Proteasome inhibition induces glutathione synthesis and protects cells from oxidative stress: relevance to Parkinson disease.
The cause of selective dopaminergic neuronal degeneration in Parkinson disease has still not been resolved, but it has been hypothesized that oxidative stress and the ubiquitin-proteasome system are important in the pathogenesis. In this report, we investigated the effect of proteasome inhibition on oxidative stress-induced cytotoxicity in PC12 cells, an in vitro model of Parkinson disease. Treatment with proteasome inhibitors provided significant protection against toxicity by 6-hydroxydopamine and H(2)O(2) in a concentration-dependent manner. The measurement of intracellular reactive oxygen species using 2',7'-dichlorofluorescein diacetate demonstrated that lactacystin, a proteasome inhibitor, significantly reduced 6-hydroxydopamineand H(2)O(2)-induced reactive oxygen species production. Proteasome inhibitors elevated the amount of glutathione and phosphorylated p38 mitogen-activated protein kinase (MAPK) prior to glutathione elevation. The treatment with lactacystin induced the nuclear translocation of NF-E2-related factor 2 (Nrf2) and increased the level of mRNA for gamma-glutamylcysteine synthetase, a rate-limiting enzyme in glutathione synthesis. Furthermore, SB203580, an inhibitor of p38 MAPK, abolished glutathione elevation and cytoprotection by lactacystin. These data suggest that proteasome inhibition afforded cytoprotection against oxidative stress by the elevation of glutathione content, and its elevation was mediated by p38 MAPK phosphorylation.
Yamamoto
Noriyuki
N
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501.
Sawada
Hideyuki
H
Department of Neurology and Clinical Research Center, Center for Neurological Diseases, Utano National Hospital, 8 Ondoyama-cho, Narutaki, Ukyo-ku, Kyoto 616-5152, and the.
Izumi
Yasuhiko
Y
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501.
Kume
Toshiaki
T
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501.
Katsuki
Hiroshi
H
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501.
Shimohama
Shun
S
Department of Neurology, Graduate School of Medicine, Kyoto University, 54 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
Akaike
Akinori
A
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, 46-29 Shimoadachi-cho, Sakyo-ku, Kyoto 606-8501. Electronic address: aakaike@pharm.kyoto-u.ac.jp.
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D018663:Adrenergic Agents / Q000633:toxicity; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000096:biosynthesis*; D006861:Hydrogen Peroxide / Q000633:toxicity; D007093:Imidazoles / Q000494:pharmacology; D008954:Models, Biological; D050983:NF-E2 Transcription Factor / Q000378:metabolism; D016877:Oxidants / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects; D016627:Oxidopamine / Q000633:toxicity; D016716:PC12 Cells; D010300:Parkinson Disease / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D061988:Proteasome Inhibitors; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
D018663:Adrenergic Agents; D015853:Cysteine Proteinase Inhibitors; D007093:Imidazoles; D050983:NF-E2 Transcription Factor; D016877:Oxidants; D061988:Proteasome Inhibitors; D011725:Pyridines; D017382:Reactive Oxygen Species; D025801:Ubiquitin; C067713:lactacystin; D016627:Oxidopamine; D006861:Hydrogen Peroxide; D048051:p38 Mitogen-Activated Protein Kinases; D046988:Proteasome Endopeptidase Complex; D005978:Glutathione; C093642:SB 203580; D000111:Acetylcysteine