c-Jun N-terminal kinase mediates lactacystin-induced dopamine neuron degeneration.
Parkinson disease is characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. It has been proposed that dysfunction of the ubiquitin proteasome system plays an important role in the pathogenesis of Parkinson disease, but the mechanisms underlying ubiquitin proteasome system-related neuron degeneration are unknown. Here, we demonstrate that the proteasome inhibitor lactacystin induces phosphorylation of c-Jun N-terminal kinase (JNK) and c-Jun, the release of cytochrome c, activation of both caspase-9 and caspase-3, and sequential apoptosis of dopaminergic neurons in vitro. Most of these effects can be attenuated by the JNK inhibitor SP600125. Furthermore, infusion of lactacystin in rats in vivo also leads to phosphorylation of JNK before nigral neuron loss; chronic administration of SP600125 also blocks this loss. These results indicate that JNK is involved in proteasome inhibition-induced dopaminergic neuron degeneration through caspase-3-mediated apoptotic pathways, suggesting that this kinase may be a therapeutic target for the prevention of substantia nigra pars compacta degeneration in Parkinson disease patients.
Li
Xuping
X
Institute of Health Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences/Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Du
Yunlan
Y
Fan
Xiaolan
X
Yang
Dehua
D
Luo
Guangrui
G
Le
Weidong
W
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000633:toxicity; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D015853:Cysteine Proteinase Inhibitors / Q000633:toxicity*; D045304:Cytochromes c / Q000378:metabolism; D004298:Dopamine / Q000502:physiology*; D007150:Immunohistochemistry; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D008297:Male; D009410:Nerve Degeneration / Q000139:chemically induced* / Q000235:genetics* / Q000473:pathology; D009474:Neurons / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013378:Substantia Nigra / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D013778:Tetrazolium Salts; D013844:Thiazoles
D015853:Cysteine Proteinase Inhibitors; D013778:Tetrazolium Salts; D013844:Thiazoles; C067713:lactacystin; D045304:Cytochromes c; D048031:JNK Mitogen-Activated Protein Kinases; D053148:Caspase 3; C022616:thiazolyl blue; D004298:Dopamine; D000111:Acetylcysteine