Rotenone induces apoptosis via activation of bad in human dopaminergic SH-SY5Y cells.
Chronic complex I inhibition caused by rotenone induces features of Parkinson's disease in rats, including selective nigrostriatal dopaminergic degeneration and Lewy bodies with alpha-synuclein-positive inclusions. To determine the mechanisms underlying rotenone-induced neuronal death, we used an in vitro model of human dopaminergic SH-SY5Y cells. In rotenone-induced cell death, rotenone induced Bad dephosphorylation without changing the amount of Bad proteins. Rotenone also increased the amount of alpha-synuclein in cells showing morphological changes in response to rotenone. Because Bad and alpha-synuclein are known to bind to 14-3-3 proteins, we examined the effects of rotenone on these complexes. Whereas a decreased Bad amount bound to 14-3-3 proteins, rotenone increased alpha-synuclein binding to these proteins. Because dephosphorylation by calcineurin activates Bad, we examined the possible involvement of Bad activation in rotenone-induced apoptosis by using the calcineurin inhibitor tacrolimus (FK506). Tacrolimus suppressed two rotenone-induced actions: Bad dephosphorylation and apoptosis. Furthermore, the inhibition of caspase-9, which functions downstream from Bad, completely suppressed rotenone-induced apoptosis. Our findings demonstrate that Bad activation plays a role in rotenone-induced apoptosis of SH-SY5Y cells.
Department of Pharmacology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi Ward, Tokyo 173-8605, Japan.
Masahiko
M
Watabe
Toshio
T
Nakaki
D017209:Apoptosis / Q000187:drug effects*; D001711:Biotransformation / Q000187:drug effects; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism*; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D053938:DNA Fragmentation; D004298:Dopamine / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004587:Electrophoresis, Agar Gel; D006801:Humans; D047468:Immunoprecipitation; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D009419:Nerve Tissue Proteins; D010766:Phosphorylation / Q000187:drug effects; D012402:Rotenone / Q000494:pharmacology*; D051843:Synucleins; D016559:Tacrolimus / Q000494:pharmacology; D014475:Uncoupling Agents / Q000494:pharmacology*; D051844:alpha-Synuclein; D051025:bcl-Associated Death Protein
C494819:BAD protein, human; D002352:Carrier Proteins; D007166:Immunosuppressive Agents; D009419:Nerve Tissue Proteins; C497604:SNCA protein, human; D051843:Synucleins; D014475:Uncoupling Agents; D051844:alpha-Synuclein; D051025:bcl-Associated Death Protein; D012402:Rotenone; C506433:CASP9 protein, human; D053453:Caspase 9; D020169:Caspases; D004298:Dopamine; D016559:Tacrolimus