An enhanced expression of the immediate early gene, Egr-1, is associated with neuronal apoptosis in culture
Cultured cerebellar granule cells grown in medium containing 10 mM K + (K10) underwent apoptosis after four to five days in vitro, unless they were rescued by the addition of insulin-like growth factor-I. The few GABAergic neurons present in the cultures were more resistant to apoptotic degeneration...
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Published in | Neuroscience Vol. 91; no. 4; pp. 1529 - 1538 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford
Elsevier Ltd
01.01.1999
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Cultured cerebellar granule cells grown in medium containing 10
mM K
+ (K10) underwent apoptosis after four to five days
in vitro, unless they were rescued by the addition of insulin-like growth factor-I. The few GABAergic neurons present in the cultures were more resistant to apoptotic degeneration, as indicated by double fluorescent staining with the chromatin dye Hoechst 33258 and with glutamate decarboxylase-67 antibodies. As compared with sister cultures grown in 25
mM K
+, K10 cultures showed an increased expression of the Egr-1 protein and a reduced expression of the Fos protein. The increase in Egr-1 was more substantial in granule cells than in GABAergic neurons, and was not oberved in K10 cultures chronically exposed to insulin-like growth factor-I. To examine the temporal relationship between the increase in Egr-1 and the development of programmed cell death, we induced apoptosis in K25 cultures at six days
in vitro by replacing their medium with serum-free K10 medium. A substantial, but transient, increase in Egr-1 expression was observed in granule cells 6
h after switching the medium, a time that preceded the appearance of the phoenotypical markers of apoptotic death. An early reduction in the Fos protein was observed after switching the medium from K25 into serum-free K10, but also after switching the medium into serum-free K25, a condition which was not associated with the development of apoptosis nor with the increase in Egr-1.
We suggest that a transient induction of Egr-1 contributes to the chain of events leading to the execution phase of neuronal apoptosis in culture. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0306-4522 1873-7544 |
DOI: | 10.1016/S0306-4522(98)00544-2 |