H2O2-induced apoptotic death in serum-deprived cultures of oligodendroglia origin is linked to cell differentiation

Abstract

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 H2O2 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 H2O2 by an initial growth arrest followed by growth resumption after 48 hr. However proliferating cells show resistance to the apoptotic effect of H2O2. This is correlated with growth arrest in the S phase at different stages of DNA replication, as well as with different timing of induced p21Waf1 expression. Thus, cells grown in serum, express elevated p21Waf1 protein levels after 4 hr, whereas serum-deprived, differentiated cells, only after 24 hr. The mRNA levels of p21Waf1 follow a similar timed pattern. Hence p21Waf1 may protect OLN 93 cells against the genotoxic effect of H2O2. The data suggest an intimate relationship between G1-arrest, morphological differentiation, and H2O2-mediated apoptosis.

N‐Methyl Bases of Ethanolamine Prevent Apoptotic Cell Death Induced by Oxidative Stress in Cells of Oligodendroglia Origin

“…An additional consequence of H 2 O 2 ‐induced stress in OLN 93 cells is death by apoptosis as recently reported (Kameshwar‐Rao et al, 1999). Therefore, the ability of dEa supplemented to rescue cells from death was deemed worthy of investigation.…”

“…The first point addressed in this study concerned whether lipid peroxidation in DHA‐enriched cells is linked or not to apoptotic death. Although the amount of H 2 O 2 used in this study was 10‐fold lower than in the previous one (Kameshwar‐Rao et al, 1999), DHA‐enriched cultures produced more TBARS and showed a greater proportion of dying cells. Thus, a direct correlation between TBARS formation (Fig.…”

Lipid constituents in oligodendroglial cells alter susceptibility to H2O2‐induced apoptotic cell death via ERK activation

“…Notably, not all cells were activated by H 2 O 2 . This indicates that H 2 O 2 ‐induced ERK activation is asynchronous with time in spite of the fact that the cells were under growth arrest for 3 days due to serum‐deprivation (Kameshwar‐Rao et al . 1999).…”

Morphological changes do not reflect biochemical and functional differentiation in OLN-93 oligodendroglial cells

“…in the study of apoptosis (Brand and Yavin, 2005;Burgmaier et al, 2000;Gerstner et al, 2005Gerstner et al, , 2006Kameshwar-Rao et al, 1999;Uberti et al, 1999), membrane trafficking (Gielen et al, 2006;Zhang et al, 2005), oxidative stress (Ernst et al, 2004;Stahnke et al, 2007), oligodendroglial proteins (Maier et al, 2006) and differentiation (Li et al, 2007;van Meeteren et al, 2006). Although used in the study of several aspects of oligodendroglial biology, an electrophysiological characterisation of OLN-93 oligodendroglial cells has never been performed.…”