title: Cultured oligodendrocytes. A role for cell-substratum interaction in phenotypic expression.
abstract: Oligodendrocytes can be maintained in two states: nonattached; we call these cells B3.f; morphologically they resemble freshly isolated cells; attached; we refer to the latter as B3.fA. Profound morphological, ultrastructural, and biochemical changes take place upon adhesion to a competent surface (Szuchet, S., Yim, S. H., and Monsma, S. (1983) Proc. Natl. Acad. Sci. U. S. A. 80, 7019-7023). Here we present evidence that the transition from B3.f to B3.fA has important consequences for the expression of myelinogenic properties by these cells. We have examined the incorporation of [3H]leucine, [35S]methionine, and [35S]cysteine into polypeptide chains by B3.f and B3.fA cells from 3 days after isolation up to 8 weeks in culture. Specific antisera against myelin and cytoskeletal proteins were used to identify the newly synthesized proteins. Our results indicate that: overall incorporation expressed as cpm/mg of protein remains essentially constant and independent of the state of adhesion or time in culture; B3.f cells keep a low profile in the synthesis of the major myelin proteins but have a high uptake of precursors into 2',3'-cyclic nucleotide phosphodiesterase, actin, and tubulin; adhesion of oligodendrocytes to a polylysine substratum activates the synthesis and phosphorylation of myelin basic protein, and the synthesis and acylation of proteolipid protein and DM-20; over time in culture there is an increased synthesis and accumulation of these proteins and of myelin-associated glycoprotein. We conclude that B3.f cells exhibit a behavior that is distinct from that of B3.fA cells. Our results are consistent with the notion that upon adhesion to a substratum, oligodendrocytes undergo a transition from myelin-maintaining cells (B3.f) to that of myelin-forming cells (B3.fA). This conclusion is substantiated by the finding of myelin membranes in these cultures.
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology*; D002448:Cell Adhesion; D002478:Cells, Cultured; D003470:Culture Media; D003545:Cysteine / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000096:biosynthesis*; D007106:Immune Sera; D007700:Kinetics; D007930:Leucine / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D008854:Microscopy, Electron; D009457:Neuroglia / Q000166:cytology*; D009836:Oligodendroglia / Q000166:cytology* / Q000648:ultrastructure; D010452:Peptide Biosynthesis; D010641:Phenotype; D012756:Sheep; D013462:Sulfur Radioisotopes; D014316:Tritium
chemical_list: D003470:Culture Media; D003598:Cytoskeletal Proteins; D007106:Immune Sera; D013462:Sulfur Radioisotopes; D014316:Tritium; D008715:Methionine; D007930:Leucine; D003545:Cysteine