In the central nervous system, oligodendroglia elaborate extensive amounts of membranes to form the multilamellar myelin sheath which enfolds segments of axons to enhance saltatory conduction of nerve impulses. In addition to being responsible for the synthesis of this membrane, oligodendroglia also maintain it during the lifetime of the animal. During the peak of myelin production, it has been calculated that this cell type may synthesize more than three times its own weight in myelin membranes each day. In diseases chracterized by demyelination, oligodendroglia may be the target cell, and its surface components may be of particular importance. We believe that by studying the proteins and glycoproteins in oligodendroglial plasma membranes, and their genetic regulation in both the normal and diseased state, we may be able to understand the mechanism of the demyelinating process at the molecular level. We have identified and are purifying two major glycoproteins in plasma membranes that are not normally present in myelin, but are present in affected myelin and membranes from a patient with metachromatic leucodystrophy. Both monoclonal and rabbit antiserum will be produced against these purified glycoproteins for use as tools to determine if the glycoproteins are surface markers for oligodendroglia and to purify larger amounts of glycoproteins for chemical analysis. Our long term goals are to study the regulation of these two glycoproteins in oligodendroglia in the normal state and during demyelination. In other studies we plan to modify our differential plating method for obtaining oligodendroglia from neonatal rat brain to obtain them from mouse brain. Once mouse oligodendroglia are obtained, they will be characterized by immunofluorescence, electron microscopy, and incorporation studies, and the results compared with those oligodendroglia obtained from rat and bovine brain. Then oligodendroglia will be prepared from the Quaking and the Jimpy mutant mouse strains (models of abnormal myelin formation or of hypomyelination) to directly compare surface antigens, morphology, and function with normal cells. Purified oligodendroglia from these mutant mice have not been studied thus far. Our long term goals are to study gene expression at the molecular level during development and in disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS014577-09
Application #
3395646
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1980-01-01
Project End
1989-08-31
Budget Start
1988-09-01
Budget End
1989-08-31
Support Year
9
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Poduslo, S E; Pak, C H; Miller, K (1990) Hydrocortisone induction during oligodendroglial differentiation. Neurosci Lett 113:84-8
Poduslo, S E; Miller, K; Pak, C H (1990) Induction of cerebroside synthesis in oligodendroglia. Neurochem Res 15:739-42
Poduslo, S E (1989) Induction of ketone body enzymes in glial cells. Arch Biochem Biophys 272:318-22
Schmelzer, C H; Poduslo, S E (1987) Glycoproteins in the whorls of membrane produced by oligodendroglia in culture. Biochim Biophys Acta 903:103-11
Hampson, D R; Poduslo, S E (1987) Comparisons of proteins and glycoproteins in neuronal plasma membranes, axolemma, synaptic membranes, and oligodendroglial plasma membranes. J Neurosci Res 17:277-84
Chechik, T; Poduslo, S E (1987) Neurotransmitter enzyme activities in neurons purified by bulk-isolation. Neurochem Res 12:79-82
Hampson, D R; Poduslo, S E (1986) Purification of proteolipid protein and production of specific antiserum. J Neuroimmunol 11:117-29
Filbin, M T; Poduslo, S E (1986) A comparison of the glycoproteins and the proteins from multiple sclerosis and normal brain tissue. Neurochem Res 11:1151-66
Poduslo, S E; Chechik, T; Filbin, M T et al. (1986) Purification and characterization of plasma membranes obtained from rat neurons prepared by bulk-isolation. J Neurosci Res 15:553-67
Schmelzer, C H; Poduslo, S E (1986) Purification and characterization of two glycoproteins from oligodendroglial plasma membranes. Biochim Biophys Acta 858:56-66

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