TY - JOUR
T1 - Persistent activation of ERK contributes to glutamate-induced oxidative toxicity in a neuronal cell line and primary cortical neuron cultures
AU - Stanciu, Madalina
AU - Wang, Ying
AU - Kentor, Ruth
AU - Burke, Nancy
AU - Watkins, Simon
AU - Kress, Geraldine
AU - Reynolds, Ian
AU - Klann, Eric
AU - Angiolieri, Maria R.
AU - Johnson, Jon W.
AU - DeFranco, Donald B.
PY - 2000/4/21
Y1 - 2000/4/21
N2 - Oxidative stress can trigger neuronal cell death and has been implicated in several chronic neurological diseases and in acute neurological injury. Oxidative toxicity can be induced by glutamate treatment in cells that lack ionotrophic glutamate receptors, such as the immortalized HT22 hippocampal cell line and immature primary cortical neurons. Previously, we found that neuroprotective effects of geldanamycin, a benzoquinone ansamycin, in HT22 cells were associated with a down-regulation of c-Raf-1, an upstream activator of the extracellular signal-regulated protein kinases (ERKs). ERK activation, although often attributed strictly to neuronal cell survival and proliferation, can also be associated with neuronal cell death that occurs in response to specific insults. In this report we show that delayed and persistent activation of ERKs is associated with glutamate-induced oxidative toxicity in HT22 cells and immature primary cortical neuron cultures. Furthermore, we find that U0126, a specific inhibitor of the ERK-activating kinase, MEK-1/2, protects both HT22 cells and immature primary cortical neuron cultures from glutamate toxicity. Glutamate-induced ERK activation requires the production of specific arachidonic acid metabolites and appears to be downstream of a burst of reactive oxygen species (ROS) accumulation characteristic of oxidative stress in HT22 cells. However, inhibition of ERK activation reduces glutamate-induced intracellular Ca2+ accumulation. We hypothesize that the precise kinetics and duration of ERK activation may determine whether downstream targets are mobilized to enhance neuronal cell survival or ensure cellular demise.
AB - Oxidative stress can trigger neuronal cell death and has been implicated in several chronic neurological diseases and in acute neurological injury. Oxidative toxicity can be induced by glutamate treatment in cells that lack ionotrophic glutamate receptors, such as the immortalized HT22 hippocampal cell line and immature primary cortical neurons. Previously, we found that neuroprotective effects of geldanamycin, a benzoquinone ansamycin, in HT22 cells were associated with a down-regulation of c-Raf-1, an upstream activator of the extracellular signal-regulated protein kinases (ERKs). ERK activation, although often attributed strictly to neuronal cell survival and proliferation, can also be associated with neuronal cell death that occurs in response to specific insults. In this report we show that delayed and persistent activation of ERKs is associated with glutamate-induced oxidative toxicity in HT22 cells and immature primary cortical neuron cultures. Furthermore, we find that U0126, a specific inhibitor of the ERK-activating kinase, MEK-1/2, protects both HT22 cells and immature primary cortical neuron cultures from glutamate toxicity. Glutamate-induced ERK activation requires the production of specific arachidonic acid metabolites and appears to be downstream of a burst of reactive oxygen species (ROS) accumulation characteristic of oxidative stress in HT22 cells. However, inhibition of ERK activation reduces glutamate-induced intracellular Ca2+ accumulation. We hypothesize that the precise kinetics and duration of ERK activation may determine whether downstream targets are mobilized to enhance neuronal cell survival or ensure cellular demise.
UR - http://www.scopus.com/inward/record.url?scp=0034697364&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034697364&partnerID=8YFLogxK
U2 - 10.1074/jbc.275.16.12200
DO - 10.1074/jbc.275.16.12200
M3 - Article
C2 - 10766856
AN - SCOPUS:0034697364
SN - 0021-9258
VL - 275
SP - 12200
EP - 12206
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 16
ER -