Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.4.37 (CNPase)
 539 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of postmortem autolysis in situ on myelin proteins and glycoproteins were studied in 25- and 125-day-old mouse brain and in adult bovine brainstem. In bovine myelin a loss of the major myelin glycoprotein was the only difference observed when the tissue was left at 19 degrees C for 24 hours compared to immediately frozen material. In the autolysed mouse brain, the myelin major glycoprotein was the most affected component with a 55% decrease. Both myelin basic protein components were degraded with a 35% loss. The other myelin proteins did not change under the conditions used for this study. There was also no change in the specific activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase, a myelin-associated enzyme. Using the double labelling technique with [3H]fucose and [3 5S] sulfate as precursors injected intracranially, a shift of the major myelin glycoprotein labelled with radioactive sulfate towards a smaller apparent molecular size was observed as a result of the autolysis whereas the electrophoretic mobility of the fucose labelled major peak was unaffected.
 ...
PMID:Changes in CNS myelin proteins and glycoproteins after in situ autolysis. 19 16

Attempts were made to transmit possible infectious agents from tissue of MS patients into three animal species, under conditions designed to enhance the development of such an agent. Myelination was monitored by measuring CNPase activity and myelin basic protein. Although no significant effects were observed, the usefulness of a new assay for CNPase was demonstrated. Nude mice were found to have a lower level of CNPase than their heterozygous littermates.
 ...
PMID:A search for the "multiple sclerosis virus"--lack of effect of brain extracts on myelin development in chickens, mice and rats. 21 27

Several detergents were investigated for their ability to increase activity of 2':3'-cyclic nucleotide 3'-phosphodiesterase in isolated myelin. The ability of Triton X-100 and Sulfobetaine DLH to solubilize the enzyme was also examined. Solubilization with Triton X-100 was only effective in the presence of salt, for example with NaCl 51% of the activity was solubilized. A single extraction with Sulfobetaine DLH yielded slightly more solubilized enzyme and did not require added salt. Both activation and solubilization of 2':3'-cyclic nucleotide 3'-phosphodiesterase appeared to be similarly dependent on detergent concentration, suggesting a common action of the detergent in the two processes. Myelin basic protein was solubilized more readily than the enzyme. In contrast with the enzyme in myelin, 2':3'-cyclic nucleotide 3'-phosphodiesterase activity in C6 cells was not increased in the presence of Triton X-100, and was partially solubilized by either Triton X-100 or NaCl alone. No myelin basic protein could be detected in C6 cells by radioimmunoassay.
 ...
PMID:Detergent activation and solubilization of 2':3'-cyclic nucleotide 3'-phosphodiesterase from isolated myelin and c6 cells. 22 62

The aim of this study was to investigate the pathological and cellular basis for radiation-induced myelopathy in guinea pigs by monitoring biochemical alterations in levels of myelin basic protein and 2',3'-cyclic nucleotide phosphohydrolase. Guinea pigs were irradiated to the lumbar region with various doses of neutrons or cobalt gamma irradiation. The ED50s for paralysis were 17.2 Gy and 67.5 Gy for neutron and cobalt irradiation, respectively, and was histologically associated with demyelination. In spinal cords taken from animals at the onset of paralysis myelin basic protein levels were decreased in direct relationship to the radiation dose. The lowest doses to cause paralysis led to a 25% decrease in MBP levels. In a separate experiment, alterations in MBP were measured in the spinal cords over the time period leading up to paralysis. Surprisingly, decreases in MBP were found immediately after the end of the 4 week irradiation period. These early changes in MBP were not markedly dose dependent and occurred with nonparalyzing doses. Dose-dependent decreases were found only just before the onset of paralysis. CNPase activity measured in the same specimens showed changes that were essentially similar to those for MBP. In the CSF, MBP levels were essentially constant until onset of paralysis. This study showed that demyelination, as assessed by the levels of the myelin-associated proteins MBP and CNPase, can occur soon after spinal cord irradiation but that profound dose-dependent changes are seen only immediately preceding the onset of paralysis. Although increases in MBP in the CSF were associated with the onset of radiation-induced myelopathy, its assay is unlikely to predict this complication of irradiation.
 ...
PMID:Alteration in myelin-associated proteins following spinal cord irradiation in guinea pigs. 753 78

Ovine oligodendrocytes (OLGs) undergo biochemical and morphological changes following attachment to polylysine. Autoradiographs of two-dimensional thin-layer chromatograms of [14C]Gal-labeled OLG cultures revealed that attachment of OLGs to a polylysine substratum and their subsequent morphological differentiation is accompanied by an increased synthesis of multiple forms of galactosylceramide, sulfogalactosylceramide, and both sulfogalactosyl- and galactosyl-diglycerides, together with an array of complex sialoglycosphingolipids, predominantly GM2 ganglioside. As previously reported, overall lipid synthesis measured by [14C]acetate incorporation into glycerophosphatides, sphingomyelin, and neutral lipids also increased dramatically for up to 60 days (last time point examined) following OLG-substratum adhesion, reflecting membrane growth. Attachment was associated with a rapid augmentation in the synthesis of ethanolamine plasmalogen from 12 to 27% within 24 hr to reach a 35% plateau at 30 days and remain constant thereafter. In contrast, the plasmalogen content of phosphatidylcholine remained constant at 3-5%. This rapid increase in lipid synthesis (especially in the ethanolamine plasmalogen content following attachment) closely paralleled increased diacylglycerol (DAG) production and protein kinase C-dependent phosphorylation of both myelin basic protein and 2',3'-cyclic nucleotide phosphohydrolase. Labeling studies indicated that the major source of [3H]arachidonate-labeled DAG following attachment was from phosphatidylinositol turnover (and to a lesser extent phosphatidylcholine) rather than polyphosphoinositides or plasmalogens. Enhanced lipid synthesis is not only required for the production of membranes in these myelin-producing cells but is also a source of second messengers required in the posttranslational modification of key myelin and cellular proteins.
 ...
PMID:Oligodendrocyte-substratum adhesion activates the synthesis of specific lipid species involved in cell signaling. 132 Dec 54

We have established permanent cell lines from the optic nerve of the rat with a temperature sensitive immortalizing oncogene (Simian Virus 40 large T-antigen carrying both the tsA58 and U19 mutations). The oncogene was transduced into primary cultures via a replication deficient retrovirus, and infected cells were selected with the antibiotic G418. A clonal cell line (tsU19-5) displayed some properties of oligodendrocyte precursors: it proliferated, bound the monoclonal antibody A2B5 (which recognizes minor ganglioside species), and expressed the intermediate filament vimentin and the enzyme 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNP) at 33 degrees C (the permissive temperature for the oncogene). At 39 degrees C (the non-permissive temperature), some cells had the potential to differentiate further, and expressed several oligodendrocyte specific components: galactocerebroside, myelin basic protein, proteolipid protein and CNP. These results suggest that conditional oncogenes can establish neural precursor cell lines which are still capable of differentiation in vitro.
 ...
PMID:An oligodendrocyte precursor cell line from rat optic nerve. 162 12

The myelin basic protein (MBPi) accounts for the main encephalitogenic antigen of the demyelinating encephalopathy, but other myelin elements also be noted by some articles. We tried to determine the relationship between W1 protein and the demyelinating encephalopathies. The 2',3'-cyclic nucleotide 3'-phospho-diesterase(CNPase, a gift from Dr. Yasuzo Tuskada) monoclonal antibody was used as a probe to study the W1 protein level in 5 different demyelinating encephalopathies and 2 normal adult brains with immunocytochemical technique. Two different demyelinating types of W1 protein level were found out. Type 1 showed the W1 protein level parallel with demyelinated feature in general pathology whereas the type 2 showed demyelinated in the general pathology but the W1 protein level was normal in the immunocytochemical study. Multiple system degeneration, Binswanger's disease and postvaccinal encephalopathy of type B encephalitis belong to type 1 and multiple sclerosis and Balo's concentric sclerosis belong to type 2. These results might indicate the different pathogenesis of demyelinating encephalopathies.
 ...
PMID:[Demyelinating elements of demyelinated encephalopathy]. 168 19

Schwann cells, on receiving the correct signal, will encircle an axon and wrap it with a myelin sheath. To begin examining some of the mechanisms underlying the process of myelination in vitro, we isolated Schwann cells from the sciatic nerves of neonatal rats and generated large cell populations with cholera toxin. The immunological and biochemical properties of these secondary Schwann cells were characterized after five to seven passages in the absence of axonal contact. These cells continued to express antigens found in both myelinating (P0 and 2',3'-cyclic nucleotide phosphohydrolase) and nonmyelinating cells in vivo (A5E3 and glial fibrillary acidic protein) in addition to the markers common to both types of cells (Ran-1, 217c, S-100, and laminin). Biochemical analyses showed that these cells synthesize the very-long-chain fatty acids (22-26 carbon atoms) found in myelin membranes. Moreover, the enzymes required for the synthesis of myelin glycolipids (including sphingosine acyltransferase, UDP-galactose:ceramide galactosyltransferase, and cerebroside sulfotransferase) were still active, and metabolic labeling studies showed that galactocerebroside and sulfatide were synthesized even though the galactocerebroside pool was insufficient to be detected by immunostaining. Secondary Schwann cells also synthesized four species of myelin basic protein and the major structural glycoprotein in myelin, P0. The pathway necessary for glycosylation of P0 protein remained active, and an analysis of the oligosaccharide chain revealed that approximately 70% was processed to a complex form. In summary, we found that secondary Schwann cells still express most of the immunological markers of differentiated cells and continue to synthesize low levels of myelin components. Therefore, Schwann cells do not dedifferentiate in culture, as previously believed.
 ...
PMID:Evidence that secondary rat Schwann cells in culture maintain their differentiated phenotype. 169 82

A monoclonal antibody (8-18C5) directed against myelin/oligodendrocyte glycoprotein (MOG) induced demyelination in aggregating brain cell cultures. With increasing doses of anti-MOG antibody in the presence of complement, myelin basic protein (MBP) concentration decreased in a dose-related manner. A similar, albeit less pronounced, effect was observed on specific activity of 2',3'-cyclic nucleotide 3'-phosphohydrolase. In the absence of complement, anti-MOG antibody did not induce detectable demyelination. In contrast to the effect of anti-MOG antibody and as expected, anti-MBP antibody did not demyelinate aggregating brain cell cultures in the presence of complement. These results provide additional support to the suggestion that MOG, a quantitatively minor myelin component located on the external side of the myelin membrane, is a good target antigen for antibody-induced demyelination. Indeed, they show that a purified anti-MOG antibody directed against a single epitope on the glycoprotein can produce demyelination, not only in vivo as previously shown, but also in cultures. Such an observation has not been made with polyclonal antisera raised against purified myelin proteins like MBP and proteolipid protein, the major protein components of the myelin membrane, or myelin-associated glycoprotein. These observations may have important implications regarding the possible role of anti-MOG antibodies in demyelinating diseases.
 ...
PMID:Demyelination induced in aggregating brain cell cultures by a monoclonal antibody against myelin/oligodendrocyte glycoprotein. 169 40

After lindane administration at several doses, brain myelin fractions of litters of male and female Wistar rats show a significant diminution of CNP (2',3'-cyclic nucleotide 3'-phosphodiesterase) activity. Furthermore, the immunohistochemical study of brains by means of a MBP (myelin basic protein) specific antibody reveals myelin deficits in some brain regions after lindane treatment. This loss of myelin protein is dose dependent. The deficit in myelin cannot be attributed to undernourishment of lindane-administered rats. This work shows the vulnerability of the developing central nervous system (CNS) to lindane and the correlation between a decrease in the CNPase activity and a deficit of MBP during the period of study of these animals.
 ...
PMID:Effect of lindane on the myelination process in the rat. 170 14


1 2 3 4 5 6 7 8 9 10 Next >>