In:
The Journal of Neuroscience, Society for Neuroscience, Vol. 24, No. 25 ( 2004-06-23), p. 5748-5757
Abstract:
Molecular chaperones and the ubiquitin-proteasome system are participants in the defense against unfolded proteins and provide an effective protein quality control system that is essential for cellular functions and survival. Ubiquitinated tau-positive inclusion bodies containing the small heat shock protein αB-crystallin in oligodendrocytes are consistent features of a variety of neurodegenerative diseases, and defects in the proteasome system might contribute to the aggregation process. Oligodendrocytes, the myelin-forming cells of the CNS, are specifically sensitive to stress situations. Here we can show that in cultured rat brain oligodendrocytes proteasomal inhibition by MG-132 or lactacystin caused apoptotic cell death and the induction of heat shock proteins in a time- and concentration-dependent manner. Specifically, αB-crystallin was upregulated, and ubiquitinated proteins accumulated. After incubation with MG-132 the tau was dephosphorylated, which enhanced its microtubule-binding capacity. Proteasomal inhibition led to ubiquitination of tau and its association with αB-crystallin and to the occurrence of thioflavine S-positive aggregates in the oligodendroglial cytoplasm. These aggregates were positive for tau and also contained ubiquitin and αB-crystallin; hence they resembled the glial cytoplasmic inclusions observed in white matter disease and frontotemporal dementias with parkinsonism linked to chromosome 17 (FTDP-17). In summary, the data underscore the specific sensitivity of oligodendrocytes to stress situations and point to a causal relationship of proteasomal impairment and inclusion body formation.
Type of Medium:
Online Resource
ISSN:
0270-6474
,
1529-2401
DOI:
10.1523/JNEUROSCI.1307-04.2004
Language:
English
Publisher:
Society for Neuroscience
Publication Date:
2004
detail.hit.zdb_id:
1475274-8
SSG:
12
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