TY - JOUR
T1 - Molecular mechanisms of 6-hydroxydopamine-induced cytotoxicity in PC12 cells
T2 - Involvement of hydrogen peroxide-dependent and -independent action
AU - Saito, Yoshiro
AU - Nishio, Keiko
AU - Ogawa, Yoko
AU - Kinumi, Tomoya
AU - Yoshida, Yasukazu
AU - Masuo, Yoshinori
AU - Niki, Etsuo
N1 - Funding Information:
This study was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (18790081).
PY - 2007/3/1
Y1 - 2007/3/1
N2 - The neurotoxin 6-hydroxydopamine (6-OHDA) has been widely used to generate an experimental model of Parkinson's disease. It has been reported that reactive oxygen species (ROS), such as the superoxide anion and hydrogen peroxide (H2O2), generated from 6-OHDA are involved in its cytotoxicity; however, the contribution and role of ROS in 6-OHDA-induced cell death have not been fully elucidated. In the present study using PC12 cells, we observed the generation of 50 μM H2O2 from a lethal concentration of 100 μM 6-OHDA within a few minutes, and compared the sole effect of H2O2 with 6-OHDA. Catalase, an H2O2-removing enzyme, completely abolished the cytotoxic effect of H2O2, while a significant but partial protective effect was observed against 6-OHDA. 6-OHDA induced peroxiredoxin oxidation, cytochrome c release, and caspase-3 activation. Catalase exhibited a strong inhibitory effect against the peroxiredoxin oxidation, and cytochrome c release induced by 6-OHDA; however, caspase-3 activation was not effectively inhibited by catalase. On the other hand, 6-OHDA-induced caspase-3 activation was inhibited in the presence of caspase-8, caspase-9, and calpain inhibitors. These results suggest that the H2O2 generated from 6-OHDA plays a pivotal role in 6-OHDA-induced peroxiredoxin oxidation, and cytochrome c release, while H2O2- and cytochrome c-independent caspase activation pathways are involved in 6-OHDA-induced neurotoxicity. These findings may contribute to explain the importance of generated H2O2 and secondary products as a second messenger of 6-OHDA-induced cell death signal linked to Parkinson's disease.
AB - The neurotoxin 6-hydroxydopamine (6-OHDA) has been widely used to generate an experimental model of Parkinson's disease. It has been reported that reactive oxygen species (ROS), such as the superoxide anion and hydrogen peroxide (H2O2), generated from 6-OHDA are involved in its cytotoxicity; however, the contribution and role of ROS in 6-OHDA-induced cell death have not been fully elucidated. In the present study using PC12 cells, we observed the generation of 50 μM H2O2 from a lethal concentration of 100 μM 6-OHDA within a few minutes, and compared the sole effect of H2O2 with 6-OHDA. Catalase, an H2O2-removing enzyme, completely abolished the cytotoxic effect of H2O2, while a significant but partial protective effect was observed against 6-OHDA. 6-OHDA induced peroxiredoxin oxidation, cytochrome c release, and caspase-3 activation. Catalase exhibited a strong inhibitory effect against the peroxiredoxin oxidation, and cytochrome c release induced by 6-OHDA; however, caspase-3 activation was not effectively inhibited by catalase. On the other hand, 6-OHDA-induced caspase-3 activation was inhibited in the presence of caspase-8, caspase-9, and calpain inhibitors. These results suggest that the H2O2 generated from 6-OHDA plays a pivotal role in 6-OHDA-induced peroxiredoxin oxidation, and cytochrome c release, while H2O2- and cytochrome c-independent caspase activation pathways are involved in 6-OHDA-induced neurotoxicity. These findings may contribute to explain the importance of generated H2O2 and secondary products as a second messenger of 6-OHDA-induced cell death signal linked to Parkinson's disease.
KW - 6-Hydroxydopamine
KW - Caspase
KW - Catalase
KW - Cytochrome c
KW - Glutathione
KW - Hydrogen peroxide
KW - Peroxiredoxin
KW - p-Quinone
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U2 - 10.1016/j.freeradbiomed.2006.12.004
DO - 10.1016/j.freeradbiomed.2006.12.004
M3 - Article
C2 - 17291991
AN - SCOPUS:33846828453
SN - 0891-5849
VL - 42
SP - 675
EP - 685
JO - Free Radical Biology and Medicine
JF - Free Radical Biology and Medicine
IS - 5
ER -