Protective effects of vacuolar H+ -ATPase c on hydrogen peroxide-induced cell death in C6 glioma cells.
We have isolated a gene, the c subunit (ATP6L) of vacuolar H(+)-ATPase, involved in oxidative stress response. In this study, we examined the role of ATP6L and its molecular mechanisms in glial cell death induced by H(2)O(2). Expression of the ATP6L gene was increased by H(2)O(2) treatment in C6 glial cells. ATP6L siRNA-transfected C6 cells treated with H(2)O(2) showed a significant decrease in viability. ATP6L siRNA-transfected cells that were pretreated with MEK1/2 inhibitor completely recovered cell viability. Pretreatment of the transfected cells with zVAD-fmk, a pan-specific caspase inhibitor, did not result in the recovery of cell viability, as determined by a H(2)O(2)-induced cytotoxicity assay. The ultrastructural morphology of the transfected cells as seen by the use of transmission electron microscopy showed numerous cytoplasmic autophagic vacuoles with double membrane. These results suggest that ATP6L has a protective role against H(2)O(2)-induced cytotoxicity via an inhibition of the Erk1/2 signaling pathway, leading to inhibition of autophagic cell death.
Byun
Yu Jeong
YJ
Department of Biochemistry, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Socho-gu, Seoul 137-701, Republic of Korea.
Lee
Seong-Beom
SB
Kim
Dong Jin
DJ
Lee
Hwa Ok
HO
Son
Min Jeong
MJ
Yang
Chul Woo
CW
Sung
Ki-Wug
KW
Kim
Ho-Shik
HS
Kwon
Oh-Joo
OJ
Kim
In-Kyung
IK
Jeong
Seong-Whan
SW
D000818:Animals; D001343:Autophagy / Q000187:drug effects / Q000502:physiology; D001921:Brain / Q000201:enzymology* / Q000503:physiopathology; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D019610:Cytoprotection / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005910:Glioma; D006861:Hydrogen Peroxide / Q000633:toxicity*; D048369:MAP Kinase Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D009457:Neuroglia / Q000187:drug effects / Q000201:enzymology*; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering; D051381:Rats; D014162:Transfection; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*; D014617:Vacuoles / Q000201:enzymology / Q000648:ultrastructure
D004791:Enzyme Inhibitors; D016877:Oxidants; D021122:Protein Subunits; D034741:RNA, Small Interfering; D006861:Hydrogen Peroxide; D048049:Extracellular Signal-Regulated MAP Kinases; D048369:MAP Kinase Kinase 1; D025262:Vacuolar Proton-Translocating ATPases