Developmental changes of tau protein and mRNA in cultured rat brain oligodendrocytes
Article first published online: 20 AUG 2001
Copyright © 2001 Wiley-Liss, Inc.
Volume 36, Issue 1, pages 89–101, October 2001
How to Cite
Gorath, M., Stahnke, T., Mronga, T., Goldbaum, O. and Richter-Landsberg, C. (2001), Developmental changes of tau protein and mRNA in cultured rat brain oligodendrocytes. Glia, 36: 89–101. doi: 10.1002/glia.1098
- Issue published online: 20 AUG 2001
- Article first published online: 20 AUG 2001
- Manuscript Accepted: 12 JUN 2001
- Manuscript Received: 12 APR 2001
- Deutsche Forschungsgemeinschaft (DFG). Grant Number: Ri 384/11-10
- rat brain;
- mRNA localization
Oligodendrocytes elaborate an extensive network of multibranched processes and flat membranous sheets. Microtubules (MT) participate in the elaboration and stabilization of myelin-forming processes and are essential for cellular sorting processes. Microtubule-associated proteins (MAPs) are involved in the regulation and stabilization of the dynamic MT network. It has been shown previously that oligodendrocytes express the MAP tau, a phosphoprotein most abundant in neurons of the CNS. In this article, we demonstrate for the first time that oligodendrocytes contain all six tau isoforms, and that tau mRNA and protein expression is developmentally regulated. Immunoblot analysis reveals that tau protein is more abundant, and mature isoforms are more prominent at later stages of development. During the first week of culture maturation, a marked decrease in phosphorylation is observable. Using an RT-PCR approach, we can show that oligodendrocytes express small amounts of exon 3 containing isoforms and that during culture maturation, tau mRNA splice products with 3 MT-binding domains (3R) decrease and mRNA with 4 MT-binding domains (4R) increase. In situ hybridization study demonstrates that tau mRNA is present in precursor cells and in mature oligodendrocytes. Tau mRNA is actively transported into the cellular processes, is specifically present in the primary and some of the secondary processes, enriched at the turning and branching points and the growing tips, and often appears as small patches. Hence, localized tau translation at specific sites in the cellular extensions might contribute to the regulation of MT stability during process formation, early axonal contact establishment, and myelination. GLIA 36:89–101, 2001. © 2001 Wiley-Liss, Inc.