scholarly journals Developmental changes in myelin-induced proliferation of cultured Schwann cells.

1987 ◽  
Vol 104 (3) ◽  
pp. 655-660 ◽  
Author(s):  
J E Yoshino ◽  
P W Mason ◽  
G H DeVries
Keyword(s):  
Cell Proliferation ◽  
Schwann Cell ◽  
Myelin Basic Protein ◽  
Schwann Cells ◽  
Basic Protein ◽  
Small Population ◽  
Developmental Changes ◽  
Cultured Schwann Cells

Schwann cell proliferation induced by a myelin-enriched fraction was examined in vitro. Although nearly all the Schwann cells contained material that was recognized by antisera to myelin basic protein after 24 h, only 1% of the cells were synthesizing DNA. 72 h after the addition of the mitogen a maximum of 10% of the cells incorporated [3H]thymidine. If the cultures were treated with the myelin-enriched fraction for 24 h and then washed, the number of proliferating Schwann cells decreased by 75% when compared with those cells that were incubated with the mitogen continuously. When Schwann cells were labeled with [14C]thymidine followed by a pulse of [3H]thymidine 24 h later, every Schwann cell labeled with [3H]thymidine was also labeled with [14C]thymidine. Although almost every Schwann cell can metabolize the myelin membranes within 24 h of exposure, a small population of cell initially utilizes the myelin as a mitogen, and this population continues to divide only if myelin is present in the extracellular media. The percentage of the Schwann cells that initially recognize the myelin-enriched fraction as a mitogen is dependent upon the age of the animal from which the cells were prepared.

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 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.

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.

Some Aspects of Remyelination after Demyelination Produced by the Intraneural Injection of Lysophosphatidyl Choline

1973 ◽  
Vol 13 (2) ◽  
pp. 461-477
Author(s):  
SUSAN M. HALL
Keyword(s):  
Cell Proliferation ◽  
Sciatic Nerve ◽  
Schwann Cell ◽  
Schwann Cells ◽  
Small Population ◽  
Post Injection ◽  
Junctional Zone ◽  
Cell Axon ◽  
Lysophosphatidyl Choline ◽  
Intraneural Injection

The morphology of remyelination following demyelination induced by the intraneural injection of lysophosphatidyl choline, LPC, has been examined in the mouse sciatic nerve, at periods up to 240 days post-injection. It was found that, in many fibres, the process resembled primary myelinogenesis. There was a moderate Schwann cell proliferation; those Schwann cells not involved in remyelination remained closely associated with the remyelinating Schwann cell/axon unit, within a common basal lamina tube. Numerous small axons, considered to be sprouts from the remyelinating axon, were observed lying in contact with the ‘supernumerary Schwann cells’. In a small population of fibres, however, atypical morphological features were consistently seen: (i) multiple mesaxons, indicating probable remyelination by tunication; (ii) paranodal reorganization in the junctional zone; (iii) the formation of internodal ‘pseudonodes’, which subsequently underwent transition into incisures of Schmidt-Lanterman. These structures are discussed in terms of the re-establishment of the Schwann cell/axon relationship.

Three markers of adult non-myelin-forming Schwann cells, 217c(Ran-1), A5E3 and GFAP: development and regulation by neuron-Schwann cell interactions

Development ◽  
1990 ◽  
Vol 109 (1) ◽  
pp. 91-103 ◽  
Author(s):  
K.R. Jessen ◽  
L. Morgan ◽  
H.J. Stewart ◽  
R. Mirsky
Keyword(s):  
Sciatic Nerve ◽  
Schwann Cell ◽  
Schwann Cells ◽  
Cell Signalling ◽  
Surface Proteins ◽  
Developmental Changes ◽  
Rat Sciatic Nerve ◽  
Ngf Receptor ◽  
Cultured Schwann Cells ◽  
Do So

Immunohistochemical methods are used to investigate in detail the development and regulation of three proteins (217c(Ran-1), A5E3 and GFAP) specifically associated with adult non-myelin-forming Schwann cells in the rat sciatic nerve, from embryo day 15 to maturity. 217c(Ran-1), which is probably the NGF-receptor, and A5E3 are expressed by the majority of cells in the nerve at embryo day 15 and by essentially all cells at embryo day 18. GFAP first appears at embryo day 18; this is an intrinsically programmed developmental event which occurs in cultured Schwann cells even in the absence of serum. Postnatally, the expression of 217c(Ran-1), A5E3 and GFAP is suppressed in cells that form myelin but retained in non-myelin-forming Schwann cells. Mature myelin-forming cells nevertheless maintain the potential to express all three proteins but will only do so if removed from contact with myelinated axons. In neuron-free cultures Schwann cells express all three proteins. This work, together with our previous observations on N-CAM, shows that removal of a diverse set of surface proteins and a change in intermediate filament expression is one of the major consequences of axon to Schwann cell signalling during myelination in the rat sciatic nerve. Unlike myelin-forming cells, adult non-myelin-forming Schwann cells remain very similar to embryonic and newborn cells with respect to expression of surface proteins, in contrast to the previously established developmental changes that occur in their surface lipids.

scholarly journals Interleukin-4 Regulates the Expression of CD209 and Subsequent Uptake of Mycobacterium leprae by Schwann Cells in Human Leprosy

2010 ◽  
Vol 78 (11) ◽  
pp. 4634-4643 ◽  
Author(s):  
Rosane M. B. Teles ◽  
Stephan R. Krutzik ◽  
Maria T. Ochoa ◽  
Rosane B. Oliveira ◽  
Euzenir N. Sarno ◽  
...  
Keyword(s):  
Schwann Cell ◽  
Peripheral Nerve ◽  
Schwann Cells ◽  
Primary Cultures ◽  
Mycobacterium Leprae ◽  
Microbial Pathogens ◽  
Interleukin 4 ◽  
Common Mechanism ◽  
Specific Cell

ABSTRACT The ability of microbial pathogens to target specific cell types is a key aspect of the pathogenesis of infectious disease. Mycobacterium leprae, by infecting Schwann cells, contributes to nerve injury in patients with leprosy. Here, we investigated mechanisms of host-pathogen interaction in the peripheral nerve lesions of leprosy. We found that the expression of the C-type lectin, CD209, known to be expressed on tissue macrophages and to mediate the uptake of M. leprae, was present on Schwann cells, colocalizing with the Schwann cell marker, CNPase (2′,3′-cyclic nucleotide 3′-phosphodiesterase), along with the M. leprae antigen PGL-1 in the peripheral nerve biopsy specimens. In vitro, human CD209-positive Schwann cells, both from primary cultures and a long-term line, have a higher binding of M. leprae compared to CD209-negative Schwann cells. Interleukin-4, known to be expressed in skin lesions from multibacillary patients, increased CD209 expression on human Schwann cells and subsequent Schwann cell binding to M. leprae, whereas Th1 cytokines did not induce CD209 expression on these cells. Therefore, the regulated expression of CD209 represents a common mechanism by which Schwann cells and macrophages bind and take up M. leprae, contributing to the pathogenesis of leprosy.

In vitro carboxymethylation of myelin basic protein

1986 ◽  
Vol 4 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Toshihiko Innami ◽  
Masaharu Miyake ◽  
Yasuo Kakimoto
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein

Remyelination of Demyelinated CNS Axons by Transplanted Human Schwann Cells: The Deleterious Effect of Contaminating Fibroblasts

2001 ◽  
Vol 10 (3) ◽  
pp. 305-315 ◽  
Author(s):  
C. M. H. Brierley ◽  
A. J. Crang ◽  
Y. Iwashita ◽  
J. M. Gilson ◽  
N. J. Scolding ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Schwann Cell ◽  
Schwann Cells ◽  
Axonal Degeneration ◽  
Autologous Transplantation ◽  
Growth Factor Receptor ◽  
Adult Rats ◽  
Demyelinating Lesions ◽  
Cell Implantation

Areas of demyelination can be remyelinated by transplanting myelin-forming cells. Schwann cells are the naturally remyelinating cells of the peripheral nervous system and have a number of features that may make them attractive for cell implantation therapies in multiple sclerosis, in which spontaneous but limited Schwann cell remyelination has been well documented. Schwann cells can be expanded in vitro, potentially affording the opportunity of autologous transplantation; and they might also be spared the demyelinating process in multiple sclerosis. Although rat, cat, and monkey Schwann cells have been transplanted into rodent demyelinating lesions, the behavior of transplanted human Schwann cells has not been evaluated. In this study we examined the consequences of injecting human Schwann cells into areas of acute demyelination in the spinal cords of adult rats. We found that transplants containing significant fibroblast contamination resulted in deposition of large amounts of collagen and extensive axonal degeneration. However, Schwann cell preparations that had been purified by positive immunoselection using antibodies to human low-affinity nerve growth factor receptor containing less than 10% fibroblasts were associated with remyelination. This result indicates that fibroblast contamination of human Schwann cells represents a greater problem than would have been appreciated from previous studies.

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