Studies on the Wolfgram High Molecular Weight CNS Myelin Proteins: Relationship to 2′,3′‐Cyclic Nucleotide 3′‐Phosphodiesterase

Sprinkle, T.J.; Wells, Michael R.; Garver, Fred A.; Smith, Dennis B.

doi:10.1111/j.1471-4159.1980.tb07876.x

Cited by 97 publications

(35 citation statements)

References 39 publications

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“…The second increase, found between 20 and 25 DIV, corresponds to the maturation of oligodendrocytes as has previously been de scribed [37], These findings are consistent with the view that CST and sulfatide are mainly localized in oligodendroglia [42,[73][74][75]. CNP, the marker enzyme of myelination [76] mainly localized in oligodendrocytes [77][78][79][80], reached its maximum level of activ ity at about the same period in culture (20 days) confirming the previous results of Bansal and Pfeiffer [81] in cultured rat brain cells. Moreover, the absence of a peak of CNP activity during the first week in culture confirms that the peak of CST at 7 days is probably unrelated to an oligodendroglial maturation process.…”

Section: Discussionsupporting

confidence: 79%

Comparison of the Mechanisms of Action of Insulin and Triiodothyronine on the Synthesis of Cerebroside Sulfotransferase in Cultures of Cells Dissociated from Brains of Embryonic Mice

Ferret-Sena¹,

Sena²,

Besnard³

et al. 1990

Dev Neurosci

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The effect of low (physiological) concentrations of insulin (2 and 20 ng/ml) and L -triiodothyronine (T₃) were studied on two myelin-related enzymes: (1) the 3''-phospho-adenosine-5''-phosphosulfate:cerebroside sulfotransferase (CST, EC 2.8.2.11) catalyzing the production of sulfatide, and (2) the myelin enzyme, 2'',3''-cyclic nucleotide 3''-phosphohydrolase (CNP, EC 3.1.4.3.7) in myelinogenic cultures of cells dissociated from embryonic mouse brain. Insulin treatment (20 ng/ml) of the cells in the presence of serum increased CST activity at 18 and 25 days in vitro (DIV) by 86 and 211%, respectively. At 18 DIV and under the same conditions, CNP was significantly stimulated (95%) by high doses of insulin (2,000 ng/ml) only, while arylsulfatase A (EC 3.1.6.1) or cerebroside sulfatase activities, both of which are involved in sulfatide degradation, were unchanged. Thus, it can be assumed that the observed increase of the incorporation of [³⁵S]0₄ into sulfatide after insulin treatment of mixed cell cultures is the result of CST induction rather than a decreased catabolism. The level of CST activity in insulin-treated cells (20 ng/ml) in serum-free medium was also increased at 18 and 25 DIV by about 50 and 70%, respectively. Conversely, none of the insulin concentrations used in the absence of serum (even at high doses) had any effect, either at 18 or 25 DIV on CNP and ASA activities. The involvement of insulin in the regulation of sulfatide synthesis was further confirmed by dose-response curves relating the activity of CST to hormone concentration in the medium. The increase in the activity of CST in insulin-treated cells was due only to the increase in the V_max of this enzyme, suggesting that it may be attributed to enzyme induction. A study of kinetic parameters of CST indicated that there were no differences in pH optimum and K_m values between control and induced enzyme. Further experiments using cycloheximide point to a direct effect of insulin on oligodendrocyte CST induction. Data similar to those described above for insulin were also obtained with T₃. As for insulin, T₃ stimulated the induction of CST but in serum-free medium only. This effect was prevented by cycloheximide. In addition, the induction of CST by T₃ was blocked by actinomycin D. This was not the case for insulin. These results suggest that T₃ and insulin act on CST by different mechanisms, i.e. at transcriptional and post-translational levels, respectively. Apart from this, the insulin effect on CST activity was additive to that of T₃. Finally, in secondary cultures of pure rat oligodendrocytes, which are capable of producing structures resembling compact myelin, high doses of insulin (5 µg/ml) increased the incorporation of 5-[¹²⁵I]iodo-2''-deoxyuridine by 68%. In contrast, T₃ did not stimulate oligodendrocyte proliferation. It can be concluded that both hormones may have specific effects on myelination.

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Section: Discussionsupporting

confidence: 79%

Comparison of the Mechanisms of Action of Insulin and Triiodothyronine on the Synthesis of Cerebroside Sulfotransferase in Cultures of Cells Dissociated from Brains of Embryonic Mice

Ferret-Sena¹,

Sena²,

Besnard³

et al. 1990

Dev Neurosci

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“…We have used the designation Wolfgram protein in the latter meaning. According to studies of Drummond and Dean (1980) as well as those of Sprinkle et al (1980) the so understood Wolfgram protein is characterized by the 2'3'-cyclic nucleotide 3'phosphohydrolase (CNP) activity or is even identical with this specific myelin protein.…”

Section: Discussionmentioning

confidence: 99%

Myelin proteins in aging human brain

Wender¹,

Adamczewska-Goncerzewicz²,

Dorszewska³

1991

Molecular and Chemical Neuropathology

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Autopsy material of 13 persons who died between 70 and 89 yrs old and of patients who died between 27 and 44 yrs old was studied. White matter of temporal, parietal, and occipital lobes was investigated using histological and biochemical methods. According to results of neuropathological studies, the material of aged patients was divided into two subgroups: (a) brains with vascular changes only and (b) patients with senile atrophy of Alzheimer type. Chemical changes found in all studied brain lobes included a mild decrease in Wolfgram protein content with reciprocal increase in large basic protein content, together with a marked decrease in myelin yield. The abovementioned chemical changes were almost identical whether they were only vascular changes or whether senile atrophy of Alzheimer type was also present. It seems, therefore, that the degeneration of vessels is the decisive factor in the pathogenetic mechanism of myelin lesions in the aged brain.

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“…CNP is the main component of the Wolfgram protein fraction (Drummond and Dean, 1980;Sprinkle et al, 1980) and has been widely used as a marker for myelin oligodendrocytes in the CNS. CNP is present in the cytoplasm-containing compartments of the oligodendrocytes and myelin sheaths but not in lamellae or cellular membranes (Braun et al, 1988).…”

Section: Colocalization Of Abc2 and Cnp In The Brainmentioning

confidence: 99%

ATP-Binding Cassette Transporter ABC2/ABCA2 in the Rat Brain: A Novel Mammalian Lysosome-Associated Membrane Protein and a Specific Marker for Oligodendrocytes But Not for Myelin Sheaths

Zhou¹,

Li²,

Inagaki³

et al. 2001

J. Neurosci.

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We recently cloned a full-length cDNA of the rat ATP-binding cassette transporter 2 (ABC2, or ABCA2) protein, a member of the ABC1 (or ABCA) subfamily (-ABC1/ABCA1 is a causal gene for Tangier disease) and found it to be strongly expressed in the rat brain. In this study, we identified ABC2 as a lysosomeassociated membrane protein that is being localized specifically in oligodendrocytes. The ABC2-immunolabeled cells were detected mainly in the white matter but were also scattered in gray matter throughout the whole brain. In addition, these cells were found to be colocalized with 2Ј,3Ј-cyclic nucleotide-3Ј-phosphodiesterase (CNPase) immunoreactivity when the marker antibody for oligodendrocytes was used. However, no such colocalization was observed with markers for other kinds of glial cells. Unlike the CNP antibody, which also intensely stains myelin sheaths in the white matter, ABC2 immunoreactivity was detected only in the cell bodies of oligodendrocytes. At the ultrastructural level, ABC2 immunoreactivity was detected mostly around lysosome and partly in Golgi apparatus by electron microscopy. This was confirmed by immunocolocalization of ABC2 and lysosomal markers in a neuroblastoma cell line. Immunoblotting analysis of ABC2 from the whole brain and the ABC2-transfected cell line revealed bands at ϳ260 kDa. The result of in situ hybridization with a riboprobe for ABC2 matched the results obtained from immunostaining. These findings strongly suggest that ABC2 is a specific marker for oligodendrocytes but not for myelinsheaths and that it is as a novel mammalian lysosome-associated membrane protein involved in myelinization or other kinds of metabolism in the CNS.

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Studies on the Wolfgram High Molecular Weight CNS Myelin Proteins: Relationship to 2′,3′‐Cyclic Nucleotide 3′‐Phosphodiesterase

Cited by 97 publications

References 39 publications

Comparison of the Mechanisms of Action of Insulin and Triiodothyronine on the Synthesis of Cerebroside Sulfotransferase in Cultures of Cells Dissociated from Brains of Embryonic Mice

Comparison of the Mechanisms of Action of Insulin and Triiodothyronine on the Synthesis of Cerebroside Sulfotransferase in Cultures of Cells Dissociated from Brains of Embryonic Mice

Myelin proteins in aging human brain

ATP-Binding Cassette Transporter ABC2/ABCA2 in the Rat Brain: A Novel Mammalian Lysosome-Associated Membrane Protein and a Specific Marker for Oligodendrocytes But Not for Myelin Sheaths

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