TY - JOUR
T1 - Exacerbated vulnerability to oxidative stress in astrocytic C6 glioma cells with stable overexpression of the glutamine transporter slc38a1
AU - Ogura, Masato
AU - Takarada, Takeshi
AU - Nakamichi, Noritaka
AU - Kawagoe, Hirofumi
AU - Sako, Aya
AU - Nakazato, Ryota
AU - Yoneda, Yukio
N1 - Funding Information:
This work was supported in part by Grants-in-Aid for Scientific Research to T.T. (Nos. 20790250 and 22500330 ) and Y.Y. (No. 21659018 ) from the Ministry of Education, Culture, Sports, Science and Technology , Japan.
PY - 2011/3
Y1 - 2011/3
N2 - We have previously demonstrated the functional expression of glutamine (Gln) transporter (GlnT) believed to predominate in neurons for the neurotransmitter glutamate pool by rat neocortical astrocytes devoid of neuronal marker expression, with exacerbated vulnerability to oxidative stress after transient overexpression. To evaluate molecular mechanisms underlying the exacerbation, we established stable GlnT transfectants in rat astrocytic C6 glioma cells. In two different clones of stable transfectants with increased intracellular Gln levels, exposure to hydrogen peroxide (H2O 2) and A23187, but not to tunicamycin or 2,4-dinitrophenol, led to significant exacerbation of the cytotoxicity compared to cells with empty vector (EV). Stable GlnT overexpression led to a significant increase in heme oxygenase-1 protein levels in a manner sensitive to H2O2, whereas H2O2 was significantly more effective in increasing NO2 accumulation and reactive oxygen species (ROS) generation in stable GlnT transfectants than in EV cells. Moreover, exposure to A23187 led to a more effective increase in the generation of ROS in stable GlnT transfectants than in stable EV transfectants. These results suggest that GlnT may play a role in the mechanisms underlying the determination of cellular viability in astrocytes through modulation of intracellular ROS generation.
AB - We have previously demonstrated the functional expression of glutamine (Gln) transporter (GlnT) believed to predominate in neurons for the neurotransmitter glutamate pool by rat neocortical astrocytes devoid of neuronal marker expression, with exacerbated vulnerability to oxidative stress after transient overexpression. To evaluate molecular mechanisms underlying the exacerbation, we established stable GlnT transfectants in rat astrocytic C6 glioma cells. In two different clones of stable transfectants with increased intracellular Gln levels, exposure to hydrogen peroxide (H2O 2) and A23187, but not to tunicamycin or 2,4-dinitrophenol, led to significant exacerbation of the cytotoxicity compared to cells with empty vector (EV). Stable GlnT overexpression led to a significant increase in heme oxygenase-1 protein levels in a manner sensitive to H2O2, whereas H2O2 was significantly more effective in increasing NO2 accumulation and reactive oxygen species (ROS) generation in stable GlnT transfectants than in EV cells. Moreover, exposure to A23187 led to a more effective increase in the generation of ROS in stable GlnT transfectants than in stable EV transfectants. These results suggest that GlnT may play a role in the mechanisms underlying the determination of cellular viability in astrocytes through modulation of intracellular ROS generation.
KW - Astrocytes
KW - Glutamine transporter
KW - HO-1
KW - Oxidative stress
KW - Reactive oxygen species
KW - slc38a1
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U2 - 10.1016/j.neuint.2011.01.007
DO - 10.1016/j.neuint.2011.01.007
M3 - Article
C2 - 21219957
AN - SCOPUS:79952104569
VL - 58
SP - 504
EP - 511
JO - Neurochemistry International
JF - Neurochemistry International
SN - 0197-0186
IS - 4
ER -