H2O2-induced apoptotic death in serum-deprived cultures of oligodendroglia origin is linked to cell differentiation
✍ Scribed by A.S.V.R. Kameshwar-Rao; S. Gil; C. Richter-Landsberg; D. Givol; E. Yavin
- Book ID
- 102652343
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 600 KB
- Volume
- 56
- Category
- Article
- ISSN
- 0360-4012
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✦ Synopsis
When deprived of serum, oligodendroglialike (OLN 93) cells grown on poly-L-lysine-coated culture dishes cease to proliferate after 3 days and morphologically extend many fibers resembling morphologically differentiated, immature oligodendrocytes. At this time no cell death is apparent unless serum deprivation is extended for a period longer than 1 week. After 3 days in serum-deprived medium, treatment of cells with 1 mM H 2 O 2 for 30 min facilitates apoptotic cell death, even when serum is added during the recovery period. Both serum-deprived, differentiated cells, and proliferating cells, respond to H 2 O 2 by an initial growth arrest followed by growth resumption after 48 hr. However proliferating cells show resistance to the apoptotic effect of H 2 O 2 . This is correlated with growth arrest in the S phase at different stages of DNA replication, as well as with different timing of induced p21 Waf1 expression. Thus, cells grown in serum, express elevated p21 Waf1 protein levels after 4 hr, whereas serumdeprived, differentiated cells, only after 24 hr. The mRNA levels of p21 Waf1 follow a similar timed pattern. Hence p21 Waf1 may protect OLN 93 cells against the genotoxic effect of H 2 O 2 . The data suggest an intimate relationship between G1-arrest, morphological differentiation, and H 2 O 2 -mediated apoptosis.