and deposition in peripheral myelin.

scholarly journals Coordinate control of axon defasciculation and myelination by laminin-2 and -8

2005 ◽  
Vol 168 (4) ◽  
pp. 655-666 ◽  
Author(s):  
Dongren Yang ◽  
Jesse Bierman ◽  
Yukie S. Tarumi ◽  
Yong-Ping Zhong ◽  
Reshma Rangwala ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Schwann Cell ◽  
Schwann Cells ◽  
Dominant Role ◽  
Pathogenic Mechanism ◽  
Structural Defects ◽  
Autocrine Factors ◽  
Coordinate Control

Schwann cells form basal laminae (BLs) containing laminin-2 (Ln-2; heterotrimer α2β1γ1) and Ln-8 (α4β1γ1). Loss of Ln-2 in humans and mice carrying α2-chain mutations prevents developing Schwann cells from fully defasciculating axons, resulting in partial amyelination. The principal pathogenic mechanism is thought to derive from structural defects in Schwann cell BLs, which Ln-2 scaffolds. However, we found loss of Ln-8 caused partial amyelination in mice without affecting BL structure or Ln-2 levels. Combined Ln-2/Ln-8 deficiency caused nearly complete amyelination, revealing Ln-2 and -8 together have a dominant role in defasciculation, and that Ln-8 promotes myelination without BLs. Transgenic Ln-10 (α5β1γ1) expression also promoted myelination without BL formation. Rather than BL structure, we found Ln-2 and -8 were specifically required for the increased perinatal Schwann cell proliferation that attends myelination. Purified Ln-2 and -8 directly enhanced in vitro Schwann cell proliferation in collaboration with autocrine factors, suggesting Lns control the onset of myelination by modulating responses to mitogens in vivo.

TGF-βs upregulate NCAM and L1 expression in cultured Schwann cells, suppress cyclic AMP-induced expression of O4 and galactocerebroside, and are widely expressed in cells of the Schwann cell lineage in vivo

Glia ◽  
1995 ◽  
Vol 15 (4) ◽  
pp. 419-436 ◽  
Author(s):  
Helen J. S. Stewart ◽  
Genevieve Rougon ◽  
Ziping Dong ◽  
Charlotte Dean ◽  
Kristjan R. Jessen ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Schwann Cell ◽  
Schwann Cells ◽  
Cell Lineage ◽  
Induced Expression ◽  
Cultured Schwann Cells ◽  
In Cells

scholarly journals Schwann cell proliferation in vitro is under negative autocrine control.

1990 ◽  
Vol 111 (6) ◽  
pp. 2663-2671 ◽  
Author(s):  
D Muir ◽  
S Varon ◽  
M Manthorpe
Keyword(s):  
Molecular Weight ◽  
Schwann Cell ◽  
Molecular Mass ◽  
Conditioned Medium ◽  
Schwann Cells ◽  
Cell Cultures ◽  
Antiproliferative Activity ◽  
Gel Filtration ◽  
Molecular Weight Form

In healthy adult peripheral nerve, Schwann cells are believed to be generally quiescent. Similarly, cultures of isolated rat sciatic nerve Schwann cells hardly proliferate in serum-supplemented medium. The possibility that Schwann cells negatively regulate their own proliferation was supported by the demonstration that conditioned media from Schwann cell cultures inhibited the proliferation of mitogen-stimulated test cultures. The inhibition could be complete, was dose dependent, and was exhibited when the test Schwann cells were under the influence of different types of mitogens such as cholera toxin, laminin, and living neurons. The inhibition of proliferation was completely reversible and a rapid doubling of cell number resulted when treatment with conditioned medium was withdrawn from mitogen-stimulated Schwann cells. Conditioned medium from cholera toxin-stimulated and immortalized Schwann cell cultures contained less antiproliferative activity than that found in medium from quiescent Schwann cell cultures. However, media conditioned by two actively proliferating rat Schwannoma cell lines were rich sources of antiproliferative activity for Schwann cells. Unlike the mitogen-stimulated Schwann cells, whose proliferation could be inhibited completely, the immortalized and transformed Schwann cell types were nearly unresponsive to the antiproliferative activity. The antiproliferative activity in Schwann and Schwannoma cell conditioned media was submitted to gel filtration and SDS-PAGE. The activity exists in at least two distinct forms: (a) a high molecular weight complex with an apparent molecular mass greater than 1,000 kD, and (b) a lower molecular weight form having a molecular mass of 55 kD. The active 55-kD form could be derived from the high molecular weight form by gel filtration performed under dissociating conditions. The 55-kD form was further purified to electrophoretic homogeneity. These results suggest that Schwann cells produce an autocrine factor, which we designate as a "neural antiproliferative protein," which completely inhibits the in vitro proliferation of Schwann cells but not that of immortalized Schwann cells or Schwannoma lines.

scholarly journals Axonal regulation of Schwann cell integrin expression suggests a role for alpha 6 beta 4 in myelination.

1993 ◽  
Vol 123 (5) ◽  
pp. 1223-1236 ◽  
Author(s):  
S Einheber ◽  
T A Milner ◽  
F Giancotti ◽  
J L Salzer
Keyword(s):  
Schwann Cell ◽  
Schwann Cells ◽  
Basal Lamina ◽  
Cell Contact ◽  
Myelin Associated Glycoprotein ◽  
Dorsal Root Ganglia Neurons ◽  
Outer Plasma Membrane

Ensheathment and myelination of axons by Schwann cells in the peripheral nervous system requires contact with a basal lamina. The molecular mechanism(s) by which the basal lamina promotes myelination is not known but is likely to reflect the activity of integrins expressed by Schwann cells. To initiate studies on the role of integrins during myelination, we characterized the expression of two integrin subunits, beta 1 and beta 4, in an in vitro myelination system and compared their expression to that of the glial adhesion molecule, the myelin-associated glycoprotein (MAG). In the absence of neurons, Schwann cells express significant levels of beta 1 but virtually no beta 4 or MAG. When Schwann cells are cocultured with dorsal root ganglia neurons under conditions promoting myelination, expression of beta 4 and MAG increased dramatically in myelinating cells, whereas beta 1 levels remained essentially unchanged. (In general agreement with these findings, during peripheral nerve development in vivo, beta 4 levels also increase during the period of myelination in sharp contrast to beta 1 levels which show a striking decrease.) In cocultures of neurons and Schwann cells, beta 4 and MAG appear to colocalize in nascent myelin sheaths but have distinct distributions in mature sheaths, with beta 4 concentrated in the outer plasma membrane of the Schwann cell and MAG localized to the inner (periaxonal) membrane. Surprisingly, beta 4 is also present at high levels with MAG in Schmidt-Lanterman incisures. Immunoprecipitation studies demonstrated that primary Schwann cells express beta 1 in association with the alpha 1 and alpha 6 subunits, while myelinating Schwann cells express alpha 6 beta 4 and possibly alpha 1 beta 1. beta 4 is also downregulated during Wallerian degeneration in vitro, indicating that its expression requires continuous Schwann cell contact with the axon. These results indicate that axonal contact induces the expression of beta 4 during Schwann cell myelination and suggest that alpha 6 beta 4 is an important mediator of the interactions of myelinating Schwann cells with the basal lamina.

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