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Query: EC:3.1.4.37 (
CNPase
)
539
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Fibroblast growth factor (FGF)-2 differentially regulates oligodendrocyte progenitor proliferation and differentiation in culture, and modulates gene expression of its own receptors, in a developmental and receptor type-specific manner (Bansal et al., 1996a,b). Three FGF receptors (types 1, 2, 3) are expressed in postmitotic, terminally differentiating oligodendrocytes. Exposure of such cells to FGF-2 results in: (a) the down-regulation of myelin-specific gene expression (e.g., ceramide galactosyltransferase,
2',3'-cyclic nucleotide 3'-phosphohydrolase
, myelin basic protein, proteolipid protein), (b) dramatic increases in the length of cellular processes in a time- and dose-dependent manner, (c) re-entrance into the cell cycle without accompanying mitosis, and (d) the alteration of the expression of both low- and high-affinity FGF receptors. Compared to oligodendrocyte progenitors, the differentiated oligodendrocytes treated with FGF-2 incorporate BrdU at a slower rates, exhibit different patterns of both FGF high- and low-affinity (syndecans) receptors, and are morphologically very different. In addition, they do not re-express the progenitor markers A2B5,
NG2
or PDGFalpha receptor. Therefore, although the FGF-treated cells lose their differentiated OL/myelin markers, they do not revert to progenitors and clearly represent a different, apparently novel, phenotype both morphologically and biochemically, which we have termed NOLs. These data indicate that terminally differentiated oligodendrocytes retain the plasticity to reprogram their differentiation fate under the influence of environmental factors. The possible significance of this response to FGF relative to normal and pathological physiology is discussed. In particular, on the basis of these data we predict the appearance of cells in and around multiple sclerosis plaques with the phenotype O4+,
NG2
-, A2B5-, O1-, MBP-.
...
PMID:FGF-2 converts mature oligodendrocytes to a novel phenotype. 937 31
Neuropsin and protease M/neurosin are serine proteases expressed by neurons and glial cells, and serve a variety of functions in the central nervous system (CNS). The current study demonstrates changes in the expression of these proteases following hemisection of the mouse spinal cord. Within unlesioned spinal cord, neuropsin mRNA expression was occasionally observed in the gray but not white matter, while the level of protease M/neurosin mRNA was higher in the white matter. After injury to the spinal cord, neuropsin mRNA expression was induced in the white matter in the area immediately adjacent to the lesion, peaking at 4 days post-injury and disappearing by 14 days. Enhanced expression of protease M/neurosin mRNA was observed throughout the white and gray matter surrounding the lesion, peaking at 4 days and persisting for 14 days. Neuropsin mRNA was expressed predominantly by
CNPase
-positive oligodendrocytes. Furthermore, most of these cells were also associated with immunoreactivity for protease M/neurosin protein. Within unlesioned spinal cord, most protease M/neurosin mRNA-expressing cells were
CNPase
-positive oligodendrocytes, and a substantial fraction of these cells also showed immunoreactivity for
NG2
, a marker for oligodendrocyte progenitors. After injury, protease M/neurosin mRNA expression within
NG2
-positive cells was significantly decreased, while the constitutive expression in
CNPase
-positive oligodendrocytes appeared to be preserved. These findings suggest that each subpopulation of oligodendrocytes based on the expression of neuropsin and protease M/neurosin has different roles in the response of the spinal cord to injury as well as in normal homeostasis.
...
PMID:Differential expression of neuropsin and protease M/neurosin in oligodendrocytes after injury to the spinal cord. 1537 60
The cellular responses to a brain injury are important steps in restoring the integrity and function of the brain. Proliferating cells, such as reactive astrocytes, oligodendrocyte precursor cells and microglia remodel the injured tissue. To spatially and temporally characterize the initial cellular responses in vivo, proliferating cells were pulse-labeled with BrdU soon after (the 2nd day) a cortical cryo-injury, and their fate was investigated by double labeling with an anti-BrdU antibody and antibodies to various cellular markers. Three days after the cryo-injury, a significant proportion of BrdU-positive cells were positive for
NG2
-proteoglycan, suggesting that oligodendrocyte progenitors (OPCs) were induced in response to injury. One-two weeks after the cryo-injury, the number of OPC was reduced and GFAP/BrdU double-positive cells, in turn, became dominant, while cells with mature oligodendrocyte markers did not increase significantly. Neuronal markers were rarely co-localized with BrdU immunoreactivity throughout the period studied. These findings imply that OPCs are prone to differentiate to astrocytes in the lesioned site. In this cryo-injury model, treatment with thyroid hormone (T4) altered cell fate; the increase in the number of GFAP/BrdU-positive cells was significantly diminished, and there was an increased number of mature oligodendrocytes (
CNPase
, PLP-positive) exhibiting BrdU immunoreactivity. These findings suggest that modification of proliferating progenitors in injured brain by hormonal or chemical treatment might benefit functional regeneration.
...
PMID:Characterization of cells with proliferative activity after a brain injury. 1573 36
Retinoic acid (RA) promotes growth and differentiation in many developing tissues but less is known about its influence on CNS regeneration. We investigated the possible involvement of RA in rat spinal cord injury (SCI) using the New York University (NYU) impactor to induce mild or moderate spinal cord contusion injury. Changes in RA at the lesion site were determined by measuring the activity of the enzymes for its synthesis, the retinaldehyde dehydrogenases (RALDHs). A marked increase in enzyme activity occurred by day 4 and peaked at days 8-14 following the injuries. RALDH2 was the only detectable RALDH present in the control or injured spinal cord. The cellular localization of RALDH2 was identified by immunostaining. In the noninjured spinal cord, RALDH2 was detected in oligodendroglia positive for the markers RIP and
CNPase
. Expression was also intense in the arachnoid membrane surrounding the spinal cord. After SCI the increase in RALDH2 was independent of the RIP- and
CNPase
-positive cells, which were severely depleted. Instead, RALDH2 was present in a cell type not previously identified as capable of synthesizing RA, that expressed
NG2
and that was negative for markers of astrocytes, oligodendroglia, microglia, neurons, Schwann cells and immature lymphocytes. We postulate that the RALDH2- and
NG2
-positive cells migrate into the injured sites from the adjacent arachnoid membrane, where the RALDH2-positive cells proliferate substantially following SCI. These findings indicate that close correlations exist between RA synthesis and SCI and that RA may play a role in the secondary events that follow acute SCI.
...
PMID:Retinoic acid synthesis by a population of NG2-positive cells in the injured spinal cord. 1584 83
To determine the possible involvement of protease M/neurosin in demyelinating diseases of the CNS, we examined its expression in myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), a recognized animal model of multiple sclerosis (MS). In situ hybridization, immunohistochemistry and quantitative real-time polymerase chain reaction (PCR) demonstrated that EAE caused an increase in the expression of protease M/neurosin mRNA and its protein product throughout the white and gray matter surrounding demyelinating lesions. Combined in situ hybridization and immunohistochemistry demonstrated that most of the cells expressing protease M/neurosin mRNA within control spinal cord showed immunoreactivity for
CNPase
or
NG2
, cell-specific markers for oligodendrocytes and their progenitors, respectively. In the spinal cord from mice with EAE, the expression of protease M/neurosin mRNA in
CNPase
-positive cells appeared to be increased while double-labeled cells positive for protease M/neurosin mRNA and
NG2
were rarely found in areas associated with demyelinating lesions. Although a prominent accumulation of inflammatory cells including T-cells was observed in the vicinity of demyelinated lesions, these cells were not associated with protease M/neurosin mRNA expression. The levels of protease M/neurosin mRNA expression were unchanged in the spleen and even decreased in the thymus during the course of EAE. These observations suggest that the differential expression of protease M/neurosin in mature oligodendrocytes and their progenitors is involved in the pathogenesis of MS and EAE.
...
PMID:Differential expression of protease M/neurosin in oligodendrocytes and their progenitors in an animal model of multiple sclerosis. 1591 Nov 26
The discoidin domain receptor (DDR1) is highly expressed in oligodendrocytes during the neurodevelopmental myelination process and is genetically associated to schizophrenia. In this study, we aimed to further assess the involvement of DDR1 in both remyelination and oligodendrocyte differentiation. In the mouse model of demyelination-remyelination induced by oral administration of cuprizone, in situ hybridization showed an upregulation of the DDR1 gene in three different white matter areas (corpus callosum, dorsal fornix, and external capsule) during the remyelination period. Moreover, real time reverse transcriptase polymerase chain reaction showed that the increase in DDR1 messenger RNA (mRNA) was strongly correlated with the number of DDR1-positive cells in the corpus callosum (Spearman coefficient = 0.987, P = 0.013). Cells positive for DDR1 mRNA were also positive for oligodendrocyte markers (OLIG2, carnosine, and APC) but not for markers of oligodendrocyte precursors (
NG2
), myelin markers (
CNPase
), microglia (CD11b), or reactive glia (GFAP). Differentiation of a human oligodendroglial cell line, HOG16, was associated with an increase in mRNA expression of DDR1 and several myelin proteins (MBP and MOBP) but not other proteins (APC and
CNPase
). Here, we demonstrate that DDR1 is upregulated in vitro and in vivo when oligodendrocyte myelinating machinery is activated. Further studies are needed to identify the specific molecular pathway.
...
PMID:Discoidin domain receptor 1, a tyrosine kinase receptor, is upregulated in an experimental model of remyelination and during oligodendrocyte differentiation in vitro. 1883 51
The mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway is important for both long-term survival and timing of the progression of oligodendrocyte differentiation. Oligodendroglial cells treated with MEK inhibitor were distinguished by using stage specific markers:
NG2
proteoglycan, A2B5, 2'3'nucleotide-cyclic 3'phosphodiesterase (
CNPase
) and myelin basic protein (MBP), and classified according to their morphology into different developmental stages. Treatment significantly increased the number of cells with more immature morphologies and decreased the number of mature cells. Furthermore, it increased the number of rounded cells that could not be classified into any of the oligodendroglial developmental stages. The strongest effects were usually observed shortly after treatment. Rounded cells were
CNPase
/MBP positive and they were not stained by anti-
NG2
or A2B5, indicating that they were mature cells unable either to extend and/or to maintain their processes. These data showed an effect of the MAPK/ERK pathway on oligodendroglial branching, with possible consequences for the formation of the myelin sheath.
...
PMID:A role for the MAPK/ERK pathway in oligodendroglial differentiation in vitro: stage specific effects on cell branching. 1972 58
In the present study, we hypothesized that thymosin beta 4 (Tbeta4) is a potential therapy of multiple sclerosis (MS). To test this hypothesis, SJL/J mice (n=21) were subjected to experimental autoimmune encephalomyelitis (EAE), an animal model of MS. EAE mice were treated with saline or Tbeta4 (6 mg/kg, n=10) every 3 days starting on the day of myelin proteolipid protein (PLP) immunization for total five doses. Neurological function, inflammatory infiltration, oligodendrocyte progenitor cells (OPCs) and mature oligodendrocytes were measured in the brain of EAE mice. Double immunohistochemical staining was used to detect proliferation and differentiation of OPCs. Tbeta4 was used to treat N20.1 cells (premature oligodendrocyte cell line) in vitro, and proliferation of N20.1 cells was measured by bromodeoxyuridine (BrdU) immunostaining. Tbeta4 treatment improved functional recovery after EAE. Inflammatory infiltrates were significantly reduced in the Tbeta4 treatment group compared to the saline groups (3.6+/-0.3/slide vs 5+/-0.5/slide, P<0.05).
NG2
(+) OPCs (447.7+/-41.9 vs 195.2+/-31/mm(2) in subventricular zone (SVZ), 75.1+/-4.7 vs 41.7+/-3.2/mm(2) in white matter),
CNPase
(+) mature oligodendrocytes (267.5+/-10.3 vs 141.4+/-22.9/mm(2)), BrdU(+) with
NG2
(+) OPCs (32.9+/-3.7 vs 17.9+/-3.6/mm(2)), BrdU(+) with
CNPase
(+) mature oligodendrocytes (18.2+/-1.7 vs 10.7+/-2.2/mm(2)) were significantly increased in the Tbeta4 treated mice compared to those of saline controls (P<0.05). These data indicate that Tbeta4 treatment improved functional recovery after EAE, possibly, via reducing inflammatory infiltrates, and stimulating oligodendrogenesis.
...
PMID:Neurological functional recovery after thymosin beta4 treatment in mice with experimental auto encephalomyelitis. 1978 21
Theiler's murine encephalomyelitis virus (TMEV)-induced demyelination is an important animal model for multiple sclerosis. The presence of oligodendrocyte precursor cells (OPCs) within demyelinated lesions together with the limited extent of remyelination has raised the question of how OPCs are affected by TMEV. It is well established that oligodendrocytes, astrocytes and microglia are targets during the chronic phase of the disease. However, whether TMEV infection interferes with the capacity of OPCs to generate oligodendrocytes has remained unclear. In the present study, a bipotential murine OPC cell line termed BO-1 was used to determine the antigenic phenotype susceptible to TMEV and the impact of TMEV infection upon cell differentiation. We show here that retinoic acid increased oligodendrocytic differentiation and decreased proliferation and TMEV infection rates. TMEV under serum-free conditions infected about 75% and 60% of early OPCs (
NG2
(+) and A2B5(+)) and immature oligodendrocytes (
CNPase
(+)), respectively, but only approximately 18% of mature oligodendrocytes (MBP(+)). Infection with TMEV prior to application of retinoic acid significantly reduced the percentage of MBP(+) BO-1 cells. These data demonstrate that TMEV preferentially infects early stages of the oligodendrocytic lineage and blocks oligodendrocyte maturation. The first demonstration of TMEV-mediated effects on OPC differentiation may shed new light on the pathogenesis of TMEV-induced demyelination and offers an explanation for the limited remyelination observed in vivo.
...
PMID:Theiler's murine encephalomyelitis virus preferentially infects immature stages of the murine oligodendrocyte precursor cell line BO-1 and blocks oligodendrocytic differentiation in vitro. 2020 47
According to previously published ultrastructural studies, oligodendrocytes in white matter exhibit gap junctions with astrocytes, but not among each other, while in vitro oligodendrocytes form functional gap junctions. We have studied functional coupling among oligodendrocytes in acute slices of postnatal mouse corpus callosum. By whole-cell patch clamp we dialyzed oligodendrocytes with biocytin, a gap junction-permeable tracer. On average 61 cells were positive for biocytin detected by labeling with streptavidin-Cy3. About 77% of the coupled cells stained positively for the oligodendrocyte marker protein
CNPase
, 9% for the astrocyte marker GFAP and 14% were negative for both
CNPase
and GFAP. In the latter population, the majority expressed Olig2 and some
NG2
, markers for oligodendrocyte precursors. Oligodendrocytes are known to express Cx47, Cx32 and Cx29, astrocytes Cx43 and Cx30. In Cx47-deficient mice, the number of coupled cells was reduced by 80%. Deletion of Cx32 or Cx29 alone did not significantly reduce the number of coupled cells, but coupling was absent in Cx32/Cx47-double-deficient mice. Cx47-ablation completely abolished coupling of oligodendrocytes to astrocytes. In Cx43-deficient animals, oligodendrocyte-astrocyte coupling was still present, but coupling to oligodendrocyte precursors was not observed. In Cx43/Cx30-double deficient mice, oligodendrocyte-to-astrocyte coupling was almost absent. Uncoupled oligodendrocytes showed a higher input resistance. We conclude that oligodendrocytes in white matter form a functional syncytium predominantly among each other dependent on Cx47 and Cx32 expression, while astrocytic connexins expression can promote the size of this network.
...
PMID:Oligodendrocytes in mouse corpus callosum are coupled via gap junction channels formed by connexin47 and connexin32. 2046 52
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