Control of oligodendrocyte precursor proliferation mediated by density-dependent cell cycle protein expression.
The proliferation of oligodendrocyte precursors is closely regulated in the developing vertebrate CNS. In previous studies we have demonstrated a cell-type-specific density-dependent feedback mechanism that contributes to the control of oligodendrocyte progenitor cell clonal expansion in vitro. Here we demonstrate a density-dependent reduction in the proliferation of oligodendrocyte precursors. This inhibition of proliferation is correlated with increases in expression levels of the cell cycle inhibitor p27(Kip1), reductions in the expression of cyclin A and changes in the relative phosphorylation levels of Rb. These changes are reversible on replating at low density suggesting that additional signals are required for terminal oligodendrocyte differentiation.
Nakatsuji
Y
Y
Department of Neurosciences, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
Miller
R H
RH
D000818:Animals; D000831:Animals, Newborn; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology*; D002478:Cells, Cultured; D002490:Central Nervous System / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D002540:Cerebral Cortex; D002999:Clone Cells / Q000166:cytology / Q000378:metabolism; D019925:Cyclin A / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27; D015536:Down-Regulation / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D009836:Oligodendroglia / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology
C493962:Cdkn1b protein, rat; D018797:Cell Cycle Proteins; D019925:Cyclin A; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27